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Operations Manual
MicroTech
®
III Unit Controller for Commercial Rooftop,
Applied Rooftop, and Self-Contained Systems
OM 920-4
Group:
Applied Systems
Part Number:
OM 920
Date:
April 2013
DPS, MPS, RAH, RCS, RDS, RDT, RFS, RPS, SWP, and SWT
© 2013 Daikin Applied
Table of Content
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Getting Started . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Using the Keypad/Display . . . . . . . . . . . . . . . . . . . . . . 5
Passwords . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Navigation Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Edit Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Service Timers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Rapid Start . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Manual Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Keypad/Display Menu Structure . . . . . . . . . . . . . . . . . 8
Menu Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Quick Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
View/Set Unit Menus . . . . . . . . . . . . . . . . . . . . . . . . 19
Unit Status Settings . . . . . . . . . . . . . . . . . . . . . . . 19
Occupancy Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Temperatures Menu . . . . . . . . . . . . . . . . . . . . . . . . . 22
Flow Status Menu . . . . . . . . . . . . . . . . . . . . . . . . . . 23
SAF Spd Control Menu . . . . . . . . . . . . . . . . . . . . . . 23
RF/EF Control Menu . . . . . . . . . . . . . . . . . . . . . . . . 24
Cooling Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Economizer Menu . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Min OA Damper Menu . . . . . . . . . . . . . . . . . . . . . . . 25
Heating Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Dehumidification Menu . . . . . . . . . . . . . . . . . . . . . . 26
Date/Time/Schedules Menu . . . . . . . . . . . . . . . . . . . 27
Time/Date . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Commission Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Unit Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Timer Settings Menu . . . . . . . . . . . . . . . . . . . . . . . 29
SAF Set-up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
RF/EF Set-Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Heat/Cool Changeover Set-Up . . . . . . . . . . . . . . . 36
Cooling Set-Up . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Econo Set-up . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Min OA Set-Up Menu . . . . . . . . . . . . . . . . . . . . . . 40
Heating Set-Up Menu . . . . . . . . . . . . . . . . . . . . . . 43
Dehum Set-Up . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Energy Recovery Set-up . . . . . . . . . . . . . . . . . . . . 46
Head Pressure Set-Up Menu . . . . . . . . . . . . . . . . 48
Evap Cond Set-Up Menu . . . . . . . . . . . . . . . . . . . 49
Alarm Configuration Menu . . . . . . . . . . . . . . . . . . . . 50
Alarm Limits Menu . . . . . . . . . . . . . . . . . . . . . . . . 50
Alarm Output Config Menu . . . . . . . . . . . . . . . . . . 50
Alarm Delays Menu . . . . . . . . . . . . . . . . . . . . . . . . 51
Manual Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
Service Menus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
Timer Settings Menu . . . . . . . . . . . . . . . . . . . . . . . 55
Modbus Status Menu . . . . . . . . . . . . . . . . . . . . . . 60
D3 Status Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
Sensor Offsets Menu . . . . . . . . . . . . . . . . . . . . . . . 61
Unit Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
BMS Communications Menu . . . . . . . . . . . . . . . . . . 63
Unit Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
Trending Menus . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
Points 1-8 (Fixed) . . . . . . . . . . . . . . . . . . . . . . . . . . 67
Points 9-24 (From List) . . . . . . . . . . . . . . . . . . . . . 67
Points 25-27 (With IDs) . . . . . . . . . . . . . . . . . . . . . 68
Points 28-30 (With IDs) . . . . . . . . . . . . . . . . . . . . . 68
Trending Selection Lists . . . . . . . . . . . . . . . . . . . . . 69
2 OM 920-4
Alarms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
About this Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
Alarms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
Alarm Clearing . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
Warnings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
Faults . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
Operator’s Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
Determining Unit State . . . . . . . . . . . . . . . . . . . . . . . 76
Off Operating State . . . . . . . . . . . . . . . . . . . . . . . . 76
Start Up Operating State . . . . . . . . . . . . . . . . . . . . 76
Recirculating Operating State . . . . . . . . . . . . . . . . 77
Fan Only . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
Min DAT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
Heating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
Economizer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
Mechanical Cooling . . . . . . . . . . . . . . . . . . . . . . . . 78
Determining Unit Status . . . . . . . . . . . . . . . . . . . . 78
Determining Control Mode . . . . . . . . . . . . . . . . . . 78
Determining Cooling Status . . . . . . . . . . . . . . . . . 79
Determining Heat Status . . . . . . . . . . . . . . . . . . . . 79
Determining Economizer Status . . . . . . . . . . . . . . 80
Determining Cooling Capacity . . . . . . . . . . . . . . . 80
Determining Supply Air Fan Capacity . . . . . . . . . . 80
Determining RF/EF Capacity . . . . . . . . . . . . . . . . 80
Determining Occupancy Mode . . . . . . . . . . . . . . . 82
Determining Occupancy Source . . . . . . . . . . . . . . 82
Unoccupied Operation . . . . . . . . . . . . . . . . . . . . . 83
Scheduling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
Temperature Control Configurations . . . . . . . . . . . 84
Heat/Cool Changeover . . . . . . . . . . . . . . . . . . . . . 84
Control Temperature . . . . . . . . . . . . . . . . . . . . . . . 85
Dehumidification . . . . . . . . . . . . . . . . . . . . . . . . . . 87
Table of Contents
Energy Recovery . . . . . . . . . . . . . . . . . . . . . . . . . 89
Outside Air Damper Control . . . . . . . . . . . . . . . . . 92
100% Outside Air Damper Control,
Two Position . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
Airside Economizer . . . . . . . . . . . . . . . . . . . . . . . . 95
Economizer to Cooling Operating State . . . . . . . . 95
Waterside Economizer . . . . . . . . . . . . . . . . . . . . . 95
Bypass Valve Control . . . . . . . . . . . . . . . . . . . . . . 96
Water Pump Control . . . . . . . . . . . . . . . . . . . . . . . 97
Cooling: Multistage . . . . . . . . . . . . . . . . . . . . . . . . 97
Cooling: Modulating . . . . . . . . . . . . . . . . . . . . . . 100
Discharge Air Temperature Setpoint Reset -
Cooling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
Condenser Fan Control . . . . . . . . . . . . . . . . . . . . 101
Heating Control . . . . . . . . . . . . . . . . . . . . . . . . . . 107
Modulating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108
RTU Gas Heating . . . . . . . . . . . . . . . . . . . . . . . . 108
Min DAT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108
MPS Gas Heating . . . . . . . . . . . . . . . . . . . . . . . . 110
Indoor Air Fan - On/Off Control . . . . . . . . . . . . . . 112
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . 116
Fan Failure Codes . . . . . . . . . . . . . . . . . . . . . . . . 116
OM 920-4 3
Introduction
Introduction
This manual provides information regarding the MicroTech
III control system. It specifically describes the operation and programmable options for units with constant air volume
(CAV) control and variable air volume (VAV) control.
The MicroTech III Controller is a self contained device that is capable of complete, standalone operation. Information in the controller can be displayed and modified by using the keypad/ display in the units main control panel. For installation and startup instructions and general information regarding a particular unit, refer to the applicable model-specific installation and maintenance manual.
For installation and startup instructions and general information regarding a particular rooftop unit, refer to the applicable model-specific installation and maintenance manual (Table 1).
Table 1: Installation and Maintenance Resources
Unit
MicroTech III Rooftop Unit Controller -
BACnet IP Communications
MicroTech III Rooftop Unit Controller -
BACnet MSTP Communications
MicroTech III Rooftop Unit Controller -
BACnet LON Communications
MicroTech III Unit Controller
MicroTech III Remote Unit Interface
RPS/RDT/RFS/RCS 015C-105C
RPS/RDT/RFS/RCS 015D-140D
SWP Self-Contained (012 to 130)
RoofPak RAH/RDS
Maverick II Rooftop 62-75 ton
Maverick II Rooftop 15-50 ton
Manual
IM 916
IM 917
IM 918
IM 919
IM 1005
IM 926
IM 893
IM 1032
IM 987
IM 991
IM 1058
NOTICE
This equipment generates, uses, and can radiate radio frequency energy and, if not installed and used in accordance with this instruction manual, may cause interference to radio communications . It has been tested and found to comply with the limits for a Class A digital device, pursuant to part 15 of the FCC rules . These limits are designed to provide reasonable protection against harmful interference when the equipment is operated in a commercial environment . Operation of this equipment in a residential area is likely to cause harmful interference in which case the user is required to correct the interference at his own expense .
Daikin disclaims any liability resulting from any interference or for the correction thereof .
WARNING
Excessive moisture in the control panel can cause hazardous working conditions and improper equipment operation .
When servicing this equipment during rainy weather, the electrical components in the main control panel must be protected from the rain .
CAUTION
Extreme temperature hazard . Can cause damage to system components .
The MicroTech III controller is designed to operate in ambient temperatures from -20°F to 125°F . It can be stored in ambient temperatures from
-40°F to 140°F . It is designed to be stored and operated in relative humidity up to 95% (non-condensing) .
CAUTION
Static sensitive components . A static discharge while handling electronic circuit boards can cause damage to the components .
Discharge any static electrical charge by touching the bare metal inside the main control panel before performing any service work .
Never unplug any cables, circuit board terminal blocks, relay modules, or power plugs while power is applied to the panel .
Getting Started
This manual contains information designed to assist the field technician with unit setup. The technician will need to be familiar with the following topics at a minimum to successfully set up unit operation.
• Keypad navigation/editing/passwords
• Control Mode
• Occ Mode
• DSP Setpoint
• BSP Setpoint
• Heat/Cool Changeover (Zone Setpoints)
• DAT Clg Setpoint
• DAT Htg Setpoint
• Clg Enable (OAT/EWT lockout)
• Htg Enable (OAT lockout)
• Econo Enable (Changeover temp/Enthalpy switch)
• Ventilation Limit/OA damper
WARNING
Electric shock hazard . Can cause personal injury or equipment damage .
This equipment must be properly grounded . Connections and service to the MicroTech II control panel must be performed only by personnel that are knowledgeable in the operation of the equipment being controlled .
4 OM 920-4
Using the Keypad/Display
The keypad/display consists of a 5-line by 22 character display, three keys and a “push and roll” navigation wheel.
There is an Alarm Button, Menu (Home) Button, and a Back
Button. The wheel is used to navigate between lines on a screen (page) and to increase and decrease changeable values when editing. Pushing the wheel acts as an Enter Button.
The first line on each page includes the page title and the line number to which the cursor is currently “pointing”. The line numbers are X/Y to indicate line number X of a total of
Y lines for that page. The left most position of the title line includes an “up” arrow to indicate there are pages “above” the currently displayed items, a “down” arrow to indicate there are pages “below” the currently displayed items or an “up/ down” arrow to indicate there are pages “above and below” the currently displayed page.
Each line on a page can contain status only information or include changeable data fields. When a line contains status only information and the cursor is on that line all but the value field of that line is highlighted meaning the text is white with a black box around it. When the line contains a changeable value and the cursor is at that line, the entire line is highlighted. Each line on a page may also be defined as a
“jump” line, meaning pushing the navigation wheel will cause a “jump” to a new page. An arrow is displayed to the far right of the line to indicate it is a “jump” line and the entire line is highlighted when the cursor is on that line.
Figure 1: Keypad Controls
Using the Keypad/Display
The keypad/display Information is organized into Menu groups; Main Menu, Quick Menu, View/Set Unit Menu,
Commission Unit Menu, Manual Control Menu, Service
Menu, Unit Configuration Menu and Alarm list Menus.
NOTE:
Only menus and items that are applicable to the specific unit configuration are displayed.
The Main Menu allows the user to enter a password, access the Quick Menu pages, view the current unit state, access the
Alarm List Menu as well as access to information about this unit. The Quick Menu provides access to status information indicating the current operating condition of the unit. The
View/Set Unit Menus include basic menus and items required to setup the unit for general operation. These include such things are control mode, occupancy mode and heating and cooling setpoints. The Commission Unit Menus include more advanced items for “tuning” unit operation such as
PI loop parameters and time delays. The Manual Control
Menu allows service personnel to test unit specific operation manually. The Unit Configuration Menu allows the user to access to the unit specific configuration information. These generally do not needing changing or accessing unless there is a fundamental change to or a problem with the unit operation.
The Alarm Lists Menu includes active alarm and alarm log information.
OM 920-4 5
Using the Keypad/Display
Using the Keypad/Display
Passwords
Various menu functions are accessible or inaccessible, depending on the access level of the user, and the password they enter, if any. There are four access levels, including no password, Level 2, Level 4, and Level 6, with Level 2 having the highest level of access. Without entering a password, the user has access only to basic status menu items. Entering the Level 6 password (5321) allows access to the Alarm Lists
Menu, Quick Menu, and the View/Set Unit Menus group.
Entering the Level 4 password (2526) allows similar access as Level 6 with the addition of the Commission Unit Menu,
Manual Control, and Service Menu groups. Entering the
Level 2 password (6363) allows similar access as Level 4 with the addition of the Unit Configuration Menu.
NOTE:
Alarms can be acknowledged without entering a password .
The main password page is displayed when the keypad/ display is first accessed, the Home Key is pressed, the Back
Key is pressed multiple times, or if the keypad/display has been idle longer than the Password Timeout (default 10 minutes). The main password page provides access to enter a password, access the Quick Menu, view the current Unit
State, access the alarm lists or view information about the unit.
Figure 2: Password Main Page
AHU 01 1/5
Enter Password
Quick Menu
Unit State=________
Alarm Lists
About This AHU
Entering an invalid password has the same effect as continuing without entering a password. Once a valid password has been entered, the controller allows further changes and access without requiring the user to enter a password until either the password timer expires or a different password is entered. The default value for this password timer is 10 minutes. It is changeable from 3 to 30 minutes via the
Timer Settings menu.
Navigation Mode
In the Navigation Mode, when a line on a page contains no editable fields all but the value field of that line is highlighted meaning the text is white with a black box around it. When the line contains an editable value field the entire line is inverted when the cursor is pointing to that line.
When the navigation wheel is turned clockwise, the cursor moves to the next line (down) on the page. When the wheel is turned counter-clockwise the cursor moves to the previous line (up) on the page. The faster the wheel is turned the faster the cursor moves.
When the Back Button is pressed the display reverts back to the previously displayed page. If the Back button is repeated pressed the display continues to revert one page back along the current navigation path until the “main menu” is reached.
When the Menu (Home) Button is pressed the display reverts to the “main page.”
When the Alarm Button is depressed, the Alarm Lists menu is displayed.
The password field initially has a value **** where each * represents an adjustable field. These values can be changed by entering the Edit Mode described below.
Figure 3: Password Entry Page
Enter Password 1/1
Enter Password
****
Edit Mode
The Editing Mode is entered by pressing the navigation wheel while the cursor is pointing to a line containing an editable field. Once in the edit mode pressing the wheel again causes the editable field to be highlighted. Turning the wheel clockwise while the editable field is highlighted causes the value to be increased. Turning the wheel counter-clockwise while the editable field is highlighted causes the value to be decreased. The faster the wheel is turned the faster the value is increased or decreased. Pressing the wheel again cause the new value to be saved and the keypad/display to leave the edit mode and return to the navigation mode.
6 OM 920-4
Using the Keypad/Display
Service Timers
A user may override timers for a period of up to 240 minutes by setting the Service Timer to a non-zero number. When the
Service Timer is not zero, the times listed below are set to the
Service Time (Default = 20 seconds) instead of the normal values. This allows the unit to be run through its operating states without having to wait for the normal time delays to expire. These times revert to the standard values when the
Service Time count down to zero or is set to zero by the user.
The affected times are:
• Cooling Stage Time
• Heating Stage Time
• Start Initial Time
• Recirculation
• ZeroOATime
Rapid Start
The user may elect to initiate a rapid startup sequence at unit power up by setting the Rapid Start flag to Yes. When this flag is set to Yes, the Service Timer is set to 10 minutes whenever the power is reset to the controller.
Manual Control
A user may manually control outputs to check operation of components when Manual Control is set to ManCtrl. When
Manual Control is set to ManCtrl, the unit is disabled and the unit is shut down in the normal manner if it is operating.
Outputs listed in the Manual Control menu of the Keypad/
Display section can then be controlled directly until Manual
Control is set to Normal.
NOTE:
Manual Control will be set to No automatically after
240 minutes so that a person could not put the unit into Manual Mode control and walk away from the unit and let it run at the manual settings .
When Manual Control is set to Yes, the Control Mode is set to
Off so that the unit will not restart automatically.
When Manual Control is set to Normal all digital outputs in the Manual Control menu are set to Off and all the analog outputs are set to 0.0% so that all outputs are in the Off or minimum position when Manual Control is set to ManCtrl.
All alarms except those listed below are overridden during
Manual Control.
During manual control, the unit will respond in the normal manner to the following alarms.
• Emergency Stop Fault
• Duct High Limit
• High Return Temperature
• High Discharge Temperature
• Low Discharge Temperature
• High Pressure - Circuit # 1
• High Pressure - Circuit # 2
• Low Pressure - Circuit # 1
• Low Pressure - Circuit # 2
OM 920-4 7
Keypad/Display Menu Structure
The following is a description of the MicroTech III menu structure. These menus and items can all be displayed with the keypad/ display. Menu items displayed will change based on the selected unit configuration.
Figure 4: Main Menu – Keypad/Display Menu Structure
Main Menu
Enter Password
Quick Menu
View/Set Unit
Unit State=_________
Unit Status=________
Ctrl Mode= Off
Occ Mode= Auto
Commission Unit
Manual Control
Service Menus
Trending
Unit Maintenance
BMS Communications
Unit Configuration
Alarm Lists
About This Unit
Enter Password
Enter Password *******
►
Quick Menu
Unit State=__________
Unit Status=_________
Dehum Status=______
Ctrl Mode= Off
Occ Mode= Auto/Net
Clg Capacity= XXX%
OAD/Econ Cap= XXX%
Htg Capacity= XXX%
Reheat Cap= XXX%
Control Temp= XXX%
Occ Clg Spt= 72 .0°F
Occ Htg Spt= 68 .0°F
Disch Air= XXX°F
DAT Clg Spt= 55 .0°F
DAT Htg Spt= 85 .0°F
Min DAT Limit= 55 .0°F
Unocc Clg Spt= 85 .0°F
Unocc Htg Spt= 55 .0°F
SAF Speed= XXX%
Duct Press= X .Xin
DuctSP Spt= 1 .0in
RF/EF Cap= XXX%
Bldg Press= X .XXin
BldgSP Spt= 0 .05in
IAQ PPM= XXXXppm
OA Flw= XXXXXCFM
MinOAFlw Spt= 2000CFM
OA Temp= XXX°F
EW Temp= XXX°F
Rel Humidity= XXX%
View/Set Unit
Unit Status/Settings
Occupancy
Temperatures
Flow Status
SAF Spd Control
RF/EF Control
Cooling
Economizer
Min OA Damper
Heating
Dehumidification
Date/Time/Schedules
For more detail go to:
8
BMS Communications
LON Set-Up
►
BACnet MSTP Set-Up
BACnet IP Set-Up
D-Net Set-Up
Network Unit Set-Up
►
►
For more detail go to:
Unit Configuration
Apply Changes= No
Unit Type= RTU(0)
Control Type= DAT(1)
Clg Type= Comp(1)
Comp Config= 424(1)
Gen Clg Stgs= 8
Low Ambient= No(0)
Cond Ctrl= Std2(0)
OA Dmpr/Econ= AirEc(3)
OA Flow Stn= None(0)
Htg Type= None(0)
Htg Stages= 1
Max Heat Rise= 100
SAF Type= CAV(0)
RAF Type= CAV(0)
RF/EF Ctrl= Track(1)
2ndDSPSnsr= No(0)
EFT/LCT Snsr= No(0)
Energy Rcvy= None(0)
Clg Circ Type= 2Air(2)
Head P Ctrl= No(0)
Bypass Ctrl= Slave(0)
Unit Size= 050
Refrig Type= R410A(2)
Reheat Type= None(0)
Unit Voltage= 460/60(2)
Alarm Lists
Active Alarms
Alarm Log
For more detail go to:
About This Unit
SO_Item= 123456_12345
Unit SN= FBOU123456789
App Version= 2506017xxx
Cf1-15= xxxxxxxxxxxxxxxx
Cf6-29= xxxxxxxxxxxxxxxx
Main BSP= X .XX
LON BSP= X .XX
LON App Ver= X .XX
BACnet BSP= X .XX
D-Net BSP= X .XX
HMI GUID= xxxxxxxx-xxxx-xxxx-xxxx- xxxxxxxxxxxx
OBH GUID= xxxxxxxx-xxxx-xxxx-xxxx- xxxxxxxxxxxx
OM 1141-2
Keypad/Display Menu Structure
Commission Unit
Unit Set-Up
Timer Settings
SAF Set-Up
RF/EF Set-Up
Htg/Clg ChgOvr Set-Up
Cooling Set-Up
Econo Set-Up
Min OA Set-Up
Heating Set-Up
Dehum Set-Up
Energy Rec Set-Up
Head Pressure Set-Up
Evap Cond Set-Up
Alarm Configuration
►
►
For more detail go to:
Manual Control
Manual Control= Normal
Supply Fan= Off
SAF Spd Cmd= 0%
RF/EF Fan= Off
RF/EF Spd Cmd= 0%
OAD/Econo= 0%
OAD OpCl= Close
Comp 1= Off
Comp 2= Off
Comp 3= Off
Comp 4= Off
Comp 5= Off
Comp 6= Off
Comp 7= Off
Comp 8= Off
U1 Comp 1= Off
U1 Comp 2= Off
U2 Comp 1= Off
U2 Comp 2= Off
CFan Outpt 1= Off
CFan Outpt 2= Off
CFan Outpt 3= Off
BP/WR Valve= 0%
CW Valve= 0%
ExhFan Out 1= Off
ExhFan Out 2= Off
ECond VFD= Off
ECFan Spd Cmd= 0%
EC Dm Valve= Close
Sump Pump= Off
Sep Flsh Vlv= Off
SV1= Off
SV2= Off
Gas Htg On/Off= Off
Htg Valve= 0%
SCR Out= 0%
F&BP Damper= 0%
Htg Stg 1= Off
SCR Ena 1= Off
Htg Stg 2= Off
SCR Ena 2= Off
Htg Stg 3= Off
Htg Stg 4= Off
Htg Stg 5= Off
Htg Stg 6= Off
Reheat Valve= 0%
RH Output= Off
LSCRH Valve= Off
HGBP Valve= Off
ERec Wheel= Off
ER Whl Cmd= 0%
ERBP Dmpr Cl= Off
ERBP Dmpr Op= Off
Cond Wtr Pump= Off
Alm Output= Off
Fan Op Out= Off
Service Menus
Timer Settings
Operating Hours
Save/Restore Settings
Active Alarms
Alarm Log
Alarm Configuration
Analog Input Status
Universal I/O Status
Digital Input Status
Digital Output Status
Network Input Status
Modbus Status
D3 Status
Sensor Offsets
Reset Counte= XXXX
For more detail go to:
Trending
Trending Ena= No
Apply Chgs= No
Sample Time= 300s
TrendOnOff= Off
Export Data= No
Clear Trend= Done
Points 1–8 (Fixed)
Points 9–24 (from List)
Points 25–27 (with IDs)
Points 28–30 (with IDs)
For more detail go to:
Unit Maintenance
Operating Hours
OM 1141-2 9
Keypad/Display Menu Structure
Figure 5: View/Set Unit – Keypad/Display Menu Structure
View/Set Unit
Unit Status/Settings
Occupancy
Temperatures
Flow Status
SAF Spd Control
RF/EF Control
Cooling
Economizer
Min OA Damper
Heating
Dehumidification
Date/Time/Schedules
Unit Status/Settings
Unit State= ___________
Unit Status= __________
Dehum Status= ________
Ctrl Mode= Off
Clg Status= ___________
Htg Status= ___________
Econo Status= _________
Clg Capacity= XXX%
Htg Capacity= XXX%
Reheat Cap= XXX%
SAF Speed= XXX%
RF/EF Cap= XXX%
OAD/Econo Cap=XXX%
Rel Humidiy= XXX%
Net Emrg Ovrd= Normal
Net App Mode= Auto
Occupancy
Occupancy= __________
Occ Mode= Auto/Net
OccSrc= _____________
UnoccSrc= ___________
Tnt Ovrde Tm= 0 min
Temperatures
Control Temp= XXX°F
Disch Temp= XXX°F
Return Air= XXX°F
Space Temp= XXX°F
OA Temp= XXX°F
EF/LC Temp= XXX°F
EW Temp= XXX°F
Mixed Air= XXX°F
ER LAT= XXX°F
ER EAT= XXX°F
Sump Temp= XXX°F
Flow Status
Airflow= ______________
Waterflow= ___________
Water Pump= _________
Supply Fan= __________
Ret/Exh Fan= _________
SAF Speed Control
SAF Speed= XXX%
Speed Cmd= XXX%
Duct Press= X .Xin
DuctSP Spt= 1 .0in
IAQ PPM= XXXXPPM
OA Flw= XXXXXCFM
MinOAFlw Spt= 2000CFM
Bldg Press= X .XXin
BldgSP Spt= 0 .05in
RF/EF Control
RF/EF Cap= XXX%
Speed Cmd= XXX%
Bldg Press- X .XXin
BldgSP Spt= 0 .050in
10 OM 1141-2
Keypad/Display Menu Structure
Cooling
Occ Clg Spt= 72 .0°F
Unocc Clg Spt= 85 .0°F
DAT Clg Spt= 55 .0°F
Economizer
OAD/Econo Pos= XXX%
DAT Clg Spt= 55 .0°F
Min OA Pos= XXX%
Occ Clg Spt= 72 .0°F
Unocc Clg Spt= 85 .0°F
Min OA Damper
Min OA Pos= XXX%
Vent Limit= 20%
LoFlo V Lmt= 30%
DCV Limit= 10%
Min OA Src= __________
Heating
Occ Htg Spt= 68 .0°F
Unocc Htg Spt= 55 .0°F
MWU Spt= 70 .0°F
DAT Htg Spt= 85 .0°F
Dehumidification
Dehum Status= ________
Rel Humidity= XXX%
Dewpoint= XXX°F
Dehum Method= None
RH Setpoint= 50%
Dewpoint Spt= 50°F
Reheat Spt= XXX°F
Reheat Cap= XXX%
Date/Time/Schedules
Time= hh:mm:ss
Date= MM/DD/YY
UTC Diff= -60min
DAILY SCHEDULE
Mon= HH:MM-HH:MM
Tue= HH:MM-HH:MM
Wed= HH:MM-HH:MM
Thu= HH:MM-HH:MM
Fri= HH:MM-HH:MM
Sat= HH:MM-HH:MM
Sun= HH:MM-HH:MM
Hol= HH:MM-HH:MM
HOLIDAY DATES
Hol 1=MMMDD/YY-MMMDD/YY
Hol 2=MMMDD/YY-MMMDD/YY
Hol 3=MMMDD/YY-MMMDD/YY
Hol 4=MMMDD/YY-MMMDD/YY
Hol 5=MMMDD/YY-MMMDD/YY
Hol 6=MMMDD/YY-MMMDD/YY
Hol 7=MMMDD/YY-MMMDD/YY
Hol 8=MMMDD/YY-MMMDD/YY
Hol 9=MMMDD/YY-MMMDD/YY
Hol 10=MMMDD/YY-MMMDD/YY
ONE EVENT SCHEDULE
Beg= MMMDD/YY@HH:MM
End= MMMDD/YY@HH:MM
OPTIMAL START
Enable= No
Htg Range= 0 .4 ºF/min
Htg OAT= 35 ºF
Des Htg OAT= 0 ºF
Clg Rate= 0 .4 ºF/min
Clg OAT= 85 ºF
Des Clg OAT= 95 ºF
DAYLIGHT SAVINGS
DLS Strt Mon= Mar
DLS Strt Wk= 2nd Week
DLS End Mon= Nov
DLS End Wk= 1st Week
DLS Active= Yes
OM 1141-2 11
Keypad/Display Menu Structure
Figure 6: Commission Unit – Keypad/Display Menu Structure
Commission Unit
Unit Set-Up
Timer Settings
SAF Set-Up
RF/EF Set-Up
Htg/Clg ChgOvr Set-Up
Cooling Set-Up
Econo Set-Up
Min OA Set-Up
Heating Set-Up
Dehum Set-Up
Energy Rec Set-Up
Head Pressure Set-Up
Evap Cond Set-Up
Alarm Configuration
Unit Set-Up
Apply Changes= No
Space Sensor= Digtl/Net
Eng Units= English
Unit Name= xxxxxxxxxxxx
Rapid Start= No
Rapid Start Tm= 10min
DO10 Clg= FanOp
Timer Settings
Service Time= 0min
Start Up= 180s
Recirculate= 180s
Zero OA Time= 0min
Tnt Override= 120min
Post Heat= 0s
Pwd Timeout= 10min
Low DAT= 6min
ClgStateDelay= 300s
Clg Stg Time= 5min
Htg Stg Time= 5min
Air Flw Ign= 120s
MinExStrtTm= 120s
MinExStopTm= 120s
ER Whl Stg Tm= 5min
ER Whl Off Tm= 20min
Srvc Time Inc= 20s
OffHtCIDelay= 120s
SAF Set-Up
SAF Ctrl= DSP
SPEED CONTROL
Rem SAF Cap= 25%
DSP CONTROL
DSP DB= 0 .1in
VFD Ramp Time= 60s
Min Period= 5s
Max Spd Chg= 15%
Duct Press 1= X .Xin
1 ZONE VAV CONTROL
Min Clg Spd= 40%
Max Clg Spd= 100%
Min Htg Spd= 40%
Max Htg Spd= 100%
Space Period= 30s
Space Gain= 1 .5
Space PAT= 100s
Space Max Chg= 10%
CO
2
CONTROL
Min PPM= 0PPM
Max PPM= 2000PPM
V/A @ Min PPM= 0V
V/A @ Max PPM= 10V
Min SAF PPM= 800PPM
BSP CONTROL
BSP DB= 0 .01in
BSP Period= 5s
BSP Gain= 0 .2
Max Spd Chg= 4%
SAF SETUP
Max SAF PPM= 1100PPM SAF Ctrl Dly= 30s
Min PPM Spd= 50%
Max PPM Spd= 100%
Min Speed= 25%
VAVBox Out= _________
CFM CONTROL
Min CFM= 0CFM
Max CFM= 10000CFM
V/A @ Min CFM= 0V
V/A @ Max CFM= 10 V
Max SAF Hz=
Max Vent Speed= 100%
Max SAF RPM= 2600
SAF CFM DB= 3%
SAF CFM Period= 30s
SAF CFM Gain= 0 .1
SAF CFM MxChg= 5%
12
Min OA Set-Up
AplyMinOAChg= No
Min OA Reset= None
BSPOAOvrd= No
RstLmtSnsr= None
EXTERNAL RESET
OA @ MinV/mA= 0%
OA @ MaxV/mA= 100%
Min V/mA= 0 .0V
Max V/mA= 10 .0V
CO
2
RESET
IAQ Reset= Yes
PPM@DCVLmt= 800PPM
PPM@VntLmt= 1000PPM
IAQ PPM= XXXXPPM
Min PPM= 0 PPM
Max PPM= 2000 PPM
V/A @Min PPM= 0 .0/V
V/A @Max PPM= 10 .0/V
CFM RESET
OA Flow= XXXXXCFM
MinOAFlwSpt= 2000CFM
Field Stn Rst= Yes
Field Stn Cfg= VDC
Min CFM= 0 CFM
Max CFM= 10000 CFM
V/A @Min CFM= 0 .0V
V/A @Max CFM= 10 .0V
OA CFM DB= 3%
OA CFM Period= 30s
OA CFM Gain= 0 .1
OA CFM Max Chg= 5%
FAN SPEED RESET
Min Clg Spd= 40%
Des Clg Spd= 100%
BSP RESET
MinRFEFTm= 120s
BSP OvdST= 5s
BSP OvdGain= 0 .2
BSP OvdMaxChg= 4%
DAMPER LIMITING
RstTLmt= 32 .0ºF
RstTSmplTm= 5s
RstTGain= 0 .2
RstPAT= 60s
RstTMaxChg= 4%
0–30% OA Max= 30%
Min Inc Rate= 0 .03
Max Inc Rate= 1 .0
Heating Set-Up
Htg Stage Time= 5min
Htg DB= 2 .0°F
Htg Period= 60s
Htg Gain= 0 .8
Htg PAT= 120s
Htg Max Chg= 10%
Htg Hi OAT Lk= 55 .0°F
OAT Diff= 2 .0°F
Htg Reset= None
Min Htg Spt= 55 .0°F
Min Htg Spt @= 0
Max Htg Spt= 120 .0°F
Max Htg Spt@= 100
Min DAT Ctrl= Yes
Min DAT Limit= 55 .0°F
F&BP Method= OpenVlv
F&BP ChgOvrT= 37°F
Occ Heating= Yes
Unocc Diff= 55 .0°F
Htg Wmup Tm= 60s
Htg Hld Period= 240s
Max Purge Hld= 20s
Gas Derate V= 10 .0v
MWUSensor= RAT
OM 1141-2
Keypad/Display Menu Structure
RF/EF Set-Up
RF/EF Ctrl= None
Rem RAF Cap= 5%
Rem ExhF Cap= 5%
BSP DB= 0 .010in
BSP Period= 5s
BSP Gain= 0 .2s
Max Spd Chg= 4%
Sup Fan Max= 100%
RF @ SF Max= 95%
Sup Fan Min= 100%
RF @ SF Min= 95%
RFEF Ctrl Dly= 30s
Min Speed= 5/33%
(Exh Fan/Return Fan)
MinExStrtTm= 120s
MinExStopTm= 120s
MinExOAPos= 5%
MinExSAFCap= 10%
ExhOnOAPos= 40%
ExhMxOAPos= 100%
Exh Stg 1 On= 40%
Exh Stg 1 Off= 30%
Exh Stg 2 On= 55%
Exh Stg 2 Off= 40%
Exh Stg 3 On= 70%
Exh Stg 3 Off= 50%
Max Vent Spd= 100%
Max RFEF RPM= 2600
ECM Status= _________
Htg/Clg ChgOvr Set-Up
Ctlr Temp Src= RAT
AplyTstatchg= No
Use Tstat Spt= No
Occ Clg DB= 2 .0°F
Clg Period= 60s
Clg Gain= 0 .1
Clg PAT= 600s
Max Clg Chg= 5 .0°F
Occ Htg DB= 2 .0°F
Htg Period= 60s
Htg Gain= 0 .1
Htg PAT= 600s
Max Htg Chg= 5 .0°F
Cooling Set-Up
Clg Stage Time= 5min
Clg DB= 2 .0°F
Clg Period= 20s
Clg Gain= 1
Clg PAT= 40s
CW Max Chg= 15%
Clg Lo OAT Lk= 55ºF
OAT Diff= 2 .0°F
Min EWT= 55°F
Clg Reset= None
Min Clg Spt= 55 .0°F
Min Clg Spt @= 0
Max Clg Spt= 65 .0°F
Max Clg Spt@= 100
Lead Circuit= #1
Staging Type= Std
CFanOut1 Spt= 55°F
CFanOut2 Spt= 65°F
CFanOut3 Spt= 75°F
Cond Fan Diff= 5°F
Econo Set-Up
Clg Stage Time= 5min
Chgover Temp= 65 .0°F
Clg DB= 2 .0°F
Econo Period= 30/40s
(air/water)
Econo Gain= 10/1
(air/water)
Econo PAT= 60/40s
(air/water)
Econo Max Chg= 10/15%
(air/water)
Flush Econo= Yes
Econo Diff= 2 .0°F
EWT Diff= 3 .0°F
Clg Reset= None
Min Clg Spt= 55 .0°F
Min Clg Spt @= 0
Max Clg Spt= 65 .0°F
Max Clg Spt@= 100
Dehum Set-Up
Dehum Method= None
RH DB= 2%
Dewpoint DB= 2°F
RH Period= 30s
RH Gain= 1
RH PAT= 30s
RH Max Chg= 10%
RH Stg Time= 10min
Stg Rht DB= 5 .0°F
Dehum Ctrl= Occupied
Sensor Loc= Return
Mn Lvg Coil T= 45 .0°F
Mx Lvg Coil T= 52 .0°F
Min Rheat Spt= 55 .0°F
Max Rheat Spt= 65 .0°F
Energy Rec Set-Up
Energy Rcvy= Yes
ER Wheel= ___________
Wheel Speed= XXX%
Whl Spd Cmd= XXX%
ER LAT= XXX°F
ER EAT= XXX°F
Min ExhT Diff= 2 .0°F
Max ExhT Diff= 6 .0°F
ER Whl Stg Tm= 5min
ER Whl Off Tm= 20min
Rel Humidity= XXX%
Min Whl Spd= 5%
Intersect Pt= XXX .XºF
Fst Mgnt Meth= Timed
OA Frst Temp= -5 .0°F
Defrost Time= 5min
Defrost Period= 60min
Defrst On Tm= 1s
Defrst Off Tm= 24s
ER Whl Period= 30s
ER Whl Gain= 1 .0
ER Whl PAT= 30s
ER Max Chg= 10%
Head Pressure Set-Up
Wtr Reg Vlv= XXX%
Head P Circ 1= XXXPSI
Head P Circ 2= XXXPSI
Setpoint= 260PSI
Head Press DB= 10PSI
WRV Period= 10s
WRV Gain= 3 .6
WRV PAT= 10s
WRV Max Chg=7%
WRV Init Tm= 60s
Min WRV Pos=10%
Min WRV Tmp= 58°F
Max WRV Tmp= 150°F
WRV Act Time= 60s
Min WRV Time= 60s
Evap Cond Set-Up
Cond Fan Spd= XXX%
CFan Spd Cmd= XXX%
Min Fan Speed= 25%
EvCond Stg Tm= 10min
Sump Temp= XXX°F
Min Sump T= 75 .0°F
Max Sump T= 85 .0°F
Sump Dump Spt= 35 .0°F
Cndtvy= XXXS/CM
Hi Cndtvy Spt= XXXS/CM
SmpWtrLvDly= 5min
PostClgTime= 10min
SepFlshtime= 1min
Dolphin Sys= No
Alarm Configuration
ALARM LIMITS
Hi Disch Temp= 170°F
Lo Disch Temp= 40°F
Hi Return Temp= 120°F
ALARM OUT CONFIG
Faults= Fast
Problems= Slow
Warnings= Off
ALARM DELAYS
Frz Delay Time= 30s
LP Delay= 2s
LP Comp Delay= 5s
Air Flw Ing=120s
Sens Alm Dly= 30s
Temp AlmDly= 30s
ALARM CONFIG
Emerg Stop= ManClr
OM 1141-2 13
Keypad/Display Menu Structure
Figure 7: Service Menu – Keypad/Display Menu Structure
Service Menus
Timer Settings
Operating Hours
Save/Restore Settings
Active Alarms
Alarm Log
Alarm Configuration
Analog Input Status
Universal I/O Status
Digital Input Status
Digital Output Status
Network Input Status
Modbus Status
D3 Input Status
Sensor Offsets
Reset Counte= XXXX
Timer Settings
Service Time= 0min
Start Up= 180s
Recirculate= 180s
Zero OA Time= 0min
Tnt Override= 120min
Post Heat= 0s
Pwd Timeout= 10min
Low DAT= 6min
ClgStateDelay= 300s
Clg Stg Time= 5min
Htg Stg Time= 5min
Air Flw Ign= 120s
MinExStrtTm= 120s
MinExStopTm= 120s
ER Whl Stg Tm= 5min
ER Whl Off Tm= 20min
Srvc Time Inc= 20s
OffHtCIDelay= 120s
Operating Hours
Supply Fan= XXXXXh
Ret/Exh Fan= XXXXXh
Exh Out1= XXXXXh
Exh Out2= XXXXXh
Comp # 1= XXXXXh
Comp # 2= XXXXXh
Comp # 3= XXXXXh
Comp # 4= XXXXXh
Comp # 5= XXXXXh
Comp # 6= XXXXXh
Comp # 7= XXXXXh
Comp # 8= XXXXXh
Heating= XXXXXh
Economizer= XXXXXh
Tnt Override= XXXXXh
Dehumid= XXXXXh
ER Wheel= XXXXXh
Save/Restore
Settings
Save Params= No
Rstr Params= No
Rstr Factory= No
SaveToCard= No
LoadFromCard= No
Active Alarms
Alm Count: xx Clr Alms= No
+Alarm 1: Alarm Type
►
+Alarm 2: Alarm Type
►
●
●
●
+Alarm 10: Alarm Type
►
14
Network Input Status
Net OAT In= XXX .XºF
Net Space In= XXX .XºF
NetCurrState= _________
NetNextState= _________
NetTmToNxtSt= XXXXXmin
Net App Mode= ________
Net Cl Ena Sw= X .X
Net Cl Ena VI= XXX%
Net Ht Ena Sw= X .X
Net Ht Ena VI= XXX%
Net Ec Ena Sw= X .X
Net Ec Ena VI= XXX%
Net SAF Cap= XXX%
Net ExhF Cap= XXX%
Net Space IAQ= XXXXPPM
Net Rel Humid= XXX%
Net DATClgSpt= XXX .XºF
Net DATHtgSpt= XXX .XºF nviSetpoint= XXX .XºF
OccManCmd= _________
Net Min OA= XXX% nvoEffSpt= XXX .XºF nciOccClgSpt= XXX .XºF nciOccHtgSpt= XXX .XºF nciHVACType= _________
Modbus Status
SF MB Status=_________
RF/EF MB Status=______
ER MB Status=________
D3 MB Status=_________
MB Resistance= Yes
ECM Config= Done
D3 Status
D3 Comm Sts= ________
D3 Addr Err= __________
D3 On/Off= ___________
D3 Mode= ____________
D3 Clg Spt= XXX .XºF
D3 Htg Spt= XXX .XºF
D3 Fan Spd= __________
D3 Min Load= XXX%
D3 Max Load= XXX%
D3 Eco Ena= __________
OA Enthalpy= XXXBTU/lb
OA Hum Ratio= g/kg
D3 SWVers= XXXXXXXXXX
OAAdd1–16= __________
OAAdd17–32= _________
OAAdd33–49= _________
OAAdd50–64= _________
SetOAAddr= XX
CurrOAAddr= XX
CurrOAAmps= XXXA
CurrOARLA= XXXA
Sensor Offsets
Disch Air= 0 .0ºF
Return Air= 0 .0ºF
Space Temp= 0 .0ºF
OA Temp= 0 .0ºF
EF/LC Temp= 0 .0ºF
ER LAT= 0 .0ºF
ER EAT= 0 .0ºF
OM 1141-2
Keypad/Display Menu Structure
Alarm Log
Log Count: xx Clr Log= No
+/-Alarm 1: Alarm Type
+/-Alarm 2: Alarm Type
●
●
●
+/-Alarm 10: Alarm Type
●
●
●
+/-Alarm 50: Alarm Type
►
►
Alarm Configuration
ALARM LIMITS
Hi Disch Temp= 170°F
Lo Disch Temp= 40°F
Hi Return Temp= 120°F
ALARM OUT CONFIG
Faults= Fast
Problems= Slow
Warnings= Off
ALARM DELAYS
Frz Delay Time= 30s
LP Delay= 2s
LP Comp Delay= 5s
Air Flw Ing=120s
Sens Alm Dly= 30s
Temp AlmDly= 30s
ALARM CONFIG
Emerg Stop= ManClr
Analog Input Status
MCB Al1= XXXXXXXX
MCB Al2= XXXXXXXX
MCB Al3= XXXXXXXX
Universal I/O Status
MCB X1= XXXXXXXX
MCB X2= XXXXXXXX
MCB X3= XXXXXXXX
MCB X4= XXXXXXXX
MCB X5= XXXXXXXX
MCB X6= XXXXXXXX
MCB X7= XXXXXXXX
MCB X8= XXXXXXXX
EMB X1= XXXXXXXX
EMB X2= XXXXXXXX
EMB X3= XXXXXXXX
EMB X4= XXXXXXXX
EMB X5= XXXXXXXX
EMB X6= XXXXXXXX
EMB X7= XXXXXXXX
EMB X8= XXXXXXXX
EMD X1= XXXXXXXX
EMD X2= XXXXXXXX
EMD X3= XXXXXXXX
EMD X4= XXXXXXXX
EMD X5= XXXXXXXX
EMD X6= XXXXXXXX
EMD X7= XXXXXXXX
EMD X8= XXXXXXXX
Digital Input Status
MCB DI1= ____________
MCB DI2= ____________
MCB DI3= ____________
MCB DI4= ____________
MCB DI5= ____________
MCB DI6= ____________
EMD DI1= ____________
Digital Output Status
MCB DO1= __________
MCB DO2= __________
MCB DO3= __________
MCB DO4= __________
MCB DO5= __________
MCB DO6= __________
MCB DO7= __________
MCB DO8= __________
MCB DO9= __________
MCB DO10= __________
EMB DO1= __________
EMB DO2= __________
EMB DO3= __________
EMB DO4= __________
EMB DO5= __________
EMB DO6= __________
EMD DO1= __________
EMD DO2= __________
EMD DO3= __________
EMD DO4= __________
EMD DO5= __________
EMD DO6= __________
Alarm Lists
Active Alarms
Alarm Log
Active Alarms
Alm Count: xx Clr Alms= No
+Alarm 1: Alarm Type
►
+Alarm 2: Alarm Type
►
●
●
●
+Alarm 10: Alarm Type
►
Alarm Log
Log Count: xx Clr Log= No
+/-Alarm 1: Alarm Type
+/-Alarm 2: Alarm Type
●
●
●
+/-Alarm 10: Alarm Type
●
●
●
+/-Alarm 50: Alarm Type
►
►
Alarm Details
+/-Alarm 1: Alarm Type
MM/DD/YYYY HH:MM:SS
OM 1141-2 15
Keypad/Display Menu Structure
Figure 8: BMS Communications – Keypad/Display Menu Structure
BMS Communications
LON Set-Up
►
BACnet MSTP Set-Up
BACnet IP Set-Up
D-Net Set-Up
Network Unit Set-Up
►
►
IM 918
LON Set-Up
Neuron ID= xxxxxxxxxxxx
SndHrtBT= 60s
RcvHrtBT= 30s
MinSndTm= 0s
Comm Status=_________
LON BSP= X .XXX
LON App Ver= XXXX
IM 917
BACnet MSTP Set-Up
ApplyMSTPChgs= No
Name= xxxxxxxxxxxxxxxx
Dev Instance= xxxxxxxxxx
MSTP Address= XXX
Baud Rate= 76800
Max Master= 127
Max Info Frm= 10
Unit Support= English
Term Resistor= No
NC Dev 1= 0
NC Dev 2= 0
Comm Status= ________
BACnet BSP= X .X .XX
IM 916
BACnet IP Set-Up
ApplyIPChgs= No
Name= xxxxxxxxxxxxxxxx
Dev Instance= xxxxxxxxxx
UDP Port= 47808
DHCP= On
Act IP= 0 .0 .0 .0
ActMsk- 0 .0 .0 .0
ActGwy= xxx .xxx .xxx .xxx
Gvn IP= 127 .0 .0 .1
GvnMsk= 255 .255 .255 .0
GvnGwy= 127 .0 .0 .1
Unit Support= English
NC Dev 1= 0
NC Dev 2= 0
Comm Status= ________
BACnet BSP= X .X .XX
D-Net Set-Up
ApplyD-NetChgs= No
DHCP= On
Act IP= 0 .0 .0 .0
ActMsk- 0 .0 .0 .0
ActGwy= xxx .xxx .xxx .xxx
Gvn IP= 127 .0 .0 .1
GvnMsk= 255 .255 .255 .0
GvnGwy= 127 .0 .0 .1
Remote Srv En= Disable
Comm Status= ________
D-net BSP= X .X .XX
Network Unit Set-Up
Space Sensor= Local/Net
UNIT MODE SETTINGS
Ctrl Mode= Off
Occ Mode= Auto/net
RESET OPTIONS
Clg Reset= None
Htg Reset= None
Min OA Reset= None
Apply Changes= No
HEAT/COOL CHANGEOVER
Ctrl Temp SRC= RAT
Occ Clg Spt= 72°F
Occ Htg Spt= 68°F
FAN CONTROL OPTIONS
SAF Ctlr= DSP
RF/EF Ctlr= Tracking
Figure 9: Trending – Keypad/Display Menu Structure
Trending
Trending Ena= No
Apply Chgs= No
Sample Time= 300s
TrendOnOff= Off
Export Data= No
Clear Trend= Done
Points 1–8 (Fixed)
Points 9–24 (from List)
Points 25–27 (with IDs)
Points 28–30 (with IDs)
Points 1–8 (Fixed)
Point 1= UnitSt
Point 2= Clg%
Point 3= Htg%
Point 4= SAF%
Point 5= OAD/Eco%
Point 6= CtrlTmp
Point 7= DAT
Point 8= OAT
Points 9–24 (from List)
Point 9= None
Point 10= None
Point 11= None
Point 12= None
Point 13= None
Point 14= None
Point 15= None
Point 16= None
Point 17= None
Point 18= None
Point 19= None
Point 20= None
Point 21= None
Point 22= None
Point 23= None
Point 24= None
Points 25–27 (with IDs)
Point 25
ID= F0AF0000
Type= 0000
Mem Num= 0100
Point 26
ID= F0AF0000
Type= 0000
Mem Num= 0100
Point 27
ID= F0AF0000
Type= 0000
Mem Num= 0100
Points 28–30 (with IDs)
Point 28
ID= F0AF0000
Type= 0000
Mem Num= 0100
Point 29
ID= F0AF0000
Type= 0000
Mem Num= 0100
Point 30
ID= F0AF0000
Type= 0000
Mem Num= 0100
16 OM 1141-2
Quick Menu
Items in the Quick Menu contain basic unit operating status and control set point parameters. The items shown in the
Quick Menu are Read Only if a valid password has not been entered. The following are brief descriptions of the Quick
Menu items. No password is required to view the Quick
Menu.
Table 1: Quick Menu
Menu Display Name Default Setting
Unit State= —
Unit Status=
Dehum Status=
Ctrl Mode=
Occ Mode=
Clg Capacity=
OAD/Econo Cap=
Htg Capacity=
Reheat Capacity=
Control Temp=
Occ Clg Spt =
Occ Htg Spt =
Disch Air=
DAT Clg Spt=
DAT Htg Spt=
Min DAT Limit=
SAF Capacity=
DSP
DuctSP Spt=
RF/EF Capacity=
BSP=
BldgSP Spt=
OA Temp=
EW Temp=
Rel Humidity=
—
—
Off
Auto/Net
—
55 .0°F
85 .0°F
55 .0°F
—
—
1 .0 in
—
—
—
—
—
72 .0°F
68 .0°F
—
—
0 .050 in
—
—
—
0–100%
-50 .0–200 .0°F
0 .0–100 .0°F
0 .0–100 .0°F
-50 .0–250 .0°F
40 .0–100 .0°F
40 .0–140 .0°F
0 .0–70 .0°F
0–100%
0 .2–4 .0 in
0 .2–4 .0 in
0–100%
-0 .25–0 .25 in
-0 .25–0 .25 in
-50 .0–200 .0°F
-50 .0–150 .0°F
0–100%
Active/Inactive
Off
HeatOnly
CoolOnly
FanOnly
HeatCool
Auto/Net
Occ
Unocc
TntOvrd
Auto/Net
0–100%
0–100%
0–100%
Range
Off
Start
Recirc
FanOnly
MinDAT
Htg
Econo
Clg
Enable
OffMan
OffMnCtl
OffNet
OffAlm
OffFnRty
Menu Descriptions
Menu Descriptions
Password Level
None
6
6
6
6
None
None
None
None
None
None
None
None
None
None
None
None
None
None
None
None
None
None
None
None
OM 920-4 17
Menu Descriptions
Menu Descriptions
Unit State
is a status only item which indicates the state of operation in which the unit is currently operating. The unit can be in any of the operating states shown.
Unit Status
is a status only item which indicates the status of operation in which the unit is currently operating. The unit status can be any of the status values shown.
Dehum Status
is a status only item which indicates the status of operation of the dehumidifier. The dehumidifier can be active or inactive.
Ctrl Mode
is an adjustable item which sets the operating mode of the unit. The unit can be in any of the modes shown.
Occ Mode
is an adjustable item which sets the occupancy mode of the unit. The unit can be in occupied, unoccupied, tenant override, or auto modes.
Clg Capacity
is a status only item which indicates the percentage of the unit maximum cooling capacity currently operating.
OAD/Econo Cap
is a status only item which indicates the percentage that the outdoor damper or economizer valve is currently open.
Htg Capacity
is a status only item which indicates the percentage of the unit maximum heating capacity currently operating.
Reheat Capacity
is a status only item which indicates the percentage of the unit maximum reheat capacity currently operating.
Control Temp
is a status only item which displays the current value of the “Control Temperature.” The “Control
Temperature” is defined as the temperature input selected by the Control Temperature Source parameter. For example, if the Control Temperature Source parameter is set to “Return,” then the control temperature parameter reads the same value as the Return Air parameter.
Occ Clg Spt
is a status only item which indicates the temperature in which the unit will go into the cooling mode of operation. Once a valid password has been entered this item becomes an adjustable item.
Occ Htg Spt
is a status only item which indicates the temperature in which the unit will go into the heating mode of operation. Once a valid password has been entered this item becomes an adjustable item.
Disch Air
is a status only item which displays the current temperature reading from the unit’s discharge air temperature sensor (DAT). This sensor is standard on all units.
DAT Clg Spt
is a status only item which indicates the temperature that the DAT should be maintained at when it is in the cooling mode of operation. Once a valid password has been entered this item becomes an adjustable item.
DAT Htg Spt
is a status only item which indicates the temperature that the DAT should be maintained at when in the heating mode of operation. Once a valid password has been entered this item becomes an adjustable item.
Min DAT Limit
is a status only item which indicates the discharge air low limit temperature on CAV zone control units. Heating will be activated to maintain this setting when the discharge temperature falls below it during the Fan Only operating state. On VAV or CAV discharge control units, the minimum discharge temperature limit is the DAT Clg Spt.
Once a valid password has been entered this item becomes an adjustable item.
SAF Capacity
is a status only item which indicates the capacity of the supply air fan.
DSP
is a status only item which displays the current duct static pressure reading.
DuctSP Spt=
is a status only item which indicates the duct static pressure set point used for controlling the VFD for the supply air fan. The VFD is modulated to maintain the duct pressure at this value. Once a valid password has been entered this item becomes an adjustable item.
RF/EF Capacity
is a status only item indicating the capacity of the return fan/exhaust air fans.
BSP
is a status only item which displays the current building static pressure reading.
BldgSP Spt
is a status only item which indicates the building static pressure set point used for controlling the return/ exhaust fan VFD. The return/exhaust fan VFD is modulated to maintain the building static pressure sensor input to this value. Once a valid password has been entered this item becomes an adjustable item.
OA Temp
is a status only item which displays the current temperature reading from the unit mounted outdoor air temperature sensor. This sensor is standard on all units.
EW Temp
is a status only item that displays the current temperature reading from the unit mounted entering water temperature sensor. The sensor is standard on all watercooled units.
Rel Humidity
is a status only item that displays the current relative humidity reading from the optional humidity sensor.
18 OM 920-4
View/Set Unit Menus
Unit Status Settings
The “Unit Status Settings” menu provides a summary of basic unit status and control items. This menu summarizes the current operating state of the unit, giving the operating state the unit is in, along with the current capacity level of that operating state.
Table 2: Unit Status/Settings
Item Display Name Default Setting
Unit State= —
Unit Status=
Dehum Status
Ctrl Mode=
Clg Status=
Htg Status=
Econo Status=
Clg Capacity=
Htg Capacity=
Reheat Cap
SAF Capacity=
RF/EF Capacity=
Rel Humidity=
Net Emrg Ovrd=
Net App Mode=
—
—
Off
—
—
—
—
—
—
—
—
—
Normal
Auto
Active/Inactive
Off
HeatOnly
CoolOnly
FanOnly
HeatCool
Auto
Enabled
None
OffAmb
OffAlarm
OffNet
OffMan
Enabled
None
OffAmb
OffAlarm
OffNet
OffMan
Range
Off
Start
Recirc
FanOnly
MinDAT
Htg
Econo
Clg
Enable
OffMan
OffMnCtl
OffNet
OffAlm
OffFnRty
Enabled
None
OffAmb
OffAlarm
OffNet
OffMan
OffDehum
0–100%
0–100%
0–100%
0–100%
0–100%
0–100%
Normal, Off
Off
HeatOnly
CoolOnly
FanOnly
Auto
Menu Descriptions
Password Level
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
OM 920-4 19
Menu Descriptions
Unit State
is a status only item which indicates the state of operation in which the unit is currently operating. The unit can be in any of the operating states shown.
Unit Status
is a status only item which indicates the status of operation in which the unit is currently operating. The unit status can be any of the status values shown.
Dehum Status
is a status only item which indicates the status of operation of the dehumidifier. The dehumidifier can be active or inactive.
Ctrl Mode
is an adjustable item which sets the operating mode of the unit. The unit can be in any of the modes shown.
Clg Status
is a status only item which indicates whether or not mechanical cooling is currently allowed. If cooling is disabled, the reason is indicated.
Htg Status
is a status only item which indicates whether or not heating is currently allowed. If heating is disabled, the reason is indicated.
Econo Status
is a status only item which indicates whether or not the economizer is currently enabled. If economizer is enabled, the reason is indicated.
Clg Capacity
is a status only item which indicates the percentage of the unit maximum cooling capacity currently operating.
Htg Capacity
is a status only item which indicates the percentage of the unit maximum heating capacity currently operating.
Reheat Capacity
is a status only item which indicates the percentage of the unit maximum reheat capacity currently operating.
SAF Capacity
is a status only item which indicates the capacity of the supply air fan.
RF/EF Capacity
is a status only item indicating the capacity of the return fan/exhaust air fans.
Rel Humidity
is a status only item that displays the current relative humidity reading from the optional humidity sensor.
Net Emrg Ovrd
is an adjustable item which indicates if the unit was shut down in an emergency situation via a network command.
Net App Mode
is a network adjustable item which indicates that the unit is set for network off, cooling only, heating only, fan only or auto heating/cooling operation via a network signal. This item has no affect on the unit operation unless the
Ctrl Mode item is set to “Auto.”
20 OM 920-4
Menu Descriptions
Occupancy Menu
Menus in the Occupancy menu contain status and control items that relate to unit occupied/unoccupied operation.
Table 3: Occupancy Menu
Item Display Name
Occupancy=
Default Setting
Occ Mode=
OccSrc=
UnoccSrc=
Auto/Net
-
-
Tnt Ovrde Time= 0
Occupancy
is a status only item which indicates whether the unit is currently in an occupied, unoccupied, or tenant override mode of operation.
OccMode
is an adjustable item which allows the unit to be set for manual occupied or unoccupied operation, automatic operation based on a time schedule input or manual tenant override operation.
OccSrc
is a status only item which indicates the input source or function that is responsible for setting the Occupancy parameter to “Occ” or “TntOvrd.”
Range
Occ
Unocc
TntOvrd
Occ
Unocc
TntOvrd
Auto/Net
None
NetSchd
IntSchd
OneEvnt
RemoteSw
OccManCmd
OccMode
TStatTO
ManTO
UnoccDehum
UnoccClg
UnoccHtg
IntOptStrt
NetOptStrt
None
0–300min
Password Level
6
6
6
6
6
UnoccSrc
is a status only item which indicates the input source or function that is responsible for running the unit while the Occupancy parameter to “Unocc.”
Tnt Ovrd Time
is an adjustable item which indicates the amount of time remaining for unit operation since tenant override operation was activated.
OM 920-4 21
Menu Descriptions
Temperatures Menu
Menus in the Temperatures menu contain unit temperature status information.
Table 4: Temperature Menu
Item Display Name
Control Temp=
Disch Air=
Return Air=
Space Temp=
OA Temp=
EF/LC Temp=
EW Temp=
Mixed Air=
ER LAT
ER EAT
Sump Temp
PA Temp
Default Setting
—
—
—
—
—
—
—
—
—
—
—
—
Range
-50 .0–200 .0°F
-50 .0–250 .0°F
-20 .0–200 .0°F
-0 .0–150 .0°F
-50 .0–200 .0°F
-50 .0–250 .0°F
-50 .0–150 .0°F
-50 .0–250 .0°F
-50 .0–200 .0°F
-50 .0–200 .0°F
-50 .0–150 .0°F
-50 .0–200 .0°F
Password Level
6
6
6
6
6
6
6
6
6
6
6
2
Control Temp
is a status only item which indicates the current Control Temperature value.
Disch Air
is a status only item which displays the current temperature reading from the unit’s discharge air temperature sensor (DAT). This sensor is standard on all units.
Return Air
is a status only item which displays the current temperature reading from the unit’s return air temperature sensor (RAT).
Space Temp
is a status only item which displays the current space (or zone) temperature reading from the optional unit space air temperature sensor input. If an optional space temperature sensor is not installed and space temperature value is not supplied by a network, the SpaceT Present= item in the Setup menu should be set to “No” to disable the alarm function associated with an open circuit at the space temperature sensor input.
OA Temp
is a status only item which displays the current temperature reading from the unit mounted outdoor air temperature sensor.
EF/LC Temp
is a status only item which displays the current entering fan/leaving coil temperature reading from the unit mounted temperature sensor. This sensor is available on RTU units with dehumidification capability. This sensor is also installed on RTU units equipped with either gas or electric heat and is used by the controller to calculate the heat rise across the heat exchanger by comparing it to the discharge air temperature input. The controller uses this information to protect the heat exchanger against overheating.
EW Temp
is a status only item that displays the current temperature reading from the unit mounted entering water temperature sensor. The sensor is standard on all watercooled units.
Mixed Air
is a status only item that displays the current temperature reading from the unit mounted mixed air temperature sensor. The sensor is standard on all Self
Contained units.
ER LAT
is status only item which displays the current discharge air temperature leaving the optional energy recovery wheel.
ER Exh T
is status only item which displays the current exhaust air temperature leaving the optional energy recovery wheel.
Sump Temp
is a status only item that displays the current evaporative condenser sump temperature.
22 OM 920-4
Menu Descriptions
Flow Status Menu
Table 5: Flow Status Menu
Item Display Name
Airflow=
Waterflow=
Water Pump=
Supply Fan=
Default Setting
—
—
—
Airflow
is a status only item that indicates whether or not discharge airflow is detected. Airflow status is sensed by a binary input delivered to the controller by a differential pressure switch (PC7). On VAV units duct static pressure is also a factor in the indication of airflow.
Waterflow
is a status only item that indicates whether or not water flow is detected on a water cooled unit. Water flow status is sensed by a binary input delivered to the controller by an optional water flow sensor (WF1) or from a network supplied water flow input.
Water pump
is a status only item that indicates whether or not the Pump Start Output is active on a water cooled unit.
The pump start output is available for field use to start a field
SAF Spd Control Menu
Table 6: Supply Fan Speed Menu
Item Display Name
SAF Speed=
Speed Cmd=
Duct Press=
DuctSP Spt=
IAQ PPM =
OA Flow =
Bldg Press =
BldgSP Spt
Default Setting
—
—
—
1 .0 in
SAF Speed
is a status only item that indicates the current supply fan speed.
Speed Cmd
is a status only item that indicates the current supply fan VFD commanded speed.
Duct Press
is a status only item which indicates the current pressure of the supply air ductwork. The duct pressure is measured at the location in which the duct static pressure tap was field installed. This device is not factory installed.
DuctSP SPT
is an adjustable item which sets the duct static pressure set point used for controlling the VFD for the supply air fan. The VFD is modulated to maintain the duct pressure at this value.
IAQ PPM =
is a status only item that indicates the current CO
2 level when the supply fan control method is set to CO
Note: CO
2 the unit control type set to Zone or DAC.
2
.
option only available on 100% OA units that have
Range
NoFlow
Flow
NoFlow
Flow
Off
On
Off
On
Password Level
6
6
6
6 supplied pump when water flow is required. For field wiring requirements for using this output refer to “Field Wiring” in the MicroTech III Installation Manual (IM 919). The Pump
Start Output is turned on whenever the economizer bypass valve is open, the unit is in the Econo or Cooling operating state, economizer flush mode is active or a Freeze fault or
Freeze problem alarm is active or has been active within the past 10 minutes. Otherwise the Pump Start Output is off.
Supply Fan
is a status only item which indicates whether or not the controller is commanding the unit supply fan on.
Ret/Exh Fan
is a status only item which indicates whether or not the controller is commanding the unit RF/EF fan on.
Range
0–100%
0–100%
0 .0–5 .0 in
0 .2–4 .0 in
Password Level
6
6
6
6
6
6
6
6
OA Flow =
is a status only item that indicates the current
CFM value when the supply fan control method is set to
CFM. Note:
CFM option only available on 100% OA units that have the unit control type set to Zone or DAC.
Bldg Press =
is a status only item which indicates the current building static pressure when the supply fan control method is set to BSP. Note:
BSP option only available on 100% OA units that have the unit control type set to Zone or DAC.
BldgSP Spt
is an adjustable item which sets the building static pressure set point used for controlling the VFD when the supply fan control method is set to BSP. Note: BSP option only available on 100% OA units that have the unit control type set to Zone or DAC.
OM 920-4 23
Menu Descriptions
RF/EF Control Menu
Table 7: Return/Exhaust Fan Speed Menu
Item Display Name
RF/EF Speed=
Speed Cmd=
Bldg Press=
BldgSP Spt=
Default Setting
-
-
-
0 .050 in
RF/EF Speed
is a status only item that indicates the current return/exhaust fan VFD speed.
Speed Cmd
is a status only item that indicates the current return/exhaust fan VFD commanded speed.
Bldg Press
is a status only item which indicates the building static pressure at the building static pressure sensor location.
Cooling Menu
Table 8: Cooling Menu
Item Display Name
Occ Clg Spt =
Unocc Clg Spt=
DAT Clg Spt=
Default Setting
72 .0°F
85 .0°F
55 .0°F
Occ Clg Spt
an adjustable item which sets the temperature above which the unit will go into the cooling mode of operation.
Unocc Clg Spt
is an adjustable item which sets the zone temperature above which the unit starts up and provides unoccupied cooling (night setup) during unoccupied periods.
NOTE:
Setting this to its maximum value will disable unoccupied cooling .
Range
0–100%
0–100%
-0 .25–0 .25 in
-0 .25–0 .25 in
Password Level
6
6
6
6
BldgSP Spt
is an adjustable item which sets the building static pressure set point used for controlling the VFD for the return/exhaust air fan. The VFD is modulated to maintain the building pressure at this value.
Range
0 .0–100 .0°F
40 .0–100 .0°F
40 .0–100 .0°F
Password Level
6
6
6
DAT Clg Spt
is an adjustable item used by the controller to set the DAT cooling setpoint. This value is adjustable only on
DAC units when it is not being set by a reset schedule. It is not adjustable on CAV units.
Economizer Menu
Table 9: Economizer Menu
Item Display Name
OAD/Econo Pos=
DAT Clg Spt=
Min OA Pos=
Occ Clg Spt =
Unocc Clg Spt=
Default Setting
—
55 .0°F
—
72 .0°F
85 .0°F
Range
0–100%
40 .0–100 .0°F
0–100%
0 .0–100 .0°F
40 .0–100 .0°F
Password Level
6
6
6
6
6
OAD/Econo Pos
is a status only item that is used to indicate percentage that the economizer dampers/waterside economizer valve is open.
DAT Clg Spt
is an adjustable item used by the controller to set the DAT cooling setpoint. This value is adjustable only on
DAC units when it is not being set by a reset schedule. It is not adjustable on CAV units.
Min OA Pos
is a status only item which indicates the current minimum position of the outdoor air damper.
Occ Clg Spt
an adjustable item which sets the temperature above which the unit will go into the cooling mode of operation.
Unocc Clg Spt
is an adjustable item which sets the zone temperature above which the unit starts up and provides unoccupied cooling (night setup) during unoccupied periods.
NOTE:
Setting this to its maximum value will disable unoccupied cooling .
24 OM 920-4
Menu Descriptions
Min OA Damper Menu
Table 10: Min OA Damper Menu
Item Display Name
Min OA Pos=
Vent Limit=
LoFlo V Lmt=
DCV Limit=
Min OA SCR=
Default Setting
-
20%
30%
10%
—
Min OA Pos
is a status only item which indicates the current minimum position of the outdoor damper. This value does not go above a value called the Ventilation Limit and does not go below a value called the Demand Control Ventilation Limit.
On CAV units the Ventilation Limit and the Demand Control
Ventilation Limit are fixed values set equal to the Vent
Limit= and DCV Limit= parameters. On VAV units the OA
Damper Position increases from the Vent Limit= value to the LoFloVent Limit= value as the VFD speed goes from
100% down to the Min Clg Spd= value. The Demand Control
Ventilation Limit in this VAV case is determined by the
Ventilation Limit X DVC Limit=/Vent Limit=. When the
Min OA Reset= parameter is set to “None” the Min OA Pos= value is set to the Ventilation Limit. If Min OA Reset= is set to Network, Ext VDC, Ext mA, IAQ VDC, or IAQ mA, the
Min OA Pos= varies between the Ventilation Limit and the
Demand Control Ventilation Limit as the reset signal varies from its maximum to minimum value.
Range
0–100%
0–100%
0–100%
0–100%
VentLmt
DesFlw
FldFlw
Network
Ext VDC
Ext mA
IAQ VDC
BSPOvrd
FanDiff
DCVLmt
ZeroOA
Password Level
6
6
6
6
4
Vent Limit
is an adjustable item that sets the value of the
Ventilation Limit on a CAV unit or when a VAV unit is at
100% discharge fan speed.
LoFlo Vent Limit
is an adjustable item that sets the maximum value for the Ventilation Limit on a VAV unit. The ventilation limit is raised toward this value as the discharge fan speed decreases toward the Min Clg Spd value.
DCV Limit
is an adjustable item that sets the value of the
Demand Control Ventilation Limit on a CAV unit or when a
VAV unit is at 100% discharge fan speed. This item is only used when the “Min OA Reset=” is set to something other than “None.”
Min OA Src =
is a status only item that indicates the action that is winning for control of the OA damper position.
Heating Menu
The Heating menu provides a summary of the control parameters for units with heating. The unit’s heating mode of operation is controlled by the control temperature and the heating setpoint temperature. The unit goes into the heating mode of operation by analyzing the control temperature.
Table 11: Heating Menu
Item Display Name
Occ Htg Spt =
Unocc Htg Spt=
MWU Spt=
DAT Htg Spt=
Default Setting
68 .0°F
55 .0°F
70 .0°F
85 .0°F
Occ Htg Spt
is an adjustable item which sets the control temperature below which the unit will go into the heating mode of operation.
Unocc Htg Spt
is an adjustable item which sets the zone temperature below which the unit starts up and provides unoccupied heating (night setback) during unoccupied periods.
The control temperature can be return temperature, space temperature or outside air temperature. The unit goes into the heating mode of operation when the control temperature is below the heating setpoint by more than ½ the deadband.
Range
0 .0–100 .0°F
40 .0–100 .0°F
40 .0–100 .0°F
40 .0–140 .0°F
Password Level
6
6
6
6
MWU Spt
is an adjustable item which sets the heating setpoint to be used during morning warm up on a discharge temperature control unit. CAV units use the Occ Htg Spt for morning warmup operation.
DAT Htg Spt
is an adjustable parameter which sets the heating discharge set point.
OM 920-4 25
Menu Descriptions
Dehumidification Menu
Table 12:
Dehumidification Menu
Item Display Name Default Setting
Dehum Status=
Rel Humidity=
Dewpoint=
Dehum Method=
—
—
—
None
Always
RH Setpoint=
Dewpoint Spt=
Reheat Spt=
Reheat Cap=
50%
50°F
—
—
Dehum Status
is a status only item that indicates whether dehumidification is enabled or disabled.
Rel Humidity
is a status only item that indicates the current relative humidity reading of the sensor.
DewPoint
is a status only item that indicates the current dew point value that is calculated by the controller using the
Rel Humidity= value and either the Space Temp= or Return
Air= value, depending on the setting of the Humidity Sensor
Location. This parameter can either be set to “Space” or
“Return.”
Dehum Method
is an adjustable item used to set the dehumidification method to either “RH” or “DewPt.” When this parameter is set to “RH,” dehumidification operation is controlled to maintain the Rel Humidity= value at the
RH Setpoint=. When this parameter is set to “DewPt,” dehumidification operation is controlled to maintain the Dew
Point value at the Dewpoint Spt=. When this parameter is set to “Always” dehumidification will be active as long as mechanical cooling is not disabled.
Range
Disabled
Enabled
0–100%
-50–150°F
None
Rel Hum
DewPt
0–100%
0–100°F
40 .0–100 .0°F
0–100%
Password Level
6
6
6
6
6
6
6
6
RH Setpoint
is an adjustable item used to set the relative humidity value at which the relative humidity will be controlled to during dehumidification operation.
Dewpoint Spt
is an adjustable item used to set the dewpoint value at which the dewpoint with will be controlled to during dehumidification operation.
Reheat Spt
is a status only item which is used to indicate the DAT temperature to which the HGRH valve will be controlled in the Cooling and Fan Only operating states while dehumidification operation is active. The Reheat Spt= equals the DAT Cooling Setpoint for DAT controlled units and will vary in between the Min Reheat Spt= and Max Reheat Spt= for Zone Controlled units.
Reheat Cap
is a status only item that indicates the current reheat capacity value.
26 OM 920-4
Date/Time/Schedules Menu
Time/Date
Table 13: Time/Date
Item Display Name
Time=
Date=
UTC Diff=
Default Setting
Time
is an adjustable item that sets the current time.
Date
is an adjustable item that sets the current date.
UTC Diff
is an adjustable parameter that can be set to indicate how the local time where the unit is situated differs from the
Coordinated Universal Time (UTC).
Daily Schedule Menu
The Daily Schedule sets the start and stop times for each of the days of the week. One start and one stop time can be set for each day.
Table 14: Daily Schedule Menu
Item Display Name
Mon=
Tue=
Wed=
Thu=
Fri=
Sat=
Sun=
Hol=
Default Setting
HH:MM — HH:MM
HH:MM — HH:MM
HH:MM — HH:MM
HH:MM — HH:MM
HH:MM — HH:MM
HH:MM — HH:MM
HH:MM — HH:MM
HH:MM — HH:MM
Holiday Schedule Menu
The Holiday Schedule is used to set the start and stop times for up to 10 different holidays.
Table 15: Holiday Schedule Menu
Item Display Name
Hol 1=
Hol 2=
Hol 3=
Hol 4=
Hol 5=
Hol 6=
Hol 7=
Hol 8=
Hol 9=
Hol 10=
Default Setting
MMMDD/99–MMMDD/99
MMMDD/99–MMMDD/99
MMMDD/99–MMMDD/99
MMMDD/99–MMMDD/99
MMMDD/99–MMMDD/99
MMMDD/99–MMMDD/99
MMMDD/99–MMMDD/99
MMMDD/99–MMMDD/99
MMMDD/99–MMMDD/99
MMMDD/99–MMMDD/99
Range
HH:MM:SS
MM/DD/YYYY
Range
00:00 — 23:59
00:00 — 23:59
00:00 — 23:59
00:00 — 23:59
00:00 — 23:59
00:00 — 23:59
00:00 — 23:59
00:00 — 23:59
Range
00/00/00–12/31/99
00/00/00–12/31/99
00/00/00–12/31/99
00/00/00–12/31/99
00/00/00–12/31/99
00/00/00–12/31/99
00/00/00–12/31/99
00/00/00–12/31/99
00/00/00–12/31/99
00/00/00–12/31/99
Menu Descriptions
Password Level
6
6
6
Password Level
6
6
6
6
6
6
6
6
Password Level
6
6
6
6
6
6
6
6
6
6
OM 920-4 27
Menu Descriptions
One Event Schedule Menu
The One Event Schedule is used to set the start and stop times for one event.
Table 16: One Event Schedule Menu
Item Display Name
Beg=
End=
Optimal Start Menu
Default Setting
MMMDD/99 @ HH:MM
MMMDD/99 @ HH:MM
Range
00/00/00-12/31/99 @ 00:00 – 23:59
00/00/00-12/31/99 @ 00:00 – 23:59
Password Level
6
6
The Optimal Start menu is used to set up the unit so it starts at the most efficient time before building occupancy.
Table 17: Optimal Start Menu
Item Display Name
Enable=
Htg Rate=
Htg OAT=
Des Htg OAT=
Clg Rate=
Clg OAT=
Des Clg OAT=
Default Setting
No
0 .4°F/min
35°F
0°F
0 .4°F/min
85°F
95°F
Enable
is an adjustable item that turns on the optimal start feature. Setting the value to yes will activate this function.
Htg Rate
is an adjustable item used by the controller in determining the amount time before occupancy to start when the Optimal Start parameter is set to “On.”
Htg OAT
is an adjustable item used by the controller in determining the amount time before occupancy to start when the Optimal Start parameter is set to “On.”
Design Htg OAT
is an adjustable item that sets the outdoor air temperature at which the heating system could just hold the load. The rate of temperature rise would equal zero.
Clg Rate
Range
No, Yes
0 .0–1 .0°F/min
-40–60°F
-40–60°F
0 .0–1 .0°F/min
-60–140°F
-60–140°F
Password Level
6
2
2
2
2
2
2
is an adjustable item that sets the rate of temperature drop in degrees per minute when the unit last started optimally in cooling.
Clg OAT
is an adjustable item that sets the outdoor air temperature when the unit was last started optimally in cooling.
Design Clg OAT
is an adjustable item that sets the outdoor air temperature at which the cooling system could just hold the load. Rate of temperature rise would equal zero.
Daylight Savings Menu
Table 18: Daylight Savings Menu
Item Display Name
DLS Strt Mon=
DLS Strt Wk=
DLS End Mon=
DLS End Week=
Default Setting
Mar
2ndWeek
Nov
1stWeek
Range
NA
Jan-Dec
1stSun
2ndSun
3rdSun
4thSun
5thSun
NA
Jan-Dec
1stSun
2ndSun
3rdSun
4thSun
5thSun
Off/Auto
Password Level
2
2
2
2
2 DLS Enable= Auto
DLS Strt Mon
is an adjustable item that sets the month for daylight savings time to begin.
DLS Strt Wk
is an adjustable item that sets the week of the month for daylight savings time to begin.
DLS End Mon
is an adjustable item that sets the month for daylight savings time to end.
DLS End Week
is an adjustable item that sets the week of the month for daylight savings time to end.
DLS Enable
is an adjustable item that sets whether or not daylight savings time is enabled.
28 OM 920-4
Menu Descriptions
Commission Unit
Unit Setup
Table 19: Unit Setup Menu
Item Display Name
Apply Changes=
RAT Sensor=
OAT Sensor=
Space Sensor
Default Setting
No
Yes
Yes
Digtl/Net
Eng Units=
Unit Name=
Rapid Start=
Rapid Start Tm=
DO10 Cfg=
English
—
No
10 min
FanOp
100% OA SCU
is an adjustable item used to select whether or not a self contained unit will be configured for 100% outside air operation.
Space Sensor
is an adjustable item to indicate if a space sensor is connected to the unit controller, or provided via a network signal.
Eng Units
is an adjustable item to indicate if the unit is to display English or Metric units of measure.
Range
No, Yes
No, Yes
No, Yes
None
Anlog/Net
Digtl/Net
English, SI
—
No, Yes
0–20 min
FanOp
VAVBox
Password Level
4
4
4
4
4
4
2
2
2
Unit Name
is an adjustable item that allows each controller to be given a unique name. This may be useful when multiple units are connected to a single remote HMI.
Rapid Start
is an adjustable item that allows the user to select to initiate a rapid startup sequence at unit power up.
Rapid Start Tm
is an adjustable item that allows the user to set the Rapid Start timing whenever the power is reset to the controller and the controller finishes its startup sequence.
DO10 Cfg
is an adjustable item that redefines the functionality of the digital output (DO10) on the main control board. The output is either a supply fan operation indication or a VAV box signal depending on how this parameter is set.
Timer Settings Menu
Table 20: Timer Settings Menu
Item Display Name
Service Time
Start Up
Recirculate
Zero OA Time
Tnt Override
Post Heat
Pwd Timeout
Low DAT
ClgStateDelay
Clg Stg Time
Htg Stg Time
Min Ex Strt Tm
Min Ex Stop Tm
ER Whl Stg Tm
ER Whl Off Tm
Air Flw Ign
Htg Wrmup Tm
Htg Hld Period
Srvc Time Inc
Off HtCl Delay
Default Setting
6 min
300s
5 min
5 min
120s
120s
5 min
0 min
180s
180s
0 min
120 min
0s
10 min
5 min
120s
240s
240s
20s
120s
Range
0–240min
1800s
3600s
0–240min
0–300min
0–180s
3–30min
0–60min
0–600s
5–60min
2–60min
60–300s
60–300s
1–100min
1–100min
0–999S
0–999s
0–999s
0–300s
0–999s
Password Level
4
4
4
4
4
4
4
4
4
4
4
4
4
4
2
2
4
2
2
2
OM 920-4 29
Menu Descriptions
Service Time
is an adjustable item that sets the amount of time the internal control timers can be temporarily sped up.
Startup
is an adjustable item that sets the time in seconds that the unit will perform its startup operation.
Recirculate
is an adjustable item that sets the time in seconds that the unit operates with only the fan, recirculating the building air upon unit start up.
Zero OA Time
is an adjustable item that sets the time in minutes that the outdoor air damper stays at a zero position upon unit start up.
Tnt Override
is an adjustable item that sets the amount of time that the unit will go into operation when the tenant override function is activated. Tenant override can be activated by the space sensor button, the network occupancy mode parameter or the keypad Occ Mode= parameter.
Post Heat
is an adjustable item that sets the duration of the post heat function available on VAV units.
Pwd Timeout
is an adjustable item that sets the amount of time in minutes that the controller will allow access to applicable menus without re-entering the necessary password.
If the keypad display remains idle for this time period, the display will revert to the “main menu” requiring a re-enter of the password.
Low DAT
is an adjustable item that sets the duration of a time period upon unit start up during which the Low Discharge
Temperature fault is ignored. This may be particularly important in colder climates when a unit has been off for a significant time period during which the unit, including the discharge air temperature sensor, has become very cold. This time period allows the unit to run long enough to turn the unit heat on and warm the discharge sensor above the alarm limit, preventing nuisance unit alarm shutdown. This time period begins when the supply fan starts.
ClgStateDelay
is an adjustable item that sets the amount of time between the fan only operating state and the mechanical cooling state. The unit will not enter the mechanical cooling state until this time has passed. This only applies on discharge control units following morning warm up heating operation.
Clg Stg Time
is an adjustable item used to set a minimum time period between compressor stage changes.
Htg Stg Time
is an adjustable item used to set a minimum time period between heating stage changes.
MinExStrtTime
is an adjustable item that sets the minimum exhaust fan on time (Default = 120 seconds).
MinExStopTime
is an adjustable item that sets the minimum exhaust fan stop time (Default = 120 seconds).
ER Whl Stg Tm
is an adjustable item used to set a minimum time period for operating at either the minimum or maximum speed before action is taken to change speed during the frost protect mode of operation.
ER Whl Off Tm
is an adjustable item used to set the minimum amount of time the energy wheel will remain off after being turned off due to a frosting/condensation condition.
Air Flw Ign
is an adjustable item that sets the amount of time the air proving switch is ignored after the supply fan is started.
Htg Wrmup Tm
is an adjustable item which is used to set the amount of time the gas burner will remain at a low fire position on 100% OSA units (default 240 seconds).
Htg Hld Period
is an adjustable item used to set the amount of time that the gas heating valve remains at its calculated value on units equipped with 100% OA (default 240 seconds). This is to allow the temperature to approach equilibrium with the modulating gas heating valve at a fixed position.
Srvc Time Inc
is an adjustable item used to set the internal stage time delay when the Service Timer is not zero, the times listed below are set to the ServiceTime (Default = 20 seconds) instead of the normal values.
• Cooling Stage Time
• Heating Stage Time
• Start Initial Time
• Recirculation
• ZeroOATime
OffHtClDelay
is an adjustable item that sets a delay in turning off the supply air fan when the unit is shut off while cooling or heating operation is active.
30 OM 920-4
Menu Descriptions
SAF Set-up
Table 21: Supply Fan Speed Menu
Item Display Name
SAF Ctrl=
AplyInputChgs=
CO
2
Input=
CFM Input=
BSP Input=
Rem SAF Cap=
DSP DB=
SAF Ramp Time=
Min Period=
Max Spd Chg=
DuctPress1=
Min Clg Spd=
Max Clg Spd=
Min Htg Spd=
Max Htg Spd=
Space Period=
Space Gain=
Space PAT=
Space Max Chg=
Default Setting
DSP
No
None
None
No
SPEED CONTROL
33% 0–100%
DSP CONTROL
0 .1in
60s
5s
15%
—
0–0 .5in
0–999s
0–999s
0–100%
0 .0–5 .0in
1 ZONE VAV CONTROL
40%
100%
40%
100%
30s
1 .5
100s
10%
0–100%
0–100%
0–100%
0–100%
0–999s
0 .0–100 .0s
0–999s
0–100%
Yes
None
VDC
MA
None
VDC
MA
No
Yes
Range
DSP
Spd/Net
1ZnVAV
BSP
CO2
CFM
No
Password Level
4
2
2
SAF Ctrl
is an adjustable parameter used to select how the supply fan is to be controlled. The supply fan can normally be controlled by duct pressure, space temperature (single zone
VAV or 1ZnVAV) or by a percentage of supply air fan speed from 33% to 100%. On 100% OA unit applications the fan can be controlled to maintain building static pressure, space carbon dioxide level or and airflow based on a field supply airflow station. The speed option is typically used with a building automation system. When single zone VAV control is selected, the supply fan is controlled with a PI_Loop to maintain the Control Temperature input at the Occupied
Cooling Set Point or Occupied Heating Set Point. When
BSP is selected the supply fan is controlled with a PI_Loop to maintain the building static pressure at a building static pressure Set Point.
When CO the CO
2
2
is selected the supply fan is controlled to maintain
ppm between adjustable limits by varying the supply fan speed between an adjustable range. When CFM is selected the supply fan is controlled with a PI_Loop to maintain the measured CFM at a CFM set point.
2
2
4
4
4
4
4
2
4
4
4
4
4
4
4
4
Item Display Name
Min PPM=
Max PPM=
V/A @ Min PPM=
V/A @ Max PPM=
Min SAF PPM=
Max SAF PPM=
Min PPM Spd=
Max PPM Spd=
Min CFM=
Max CFM=
V/A @Min CFM=
V/A @Max CFM=
SAF CFM DB=
SAFCFM Period=
SAF CFM Gain=
SAF CFM MxChg=
BSP DB=
BSP Period=
BSP Gain=
Max Spd Chg=
SAF Ctrl Dly=
Min Speed=
VAVBox Out=
MaxVentSpd=
Max SAF RPM=
Default Setting
SAF SETUP
30s
33%
—
100%
2600
Range
CO
2
CONTROL
0ppm
2000ppm
0 .0/V
10 .0/V
800
1100
0–5000ppm
0–5000ppm
0 .0–20 .0/V/mA
0 .0–20 .0/V/mA
0–5000ppm
0–5000ppm
50
100
0–100%
0–100%
CFM CONTROL
0CFM
10000CFM
0 .0/V
10 .0/V
3%
0–60000CFM
0–60000CFM
0 .0–20 .0/V/mA
0 .0–20 .0/V/mA
0–100%
30s
0 .1
5%
0–999s
0 .0–100 .0
0–100%
BSP CONTROL
0 .01in
5s
0 .2
4%
0 .0–0 .1in
0–999s
0 .0–100 .0s
0–100%
0–999s
0–100%
Heat
Cool
0–100%
0–5000
Password Level
4
4
4
2
2
2
2
4
4
4
4
4
2
2
2
2
4
4
4
4
4
4
2
2
2
AplyInputChgs
is the Apply Input Changes flag must be changed from no to yes in order for the controller to recognize the changes. Setting the Apply Input Changes flag to YES will automatically reset the controller.
CO
2
Input
is an adjustable item used to select the type of input for a field installed CO controller ignores any CO
2
2
sensor. If this is set to None the
sensor input. If CO
2
control and/ or monitoring is desired this parameter is set to VDC or mA to match the input type of the field supplied CO
2
sensor input.
This parameter applies only to 100% OA unit configurations.
CFM Input
is an adjustable item used to select the type of input for a field installed airflow station. If this is set to None the controller ignores any field airflow station input. If CFM control and/or monitoring is desired this parameter is set to VDC or mA to match the input type of the field supplied airflow input. This parameter applies only to 100% OA unit configurations.
OM 920-4 31
Menu Descriptions
BSP Input
is an adjustable item used to select whether on not a building static pressure sensor is connected to the unit controller. If this is set to No the controller ignores any building static pressure input. If BSP control of the supply fan is desired this parameter must be set to Yes. This parameter applies only to 100% OA unit configurations.
Remote SF Cap
is an adjustable item for setting the supply fan speed by the keypad or by a network control signal.
DSP DB
is an adjustable item which sets a dead band around the DuctSP Spt= parameter. No duct static pressure control action is taken when the current duct static pressure input is within this dead band.
SAF Ramp Time
is an adjustable item that sets the amount of time it will take for the variable speed fan to drive from its minimum to maximum speed as well as its maximum to minimum speed. The SAF Ramp Time= value on the keypad must be changed whenever the ramp time of the variable speed fan is changed. The ramp up time must equal the ramp down time, and both must equal the SAF RampTime value to provide stable operation.
Min Period
is an adjustable item that sets the duration of the sample time between speed changes. The sample time must be long enough to allow the static pressure to get very close to its steady state value before another calculation is made.
Max Spd Chg
is an adjustable item that sets the maximum value for a speed increase or decrease. This speed change
(either a positive or negative value) is added to the current fan speed whenever the duct static pressure is outside of the deadband, and the Min Period time has passed since the previous speed change.
DuctPress1
is a status only item that indicates the current value for the duct status pressure sensor.
Min Clg Spd
is an adjustable item that sets the minimum supply fan speed used for cooling operation when 1ZnVAV is selected as the method of supply fan control.
Max Clg Spd
is an adjustable item that sets the maximum supply fan speed used for cooling operation when 1ZnVAV is selected as the method of supply fan control.
Min Htg Spd
is an adjustable item that sets the minimum supply fan speed used for heating operation when 1ZnVAV is selected as the method of supply fan control.
Max Htg Spd
is an adjustable item that sets the maximum supply fan speed used for heating operation when 1ZnVAV is selected as the method of supply fan control.
Space Period
is an adjustable item that sets the “sampling time” used in the PI control function to vary the supply fan speed when 1ZnVAV supply fan control is selected.
Space Gain
is an adjustable item that sets the “gain” used in the PI control function to vary the supply fan speed when
1ZnVAV supply fan control is selected.
Space PAT
is an adjustable item that sets the “project ahead time” used in the PI control function to vary the supply fan speed when 1ZnVAV supply fan control is selected.
Space Max Chg
is an adjustable item that sets the maximum value of increase or decrease of the supply fan speed each period used in the PI control function to vary the supply fan speed when 1ZnVAV supply fan control is selected.
Min PPM
is an adjustable item that sets the minimum PPM value of the field supplied CO
2
input signal.
Max PPM
is an adjustable item that sets the maximum PPM value of the field supplied CO
2
input signal.
V/mA @ Min PPM
is an adjustable item that sets the DC voltage or mA value at the minimum PPM value of the field supplied CO
2
input signal.
V/mA @ Max PPM
is an adjustable item that sets the DC voltage or mA value at the maximum PPM value of the field supplied CO
2
input signal.
Min SAF PPM
is an adjustable item that sets the PPM value at which the supply fan speed is controlled to minimum when
CO
2
supply fan control is selected.
Max SAF PPM
is an adjustable item that sets the PPM value at which the supply fan speed is controlled to maximum when
CO
2
supply fan control is selected.
Min PPM Spd
is an adjustable item that sets the supply fan speed when the CO
2
input signal is at minimum when CO2 supply fan control is selected.
Max PPM
Spd is an adjustable item that sets the supply fan speed when the CO
2
input signal is at maximum when CO2 supply fan control is selected.
32 OM 920-4
Menu Descriptions
Min CFM
is an adjustable item that sets the minimum CFM value of the field supplied airflow station input signal.
Max CFM
is an adjustable item that sets the maximum CFM value of the field supplied airflow station input signal.
V/mA @ Min CFM
is an adjustable item that sets the DC voltage or mA value at the minimum CFM value of the field supplied airflow station input signal.
V/mA @ Max CFM
is an adjustable item that sets the DC voltage or mA value at the maximum CFM value of the field supplied airflow station input signal.
SAF CFM DB
is an adjustable item that sets the “deadband” used in the PI control function to vary the supply fan speed when airflow (CFM) supply fan control is selected.
SAF CFM
Period is an adjustable item that sets the “sample time” used in the PI control function to vary the supply fan speed when airflow (CFM) supply fan control is selected.
Space Gain
is an adjustable item that sets the “gain” used in the PI control function to vary the supply fan speed when airflow (CFM) supply fan control is selected.
Space Max Chg
is an adjustable item that sets the maximum value of increase or decrease of the supply fan speed each period used in the PI control function to vary the supply fan speed when airflow (CFM) supply fan control is selected.
BSP DB
is an adjustable item that sets the “deadband” used in the PI control function to vary the supply fan speed when building static pressure (BSP) supply fan control is selected.
BSP Period
is an adjustable item that sets the “sample time” used in the PI control function to vary the supply fan speed when building static pressure (BSP) supply fan control is selected.
BSP Gain
is an adjustable item that sets the “gain” used in the PI control function to vary the supply fan speed when building static pressure (BSP) supply fan control is selected.
Max Spd Chg
is an adjustable item that sets the maximum value of increase or decrease of the supply fan speed each period used in the PI control function to vary the supply fan speed when building static pressure (BSP) supply fan control is selected.
DSP Ctrl Dly
is an adjustable item that sets the duration of time that the minimum speed signal is sent to the variable speed supply air fan after the supply fan is started via a digital output. Control reverts to either duct pressure or speed after the fan has been on for the DSPCtrlDelay (default 30 seconds).
Min Speed
is an adjustable item which is used to set the minimum supply fan speed (default 33%).
VAVBox Out
is a status only item that indicates the current value of the VAV output. The VAV output is only available to the field via network communications.
Max Vent Speed
is an adjustable item that sets the supply fan speed when an external ventilation override input to the supply fan is present.
Max SAF RPM
is an adjustable item that sets the maximum
RPM value for the supply air fan. Note this is set based on the supply fan model size and the system specifications.
OM 920-4 33
Menu Descriptions
RF/EF Set-Up
Table 22: Return Fan/Exhaust Fan Set-up Menu
Item Display Name Default Setting
RF/EF Ctrl=
Rem ExhF Cap=
BSP DB=
BSP Period=
BSP Gain=
Max Spd Chg=
RFEF Ctrl Dly=
Min Speed=
MinExStrtTime=
MinExStopTime=
MinExhOAPos=
MinExhSAFCap=
Exh On OA Pos
Exh Mx OA Pos
MaxVentSpd=
Max RFEF RPM=
BuildingP
5%
0 .01in
5s
0 .2
4%
30s
5%
120s
120s
5%
10%
40%
100%
100%
2600
ECM Status
DPA/MPS units only
—
* Not applicable on DPS Units
0–100%
0–999s
0–100%
60–300s
60–300s
0–100%
0–100%
0–100%
0–100%
0–100%
0–5000
OK
HalSnsr
ElctHiT
Range
None
Tracking*
BldgP
Spd/Net
OAD
0–100%
0 .0–0 .1in
0–999s
0 .0–100 .0s
MtrHiT
PModHiT
MtrLckd
PhzFail
LoDcVlt
HiDcVlt
LoMainV
HiMainV
NoComm
Password Level
6
4
4
4
4
4
4
4
2
2
4
4
6
4
4
4
2
34 OM 920-4
Menu Descriptions
RF/EF Ctrl
is an adjustable parameter used to select how the return/exhaust fans are to be controlled. The exhaust fans can be controlled by the building pressure or by a percentage of return/exhaust air fan speed from 5% to 100%. The speed option is typically used with a building automation system.
Remote RAF Cap
is an adjustable item for setting the return fan speed by the keypad or by a network control signal.
Remote ExhF Cap
is an adjustable item for setting the exhaust fan speed by the keypad or by a network control signal.
BSP DB
is an adjustable item which sets a dead band around the BldgSP Spt parameter. No building static pressure control action is taken when the current building static pressure input is within this dead band.
BSP Period
is an adjustable item which sets the “sampling period” used in the PI control function that modulates the return air or exhaust fan speed.
BSP Gain
is an adjustable item which sets the “gain” used in the PI control function that modulates the return air or exhaust fan speed.
Max Spd Chg
is an adjustable item that sets the maximum value for a exhaust speed increase or decrease. This speed change (either a positive or negative value) is added to the current fan speed whenever the building static pressure is outside of the deadband, and the BSP Period= time has passed since the previous speed change.
RFEF Ctrl Delay
is an adjustable item that sets the duration of time that the minimum speed signal is sent to the variable speed supply air fan after the return fan is started via a digital output. Control reverts to either building pressure or speed after the fan has been on for the BSPCtrlDelay (default 30 seconds).
Min Speed
is an adjustable item the sets the minimum speed of the RF/EF fan.
MinExStrtTime
is an adjustable item that sets the Minimum
Exhaust Fan On Time (Default = 120 seconds). Once started, the exhaust fan must run for a minimum of this time before it is turned back off.
MinExStopTime
is an adjustable item that sets the Minimum
Exhaust Fan Stop Time (Default = 120 seconds). Once stopped, the exhaust fan must remain off for a minimum of this time before it can be re-started.
MinExhOAPos
is an adjustable item that sets the Minimum
Exhaust OA Position (default 5%). The outdoor air dampers must be open more that this value for prop exhaust fan operation.
MinExhSAFCap
is an adjustable item that sets the Minimum
Exhaust SAF capacity (default 10%). The supply air fan speed must be higher than this value for prop exhaust fan operation.
Exh On OA Pos
is an adjustable item that turns on the exhaust fan when the OA damper position reaches this setting.
Exh Mx OA Pos
is an adjustable item that sets the OA damper position at which the exhaust fan will be at is maximum speed.
MaxVentSpd
is an adjustable item that sets the exhaust fan speed when an external ventilation override input to the exhaust fan is present.
Max RFEF RPM
is an adjustable item that sets the maximum
RPM value for the exhaust air fan.
NOTE:
This is set based on the exhaust fan model size .
ECM Status
is a status only item that indicates the current status of the return/exhaust fan motor
OM 920-4 35
Menu Descriptions
Heat/Cool Changeover Set-Up
Table 23: Heat/Cool Changeover Setup Menu
Item Display Name Default Setting
Ctrl Temp Src= RAT
Use Tstat Spt=
Occ Clg DB=
Clg Period=
Clg Gain=
Clg PAT=
Max Clg Chg=
Occ Htg DB=
Htg Period=
Htg Gain=
Htg PAT=
Max Htg Chg=
AplyTstatChg=
No
2 .0°F
60s
0 .1
600s
5 .0°F
2 .0°F
60s
0 .1
600s
5 .0°F
No
Ctrl Temp Src
is an adjustable item which selects the temperature sensor input to be used for the unit heating/ cooling changeover or occupied cooling and heating capacity change decisions. For example, if the CtrlTemp Src parameter is set to “Return,” then the Control Temp parameter reads the same value as the Return Air parameter.
Use Tstat Spt
is an adjustable item used to set whether or not to use the Tstat set point adjustment value for the Occ Clg Spt and Occ Htg Spt.
Occ Clg DB
is an adjustable item which sets a dead band around the Occ Cooling Set Point parameter. For example, if the Occ Cooling Set Point parameter is set to 75ºF and the Clg
Deadband parameter is set to 2ºF the dead band around the set point would be from 76.0ºF to 74.0ºF.
Clg Period
is an adjustable item which sets the “sampling time” used in the PI control function to vary the DAT Clg Spt in zone control applications.
Clg Gain
is an adjustable item which sets the “gain” used in the PI control function to vary the DAT Clg Spt in zone control applications.
Clg PAT
is an adjustable item which sets the “project ahead time” used in the PI control function to vary the DAT Clg Spt in zone control applications.
Max Clg Change
is an adjustable item that sets the maximum value for an increase or decrease of the DAT Clg Spt in zone control applications.
Range
RAT
Space
MAT
OAT
None
No, Yes
0 .0–10 .0°F
0–999s
0 .0–100 .0
0–999s
0 .0–50 .0°F
0 .0–10 .0°F
0–999s
0 .0–100 .0
0–999s
0 .0–50 .0°F
No, Yes
Password Level
4
4
4
4
4
4
4
4
4
4
4
4
4
Occ Htg DB
is an adjustable item which sets a dead band around the Occ Heating Set Point parameter. For example, if the Occ Heating Set Point parameter is set to 70ºF and the Htg
Deadband parameter is set to 2ºF the dead band around the set point would be from 69.0ºF to 71.0ºF.
Htg Period
is an adjustable item which sets the “sampling time” used in the PI control function to vary the DAT Htg Spt in zone control applications.
Htg Gain
is an adjustable item which sets the “gain” used in the PI control function to vary the DAT Htg Spt in zone control applications.
Htg PAT
is an adjustable item which sets the “project ahead time” used in the PI control function to vary the DAT Htg Spt in zone control applications.
Max Htg Chg
is an adjustable item that sets the maximum value for an increase or decrease of the DAT Htg Spt in zone control applications.
AplyTstatChg
is an adjustable item that resets the controller.
This is required to affect changes to the Use TstatSpt parameter.
36 OM 920-4
Menu Descriptions
Cooling Set-Up
Table 24: Cooling Set-up Menu
Item Display Name
Clg Stage Time=
Clg DB=
Clg Lo OAT Lk=
OAT Diff=
Clg Reset=
Min Clg Spt=
Min Clg Spt @=
Max Clg Spt=
Max Clg Spt @=
Default Setting
5min
2 .0°F
55°F
2°F
None
65 .0°F
0/NA
65 .0°F
100/NA
Unocc Diff= 3°F
Clg Stage Time
is an adjustable item used to set a minimum time period between compressor stage changes.
Clg DB
is an adjustable item which sets a dead band around the discharge cooling set point parameter. For example, if the discharge cooling set point parameter is set to 55ºF and the
Clg Db parameter is set to 2ºF the dead band around the set point would be from 56.0ºF to 54.0ºF.
Clg Lo OAT Lk
is an adjustable item which sets the low outdoor air temperature mechanical cooling lockout point.
Mechanical cooling operation is disabled when the outdoor air temperature sensor input falls below this set point.
OATDiff
is an adjustable item which sets a differential above the OAT Clg Lock parameter. Mechanical cooling operation is re-enabled when the outdoor air temperature sensor input rises above the OAT Clg Lock value by more than this differential.
Range
5–60min
1 .0–10 .0°F
0–100°F
0–10°F
None
Ntwrk
Space
Return
OAT
ExtmA
ExtV
Airflow
40 .0–100 .0°F
0–100/
NA
°F
°C mA
%
40 .0–100 .0°F
0–100/
NA
°F
°C mA
%
0–10°F
Password Level
4
4
4
4
6
6
6
6
6
2
Clg Reset
is an adjustable item that is used to set the type of cooling reset to be used.
Min Clg Spt
is an adjustable item which sets the minimum cooling discharge set point for use with a cooling discharge air temperature set point reset schedule.
Min Clg Spt @
is an adjustable item which sets the value of the sensor input, selected with the Cooling Reset parameter, at which the DAT cooling set point parameter is reset to the minimum DAT cooling set point value.
Max Clg Spt
is an adjustable item which sets the maximum cooling discharge set point for use with a cooling discharge air temperature set point reset schedule.
Max Clg Spt @
is an adjustable item which sets the value of the sensor input, selected with the Cooling Reset parameter, at which the DAT cooling set point parameter is reset to the maximum DAT cooling set point value.
OM 920-4 37
Menu Descriptions
graphically shows the cooling reset operation. The normal DAT cooling set point is 55.0 F. The cooling reset scheme is set to airflow. The unit is to adjust the DAT from
55.0 F to 65.0 F. When the unit is at 35% of the design airflow the discharge temperature is to be 65.0 F. When the unit is at
80% of its airflow the DAT is to be 55.0F. This example would give the following inputs:
• Min Clg Spt= 55.0 F
• Min Clg Spt @= 80%
• Max Clg Spt= 65.0 F
• Max Clg Spt @= 35%
Based on the above, the unit will have a discharge air temperature set point of 55.0 F from 80% to 100% of the airflow.
Unocc Diff
is an adjustable item that sets the unoccupied cooling differential.
Figure 10: Cooling Setpoint
Econo Set-up
Table 25: Economizer Setup Menu
Item Display Name
Clg Stage Time
Chgover Temp=
Clg DB=
Econo Period=
Econo Gain=
Econo PAT=
Econo Max Chg=
Flush Econo=
Econo Diff=
EWT Diff=
Default Setting
5min
65 .0°F
2 .0d°F
30/40s
(air/water)
10/1
(air/water)
60/40s
(air/water)
10/15%
(air/water)
Yes
2°F
3 .0d°F
Clg Reset=
Min Clg Spt=
Min Clg Spt @
Max Clg Spt=
Max Clg Spt @
MWU Sensor=
None
65 .0°F
0/ NA
65 .0°F
100/ NA
RAT
Range
5–60min
0 .0–100 .0°F
1 .0–10 .0d°F
0–999s
0 .0–100 .0
0–999s
0–100%
No
Yes
0–10°F
0 .0–10 .0d°F
None
Ntwrk
Space
Return
OAT
ExtmA
ExtV
Airflow
40 .0–100 .0°F
0–100/
NA
°F
°C mA
%
40 .0–100 .0°F
0–100/
NA
°F
°C mA
%
NonRAT
Space
6
6
6
6
6
4
Password Level
4
6
4
4
4
4
4
4
4
6
38 OM 920-4
Menu Descriptions
Clg Stage Time
is an adjustable item used to set a minimum time period between compressor stage changes.
Chgover Temp
is an adjustable item which sets the OA dry bulb temperature at which the units changes over to the economizer operation.
Clg DB
is an adjustable item which sets a dead band around the discharge cooling setpoint parameter. For example, if the discharge cooling setpoint parameter is set to 55ºF and the
Clg DB parameter is set to 2ºF the dead band around the set point would be from 56.0ºF to 54.0ºF.
Econo Period
is an adjustable item which sets the “sampling time” used in the PI control function of the economizer actuator.
Econo Gain
is an adjustable item which sets the “Gain” used in the PI control function of the economizer actuator.
Econo PAT
is an adjustable item which sets the “project ahead time” used in the PI control function of the economizer actuator.
Econo Max Chg
is an adjustable item that sets the maximum value for an increase or decrease of the economizer actuator.
Flush Econo
is an adjustable item used to enable the waterside economizer flush mode sequence.
Econo Diff
is an adjustable item which sets a differential above the EconChgovrT parameter. Economizer operation is disabled when the OA Temp parameter indicates a value above the EconChgovrT= parameter by more than this differential.
EWT Diff
is an adjustable item that sets a differential below the MAT at which waterside economizer operation is enabled based on entering water temperature.
Min Clg Spt
is an adjustable item which sets the minimum cooling discharge set point for use with a cooling discharge air temperature set point reset schedule.
Min Clg Spt @
is an adjustable item which sets the value of the sensor input, selected with the Cooling Reset parameter, at which the DAT cooling setpoint parameter is reset to the minimum DAT cooling setpoint value.
Max Clg Spt
is an adjustable item which sets the maximum cooling discharge set point for use with a cooling discharge air temperature set point reset schedule.
Max Clg Spt @
is an adjustable item which sets the value of the sensor input, selected with the Cooling Reset parameter, at which the DAT cooling setpoint parameter is reset to the maximum DAT cooling setpoint value.
MWU Sensor
is an adjustable item that sets the temperature sensor input to be used for morning warmup heating operation on discharge air control units. Setting this parameter to none disables morning warm up operation.
OM 920-4 39
Menu Descriptions
Min OA Set-Up Menu
Table 26: Min OA Damper Menu
Item Display Name
Apply Changes
Min OA Reset=
BSP OA Ovrd
Rst Lmt Snsr
OA @ MinV/mA=
OA @ MaxV/mA=
Min V/mA=
Max V/mA=
PPM @DCV Lmt=
PPM @Vnt Lmt=
IAQ PPM=
Min PPM=
Max PPM=
V/A @Min PPM=
V/A @Max PPM=
V mA
Min CFM
Max CFM
V/A @ Min CFM
V/A @ Max CFM
Min Fan Diff=
Max Fan Diff=
Min Clg Spd=
Des Clg Spd
DesignFlow=
Field AO Stn
OA Flow=
Min OA Flw Spt=
Des Flo DB=
DF Period=
Des Flo Gain=
DF Max Chg=
OA CFM DB
OA CFMPerod
OA CFM Gain
OA CFM Max Chg
LH Lvl Pos=
RH Lvl Pos=
MinRFEFTm=
BSPOvdST=
BSPOvdGain=
BSPOvdMxChg=
ResetTLmt=
RstTSmplT=
RstTGain=
RstTPAT=
40
Default Setting
No
None
No
None
4
0CFM
10000CFM
0 .0/
V
10 .0/
V
20%
50%
40%
100%
Yes
None
-
2000CFM
3%
30s
0 .1
5%
3%
30s
0 .1
5%
-
-
120sec
5sec
0 .2
4%
32 .0°F
5sec
0 .2
60sec
0%
100%
0 .0/
V
10 .0/
V
800ppm
1000ppm
-
0ppm
2000ppm
0 .0/
V
10 .0/
V
Range
No, Yes
None
Network
Ext VDC
Ext mA
IAQ VDC
IAQ mA
No/Yes
None
DAT
EFT
MAT
0–100%
0–100%
0 .0–20 .0/
V mA
0 .0–20 .0/
V mA
0–5000ppm
0-5000ppm
0–5000ppm
0–5000ppm
0–5000ppm
0 .0–20 .0/
V mA
0 .0–20 .0/
0–60000CFM
0–60000CFM
0 .0–20 .0/
V mA
0 .0–20 .0/
V mA
0–100%
0–100%
0–100%
0–100%
Yes, No
None
VDC mA
0–60000CFM
0–60000CFM
0–100%
0–999s
0 .0–100 .0
0–100%
0–100%
0–999s
0 .0–100 .0
0–100%
0 .00–100 .00%
0 .00–100 .00%
0–3600sec
0–999sec
0–999
0–100%
0–100°F
0–999sec
0–999
0-999sec
Password Level
4
4
2
2
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
2
2
2
2
4
2
2
2
2
4
4
4
4
4
4
4
4
4
4
4
4
4
4
OM 920-4
Menu Descriptions
Table 26 continued: Min OA Damper Menu
Item Display Name
RstTMaxChg=
Min Inc Rate=
Max Inc Rate=
0-30% OA Max=
Default Setting
4%
0 .03
1 .0
30%
Apply Changes
- the Apply Changes flag must be changed from no to yes in order for the controller to recognize the changes. Setting the Apply Changes flag to YES will automatically reset the controller.
Min OA Reset
is an adjustable item that sets the type of minimum OA damper position reset to be used. When this is set to “None” the Min OA Pos= parameter is set to the
Ventilation Limit. When this is set to “Network,” “Ext VDC,”
“Ext mA,” “IAQ VDC,” or “IAQ mA” then the Min OA Pos= parameter varies from the Ventilation Limit down to the
Demand Control Ventilation Limit as the reset signal goes from its maximum to minimum value.
NOTE:
When the Min OA Reset type is set to Network and the Apply changes flag is set to yes, the value of the
Vent Limit is automatically set to 100%, the value of the DCV limit is set to 0% and the LoFlo V Lmt is set to 0% .
BSP OA Ovrd
is an adjustable item used to enable/disable the building static pressure override feature.
Rst Lmt Snsr
is an adjustable item used to set the sensor to be used in conjunction with the OA reset limit function.
OA @ MinV/mA
is an adjustable item used when Min OA
Reset= is set to “Ext VDC” or “Ext mA” to define the Min
OA Pos= is when the field signal is at minimum value.
NOTE:
Min OA Pos= is limited above the Demand Control
Ventilation Limit .
OA @ MaxV/mA
is an adjustable item used when Min OA
Reset= is set to “Ext VDC” or “Ext mA” to define the Min
OA Pos= when the field signal is at the minimum value.
NOTE:
Min OA Pos= is limited below the ventilation limit .
Min V/mA
is an adjustable item used to set the minimum value of the field input signal.
Max V/mA
is an adjustable item used to set the maximum value of the field input signal.
PPM @ DCV Limit
is an adjustable item used when Min OA
Reset= is set to “IAQ VDC” or “IAQ mA” to define at what
PPM value the Min OA Pos= is to be at the Demand Control
Ventilation Limit value.
PPM @ Vent Limit
is an adjustable item used when Min OA
Reset= is set to “IAQ VDC” or “IAQ mA” to define at what
PPM value the Min OA Pos= is to be at the Ventilation Limit value.
IAQ PPM
is a status only item which indicates the current reading from the CO2 sensor.
Range
0–100%
0 .0–100 .0
0 .0–100 .0
0–100%
Password Level
2
2
2
2
Min PPM
is an adjustable item that sets the minimum PPM value.
Max PPM
is an adjustable item that sets the maximum PPM value.
V/mA @ Min PPM
is an adjustable item that sets the minimum
PPM value at the minimum DC voltage or mA value of the
CO2 sensor used when Min OA Reset= is set to “IAQ VDC” or “IAQ mA.”
V/mA @ Max PPM
is an adjustable item that sets the maximum PPM value at the maximum DC voltage or mA value of the CO2 sensor used when Min OA Reset= is set to
“IAQ VDC” or “IAQ mA.”
Min CFM
is an adjustable item that sets the minimum CFM value of the field supplied flow station.
Max CFM
is an adjustable item that sets the maximum CFM value of the field supplied flow station.
V/A @ Min CFM
is an adjustable item that sets the sensor input value at minimum CFM reading.
V/A @ Max CFM
is an adjustable item that sets the sensor input value at maximum CFM reading.
Min Fan Diff
is an adjustable item which sets a differential between the discharge and return fan capacities above which the minimum allowable Min OA Pos= begins to be reset upwards from the Demand Control Ventilation Limit toward the Ventilation Limit.
Max Fan Diff
is an adjustable item which sets a differential between the discharge and return fan capacities at which the minimum allowable Min OA Pos= is fully reset up to the
Ventilation Limit.
Min Clg Spd
is an adjustable item that sets the discharge fan speed on a VAV unit at which the Ventilation Limit reaches the LoFloVent= value.
Des Clg Spd
is an adjustable item used to adjust the design cooling speed setpoint.
Design Flow
is an adjustable item used to turn the optional
DesignFlow outdoor airflow measuring reset function on and off. This is one of several available methods of automatically resetting the Min OA Pos parameter.
Field OA Stn
is an adjustable item used to turn the optional field supplied outdoor airflow measuring station function on and off.
OM 920-4 41
Menu Descriptions
OA Flow
is a status only item which indicates the current outdoor airflow based on an optional OA airflow sensor input used when the unit is equipped the DesignFlow OA control feature, or a field supplied OA measuring station.
Min OAFlw Spt
is an adjustable item that is used to set the minimum design flow CFM’s when the unit is equipped with the optional DesignFlow OA control feature, or a field supplied OA measuring station.
OA CFM DB
is an adjustable item which sets the “deadband” used in the control function that modulates Min OA Pos parameter to maintain the OA Flow parameter at the MinOA
Flow set point when a unit is equipped with the optional
DesignFlow outdoor airflow measuring feature, or a field supplied OA measuring station.
OA CFMPeriod
is an adjustable item which sets the
“sampling time” used in the PI control function that modulates the Min OA Pos parameter to maintain the OA
Flow parameter at the MinOA Flow set point when a unit is equipped with the optional DesignFlow outdoor airflow measuring feature, or a field supplied OA measuring station.
OA CFM Gain
is an adjustable item which sets the “Gain” used in the PI control function that modulates the Min OA
Pos parameter to maintain the OA Flow parameter at the
MinOA Flow set point when a unit is equipped with the optional DesignFlow outdoor airflow measuring feature, or a field supplied OA measuring station.
OA CFM Max Chg
is an adjustable item which sets the “maximum step” used in the control function that modulates the Min OA Pos parameter to maintain the OA
Flow parameter at the MinOA Flow set point when a unit is equipped with the optional DesignFlow outdoor airflow measuring feature, or a field supplied OA measuring station.
LH Lvl Pos
is a status item which is used to calibrate the left-hand side (unit opposite drive side) of the optional
DesignFlow outdoor measuring apparatus. For details regarding calibration of the DesignFlow apparatus, refer to the applicable model-specific installation and maintenance manual.
RH Lvl Pos
is a status item which is used to calibrate the right-hand side (unit drive side) of the optional DesignFlow outdoor measuring apparatus. For details regarding calibration of the DesignFlow apparatus, refer to the applicable model-specific installation and maintenance manual.
MinRFEFTm
is an adjustable item used to set the time period for which the return/exhaust fan must operate at the minimum speed before the building static pressure override function is activated.
BSPOvdST
an adjustable item which sets the “sampling time” used in the PI control function used for the building static pressure override feature.
BSPOvdGain
is an adjustable item which sets the “Gain” used in the PI control function used for the building static pressure override feature.
BSPOvdMxChg
is an adjustable item that sets the maximum value for an increase or decrease of the outside air damper position due to the building static pressure override feature.
ResetTLmt
is an adjustable item which sets a temperature low limit which overrides functions that reset the outside air damper position if the temperature gets too cold.
RstTSmplT
an adjustable item which sets the “sampling time” used in the PI control function used for the Reset
Temperature Limit feature.
RstTGain
is an adjustable item which sets the “Gain” used in the PI control function used for the Reset Temperature Limit feature.
RstTPAT
is an adjustable item which sets the “project ahead time” used in the PI control function used for the Reset
Temperature Limit feature.
RstTMaxChg
is an adjustable item that sets the maximum change value PI loop used for the Reset Temperature Limit feature.
Min Inc Rate
is an adjustable item used to set the minimum increase rate for the outside air damper “cold start” sequence.
Max Inc Rate
is an adjustable item used to set the maximum increase rate for the outside air damper “cold start” sequence.
0-30% OA Max
is an adjustable item used to set the maximum outside air damper position when the unit is configured for a
30% damper.
42 OM 920-4
Menu Descriptions
Heating Set-Up Menu
The Heating menu provides a summary of the control parameters for units with heating. The unit’s heating mode of operation is controlled by the control temperature and the heating setpoint temperature. The unit goes into the heating mode of operation by analyzing the control temperature.
Table 27: Heating Set-Up Menu
Item Display Name
Htg Stage Time
Htg DB
Htg Period=
Htg Gain=
Htg PAT=
Htg Max Chg
Htg Hi OAT Lock
OAT Diff
Default Setting
5min
2 .0°F
60s
0 .1
600s
10%
55°F
2°F
Htg Reset=
Min Htg Spt=
Min Htg Spt @
Max Htg Spt=
Max Htg Spt @
Min DAT Ctrl=
Min Dat Limit
F&BP Method=
F&BP ChgOvrT=
Occ Heating=
Unocc Diff=
Htg Warmup Tm=
Htg Hld Period=
Max Purge Hld=
Gas Derate V=
MWU Sensor
None
55 .0°F
0/
NA
55 .0°F
100 .0°F
Yes
55 .0°F
OpenVlv
37°F
Yes
3°F
240s
240s
20s
10 .0V
RAT
The control temperature can be return temperature, space temperature or outside air temperature. The unit goes into the heating mode of operation when the control temperature is below the heating setpoint by more than ½ the deadband.
Range
0–100/
NA
°F
°C mA
40 .0–140 .0°F
0–100/
NA
°F
°C mA
Yes, No
0 .0–70 .0°F
OpenVlv
ModVlv
0–60°F
Yes, No
2–60min
1 .0–10 .0°F
0–999s
0 .0–100 .0
0–999s
0–100%
0–100°F
0–10°F
None
Ntwrk
Space
Return
OAT
ExtmA
ExtV
40 .0–140 .0°F
0–10°F
0–999s
0–999s
10–180s
0–10 .0V
RAT
Space
None
Password Level
4
4
4
4
4
4
4
4
6
6
6
6
6
4
2
2
2
4
6
2
2
6
4
2
OM 920-4 43
Menu Descriptions
Htg Stage Time
is an adjustable item used to set a minimum time period between heating stage changes.
Htg DB
is an adjustable item which sets a dead band around the discharge heating setpoint parameter. For example, if the discharge heating setpoint parameter is set to 100ºF and the
Htg DB= parameter is set to 2ºF, the dead band around the set point would be from 101.0ºF to 99.0ºF.
Htg Period
an adjustable item which sets the “sampling time” used in the PI control function that modulates the heating valve or face & bypass dampers.
Htg Gain
is an adjustable item which sets the “Gain” used in the PI control function that modulates the heating valve or face & bypass dampers.
Htg PAT
is an adjustable item which sets the “project ahead time” used in the PI control function that modulates the heating valve or face & bypass dampers.
Htg Max Chg
is an adjustable item that sets the maximum value for an increase or decrease of the heating valve or face
& bypass damper position.
Htg Hi OAT Lock
is an adjustable item which sets the high outdoor air temperature heating lockout point. Heating operation is disabled when the outdoor air temperature sensor input rises above this set point.
OAT Diff
is an adjustable item which sets a differential below the OATHtg Lock parameter. Heating operation is re-enabled when the outdoor air temperature sensor input falls below the
OATHtg Lock value by more than this differential.
Htg Reset
is an adjustable item used to set the type of heating reset to be used.
Min Htg Spt
is an adjustable item which sets the minimum heating discharge set point for use with a heating discharge air temperature set point reset schedule.
Min Htg Spt @
is an adjustable item which sets the value of the sensor input, selected with the heating reset parameter, at which the heating setpoint is reset to the Min Htg Spt value.
Max Htg Spt
is an adjustable item which sets the maximum heating discharge set point for use with a heating discharge air temperature set point reset schedule.
Max Htg Spt @
is an adjustable item which sets the value of the sensor input, selected with the heating reset parameter, at which the heating setpoint is reset to the Max Htg Spt value.
Min DAT Ctrl
is an adjustable item used on VAV or CAV discharge control units to activate or deactivate the low discharge temperature limit function available on units equipped with modulating or multistage heat.
Min DAT Limit
is a status only item which indicates the discharge air low limit temperature on CAV zone control units. Heating will be activated to maintain this setting when the discharge temperature falls below it during the Fan Only operating state. On VAV or CAV discharge control units, the minimum discharge temperature limit is the DAT Clg Spt.
F&BP Method
is an adjustable item used to set the face and bypass control method. When a unit equipped with steam or hot water and face and bypass damper, there are two methods available for controlling the heating arrangement. These are the “Open Valve” and “Modulating Valve” methods.
F&BP ChgOvrT
is an adjustable item used to set the face and bypass changeover temperature.
Htg Warmup Tm
is an adjustable item which is used to set the amount of time the gas burner will remain at a low fire position on 100% OSA units (default 240 seconds) during the special cold start sequence.
Htg Hld Period
is an adjustable item used to set the amount of time that the gas heating valve remains at its calculated value on units equipped with 100% OA (default 240 seconds) during the special cold start sequence. This is to allow the temperature to approach equilibrium with the modulating gas heating valve at a fixed position.
Occ Heating
is an adjustable item which enables and disables the “daytime” heating mode of operation. If the Occ Heating parameter is set to No, the unit will only go into heating during the initial morning warm-up cycle. If the Occ Heating parameter is set to Yes, the unit can go into the heating mode of operation any time during the day.
Unocc Diff
is an adjustable item that sets the unoccupied heating differential.
Max Purge Hld
is an adjustable item that sets the value of the maximum purge hold timer.
Gas Derate V
is an adjustable item used to set the maximum analog output value for controlling the modulating gas valve actuator.
MWU Sensor
is an adjustable item that sets the temperature sensor input to be used for morning warmup heating operation on discharge air control units. Setting this parameter to none disables morning warm up operation.
44 OM 920-4
Menu Descriptions
Dehum Set-Up
Table 28:
Dehumidification Menu
Item Display Name
Dehum Method=
RH DB=
Dewpoint DB=
RH Period=
RH Gain=
RH PAT=
RH Max Chg=
LSC Lo Gain=
RH Stg Time=
Stg Rht DB=
Dehum Ctrl=
Default Setting
None
2%
2 .0°F
30s
1
30s
10%
0 .2
10min
5°F
Occupied
Sensor Loc=
Mn Lvg Coil T=
Mx Lvg Coil T=
Min Rheat Spt=
Max Rheat Spt =
RH Sens Type=
RH Min Sig=
RH Max Sig=
Min Dehum Spd=
Max Dehum Spd=
Rht Min Pos=
RH Dec Rate=
Return
45 .0°F
52 .0°F
55 .0°F
65 .0°F
VDC
0 .0V
10 .0V
33%
100%
10% (RPS)
15% (MPS, DPS, DPH)
1
Dehum Method
is an adjustable item used to set the dehumidification method to either “RH” or “DewPt.” When this parameter is set to “RH,” dehumidification operation is controlled to maintain the Rel Humidity value at the Relative
Humidity Set Point. When this parameter is set to “DewPt,” dehumidification operation is controlled to maintain the Dew
Point= value at the Dew Point Set Point. When this parameter is set to “Always” dehumidification will be active as long as mechanical cooling is not disabled.
RH DB
is an adjustable item that sets a dead band around the relative humidity set point. For example, if the RH Setpoint parameter is set to 50% and the RH Db parameter is set to
2% the dead band around the set point would be from 49% to
51%.
Dewpoint DB
is an adjustable item that sets a dead band around the dew point set point. For example, if the DewPoint
Spt parameter is set to 50ºF and the DewPntDb parameter is set to 2ºF the dead band around the set point would be from
49ºF to 51ºF.
Range
None
Rel Hum
DewPt
Always
0-10%
2-10°F
0-999s
0 .0-100 .0
0-999s
0-100%
0 .0-100 .0
0-60min
0-20°F
Occupied
Always
Return
OAT
Space
40-100°F
40-100°F
40 .0-100 .0°F
40 .0-100 .0°F
VDC mA
0 .0-20 .0
V/mA
0 .0-20 .0
V/mA
0-100%
0-100%
0-100%
0-10 .00%/s
Password Level
4
4
4
4
4
4
2
2
2
2
2
2
2
4
4
4
4
4
4
4
4
2
4
RH Period
is an adjustable item which sets the “sampling time” used in the PI control function for controlling the reheat valve.
RH Gain
is an adjustable item which sets the “Gain” used in the PI control function for controlling the reheat valve.
RH PAT
is an adjustable item which sets the “project ahead time” used in the PI control function for controlling the reheat valve.
RH Max Chg
an adjustable item that sets the maximum value for an increase or decrease for controlling the reheat valve.
LSC Lo Gain
- is an adjustable item which sets the “Gain” used in the PI control function for controlling the liquid subcooling reheat valve.
RH Stg Time
is an adjustable item is an adjustable item which sets a stage time period for controlling reheat on units eqquipped with a single stage of hot gas reheat.
OM 920-4 45
Menu Descriptions
Stg Rht DB
is an adjustable item which sets a dead band around the reheat setpoint parameter.
Dehum Ctrl
is an adjustable item used to select whether dehumidification as “always” allowed or only during
“occupied” modes of operation.
Sensor Loc
is an adjustable item which is used to select the location of the humidity sensor. The location is selected by setting the Sensor Location value on the keypad to Return,
Space, or OAT. The significance of the sensor location is that this determines which temperature sensor is use to calculate the Dewpoint. OAT can only be selected for units with DAT control.
Mn Lvg Coil T
is an adjustable item which is used to set the minimum leaving coil temperature (Default = 45°F).
Mx Lvg Coil T
is an adjustable item which is used to set the maximum leaving coil temperature (Default = 52°F).
Min Reheat Spt
is an adjustable item which is used to set the minimum DAT during dehumidification.
Max Reheat Spt
is an adjustable item which is used to set the maximum DAT during dehumidification.
RH Sen Type
is an adjustable item used to define the field supplied humidity sensor input signal type.
RH Min Signal
is an adjustable item used to define the minimum value of the field supplied humidity sensor current or voltage signal.
RH Max Signal
is an adjustable item used to define the maximum value of the field supplied humidity sensor current or voltage signal.
Min Dehum Spd
is an adjustable item used to set the minimum supply fan VFD speed during dehumidification.
Max Dehum Spd
is an adjustable item used to set the maximum supply fan VFD speed during dehumidification.
Rht Min Pos
is an adjustable item used to set the minimum position of the reheat valve when the PI loop is active.
RH Dec Rate
is an adjustable item used to set the rate of decrease for the reheat valve, where the unit leaves the dehumidification operation.
Energy Recovery Set-up
The Energy Recovery Set-up menu contains parameters that relate to or are used to control the enthalpy wheel and exhaust fan when a unit is equipped with an optional energy recovery wheel system.
Table 29: Energy Recovery
Item Display Name
Energy Rvcy=
ER Wheel=
Wheel Speed=
Whl Spd Cmd=
ER LAT=
ER EAT=
Min ExhT Diff=
Max ExhT Diff=
ER Whl Stg Tm=
ER Whl Off Tm=
Rel Humidity=
Min Whl Spd
Intersect Pt=
Fst Mgmt Meth=
OA Fst Temp=
Defrost Time=
Defrst Period=
Defrst On Tm=
Defrst Off Tm=
ER Whl Period=
ER Whl Gain=
ER Whl PAT=
ER Max Chg=
Default Setting
Timed
-20 .56°C
5min
60min
1s
24s
30 .0s
1 .0
30 .0s
10%
2 .0°F
6 .0°F
5min
20min
—
5%
—
Yes
—
—
—
—
—
Range
Yes, No
On, Off
0–100%
0–100%
-50 .0–200 .0°F
–50 .0–200 .0°F
1 .0–20 .0°F
1 .0–20 .0°F
1–100min
1–100min
0–100%
0–100%
-146 .2 .0–150 .0°F
Timed ExhAir
-40 .0 – 37 .78°C
0–60min
0–1440min
0–999s
0–999s
0–999 .0s
0–100
0–999 .0s
0–100%
Password Level
2
2
4
2
4
4
4
2
2
2
4
4
2
4
4
4
4
4
4
4
4
4
4
46 OM 920-4
Menu Descriptions
Energy Rvcy
is an adjustable item which turns the optional energy recovery system on /off.
ER Wheel
is a status only item used to indicate whether the energy recovery wheel is currently on or off.
Wheel Speed
is a status only item that indicates the energy wheel variable speed supply air fan speed.
Wheel Spd Cmd
is a status only item that indicates the current energy wheel variable speed supply air fan commanded speed.
ER LAT
is status only item which displays the current discharge air temperature leaving the optional energy recovery wheel.
ER EAT
is status only item which displays the current exhaust air temperature leaving the optional energy recovery wheel.
Min Exh T Diff
is an adjustable item that sets a differential below the calculated potential energy recovery exhaust air frosting point. When the ER Exh T falls below the calculated frosting point by more that this value, the energy wheel will be driven to its minimum speed, or turned off, to prevent frosting.
Max Exh T Diff
is an adjustable item that sets a differential above the calculated potential energy recovery exhaust air frosting point. Once the wheel is driven to minimum speed, or turned off, to prevent frosting, it is driven back to maximum speed, or turned on, only when ER Exh T rises back above the calculated frosting point by more that this value.
ER Whl Stg Tm
is an adjustable item used to set a minimum time period for operating at either the minimum or maximum speed before action is taken to change speed during the frost protect mode of operation.
ER Whl Off Tm
is an adjustable item used to set the minimum amount of time the energy wheel will remain off after being turned off due to a frosting/condensation condition.
Rel Humidity
is a status only item that indicates the current relative humidity reading of the sensor.
Min Whl Spd
is an adjustable item used to set the energy recovery minimum wheel speed.
Intersect Pt
is a status only item used to indicate the current intersection point value from the psychometric chart where potential for wheel frosting exists.
Fst Mgmt Meth
is an adjustable item used to select the frost protection method to be used on a constant speed energy wheel application.
OA Fst Temp
is an adjustable item used to set the outside air frost temperature.
Defrost Time
is an adjustable item used to set the duration of a defrost cycle.
Defrst Period
is an adjustable item used to set how often a defrost cycle will be initiated.
Defrst On Tm
is an adjustable item used to select how long the constant speed energy wheel is energized during defrost.
Defrst Off Tm
is an adjustable item used to select how long the constant speed energy wheel is de-energized during defrost.
ER Whl Period
an adjustable item which sets the “sampling time” used in the PI control function.
ER Whl Gain
is an adjustable item which sets the “Gain” used in the PI control function.
ER Whl PAT
is an adjustable item which sets the “project ahead time” used in the PI control function.
ER Max Chg
is an adjustable item that sets the maximum value for an increase or decrease of the energy recovery wheel speed.
OM 920-4 47
Menu Descriptions
Head Pressure Set-Up Menu
The Head Pressure Set-Up menu contains parameters that are used to maintain head pressure control.
Table 30: Head Pressure Setup Menu
Item Display Name
Wtr Reg Vlv=
Head P Circ 1=
Head P Circ 2=
Setpoint=
Head Press DB=
WRV Period=
WRV Gain=
WRV PAT=
WRV Max Chg=
WRV Init Tm=
Min WRV Pos=
Min WRV Tmp=
Max WRV Tmp=
WRV Act Time=
Min WRV Time=
Default Setting
10s
7%
60s
10%
58°F
105°F
130s
60s
—
—
—
260psi
10psi
10s
3 .6
Wtr Reg Vlv
is a status only item that indicates the current water regulating valve position.
Head P Circ 1
is a status only item that indicates the current refrigerant pressure for circuit 1.
Head P Circ 2
is a status only item that indicates the current refrigerant pressure for circuit 2.
Setpoint
is an adjustable item that sets the refrigerant setpoint used for controlling the water regulating valve.
The water-regulating valve is modulated to maintain the refrigerant pressure.
Head Press DB
is an adjustable item that sets a deadband around the Head Pressure Setpoint parameter.
WRV Period
is an adjustable item which sets the “sampling time” used in the PI control function of the water regulating valve.
WRV Gain
is an adjustable item which sets the “Gain” used in the PI control function of the water regulating valve.
WRV PAT
is an adjustable item which sets the “project ahead time” used in the PI control function of the water regulating valve.
WRV Max Chg
is an adjustable item that sets the maximum value for an increase or decrease of the water regulating valve.
Range
0–100%
0–750psi
0–750psi
230–340psi
0–50psi
0–999s
0 .0–100 .0
0–999s
0–100%
0–3600s
0–100%
20–150°F
20–150°F
0–300s
0–3600s
Password Level
2
2
2
2
4
4
2
2
4
4
6
4
6
6
6
WRV Init Tm
is an adjustable item that sets a minimum time period that the WRV remains at an initial startup position
(InitPos) during the WRV start sequence..
Min WRV Pos
is an adjustable item used which sets the minimum WRV position used in the WRV start sequence
(default 10%).
Min WRV Tmp
is an adjustable item which is used to set the edited temperature where WRV at a minimum position does not result in a high pressure condition.This is used in the
WRV start sequence.
Max WRV Tmp
is an adjustable item which is used to set the edited temperature where WRV at 100% does not result in a low pressure condition.This is used in the WRV start sequence.
WRV Act Time
is an adjustable item which is used to set the time required for the WRV to be driven from 0 to 100%.
Min WRV Time
is an adjustable item which sets the minimum
WRV time (default 60 seconds) used in the WRV start sequence.
48 OM 920-4
Menu Descriptions
Evap Cond Set-Up Menu
Table 31: Evap Condensing Menu
Item Display Name
Cond Fan Spd=
CFan Spd Cmd=
Min Fan Speed=
EvCond Stg Tm=
Sump Temp=
Min Sump T=
Max Sump T=
Sump Dump Spt=
Cndtvy=
Hi Cndtvy Spt=
SmpWtrLvlDly=
PostClgTime=
SepFlshTime=
Dolphin Sys=
Default Setting
-
-
33%
10min
-
75 .0°F
85 .0°F
35 .0°F
-
1100 S/cm
5mim
10min
1min
No
Range
0-100%
0-100%
0-100%
0-100min
-50 .0-150 .0°F
0 .0-100 .0°F
0 .0-100 .0°F
0 .0-100 .0°F
0-5000S/cm
0-5000S/cm
0-60min
0-60min
0-60min
No
Yes
Password Level
4
4
4
4
4
4
4
4
4
4
4
4
4
4
Cond Fan Speed
is a status only item that displays the current VFD speed when the evaporative condenser option includes a VFD to control the first condenser fan on each circuit.
Cond Fan Spd Cmd
is a status only item that indicates the current condenser fan VFD commanded speed.
Min Fan Speed
is an adjustable item used to set the minimum speed for the VFD speed when the evaporative condenser option includes a VFD to control the first condenser fan on each circuit.
EvCond Stg Tm
is an adjustable item used to set a minimum time period between condenser fan stage changes.
Sump Temp
is a status only item that displays the current evaporative condenser sump temperature.
Min Sump T
is an adjustable item used to set a minimum evaporative condenser sump temperature set point. This value is used to determine when condenser fans are turned off.
Max Sump T
is an adjustable item used to set a maximum evaporative condenser sump temperature set point. This value is used to determine when condenser fans should be turned on.
Sump Dump Spt
is an adjustable item used to set a minimum sump temperature. The sump is emptied to prevent freezing if the sump temperature drops below this set point.
Sump Pump Status
is a status only item that displays the current evaporative condenser sump pump status.
Smp Pmp Delay
adjustable item used to set the amount of time the sump pump fail alarm is delayed. If the Sump Pump status remains Off after the Sump Pump Output has been turned on for more than the Sump Pump Delay time, a Sump
Pump fail alarm is initiated.
Conductivity
is a status only item that displays the conductivity level of the water in the sump of an evaporative cooled condenser on rooftop units.
Hi Cndtvy Spt
is an adjustable item that sets the alarm value setpoint used to generate a conductivity problem alarm
SmpWtrLvlDly
is an adjustable item that sets the amount of time sump water level input is ignored once the unit enters the cooling state
PostClgTime
is an adjustable item that sets the amount of time the sump pump output remains on after the unit leaves the cooling state.
SepFlshTime
is an adjustable item that sets the amount of time the Purge Valve Binary Output is turned on to flush the solids out of the system separator.
Dolphin System
is an adjustable parameter that indicates to the controller whether or not a Dolphin water treatment method is being used. When set to “yes” the controller assures the sump pump is run every three days to reduce scaling.
OM 920-4 49
Menu Descriptions
Alarm Configuration Menu
Alarm Limits Menu
The Alarm Limits menu is used to set the limits of the discharge air temperature sensor and the return air temperature sensor.
Table 32: Alarm Limits Setup Menu
Item Display Name
Hi Disch Temp=
Lo Disch Temp=
Hi Return Temp=
Default Setting
170°F
40°F
120°F
Hi Disch Alm
is an adjustable item that sets the high temperature limit for the DAT sensor. When the discharge air temperature sensor reaches this set point the unit will go into the high discharge air alarm.
Lo Disch Alm
is an adjustable item that sets the low temperature limit for the DAT sensor. When the discharge air temperature sensor reaches this set point the unit will go into the low discharge air alarm.
Hi Return Alm
is an adjustable item that sets the high temperature limit for the return air temperature. When the
RAT sensor reaches this set point the unit will go into the high return air temperature alarm.
Alarm Output Config Menu
Table 33:
Alarm Out Configuration Setup Menu
Item Display Name Default Setting
Faults= Fast
Problems=
Warnings=
Slow
Off
The digital alarm output indicates the alarm group that contains the highest priority active alarm. This output is On when no alarms are active. The options for the action of this output when an alarm in a group occurs are On, Fast Blink,
Slow Blink, or Off. These can be edited via the keypad/ display.
Range
90–250°F
-50–50°F
90–150°F
Password Level
4
4
4
Range
On
Off
Fast
Slow
On
Off
Fast
Slow
On
Off
Fast
Slow
Password Level
4
4
4
The default values for the three groups of alarms are:
• Warnings - Off
• Problems - Slow Blink
• Faults - Fast Blink
A user could eliminate any signal of a particular group of alarms through this output by selecting On for that alarm group in the keypad/display.
50 OM 920-4
Alarm Delays Menu
The Alarm Delays Setup Menu can be accessed when a level
2 password has been entered. The default settings are the result of many years of testing and should not be changed.
Table 34: Alarm Delays Setup Menu
Item Display Name
OffHtClDelay=
Frz DelayTime=
LP Delay=
LP Comp Delay=
Aflw Ignr Tm=
Sens Alm Dly=
Temp Alm Dly=
Default Setting
120s
30s
2s
5s (410A)
65s (R22/407C)
120s
30s
30s
Alarm Config
Emerg Stop= Man Clr
OffHtClDelay
is an adjustable item that is used to set the duration the supply fan will remained energized when a unit transitions to the off state while DX cooling or staged heating is active.
Frz DelayTime
is an adjustable item used to set the freeze alarm delay time.
LP Delay
is an adjustable item used to set the low pressure switch delay time.
LP Comp Delay
is an adjustable item used to set the low pressure compressor delay time.
Aflw Ignr Tm
is an adjustable item that sets the amount of time the air proving switch is ignored after the supply fan is started.
Sens Alm Dly
is an adjustable item used to set the sensor alarm delay time.
Temp Alm Dly
is an adjustable item used to set the temperature alarm delay time
Emerg Stop
is an adjustable item used to set the emergency shutdown to either manual or automatic restart.
Range
0–999s
0–180s
0–10s
0–300s
0–999s
0–300s
0–300s
Man Clr
Auto Clr
Menu Descriptions
Password Level
2
2
2
2
2
2
2
2
OM 920-4 51
Menu Descriptions
Manual Control
The manual control of operation is a function that is used for operating the unit during a service call only. The unit must not be operated in this mode for any extended period of time.
Table 35: Manual Control Menu
Item Display Name
Manual Ctrl=
Supply Fan=
SAF Spd Cmd=
RF/EF VFD=
RF/EF Spd Cmd=
OAD/Econo=
OAD OpCl=
Comp 1 =
Comp 2 =
Comp 3 =
Comp 4 =
Comp 5 =
Comp 6 =
Comp 7 =
Comp 8 =
U1 Comp 1=
U1 Comp 2=
U2 Comp 1=
U2 Comp 2=
Cfan Outpt 1=
Cfan Outpt 2=
Cfan Outpt 3=
BP/WR Valve=
CW Valve=
ExhFan Out 1=
ExhFan Out 2=
ECond VFD=
ECFan Spd Cmd=
EC Drn Valve=
Sump Pump=
Sep Flsh Vlv=
SV1=
SV2=
Off
Off
Off
Off
Off
Off
Off
Off
Default Setting
Normal
Off
0%
Off
0%
0%
Close
Off
Off
Off
Off
Off
Off
Off
0%
Close
Off
Off
0%
0%
Off
Off
Off
Off
Off
On
Off
On
Off
On
0-100%
0-100%
Off
On
Off
On
Off
On
0-100%
Close
Open
Off
On
Off
On
Off
On
Off
On
Off
On
Off
On
Off
On
Off
Off
On
Off
On
Off
On
Off
On
Range
Normal
ManCtrl
Off
On
0-100%
Off
On
Off
On
Off
On
Off
On
Off
On
0-100%
0-100%
Close
Open
Off
On
4
4
4
4
4
4
4
4
Password Level
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
52 OM 920-4
Menu Descriptions
Table 35 continued: Manual Control Menu
Item Display Name Default Setting
GasHtg OnOff=
Htg Valve=
SCR Out=
F&BP Damper=
Htg Stg 1=
Off
0%
0%
0%
Off
SCR Ena 1=
Htg Stg 2=
SCR Ena 2=
Htg Stg 3=
Htg Stg 4=
Htg Stg 5=
Htg Stg 6=
Reheat Valve=
RH Output=
LSCRH Valve=
HGBP Valve=
ERec Wheel=
ER Whl Cmd=
ERBP Dmpr Cl=
ERBP Dmpr Op=
Cond Wtr Pump=
Alm Output=
Fan Op Out=
Off
Off
Off
0%
Off
0%
Off
Off
0%
Off
Off
Off
Off
Off
Off
Off
Off
Off
Range
Off
On
0-100%
0-100%
0-100%
Off
On
Off
On
Off
On
Off
On
0-100%
On
Off
On
Off
On
Off
On
Off
Off
On
Off
On
Off
On
Off
On
Off
On
0-100%
Off
On
Off
On
0-100%
Off
On
4
4
4
4
4
4
4
4
4
4
4
4
4
4
Password Level
4
4
4
4
4
4
4
4
4
Manual Ctrl
is an adjustable item that puts the unit into manual control. Major components of the unit are turned on and off by this control. The units normal control sequences are overridden in this state with the exception of all the
“fault” alarms and the cooling circuit high pressure and low pressure alarms.
Supply Fan
is an adjustable item that turns on the supply fan.
RF/EF
is an adjustable item that turns on the return/exhaust fan.
SAF Spd Cmd
is an adjustable item only on VAV units that sets the speed of the supply air fan.
RF/EF Spd Cmd
is an adjustable item for units with VFD on the return/exhaust fans that sets the speed of the return/ exhaust fan.
OAD/Econo
is an adjustable item which is used to set the economizer damper position.
OAD OpCl
is an adjustable item which is used to turn the
OA damper output on. This output is available only on self contained units.
Comp 1 OnOff
is an adjustable item that turns on compressor #1.
Comp 2 OnOff
is an adjustable item that turns on compressor #2.
Comp 3 OnOff
is an adjustable item that turns on compressor #3.
Comp 4 OnOff
is an adjustable item that turns on compressor #4.
Comp 5 OnOff
is an adjustable item that turns on compressor #5.
Comp 6 OnOff
is an adjustable item that turns on compressor #6.
Comp 7 OnOff
is an adjustable item that turns on compressor #7.
Comp 8 OnOff
is an adjustable item that turns on compressor #8.
U1 Comp 1
is an adjustable item the turns on unloader 1 on compressor 1.
U1 Comp 2
is an adjustable item the turns on unloader 1 on compressor 2.
U2 Comp 1
is an adjustable item the turns on unloader 2 on compressor 1.
OM 920-4 53
Menu Descriptions
U2 Comp 2
is an adjustable item the turns on unloader 2 on compressor 2.
CFan Outpt 1
is an adjustable item that turns on the condenser fan output #1.
CFan Outpt 2
is an adjustable item that turns on the condenser fan output #2.
CFan Outpt 3
is an adjustable item that turns on the condenser fan output #3.
NOTE:
Turning on any one of the compressors will automatically turn on the first condenser fan on the circuit . Other condenser fans must be manually turned on to control the head pressure of the unit .
Refrigerant gauges must be connected to the unit for observation of the head pressure in the manual control mode of operation . Additional condenser fans must be turned on to maintain the head pressure .
BP/WR Valve
is an adjustable item used to manually drive the bypass/water regulating valve open and closed.
CW Valve
is an adjustable item used to manually drive the chilled water valve open and closed.
Exh Fan Out 1
is an adjustable item that turns on Exhaust fan output # 1.
Exh Fan Out 2
is an adjustable item that turns on Exhaust fan output # 2.
ECond VFD
is an adjustable item which is used to turn on/off the evaporative cooling condenser fan VFD.
ECFan Spd Cmd
is an adjustable item which is used to set the evaporative cooling condenser fan VFD speed position.
EC Drn Valve
is an adjustable item which is used to open/ close the evaporative cooling drain valve.
Sump Pump
is an adjustable item which is used to turn on/ off the evaporative cooling sump pump.
Sep Flsh Vlv
is an adjustable item that turns on the Separator
Flush Valve output.
SV1
is an adjustable output that turns on the circuit 1 liquid line solenoid valve.
SV2
is an adjustable output that turns on the circuit 2 liquid line solenoid valve.
GasHtgOnOff
is an adjustable item used to manually turn the main gas valve output on/off.
Htg Valve
is an adjustable item used to manually drive the modulating heating valve open and closed.
SCR Out
is an adjustable item used to manually drive the output signal to the SCR.
F&BP Damper
is an adjustable item used to manually drive the F&BP damper open and closed.
Htg Stg 1
is an adjustable item that turns on the first stage of heat on units equipped with staged heating.
SCR Ena 1
is an adjustable item that enables the SCR heater.
Htg Stg 2
is an adjustable item that turns on the second stage of heat on units equipped with staged heating.
SCR Ena 1
is an adjustable item that enables the SCR heater.
Htg Stg 3
is an adjustable item that turns on the third stage of heat on units equipped with staged heating.
Htg Stg 4
is an adjustable item that turns on the fourth stage of heat on units equipped with staged heating.
Htg Stg 5
is an adjustable item that turns on the fifth stage of heat on units equipped with staged heating.
Htg Stg 6
is an adjustable item that turns on the sixth stage of heat on units equipped with staged heating.
Reheat Valve
is an adjustable item used to manually drive the reheat valve open and closed.
RH Output
is adjustable output that turns on the Reheat valve output.
LSCRH Valve
is adjustable output that turns on the Liquid
Subcooler Reheat Valve output
HGBP Valve
is an adjustable item used to manually drive the
HGBP Valve open and closed.
ERec Wheel
is an adjustable item which is used to turn on/off the energy recovery wheel output.
ERec Whl Cmd
is an adjustable item is an adjustable item which is used to set the energy recovery wheel VFD speed.
ERBP Dmpr Cl
is an adjustable item which is used to close the energy recovery bypass damper.
ERBP Dmpr OP
is an adjustable item which is used to open the energy recovery bypass damper.
Cond Wtr Pump
is an adjustable item which is used to turn on/off the condenser water pump output.
Alm Output
is an adjustable item which is used to turn on/off the alarm output.
FanOp
is an adjustable item which is used to turn on/off the fan operation output.
NOTE:
When Manual Control is set to ManCtrl, the Control
Mode is set to Off so that the unit will not restart automatically . When Manual Control is set to Normal all digital outputs in the Manual Control menu are set to Off and all the analog outputs are set to 0 .0% so that all outputs are in the Off or minimum position when Manual Control is set to ManCtrl .
54 OM 920-4
Menu Descriptions
Service Menus
Timer Settings Menu
The Timer Settings Menu is also available from the
Commission Unit Menu, and is described on
Save/Restore Menu
The Save/Restore menu can be used to save or restore the user configured parameters as well as reset the controller back to the factory default parameters.
Table 36: Save/Restore Menu
Item Display Name
Save Params=
Rstr Params=
Rstr Factory=
SaveToCard=
LoadFromCard
Default Setting
No
No
No
No
No
Save Params
is an adjustable item used to save the current parameters and configuration.
Rstr Params
is an adjustable item used to restore the current parameters and configuration.
Rstr Factory
is an adjustable item used to restore the factory parameters and configuration.
Range
No/Yes
No/Yes
No/Yes
No/Yes
No/Yes
Password Level
2
2
2
2
2
SaveToCard
is an adjustable item used to save the current parameters and configuration to an SD card.
LoadFromCard
is an adjustable item used to restore the current parameters and configuration from an SD card.
NOTE:
The controller will automatically perform a reset when the value of Load From Card is changed from No to
Yes and the enter button is pushed .
Active Alarms Menu
All active alarms as well as the date and time that they were detected are displayed on the Active Alarm menu. These alarms are displayed in order of group priority: Faults first,
Problems second, and Warnings last. Within each group, alarms are displayed in the order that they were detected.
Table 37: Active Alarm Menu
Item Display Name
Active Alm Count=
Default Setting
—
Password Level
None
ClrAlms= No
Range
0–10
No
ClrFlts
ClrPrblms
ClrWrngs
ClrAllAlms
None
+Alarm 1:Alarm Type
+Alarm 2:Alarm Type
—
—
None
None
OM 920-4 55
Menu Descriptions
Alarm Log Menu
The last fifty alarm events (alarm detection and return to normal) as well as the date and times that they were detected are displayed on the Alarm Log menu. These alarm events are displayed in the order that they were detected. The alarm event that was detected most recently is displayed first.
Multiple occurrences of the same alarm may appear.
Table 38: Alarm Log Menu
Item Display Name
Log Alm Count=
ClrLog=
+Alarm 1:Alarm Type
+Alarm 2:Alarm Type
Default Setting
—
No
—
—
Once an alarm is cleared there will be two entries in the
Alarm Log. A (+) sign will be shown next to the entry added when the alarm became active and a (-) sign will be shown next to the entry added when the alarm has been cleared.
Alarm Configuration Menu
The Alarm Configuration menu is also available under the
Commission Unit menu. Refer to
.
Analog Input Status Menu
The Analog Input Status Menu provides diagnostic information to qualified service personnel. The items listed in this menu will provide current status information of the unit’s analog inputs. The value shown is the input resistance shown in 1/10th of an ohm scale. Example: MCB-AI1 (DAT sensor) shows a value of 181380, the actual resistance would be 18,138 ohms. This would translate to a temperature of 53.5 ºF.
Table 39: Analog Input Status Menu
Item Display Name
MCB-AI1=
MCB AI2=
MCB AI3=
Default Setting
—
—
—
Range
0–50
No
Yes
Range
0–99999999
0–99999999
0–99999999
Password Level
None
None
None
None
Password Level
2
2
2
56 OM 920-4
Menu Descriptions
Universal I/O Status Menu
The Universal I/O Status Menu provides diagnostic information to qualified service personnel. The items listed in this menu will provide current status information of the Universal inputs and outputs. If the universal I/O is configured for resistance, the value will be displayed in 1/10th
Table 40: Universal I/O Status Menu
Item Display Name Default Setting
EMA X7=
EMA X8=
EMB X1=
EMB X2=
EMB X3=
EMB X4=
EMB X5=
EMB X6=
EMB X7=
EMB X8=
MCB X1=
MCB X2=
MCB X3=
MCB X4=
MCB X5=
MCB X6=
MCB X7=
MCB X8=
EMA X1=
EMA X2=
EMA X3=
EMA X4=
EMA X5=
EMA X6=
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
Range
0–9999999
0–9999999
0–9999999
0–9999999
0–9999999
0–9999999
0–9999999
0–9999999
0–9999999
0–9999999
0–9999999
0–9999999
0–9999999
0–9999999
0–9999999
0–9999999
0–9999999
0–9999999
0–9999999
0–9999999
0–9999999
0–9999999
0–9999999
0–9999999 ohm scale. If the I/O is configured for mA, the value will be displayed in micro amps (1 mA = 1000 micro amps). If I/O is configured for voltage, the value is displayed in 1/1000th volt scale. Example: MCB-X7 (OA Damper analog output) shows a value of 3000, this would translate into 3 VDC.
Password Level Item Display Name
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
EMD X7=
EMD X8=
EME X1=
EME X2=
EME X3=
EME X4=
EME X5=
EME X6=
EME X7=
EME X8=
EMC X1=
EMC X2=
EMC X3=
EMC X4=
EMC X5=
EMC X6=
EMC X7=
EMC X8=
EMD X1=
EMD X2=
EMD X3=
EMD X4=
EMD X5=
EMD X6=
Default Setting
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
Range
0–9999999
0–9999999
0–9999999
0–9999999
0–9999999
0–9999999
0–9999999
0–9999999
0–9999999
0–9999999
0–9999999
0–9999999
0–9999999
0–9999999
0–9999999
0–9999999
0–9999999
0–9999999
0–9999999
0–9999999
0–9999999
0–9999999
0–9999999
0–9999999
Password Level
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
OM 920-4 57
Menu Descriptions
Digital Input Status Menu
The Digital Input Status Menu provides diagnostic information to qualified service personnel. The items listed in this menu will provide current status information of the controller’s digital inputs.
Table 41: Digital Input Status Menu
Item Display Name
MCB DI1=
MCB-DI2=
MCB DI3=
MCB DI4=
MCB DI5=
MCB DI6=
Default Setting
Off
Off
Off
Off
Off
Off
Range
Off/On
Off/On
Off/On
Off/On
Off/On
Off/On
Digital Output Status Menu
The Digital Output Status Menu provides diagnostic information to qualified service personnel. The items listed in this menu will provide current status information of the controller’s digital outputs.
Table 42: Digital Output Status Menu
Item Display Name Default Setting
MCB DO1=
MCB DO2=
Off
Off
MCB DO3=
MCB DO4=
MCB DO5=
MCB DO6=
MCB DO7=
MCB DO8=
MCB DO9=
Off
Off
Off
Off
Off
Off
Off
MCB DO10=
EMA DO1=
EMA DO2=
EMA DO3=
EMA DO4=
EMA DO5=
EMA DO6=
EMB DO1=
EMB DO2=
EMB DO3=
EMB DO4=
EMB DO5=
EMB DO6=
Off
Off
Off
Off
Off
Off
Off
Off
Off
Off
Off
Off
Off
Off/On
Off/On
Off/On
Off/On
Off/On
Off/On
Off/On
Off/On
Off/On
Off/On
Off/On
Off/On
Off/On
Range
Off/On
Off/On
Off/On
Off/On
Off/On
Off/On
Off/On
Off/On
Off/On
2
2
2
2
2
2
2
2
2
2
2
2
2
Password Level
2
2
2
2
2
2
2
2
2
Item Display Name Default Setting
EMC DO1=
EMC DO2=
Off
Off
EMC DO3=
EMC DO4=
EMC DO5=
EMC DO6=
EMD DO1=
EMD DO2=
EMD DO3=
Off
Off
Off
Off
Off
Off
Off
EMD DO4=
EMD DO5=
EMD DO6=
EME DO1=
EME DO2=
EME DO3=
EME DO4=
EME DO5=
EME DO6=
Off
Off
Off
Off
Off
Off
Off
Off
Off
Range
Off/On
Off/On
Off/On
Off/On
Off/On
Off/On
Off/On
Off/On
Off/On
Off/On
Off/On
Off/On
Off/On
Off/On
Off/On
Off/On
Off/On
Off/On
Password Level
2
2
2
2
2
2
Password Level
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
58 OM 920-4
Menu Descriptions
Network Input Status Menu
The Network Input Status Menu provides diagnostic information to qualified service personnel. The items listed in this menu will provide current status information of the controller’s network inputs.
Table 43: Network Input Status Menu
Item Display Name
Net OAT In=
Net SpaceT In=
NetCurrState=
Default
Setting
—
—
—
Range
(No Network value in Bold)
-50 .0–200 .0°F
(621 .8°F)
-0 .0–150 .0°F
(621 .8°F)
Occ
Unocc
TntOvrd
Standby
Auto
NetNextState=
NetTmToNxtSt=
Net App Mode=
Net Cl Ena Sw=
—
—
—
—
(NULL)
Occ
Unocc
TntOvrd
Standby
Auto
(NULL)
0–65534min
(65535min)
Off
HeatOnly
CoolOnly
FanOnly
Auto
(Auto)
-1 .0–1 .0(-1 .0)
Password
Level
2
2
2
2
2
2
2
Item Display
Name
Net Cl Ena Vl=
Net Ht Ena Sw=
Net Ht Ena Vl=
Net Ec Ena Sw=
Net Ec Ena Vl=
Net SAF Cap=
Net ExhF Cap=
Net Space IAQ=
Net Rel Humid=
Net DATClgSpt=
Net DATHtgSpt= nviSetpoint=
OccManCmd=
Net MinOA= nvoEffSpt= nciOccClgSpt= nciOccHtgSpt= nciHVACType=
Default
Setting
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
Range
(No Network value in Bold)
0–255% (255%)
-1 .0–1 .0 (-1 .0)
0–255% (255%)
-1 .0–1 .0 (-1 .0)
0-255% (255%)
0–100% (164%)
0–100% (164%)
0–5000ppm
(65535ppm)
0-100% (164%)
40 .0–100 .0°F
40 .0–140 .0°F
0 .0-100 .0°F
(621 .8°F)
Occ
Unocc
TntOvrd
Standby
Auto
0–100%
0 .0–100 .0°F
0 .0–100 .0°F
0 .0–100 .0°F
HVT_GEN
Password
Level
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
OM 920-4 59
Menu Descriptions
Modbus Status Menu
The Modbus Status Menu provides diagnostic information to qualified service personnel. The items listed provide the status of the Modbus communications with the various devices controlled by the internal Modbus network
Table 44: Modbus Status Menu
Item Display Name
SF MB Status=
RFEF MB Status=
ER MB Status=
IFB MB Status=
D3 MB Status=
MB Resistance=
ECM Config=
Default Setting
—
—
—
—
—
Yes
Done
SF MB Status
is a status only item which indicates the status of the Modbus communications between the main controller and the supply fan motor.
RFEF MB Status
is a status only item which indicates the status of the Modbus communications between the main controller and the return/exhaust fan motor.
Range
Fault/OK
Fault/OK
Fault/OK
Fault/OK
Fault/OK
Yes/No
Set Add 1
Set Add 2
Set AICtl
Password Level
2
2
2
2
2
2
2
ER MB Status
is a status only s item which indicates the status of the Modbus communications between the main controller and the energy recover wheel variable speed supply air fan.
D3 Status Menu
The D3 Status menu is provided for viewing the status of an interface with the unit via a D3 gateway. Refer to IM 1133
–
DIII-Net Communication Gateway for detailed information.
Table 45: D3 Status Menu
Item Display Name Default Setting
D3 Comm Sts= —
D3 Addr Err= —
D3 On/Off= —
D3 Mode=
D3 Clg Spt=
D3 Htg Spt=
D3 SAF Spd=
D3 Min Load=
D3 Max Load=
D3 Eco Ena=
OA Enthalpy=
—
—
—
—
—
—
—
—
Range
OK
Error
OK
Error
On
Off
Auto
Cooling
Heating
Fan
0–100ºF
0–120ºF
NA
Low
Med
High
0–100%
0–100%
Enabled
Disabled
0–86 BTU/lb
Password Level
2
2
2
2
Item Display Name Default Setting
OA Hum Ratio= g/kg
D3 SWVers=
OAAdd1–16=
OAAdd17–32=
—
—
—
—
OAAdd33–49= —
OAAdd50–64= —
SetOAAddr=
CurrOAAddr=
CurrOAAmps=
CurrOARLA=
0
—
—
—
2
2
2
2
2
2
2
Range
0–30 g/Kg
XXXXXXXXXX
XXXXXXXX
XXXXXXXX
XXXXXXXX
XXXXXXXX
0–64
0–64
0–200A
0–200A
Password Level
2
2
2
2
2
2
2
2
2
2
60 OM 920-4
Sensor Offsets Menu
The Sensor Offsets Menu provides a means of calibrating the various temperature sensor inputs to the unit. Each sensor can be “biased” by as much as +/- 10.0°F.
Table 46: Sensor Offset Menu
Item Display Name
Disch Air=
Return Air=
SpaceTemp=
OA Temp=
ER LAT=
ER EAT=
Default Setting
0 .0°F
0 .0°F
0 .0°F
0 .0°F
0 .0°F
0 .0°F
Range
0 .0-10 .0°F
0 .0-10 .0°F
0 .0-10 .0°F
0 .0-10 .0°F
0 .0-10 .0°F
0 .0-10 .0°F
Menu Descriptions
Password Level
2
2
2
2
2
2
OM 920-4 61
Menu Descriptions
Unit Maintenance
Operating Hours
The Operating Hours menu gives a summary of the hours of operation for each of the supply fans, return/exhaust fans, compressors, heating and economizer operation.
Table 47: Operating Hours Menu
Item Display Name
Supply Fan=
Ret/Exh Fan=
Mech Cool=
Comp # 1=
Comp # 2=
Comp # 3=
Comp # 4=
Comp # 5=
Comp # 6=
Comp # 7=
Comp # 8=
Heating=
Economizer=
Tnt Override=
Dehumid=
ER Wheel=
Exh Out 1=
Exh Out 2=
Reheat=
Default Setting
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
Supply Fan
is a status item which gives the number of hours the supply fan has operated.
Return/Exhaust Fan
is a status item which gives the number of hours the return/exhaust fans have operated.
Mech Cool
is a status item which gives the number of hours that mechanical cooling has operated.
Comp #1
is a status item which gives the number of hours that compressor #1 has operated.
Comp #2
is a status item which gives the number of hours that compressor #2 has operated.
Comp #3
is a status item which gives the number of hours that compressor #3 has operated.
Comp #4
is a status item which gives the number of hours that compressor #4 has operated.
Comp #5
is a status item which gives the number of hours that compressor #5 has operated.
Comp #6
is a status item which gives the number of hours that compressor #6 has operated.
Comp #7
is a status item which gives the number of hours that compressor #7 has operated.
Comp #8
is a status item which gives the number of hours that compressor #8 has operated.
Range
0–50000H
0–50000H
0–50000H
0–50000H
0–50000H
0–50000H
0–50000H
0–50000H
0–50000H
0–50000H
0–50000H
0–50000H
0–50000H
0–50000H
0–50000H
0–50000H
0-50000h
0-50000h
0-50000h
Password Level
6
6
6
6
6
6
6
6
6
4
4
4
6
6
6
6
6
6
6
Heating
is a status item which gives the number of hours that the heating mode has operated.
Economizer
is a status item which gives the number of hours that the economizer has operated.
Tnt Override
is a status item which gives the number of hours that the unit has operated in the Tenant Override mode of operation.
Dehumid
is a status item which gives the number of hours that the dehumidification has operated.
ER Wheel
is a status item which gives the number of hours that the energy recovery wheel has operated.
Exh Out 1
is a status item which gives the number of hours the first stage exhaust fan has operated.
Exh Out 2
is a status item which gives the number of hours the second stage exhaust fan has operated.
Reheat
is a status item which gives the number of hours the
Reheat has operated
62 OM 920-4
Menu Descriptions
BMS Communications Menu
LON/BACnetIP/BACnetMSTP Setup Menu
See the Installation & Maintenance Manuals below for detailed instructions
• IM 916 MicroTech III Rooftop unit controller - BACnet
IP communications
• IM 917 MicroTech III Rooftop unit controller - BACnet
MSTP communications
• IM 918 MicroTech III Rooftop unit controller - BACnet
LON communications
Network Unit Set-up Menu
The Network Unit Set-up menu provides one location for the Set-up of items that can be controlled via a network BMS system.
Table 48: Network Unit Set-up Menu
Item Display Name
Space Sensor=
Ctrl Mode=
Occ Mode=
Clg Reset=
Htg Reset=
AplyMinOAChg=
Min OA Reset=
Default
Setting
Range
Digtl/Net
Unit Mode Settings
Off
Auto/Net
Off
Heat Only
Cool Only
Fan Only
Heat/Cool
Auto/Net
Occ
Unocc
TntOvrd
Auto/Net
Reset Options
None
Anlog/Net
Digtl/Net
None
None
No
None
None
Network
Space
Return
OAT
ExtmA
ExtV
Airflow
None
Network
Space
Return
OAT
ExtmA
ExtV
Airflow
No, Yes
None
Network
Ext VDC
Ext mA
IAQ VDC
IAQ mA
Password
Level
2
2
2
2
2
2
2
Item Display Name
Ctrl Temp Src=
AplyTstatChg=
UseTstatSpt=
Oc c Clg Spt=
Occ Htg Spt=
SAF Ctrl=
RFEF
Default
Setting
Range
Heat/Cool Changeover
RAT
No
No
72 .0°F
68 .0°F
RAT
Space
MAT
OAT
None
No
Yes
No
Yes
0 .0-100 .0°F
0 .0-100 .0°F
Fan Control Options
DSP
Spd/Net
DSP
BldgP
1ZnVAV
BPS
CO2
CFM
None
Tracking
BldgP
Spd/Net
OA Damper
Password
Level
2
2
2
2
2
2
2
OM 920-4 63
Menu Descriptions
Unit Configuration
Unit Configuration Setup Menu
After the main control board application software is loaded into the MCB, it must be “configured” for the specific control application. This consists of setting the value of 25 configuration variables within the MCB. These variables define things such as the type of cooling, number of compressors and cooling stages and the type of heat. If all of these items are not set appropriately for the specific unit, the unit will not function properly. The correct settings for these parameters are defined for a given unit by the unit “Software
Configuration Code.”
The “Software Configuration Code” consists of a
29-character string of numbers and letters. The code can be
Table 49:
Unit Configuration Menu
Configuration Code Position
Description
1
2
3
4
5
6
Unit Type
Control Type
Cooling Type
Compressorized Cooling
Configuration
Generic Condenser Stages
Low Ambient found on the Unit Software Identification Label located on the back side of the control panel door.
Table 49 lists the configuration code variables including the
position within the code, description of the parameter, and the applicable settings for each. The default values are shown in bold font. The unit is configured at the factory however may also be configured in the field by accessing the Unit
Configuration Menu. Once changes have been made to the
Unit Configuration Menu, the Apply Changes flag must be changed from no to yes in order for the controller to recognize the changes. Setting the Apply Changes flag to yes will automatically rest the controller.
Values (Default in Bold)
0=Applied Rooftop (RTU)
1=Self-Contained (SCU)
2=Commercial Rooftop (MPS)
3=Rebel Cool Only (DPS)
4=Rebel Heat Pump (DPH)
0=Zone Control
1=DAT Control
2=1ZoneVAV
0 = None
1=Standard Compressorized
Clg
2=Chilled Water
3=F&BP
4=Inverter Compressorized Clg
0=None
1=Generic Condenser
2=2Cmp/2Circ/3Stg
3=3Cmp/2Circ/4Stg
4=2Cmp/2Circ/2or6Stg (6 stg if
7=2,3,4or5)
5=3Cmp/3Circ/3Stg_NoWRV
6=3Cmp/3Circ/3Stg_WRV
7=4Cmp/2Circ/4Stg
8=4Cmp/4Circ/4Stg_NoWRV
9=4Cmp/4Circ/4Stg_WRV
A=6Cmp/2Circ/6Stg
B=6Cmp/6Circ/6Stg_NoWRV
C=6Cmp/6Circ/6Stg_WRV
D=3Cmp/2Circ/5Stg
E=4Cmp/2Circ/5or8Stg (8 stg if
7=2,3,4or5)
F=8Cmp/4Circ/8Stg
G=8Cmp/8Circ/8Stg
H=6Cmp/3Circ/6Stg
I=Not Used
J=Spare
K=Spare
L=1INV/1Circ
M=1INV/1STD/1Circ
1 – 8 Stages (default = 8)
0 = No
1 = Yes
Special Condition
This position is applicable only when Position 3=1 .
This position is applicable only when Position 4=1 .
This position currently has no effect on unit operation .
RTU MPS DPS DPH SCU
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
64 OM 920-4
Menu Descriptions
Table 49 continued: Unit Configuration Menu
Configuration Code Position
7
8
9
10
11
12, 13, 14
15
16
17
18
19
Description
Condenser Control
Damper Type
OA Flow Station
Heating Type
Max Heating Stages
Max Heat Rise
Supply Fan Type
Return Fan Type
Return/Exhaust Fan Capacity
Control Method
Second Duct Pressure Sensor
Entering Fan Temp Sensor
Values (Default in Bold)
0=Std Method 1
1=Std Method 2
2=Evap ABB
3=Evap MD2
4=Evap MD3
5=Evap DF
6=Not Used
7=EBM
8=INV
0=None
1=Single Position 30%
2=Single Position 100%
3=Economizer Airside
4=Economizer Waterside
5=100%OA_DOAS
6=AirEcon_DOAS
7=30%_DOAS
0=None
1=DF_015-030 (800)
2=DF_036-042 (802)
3=DF_045-075 (047)
4=DF_080-135 (077)
5=Generic Flow Station
6=Generic Flow Station w/CO
2
7=Ebtron MB
0=None
1=F&BP Control
2=Staged
3=Modulated Gas, 3-1
4=Modulated Gas 20-1
5=Steam or Hot Water
6=SCR Electric
7=MPSLoGas
8=MPSHiGas
1-8 Stages (default = 1)
Three Digits (default = 100)
0=Constant Volume
1=VFD/ABB
2=VFD/DF
3=VFD/MD2
4=VFD/MD3
5=VFD/MD6
6=EBMVAV
7=EBMCAV
0=CAV
1=RF_EF VFD/ABB
2=RF_EF VFD/DF
3=RF_EF VFD/MD2
4=RF_EF VFD/MD3
5=RF_EF VFD/MD6
6=PrpEx VFD/ABB
7=PrpEx VFD/DF
8=PrpEx VFD/MD2
9=PrpEx VFD/MD3
A=PrpEx VFD/MD6
B=None
C=1StageExh
D=2StageExh
E=3StageExh
F=EBMVAV
G=EBMCAV
Special Condition
This Position is applicable only when Position 1=0 or 2(RTU or MPS) .
Values 1 & 2 only apply if Postion 1 = 0 (RTU) or
Position 1=2 (MPS)
Value 4 only applies if Position 1 = 1 (SCU)
This position is only valid if
Position 1 = 0 or 2 (RTU or
MPS) and Position 8 = 3
Values 3 and 4 are valid selections only if
Position 1 = 0 (RTU)
Values 7 and 8 are valid selections only if
Position 1 = 2 (MPS)
This value is only valid if:
Position 10=2,3,4, 6, 7 or 8
This position valid only when
Position 1=0 (RTU) or Position
1 = 2 (MPS) .
0=None
1=Tracking
2=Building Pressure
3=Speed
4=OADamper
This position is valid only when Position 1 = 0 (RTU) or
Position 1 = 2 (MPS) .
A value of 1 is only valid if
Position 16=1 through 5 .
A value of 2 or 3 is only valid if
Position 16 = 1 through A .
0=No
1= Yes
0=No
1=Yes
RTU MPS DPS DPH SCU
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
OM 920-4 65
Menu Descriptions
Table 49 continued: Unit Configuration Menu
Configuration Code Position
Description
20
21
Energy Recovery
Cooling Circuit Type
Values (Default in Bold)
0=None
1=ConstSpdWhl/NoRH
2=VarSpdWhl/Danfoss
3=VarSpdWhl/MD2
4=VarSpdWhl/MD3
5=VarSpdWhl/ABB
6=ConstSpdWhl/wRH
0=Individual
1=2, 3 or 4 Circ . Water Condenser
2=2 Circ . Air Condenser
22
23
24, 25, 26
27
28
29
Head Pressure Control
Bypass Valve Control
Unit Size
Refrigerant Type
Reheat Type
Unit Voltage
0=No
1=Yes
0=Slave
1=Bypass
Three digits (default 050)
0=R22
1=R407C
2=R410A
0=None
1=StgHG
2=ModHG
3=StdHtRht
4=ModLSC
5=ModHG&LSC
0=208/60Hz
1=230/60Hz
2=460/60Hz
3=575/60Hz
4=208/50Hz
5=230/50Hz
6=460/50Hz
7=575/50Hz
Special Condition
This position is valid only when Position 1 = 0 (RTU) or
Position 1 = 2 (MPS) .
Values 0 and 1 are valid only when Position 1 = 1 (SCU)
This position is valid only when
Position 1 = 1 (SCU) .
This position is valid only when
Position 1 = 1 (SCU) .
RTU MPS DPS DPH SCU
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
Alarm Lists Menu
The Alarm Lists Menu is also available from the Service
Menu and is described on
66 OM 920-4
Menu Descriptions
Trending Menus
The Trending Menus allow for setting up and managing onboard trending of up to 30 data points within the controller. This data can then be exported to an SD card. The trending memory will begin over-writing the oldest existing data in the controller’s memory when the allocated trending memory fills up. If an SD card is installed in the controllers
SD card reader slot, an automatic export of the data will occur every night at midnight.
Table 50: Trending Menu
Item Display
Name
Trending Ena=
Apply Chgs=
Sample Time=
TrendOnOff=
Export Data=
Clear Trend=
Default Setting
No
No
300s
Off
No
Done
Range
No
Yes
No
Yes
1–3600s
Off
On
No
Yes
Done
ClrData
ClrCfg
Password
Level
2
2
2
2
2
2
Trending Ena
is an adjustable item which enables and disables the on board trending function.
Apply Changes
is an adjustable item which must be set to make changes to trending point definitions and sampling rate take effect.
Sample Time
is an adjustable item used to the sampling rate for trending data points.
TrendOnOff
is an adjustable item which starts and stops the on board trending function.
Export Data
is an adjustable item which initiates a manual export of the current on board trend data to an SD card.
Clear Trend
is an adjustable item used to either clear only the current trend data or the entire trend configuration.
Points 1-8 (Fixed)
The first 8 trending points are fixed and will automatically be trended when ever the trending function is activated.
Table 51: Points 1-8 (Fixed)
Item Display
Name
Point 1=
Point 2=
Point 3=
Point 4=
Point 5=
Point 6=
Point 7=
Point 8=
Default Setting
UnitSt
Clg%
Htg%
SAF%
OAD/Eco%
CtrlTmp
DAT
OAT
Range
UnitSt
Clg%
Htg%
SAF%
OAD/Eco%
CtrlTmp
DAT
OAT
Password
Level
2
2
2
2
2
2
2
2
Points 9-24 (From List)
Trending Points 9 through 16 can be selected from a primary list of available date points. Trending Points 17 through 24 can be selected from a secondary list of available date points.
See Appendix–page <?> for the primary and secondary listing of points.
Table 52: Points 9-4 (From List)
Item Display
Name
Point 9=
Point 10=
Point 11=
Point 12=
Point 13=
Point 14=
Point 15=
Point 16=
Point 17=
Point 18=
Point 19=
Point 20=
Point 21=
Point 22=
Point 23=
Point 24=
Default Setting
None
None
None
None
None
None
None
None
None
None
None
None
None
None
None
None
Range
Primary List
Primary List
Primary List
Primary List
Primary List
Primary List
Primary List
Primary List
Secondary List
Secondary List
Secondary List
Secondary List
Secondary List
Secondary List
Secondary List
Secondary List
Password
Level
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
OM 920-4 67
Menu Descriptions
Points 25-27 (With IDs)
Trending Points 25 through 27 can be freely selected all the available points and point members that exist within the controller. In this case the user must know and enter the point
ID number, point Type number and point Member number.
Factory assistance will generally be necessary to indentify this information for a specific point.
Table 53: Points 25-27 (With IDs)
Item Display
Name
ID=
Type=
Mem Num=
ID=
Type=
Mem Num=
ID=
Type=
Mem Num=
Default Setting
Point 25
F0AF0000
0000
0100
Point 26
F0AF0000
0000
0100
Point 27
F0AF0000
0000
0100
Range
00000000–
FFFFFFFF
0000–FFFF
0000–FFFF
00000000–
FFFFFFFF
0000–FFFF
0000–FFFF
00000000–
FFFFFFFF
0000–FFFF
0000–FFFF
Password
Level
2
2
2
2
2
2
2
2
2
Points 28-30 (With IDs)
Trending Points 28 through 30 can be freely selected all the available points and point members that exist within the controller. In this case the user must know and enter the point
ID number, point Type number and point Member number.
Factory assistance will generally be necessary to indentify this information for a specific point.
Table 54: Points 28-30 (With IDs)
Item Display
Name
ID=
Type=
Mem Num=
ID=
Type=
Mem Num=
ID=
Type=
Mem Num=
Default Setting
Point 28
F0AF0000
0000
0100
Point 29
F0AF0000
0000
0100
Point 30
F0AF0000
0000
0100
Range
00000000–
FFFFFFFF
0000–FFFF
0000–FFFF
00000000–
FFFFFFFF
0000–FFFF
0000–FFFF
00000000–
FFFFFFFF
0000–FFFF
0000–FFFF
Password
Level
2
2
2
2
2
2
2
2
2
68 OM 920-4
Trending Selection Lists
Table 55: Primary Trending Select List
HMI Name
Bldg Press=
Clg State=
Clg Status=
Clg Press Lmtg=
Cmp Ratio Lmtg=
DAT Clg Spt=
Dehum Status=
DFT=
Ref DLT Lmtg=
DRT1=
DRT3=
Duct Press=
Econo Status=
EF/LC Temp=
ER EAT=
ER LAT=
EVI Pos=
EVO Pos=
EW Temp=
Htg Press Lmtg=
INV Brd Lmtg=
INV Cmp Spd=
Mixed Air=
Min OA Pos=
Occ Clg Spt=
OccSrc=
PTD=
PTS=
Return Air=
Reheat Cap=
RF/EF Cap=
Subcooling=
Space Temp=
SRT=
Superheat=
STD3=
Sump Temp=
UnoccSrc=
Unit Status =
Not all listed points may be available depending on the specific unit configuration
Select Abbreviation
BSP
ClgSt
ClgSts
ClPLmtg
CpRLmtg
DAClgSp
DeHmSts
DFT
DLLmtg
DRT1
DRT3
DSP
EcoSts
EFT/LCT
EREAT
ERLAT
EVI%
EVO%
EWT
HtPLmtg
IBLmtg
INV%
MAT
MinOA%
OcClgSp
OcSrc
PTD
PTS
RAT
ReHt%
RFEF%
SbClg
SpaceT
SRT
SSH
STD3
SumpT
UnOcSrc
UntSts
2203
2203
2203
230B
230B
2203
2203
2203
2203
230A
230B
2203
2203
2203
Type
2203
230B
230B
230B
230B
2300
230B
2203
230B
2203
230A
2203
2203
230A
2207
2203
230B
230B
230A
2300
230B
2203
2203
2203
230A
Menu Descriptions
ID
F0AFC4BB
F0AF3991
F0AFF6A6
F0AF3B4E
F0AF7BA2
F0AF64FD
F0AF56EA
F0AFCA19
F0AFB273
F0AFD8D7
F0AFF895
F0AF143C
F0AFC1AB
F0AF356B
F0AF0DBB
F0AFFD44
F0AF3028
F0AF17B1
F0AFCD6B
F0AF3FE7
F0AFBAB2
F0AFDA3E
F0AFCD1F
F0AFEEC9
F0AFF8A8
F0AFF838
F0AF229A
F0AF404C
F0AFA24D
F0AF00F8
F0AFAECF
F0AF842E
F0AFF74A
F0AFC35D
F0AFB846
F0AF03CC
F0AF503D
F0AFF6B4
F0AF4FF0
OM 920-4 69
Menu Descriptions
Table 56: Secondary Trending Select List
HMI Name
Alarm Enumeration
IAQ PPM=
Cmp Ratio Lmtg=
DAT Htg Spt=
Dewpoint=
Dewpoint Spt=
Defrost State=
Ref DLT Lmtg=
EF/LC Temp=
Wheel Speed=
EVI Pos=
EVO Pos=
EW Temp=
Head P Circ 1=
Head P Circ 2=
Htg State=
Htg Status=
Htg Press Lmtg=
INV Brd Lmtg=
INV Cmp Spd=
Mixed Air=
OA Flow=
MinOAFlw Spt=
Occ Htg Spt=
PTD=
PTS=
Return Air=
Rem ExhF Cap=
Rem RAF Cap=
Rem SAF Cap=
Rel Humidity=
RH Setpoint=
Reheat Spt=
Subcooling=
Space Temp=
SuplHtgStatus=
Superheat=
Supl Htg Cap=
STD3=
Not all listed points may be available depending on the specific unit configuration.
Select Abbreviation
Alm
CO2
CpRLmtg
DAHtgSp
Dewpt
DewptSp
DFSt
DLLmtg
EFT/LCT
ERWhl%
EVI%
EVO%
EWT
HdPr1
HdPr2
HtgSt
HtgSts
HtPLmtg
IBLmtg
INV%
MAT
OAFlw
OAFlwSp
OcHtgSp
PTD
PTS
RAT
RemEF%
RemRF%
RemSF%
RH
RHSp
RhtSp
SbClg
SpaceT
SpHtSts
SSH
SupHt%
STD3
230B
230B
230B
2203
2203
230A
2300
2203
2203
2203
2203
2203
2203
230B
Type
230A
2203
230B
2300
230A
2300
230B
230B
2203
2203
2300
230A
230A
2203
230B
230A
230A
2207
2300
2203
2203
2203
2300
2300
2300
ID
F0AFCF76
F0AF7F77
F0AF7BA2
F0AF6054
F0AF532C
F0AF75C1
F0AFBD68
F0AFB273
F0AF356B
F0AF101D
F0AF3028
F0AF17B1
F0AFCD6B
F0AFD3C4
F0AFE3A7
F0AF4BE8
F0AFD173
F0AF3FE7
F0AFBAB2
F0AFDA3E
F0AFCD1F
F0AFF10A
F0AF6B95
F0AF8A33
F0AF229A
F0AF404C
F0AFA24D
F0AF1969
F0AF57A7
F0AF211F
F0AF1DDC
F0AFFA18
F0AF335D
F0AF842E
F0AFF74A
F0AF7D21
F0AFB846
F0AF1FEA
F0AF03CC
70 OM 920-4
Alarms
Alarms
About this Unit
Table 57: About this Unit Menu
Menu Display Name
About this Unit
Item Display Name
SO_Item=
Unit SN=
App Version=
Cf1-15=
Cf16-29=
Main BSP=
LON BSP=
LON App Ver=
BACnet BSP=
D-Net BSP=
HMI GIUD=
OBH GIUD=
SO_Item
is an adjustable item which can be used to store the sales order number of the unit for reference purposes.
Unit SN
is an adjustable item which can be used to store the serial number of the unit for reference purposes.
App Version
is the version of application code loaded into the controller
Cf1-15
describe positions 1-15 of the unit configuration string
Cf16-29
describe positions 16-29 of the unit configuration string
Main BSP
is the current version of firmware in the main controller
LON BSP
is a status only item which indicates the current version of firmware in the LON communication module connected to the main controller.
LON App Ver
is a status only item which indicates the current version of application code in the LON communication module connected to the main controller.
BACnet BSP
is a status only item which indicates the current version of firmware in the BACnet communication module connected to the main controller.
D-Net BSP
is a status only item which indicates the current version of firmware in the D-Net communication module connected to the main controller.
HMI GUID
is the HMI software identifier number unique to each application code version
OBH GUID
is the OBH software identifier number unique to each application code version
Alarms
Alarms provide the user with information about abnormal conditions that affect unit operation. The cause of the alarm should be investigated and eliminated before the unit or any disabled equipment in it is placed back into service.
Faults
are conditions that are serious enough to shut down the unit. The alarm must be manually cleared to allow unit operation.
Problems
are conditions that result in some limitation of unit operation, but the unit is allowed to continue to operate. Some of these alarms must be cleared manually, but others clear automatically.
Warnings
inform the user of conditions that should be addressed, but do not limit operation in any way. The alarm condition needs to be fixed and the alarm must be manually cleared to cause this alarm to no longer be active.
All active alarms as well as the date and time that they were detected are displayed on the Active Alarm menu. These alarms are displayed in order of priority. Higher priority alarms are displayed first. The last fifty alarm “events” detected as well as the date and times that they were detected are displayed on the Alarm Log menu. An alarm “event” is either an alarm becoming active or being cleared. A “+” symbol precedes the active alarm event and a “-” symbol precedes the cleared alarm event. These alarms are displayed in the order that they were detected. The alarm that was detected most recently is displayed first. Multiple occurrences of the same alarm may appear.
Alarm Clearing
Active alarms can be cleared through the keypad/display or a
BAS network. Alarms are automatically cleared when power is cycled. Alarms are cleared only if the conditions required to initiate the alarm do not exist. All alarms and groups of alarms can be cleared via the network or keypad by setting the ClearAlms variable to a non-zero value as indicated in the table below. Emergency Off Faults can be set to automatically clear once the condition that caused the alarm is corrected.
This can be accomplished by navigating to Commission Unit/
Alarm Configuration/Emerg Stop and changing the default
ManClr value to AutoClr.
NOTE:
The enumeration text is what shows up on the keypad/display not the number . The value of this variable automatically reverts to zero when the alarms are cleared . This variable may be set through the keypad in the Active Alarm menu . It may be set via LON using nviClearAlarms and via BACnet using the ClearAlarms object .
Table 58: Alarm Clearing
Value
0
1
2
3
4
Action
None
Clear All Faults
Clear All Problems
Clear All Warnings
Clear All Alarms
OM 920-4 71
Alarms
Alarms
Warnings
Dirty Filter - (Dirty Filter: Warning)
If the pressure drop across the filter section in the unit exceeds the setting of the differential pressure switch the
Dirty Filter warning occurs. When the Dirty Filter warning occurs, unit operation is not affected. The Dirty Filter warning must be manually cleared through the unit keypad or via a network signal.
Airflow Switch - (Airflow Sw: Warning)
If the unit has been in the Off operating state for at least thirty minutes and the PC7 airflow switch input to the main controller indicates airflow, the Airflow Switch warning occurs. This normally indicates a problem with the PC7 airflow switch. When the Airflow Switch warning occurs, unit operation is not affected. When the alarm condition is corrected, the Airflow Switch warning must be manually cleared through the unit keypad or via a network signal.
Conductivity - (Conductivity: Warning)
If the unit is equipped with a Dolphin system and the
Conductivity value rises above the alarm setpoint value, the conductivity alarm occurs. When the alarm condition is corrected, the conductivity warning must be manually cleared through the unit keypad or via a network signal.
Return/Exh Fan Warning
When the unit is equipped with a Return/Exhaust fan VFD or
ECM motor and a loss of Modbus communications for longer than 10 seconds a Return/Exhaust fan warning alarm occurs.
The alarm is automatically clears when the condition causing the alarm is corrected.
Problems
No Water Flow Problem - (Water Flw Sw: Problem) (Self
Contained only)
When a unit is equipped with a water flow switch WFS, the
No Water Flow problem occurs when lack of water flow is indicated by an open water flow switch or a network signal and all of the following conditions are true:
• Lack of water flow is indicated by an open water flow switch or a Network signal
• Either of the following is true:
• The Bypass Valve has been opened greater than 50% for more than the Bypass Valve Timer
• A water side economizer is installed and its position is greater than 50%
• Unit is not in the Off, Start or Recirc operating state
When the No Water Flow problem occurs, the unit continues to operate however cooling provided by compressors disabled.
When all of the alarm condition are no longer present, the
No Water Flow problem normally clears automatically and normal unit operation resumes. If the alarm occurs three times between 2:00 am of one day and 2:00 am of the next day, it becomes necessary to manually clear the alarm.
Water Regulating Valve Problem - (Water RegVlv:
Problem) (Self Contained only)
When a unit is equipped with the head pressure control option, the Water Regulating Valve Problem occurs when the greater of the two refrigerant pressure readings drops below the head pressure setpoint by more than the deadband while at least one compressor is operating and the entering water temperature is less than 58°F. These conditions have to be true for more than 5 minutes for the alarm to become active. When the Water Regulating Valve problem occurs, the unit continues to operate but mechanical cooling is disabled.
Mechanical cooling remains disabled until the Water
Regulating Valve problem is manually cleared through the unit keypad or via a network signal.
Low Pressure - Circuit 1, 2, 3,4,5,6 - (Lo Press 1,2,3,4,5,6:
Problem)
When a unit is equipped with individual cooling circuits, the
Low Pressure Circuit 1 problem occurs when the compressor on circuit #1 has been running longer than the low pressure alarm delay (65 seconds factory default for R22 or 407C application, 5 seconds for 410A) and the low pressure switch
LP1 remains open. The alarm also occurs any time afterward if the low pressure switch opens up while the compressor on the circuit is running. Note: The Low Pressure Circuit 2, 3, 4,
5, & 6 problems occur in the same manner for cooling circuits
2, 3,4,5,6. Compressor #1 (2, 3, 4, 5 or 6) remains disabled for at least one cooling stage time period. After the cooling stage time period expires, the alarm automatically clears and the circuit is re-enabled. If the alarm occurs three times between
2:00 a.m. of one day and 2:00 a.m. of the next, the alarm does not automatically clear the third time but must be manually cleared through the unit keypad or via a network signal.
High Pressure - Circuit 1, 2, 3, 4, 5, 6 - (Hi Press
1,2,3,4,5,6: Problem)
This alarm occurs on units equipped with compressorized cooling only. If the high pressure switch opens indicating a high refrigerant pressure situation, the High Pressure Circuit
1, 2, 3,4,5,6 problems occurs.
When the High Pressure Circuit 1, 2, 3,4,5,6 problem occurs, the unit continues to operate but the cooling circuit is disabled. Note: The Circuit remains disabled until the high pressure switch closes and the High Pressure Circuit problem is manually cleared through the unit keypad or via a network signal.
72 OM 920-4
Alarms
Sump Water Level Problem
Unit state has been cooling for the Sump Water Level Delay time and the Sump Water Level input remains in the open position
Entering Fan Temperature/Leaving Coil Temperature
Sensor Problem (EFT/LCT Snsr: Problem)
This alarm occurs when the Entering Fan Temperature/
Leaving Coil Temperature sensor is present and either shorted or open circuited for longer than the Sensor Alarm Delay
(Default = 30 seconds). When this alarm occurs the unit continues to operate however dehumidification operation is disabled until the sensor becomes reliable. The maximum
DAT limit function associated with gas or electric heat is also disabled until the sensor becomes reliable.
Return Air Temperature Sensor Problem - (RAT Sensor:
Problem)
If the return air temperature sensor (RAT) is present and either shorted or open circuited for longer than the Sensor
Alarm Delay (default is 30 seconds), the Return Air Sensor problem occurs. When the RAT Sensor problem occurs, the unit continues to operate with the following modifications:
• Cooling Reset and Heating Reset revert to none if they are set to Return
• Control temperature source reverts from return to space if a space temperature sensor is present and reliable
When the alarm condition is no longer present, the RAT
Sensor problem automatically clears.
Space Temperature Sensor Problem - (Space Sensor:
Problem)
If the Space Sensor Present setting is set to Yes, a valid Space
Temperature value is not provided via a network signal and the local space sensor is shorted or open circuited longer than the Sensor Alarm Delay (default is 30 seconds), the
Space Temperature Sensor problem occurs. When the Space
Temperature Sensor problem occurs, the unit continues to operate with the following modifications:
• Cooling Reset and Heating Reset revert to none they are set to Space
• Control temperature source reverts from space to return if a return air sensor is present and reliable.
When the alarm condition is no longer present, the Space
Temperature Sensor problem automatically clears.
OAT Temperature Sensor Problem -(OAT Sensor:
Problem)
If the outside air temperature sensor (OAT) is present, a valid
OAT value is not provided via the network and the local OAT sensor is either shorted or open circuited for longer than the Sensor Alarm Delay (default is 30 seconds), the Outside
Air Sensor problem occurs. When the OAT Sensor problem occurs, the unit continues to operate with the following modifications:
• Heating is not locked out due to high OAT
• Cooling is not locked out due to low OAT
• Cooling Reset and Heating Reset revert to none if they are set to OAT
• Economizer is locked out due to high OAT
When the alarm condition is no longer present, the OAT
Sensor problem automatically clears.
Entering Water Temperature Sensor Problem - (EWT
Sensor: Problem)
If the entering water temperature sensor (EWT) is present and either shorted or open circuited for longer than the Sensor
Alarm Delay (default is 30 seconds), the EWT Sensor problem occurs. When the EWT Sensor problem occurs, waterside economizer cooling is disabled. Mechanical cooling is not locked out based on EWT. When the alarm condition is no longer present, the EWT Sensor problem automatically clears.
Mixed Air Temperature Sensor Problem - (MAT Sensor:
Problem)
If the Mixed Air Temperature (MAT) sensor is present and either shorted or open-circuited for longer than the sensor alarm delay (default is 30 seconds), the MAT sensor problem occurs. When the MAT sensor problem occurs, waterside economizer cooling is disabled. When the alarm condition is no longer present, the MAT sensor problem automatically clears.
OM 920-4 73
Alarms
Freeze Problem - (Freeze: Problem)
When a unit is equipped with a waterside economizer, chilled water, hot water, or steam coil, the Freeze problem occurs when the optional freezestat contacts open as a result of detecting an abnormally low water or steam coil temperature while the fans are off.
When the Freeze problem occurs, the controller opens the waterside economizer valve, chilled water and heating valves, and sets a 10-minute timer. If the unit is equipped with a waterside economizer, the pump output is also turned on.
When the 10-minute timer expires, the controller checks the freezestat input again. If the freezestat contacts are closed the pump output is de-energized and the valves close. If the freezestat contacts are still open the pump output remains energized, the valves remain open, and the 10-minute timer resets. This continues while the unit remains off. Whenever the freezestat closes the Freeze problem automatically clears.
This feature protects the coil(s) and allows the system to start normally when an occupied command is received.
Heat Fail Problem - (Heat Fail: Problem)
If an RPS unit is equipped with a Daikin gas furnace and the burner flame safeguard (FSG) control enters the “safety lockout” state after a call for heat, a digital input is provided to EXP B-X4 on the controller. When this digital input is present the Heat Fail problem occurs. When the Heat Fail problem occurs, the unit continues to operate with the heating system disabled by the FSG. Heating remains disabled until the flame safeguard control is manually reset. The heat fail problem clears automatically when the FSG control is reset.
Faults
Airflow Fault - (Airflow: Fault)
If differential pressure switch PC7 fails to detect airflow for longer than the airflow timer (default = 120 seconds) and on
VAV units the current duct static pressure indication is less than half the static pressure setpoint after the unit leaves the
Startup operating state or any time afterward, while the unit is running, the Fan Fail fault occurs. When the Fan Fail fault occurs, the unit is shut down. It remains shut down until the
Fan Fail fault is manually cleared through the unit keypad or via a network signal. On units equipped with a discharge fan VFD, the Fan Fail fault only occurs if the Fan Retry condition described above has first occurred twice within the previous twenty-four hour period. The conditions that cause the Fan Retry and the action taken are the same as for the
Fan Fail fault with the difference being that the Fan Retry is automatically reset once the unit is shut off. This allows the unit to attempt to restart up to three times within a twentyfour hour period.
NOTE:
There is no Fan Retry function or three retry function when a unit has a CAV supply fan .
If Modbus communication is lost between the MCB and the supply fan VFD the duct static pressure is not considered in the Fan Fail logic .
Low Discharge Air Temperature - (Lo Disch Temp: Fault)
If the unit is not in the operating state and the discharge air temperature is less than the Low Discharge Temperature
Limit (Default = 40°F) for longer than 30 seconds and the supply fan has been on for longer than the LowDAT temperature alarm delay (Default = 6 minutes), the Low
Discharge Air Temperature fault occurs. When the Low
Discharge Air Temperature fault occurs, the unit is shut down. It remains shut down until the Low Discharge Air
Temperature fault is manually cleared through the unit keypad or via a network signal.
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Alarms
High Discharge Air Temperature - (Hi Disch Temp: Fault)
If the discharge air temperature is greater than the High
Discharge Temperature Limit (Default = 170°F) and the supply fan has been on for longer than the Temperature
Alarm Delay (Default = 30 seconds), the High Discharge
Air Temperature fault occurs. When the High Discharge Air
Temperature fault occurs, the unit is shut down. It remains shut down until the High Discharge Air Temperature fault is manually cleared through the unit keypad or via a network signal.
High Return Air Temperature - (Hi Return Tmp: Fault)
If the return air temperature is greater than the Return Air
Temperature Limit (Default = 120°F) and the supply fan has been on for longer than the temperature alarm delay (Default
= 30 seconds), the High Return Air Temperature fault occurs.
When the High Return Air Temperature fault occurs, the unit is shut down. It remains shut down until the High Return
Air Temperature fault is manually cleared through the unit keypad or via a network signal.
Duct High Limit Fault - (Duct Hi Limit: Fault)
If the unit is variable air volume, the contacts of the duct high pressure limit control (DHL) open, and the unit state is not Off or Startup, the Duct High Limit fault occurs. When the Duct High Limit fault occurs, the unit is shut down. The unit remains shut down until the Duct High Limit fault is manually cleared through the unit keypad or via a network signal.
Discharge Air Sensor Fault -(Disch Tmp: Fault)
If the discharge air temperature sensor (DAT) is open or short circuited for longer than the Sensor Alarm Delay
(Default= 30 seconds), the Discharge Air Sensor fault occurs.
When the Discharge Air Sensor fault occurs, the unit is shut down. It remains shut down until the Discharge Air Sensor fault is manually cleared through the unit keypad or via a networksignal.
Control Temperature Fault - (Control Temp: Fault)
If the temperature sensor (ZNT1, RAT, OAT, MAT) selected as the control temperature source is not reliable for longer than the Sensor Alarm Delay (Default= 30 seconds), a Control
Temperature Fault occurs. When the Control Temperature
Fault occurs, the unit is shut down. It remains shut down until the Control Temperature Fault is manually cleared through the unit keypad or via a network signal.
Emergency Stop Fault - (Emerg Stop: Fault)
An Emergency Stop Fault will occur if either of the following conditions is true:
• Emergency Stop Input in the Alarm (Open) condition
• The Net Emrg Ovrd input is set to Off via a network signal or the keypad/display
Freeze Fault - (Freeze: Fault)
When a unit is equipped with a waterside economizer, chilled water, hot water, or steam coil, the Freeze Fault occurs when the optional freezestat contacts open as a result of detecting an abnormally low water or steam coil temperature while the fans are running.
When the Freeze fault occurs, the controller shuts down the fans, opens the chilled water, economizer, and heating valves and set a 10-minute timer. If the unit is equipped with a waterside economizer, the pump output is also turned on.
When the 10-minute timer expires, the controller checks the freezestat input again. If the freezestat contacts are closed the pump output is de-energized and the valves close. If the freezestat contacts are still open the pump output remains energized, the valves remain open, and the 10-minute timer resets. This continues until the fault is manually cleared through the keypad or via a network signal.
NOTE:
Water valves remain open and Pump output remains on for 10 minutes after alarmconditions disappear .
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Operator’s Guide
Operator’s Guide
The following “Operator’s Guide” sections provide information regarding the day-to-day operation of the
MicroTech III Unit Controller. Topics covered are such common tasks as scheduling, displaying and clearing alarms, and setting the controller for manual operation.
Figure 11: State Diagram
The transition from any operating state to another is graphically represented in this figure. With a “start up” command from an Off State the unit will always go into the
“Start Up” state of operation for 3 minutes (adjustable). Next, it will transition into the “Recirculation” state of operation for another 3 minutes (adjustable) before finally going into the Fan Only state of operation. Then, based on sensor inputs it will go into any of the 4 remaining states of operation - heating, cooling, economizer, or minimum discharge air heating.
Determining Unit State
The unit will operate in one of eight operating states. The current state will be displayed by the Unit State parameter in the system summary menu.
In the off state, all heating, cooling, and fans are off. The alarm output indicates the type of alarm, if any, that is active.
In the start up state, the Fan Operation output is turned on to allow shut off dampers to be opened before any the supply fan is turned on. The outdoor air dampers remain closed.
The supply fan is turned on when the unit enters the
Recirculation state. The supply fan in VAV units is controlled as described in the Supply Fan Capacity Control section, page
110. The outdoor dampers remain closed.
A separate morning warm-up state is not provided, but an edited ZeroOATime is used to keep the outside air damper closed when the unit first starts. The Minimum OA Position is set to zero as long as the as the fan has been on for less than the ZeroOATime.
DAT Control units have a MWU setpoint available.
The Minimum OA Position is set to zero as long as the as the fan has been on for less than the ZeroOATime. This allows the Return Air type units to cool down the space with mechanical cooling or to warm up the space with the dampers closed. If the ZeroOATime is set correctly, the OA dampers will be open only during occupied periods. When
Optimum Start is used Zero OA Time is set equal to the time to occupancy when the unit starts so that the OA dampers will open at occupancy time.
Neither heating nor cooling is provided when the unit is in the fan only state, with the exception of when dehumidification is active. The outdoor dampers are opened to the minimum position in this state when the fan on time exceeds the Zero
OA Time.
In the other four states, temperature is controlled as describe in the appropriate sections of this document. These states are Minimum DAT, Heating, Economizer, and Cooling. The outdoor dampers are opened to at least the minimum position in these states when the fan on time exceeds the Zero OA
Time.
Off Operating State
In the Off operating state the fans are off, the outside air dampers are closed and any VFD’s are driven to 0%. Cooling and heating are disabled. The unit is in the off state when it is not enabled, or when it is in the unoccupied mode with no call for unoccupied operation. refer to “Determining Unit Status” on page 70 for reasons the unit can be disabled.
Start Up Operating State
When a unit is commanded to start it will always enter the
Startup operating state from the Off operating state. The unit remains in the Startup operating state for an adjustable time period (default 180 seconds) before entering the Recirculating operating state.
During the Start up operating state the fans remain off, the outdoor air dampers are driven closed, and VFD’s remain at
0%. Cooling and heating are disabled, except for 100% OA heating start sequences.
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Recirculating Operating State
Units with return air always enter the Recirculating operating state after the completion of the Startup operating state. In the Recirculating operating state fans are started and operate while the outdoor air dampers remain closed.
This allows temperature conditions throughout the unit and space to equalize before temperature control begins.
Cooling and heating remain disabled. The unit remains in the
Recirculating operating state until the Recirculate State Timer
(default 180 seconds) expires.
NOTE:
100% outdoor air units do not transition through the
Recirculating operating state .
Fan Only
The unit enters the Fan Only operating state after the recirculation timer expires. Units configured for 100% outside air operation will transition directly from the Start up operating state into the Fan Only operating state. Once entering the Fan Only state of operation the unit will then, based on sensor inputs transition into any of the 4 remaining states of operation - heating, cooling, economizer, or minimum discharge air heating.
Min DAT
If heating is enabled and there is no heating load (normally
FanOnly operating state), the controller activates the units heating equipment as required to prevent the discharge air temperature from becoming too cool if the Min DAT
Control Flag is set to yes via the Heating menu (Commission
Unit/Heating/MinDAT Ctrl). The unit enters the Min DAT operating state during occupied operation when neither cooling nor heating is required based on the heat/cool changeover function but the discharge temperature falls below a minimum discharge temperature limit. If the discharge air temperature falls below the this minimum discharge temperature limit by more than half the discharge heating deadband, the unit operating state changes from Fan Only to
Min DAT. The unit transitions out of the Min DAT operating state once the discharge air temperature is above minimum discharge temperature limit and the heating capacity has been at its minimum position for the duration of the heating stage timer.
NOTE:
On VAV or CAV discharge control units, the DAT cooling setpoint parameter in the Cooling menu acts as the minimum discharge temperature limit . On CAV zone control units the Min DAT Limit parameter in the Heating menu acts as the minimum discharge temperature limit .
Heating
Operator’s Guide
The unit enters the Heating operating state when the control temperature falls below the Occupied or Unoccupied Heating
Setpoint by more than ½ the occupied or unoccupied heating deadband. During the Heating operating state, the outdoor air dampers are either 100% open if the unit is a 100% outdoor air unit or controlled to the minimum outside air position.
Cooling is disabled.
Economizer
If the unit is equipped with a 0-100% modulating economizer
(waterside or airside) and the conditions are suitable for free cooling, the unit attempts to satisfy the cooling load by using either outdoor air or the waterside economizer before using mechanical cooling.
If the unit is configured for Zone Temperature Control the transition to economizer operation will occur if all the following are true:
• The control temperature rises above the occupied or unoccupied cooling setpoint by more that ½ the occupied or unoccupied cooling high deadband
• The discharge air temperature is greater than the Min
DAT limit by more than ½ the DAT
• heating deadband. This will prevent more cold air from being brought in when the DAT is already cold
• The economizer operation is not disabled
• If the unit is configured for Discharge Air Temperature
Control the transition to Mechanical cooling will occur if all the following are true:
• The control temperature rises above the occupied or unoccupied cooling setpoint by more that ½ the occupied or unoccupied cooling deadband
• The discharge air temperature is greater than the DAT cooling setpoint
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Mechanical Cooling
The unit enters the mechanical cooling operating state when cooling is required and the economizer is disabled, not present, or already fully open.
If the unit is configured for Zone Temperature Control the transition to Mechanical cooling will occur if all the following are true:
• The control temperature rises above the occupied or unoccupied cooling setpoint by more that ½ the occupied or unoccupied cooling deadband
• The discharge air temperature is greater than the Min
DAT limit by more than ½ the DAT heating deadband.
This will prevent more cold air from being brought in when the DAT is already cold
• The economizer operation is disabled or not present
• Mechanical cooling is enabled
• If the unit is configured for Discharge Air Temperature
Control the transition to Mechanical cooling will occur if all the following are true:
• The control temperature rises above the occupied or unoccupied cooling setpoint by more that ½ the occupied or unoccupied cooling deadband
• The discharge air temperature is greater than the DAT cooling setpoint by more than ½ the DAT cooling deadband
• Post heat operation is complete
• Economizer operation is disabled
• Mechanical cooling is enabled
Determining Unit Status
Unit Status is a status only item which indicates whether or not the unit is enabled and if not why.
Enabled
Unit operation has not been disabled for any of the following reasons.
Off Manual
The unit operating state is off and the unit status is OffMan when the control mode is set to off via the keypad. The control mode can only be changed via the System menu on the keypad/display.
OffManCtrl
The unit operating state is off and the unit status is
OffManCtl when the controller is set to manual control via the Manual Control menu.
Off Network
The unit operating state is off and the unit status is Off Net when the control mode is set to Auto via the System menu and the network Net App Mode is set to off.
Off Alarm
The unit operating state is off and the unit status is OffAlm when an active alarm of the “fault” type has the unit shutdown.
Off Fan Retry
The unit operating state is off and the unit status is OffFnRty when The fan retry conditions below indicate that the unit should be shutdown and restarted after airflow is lost.
• The supply fan is controlled by a VFD
• The airflow switch (PC7) is open AND the duct static pressure is less than ½ the duct static pressure setpoint
• There are no active faults that would shut down the unit
Determining Control Mode
The unit cooling and heating can be set up for automatic heat/ cool, cool only, heat only, fan only, or network cool/heat operation by setting the Control Mode. The unit can also be manually disabled via the Control Mode. The following are descriptions of the six available Control Mode selections.
Off
When the Control Mode is set to “Off,” the Unit Status is
“Off Man” and the unit is completely disabled.
Heat Only
When the Control Mode is set to “Heat Only,” heating operation is allowed to operate to maintain the heating set points. Cooling operation is disabled (Cooing Status is “Off
Man”).
Cool Only
When the Control Mode is set to “Cool Only,” cooling operation is allowed to operate to maintain the cooling set points. Heating operation is disabled (Heating Status is “Off
Man”).
Fan Only
When the Control Mode is set to “Fan Only,” the fans are allowed to operate but cooling and heating operation is disabled (Cooling Status and Heating Status are “Off Man”).
Heat Cool
When the Control Mode is set to “Heat/Cool,” both cooling and heating operation are allowed to operate as required to maintain the cooling and heating set points.
Auto
When the Control Mode is set to “Auto,” the heat/cool, cool only, heat only, and fan only decision is determined by the network application mode parameter, which is set via a network signal as described below. The NetApp Mode parameter has no effect on unit operation unless the Control
Mode is set to “Auto.”
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Determining Cooling Status
Clg Status is a status item which indicates whether or not mechanical cooling is currently allowed. If cooling is disabled, the reason is indicated.
The following are descriptions of cooling status states.
Enabled
Mechanical cooling is enabled if all the following are true:
• Cooling capability is provided
• Control mode is not set via the keypad to fan only or heat only
• Control mode is set via the keypad to auto and not disabled via a network command
• The outdoor air temperature (OAT) on air cooled units or the entering water temperature (EWT) on water cooled units is high enough for operation
• Compressor operation is not disabled by an alarm condition
None
Cooling capability is not provided.
Off Ambient
The outdoor air temperature (OAT) on air cooled units or the entering water temperature (EWT) on water cooled units is too low for operation.
The OAT becomes too low for operation when it drops below the OAT cooling lockout setting. OAT becomes high enough for operation when it rises above the OAT cooling lockout setting by more than 2°F (adjustable - OAT Diff). The EWT becomes too low for operation when it drops below the minimum EWT set point. EWT becomes high enough for operation when it rises above the minimum EWT set point by more than 2°F (adjustable - Econo Diff).
NOTE:
The OAT cooling lockout cannot be set lower than
40°F when the unit is equipped with an evaporative condenser and should not be set lower than 50°F unless the unit is equipped with low ambient capability .
Off Alarm
Compressor operation is disabled by an alarm condition. This happens when either all circuits are disabled by either a high or low pressure alarm, when applicable the water flow switch alarm is active, when applicable sump pump fail alarm is active or applicable water regulating valve alarm is active.
Off Network
Control mode is set via the keypad to auto and cooling is disabled via a network command.
Off Manual
Control mode is set to Fan Only or Heat Only via the keypad display.
Determining Heat Status
Htg Status is a status item which indicates whether or not heating is currently allowed. If heating is disabled, the reason is indicated.
The following are descriptions of heating status states:
Enabled
Heating is enabled if all the following are true:
• Heating capability is provided
• Control mode is not set via the keypad to fan only or cool only
• Control mode is set via the keypad to auto and not disabled via a network command
• The outdoor air temperature (OAT) is low enough for operation
None
Heating capability is not provided.
Off Ambient
The OAT is too high for operation. The OAT becomes too high for operation when the OAT rises above the OAT heating lockout set point. OAT becomes low enough for operation when the OAT drops below the OAT heating lockout set point by more than the Heating Lockout Differential.
Off Network
Control mode is set via the keypad to auto and the unit is disabled via a network command.
Off Manual
Control mode is set to Fan Only or Cool Only via the keypad.
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Determining Economizer Status
Econo Status is a status item which indicates whether or not economizer operation is currently allowed. If economizer operation is disabled, the reason is indicated.
The following are descriptions of economizer status states.
Economizer is enabled if all the following are true:
• Economizer capability is provided
• Dehumidification operation is not enabled
• The unit is configured for waterside economizer and the EWT is below the mixed air temperature minus the
EWT differential or the unit is configured for airside economizer, the enthalpy switch input indicates low enthalpy, and the outdoor air temperature (OAT) is low enough for operation
None
Economizer capability is not provided.
Off Ambient
Economizer status is Off Ambient if any of the following conditions exist:
• The unit is configured for waterside economizer and the
Entering Water Temperature (EWT) exceeds the mixed air temperature minus the EWT differential set point.
• The unit is configured for airside economizer and the outdoor air temperature (OAT) is too high for operation.
• Unit is configured for waterside economizer and the
EWT sensor is unreliable.
• Unit is configured for airside economizer and the outdoor air temperature (OAT) sensor is unreliable.
Off Network
Economizer operation is disabled via a network command.
Off Dehumidification
Economizer operation is disabled if dehumidification operation is enabled.
Determining Cooling Capacity
Clg Capacity is a status item which indicates the percentage of the unit maximum cooling capacity currently operating.
When the unit is equipped with chilled water cooling,
0-100% is displayed as the cooling valve actuator strokes from the closed to open position. When the unit is equipped with compressorized cooling, the percentage value changes incrementally based on the number of operating cooling stages.
Determining Heating Capacity
Htg Capacity is a status item which indicates the percentage of the unit maximum heating capacity currently operating.
When the unit is equipped with modulating heat, 0-100% is displayed as the heating valve actuator strokes from the closed to open position. When the unit is equipped with staged heat, the percentage value changes incrementally based on the number of operating heating stages.
Determining Supply Air Fan Capacity
SAF Speed is a status only item which indicates the supply air fan capacity. 0-100% of VFD maximum speed is indicated if the unit is equipped with a supply air fan VFD. 100% is indicated if the supply fan is constant volume and is running.
Determining RF/EF Capacity
RF/EF capacity is a status only item which indicates the current return or exhaust fan capacity. 0-100% of VFD maximum speed is indicated if the unit is equipped with a modulating return or exhaust fan VFD. 100% is indicated if the return/exhaust fan is constant volume and is running.
When the unit is equipped with staged exhaust fans, the percentage value changes incrementally based on the number of operating exhaust fan stages.
Determining Outside Air Damper Position
OAD/Econo Cap is a status only item which indicates the current outdoor air damper or economizer valve position.
Determining Emergency Mode
Emergency Mode is an adjustable item which is normally used by a network system to shutdown the unit in an emergency situation.
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Determining Application Mode
The unit heating and cooling can be set up for automatic heat/cool, heat only, cool only or fan only operation based on a network signal by setting the Control Mode parameter to “Auto.” With the Control Mode parameters set to “Auto,” the heat/cool, cool only, heat only, and fan only decision is determined by the Net App Mode. The Net App Mode is set by a network signal. The following sections describe the five available Net App Mode selections.
NOTE:
The Net App Mode has no effect on the unit operation unless the Control Mode parameter is set to “Auto .”
Off
When the Net App Mode is set to “Off,” the Unit Status is
“Off Net” and the unit is completely disabled, including unoccupied heating (night set back) and unoccupied or unoccupied cooling (night set up) operation.
Heat Only
When the Net App Mode is set to “Heat Only,” heating operation is allowed to operate as required to maintain the heating set points. Cooling operation is disabled (Cooling
Status is “Off Net”).
Cool Only
When the Net App Mode is set to “Cool Only,” cooling operation is allowed to operate as required to maintain the cooling set points. Heating operation is disabled (Heating
Status is “Off Net”).
Fan Only
When the Net App Mode is set to “Fan Only,” the fans are allowed to operate but cooling and heating operation is disabled (Cooling Status and Heating Status are “Off Net”).
Auto
When the Net App Mode is set to “Auto” heating and cooling operation are allowed to operate as required to maintain the heating and cooling set points.
Determining Occupancy Status
Occupancy is a status item which indicates whether the unit is in an occupied, unoccupied or tenant override mode of operation.
The following are descriptions of the various “Occupancy” states.
Occ
The Occupancy parameter indicates “Occ” when the unit is in the occupied mode. In this mode, the unit starts and runs continuously, cooling and heating as required to maintain the occupied temperature set points. The unit is in the occupied mode if any of the following conditions are true:
• The Occ Mode entry on the keypad is set to occupied
• The Occ Mode entry on the keypad is set to Auto, and a manual network occupancy command is sent to the controller
• The Occ Mode entry on the keypad is set to Auto, a manual network occupancy command is set to Auto, and any of the following is true:
• The External Start/Stop switch is closed
• A network schedule signal is set to Occupied or Standby
• The internal schedule function is in the Occupied condition
Unocc
The Occupancy parameter indicates “Unocc” when the unit is in the unoccupied mode. In this mode, the unit remains off unless unoccupied operation becomes active. When unoccupied operation is active the unit operates normally except that Minimum OA Position is set to zero. See
Unoccupied Operation below for information regarding when unoccupied operation is activated.
TntOvrd
The Occupancy parameter indicates “TntOvrd” when the unit is in the tenant override mode. In this mode, the unit starts and runs continuously, cooling and heating as required to maintain the occupied temperature.
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Tenant override operation is initiated when the Tenant
Override Timer is greater than zero. The Tenant Override
Timer is set equal to the Local Tenant Override Time (Timer
Settings menu) if the unit is enabled and any of the following is true:
• The Space Temperature sensor is present and its tenant override button is pressed for less than 10 seconds.
Nothing happens if the button is pushed for more than
10 seconds but less than the time required to initiate a shorted sensor alarm (30 seconds). Subsequent presses on the button resets the Tenant Override Timer to the
Local Tenant Override Time, i.e. the max time
• The Occ Mode entry on the keypad is set to Tenant
Override. After the Tenant Override Timer is set, the
Occ Mode entry on the keypad reverts to auto after a 2 second time delay
• The Occ Mode entry on the keypad is set to Auto or
Unocc, and a manual network occupancy command is set to Bypass. After the Tenant Override Timer is set, the network occupancy command reverts to Auto
Subsequent presses on the button, setting of the keypad occupancy entry to Tenant Override again, or setting of the network occupancy command to Bypass again resets the Tenant Override Timer to the Local Tenant Override
Time.
The TOTime entry on the keypad can also be manually set to a non-zero value. In this case the value begins timing down from the edited value.
Tenant Override Operation may be terminated by manually setting the Tenant Override parameter on the keypad to zero or by disabling the unit.
Determining Occupancy Mode
Occ Mode is an adjustable item which sets the unit for manual occupied, unoccupied, tenant override or automatic operation.
Occ
When Occ Mode is set to “Occ,” the unit is manually placed in the occupied mode of operation.
Unocc
When Occ Mode is set to “Unocc,” the unit is manually placed in the unoccupied mode of operation.
TntOvrd
When Occ Mode is set to “TntOvrd,” the unit is manually placed in the tenant override mode of operation.
NOTE:
Once tenant override operation is activated the parameter automatically reverts back to “Auto .”
Auto
When Occ Mode is set to “Auto” the automatically changes between occupied, unoccupied and tenant override operation.
Determining Occupancy Source
When the Occupancy parameter indicates Occ, the occupancy source is set to one of the following values to indicate the function responsible for placing the unit into the occupied mode of operation.
None
The Occ Src= parameter indicates “None” when the
Occupancy= parameter indicates “Unocc” or “Tnt Ovrd.”
NetSchedule
The Occ Src= parameter indicates “Net Schd” when the Occupancy= parameter indicates “Occ” due to a network schedule indicating an occupied period.
IntSchedule
The Occ Src= parameter indicates “Int Sched” when the Occupancy= parameter indicates “Occ” due to the unit internal schedule.
OneEventSchedule
The Occ Src= parameter indicates “Int
Sched” when the Occupancy= parameter indicates “Occ” due to the unit one event schedule.
RemoteSwitch
The Occ Src= parameter indicates “Remote
Sw” when the Occupancy= parameter indicates “Occ” due to a field supplied external time clock or a tenant override switch signal in the form of a set of dry contacts is closed across terminals 101 and102 on the unit field terminal block TB2.
OccManCmd
The Occ Src= parameter indicates
“OccManCmd” when OccMode is set to Auto and the network manual occupancy command is set to Occupied.
OccMode
The Occ Src= parameter indicates “Occ Mode” when the Occupancy= parameter indicates “Occ” due to the
Occupancy Mode being manually set to “Occ.”
TStatTO
The Occ Src = parameter indicates “TStatTO” when the Occupancy= parameter indicates “TntOvrd” due to the tenant override button on the zone thermostat being pushed.
The button must be held for at least 1 second but not more than 10 seconds.
ManTO
The TntOvrd Src = parameter indicates “ManTO” when the Occupancy= parameter indicates “Occ” due to the being manually set via the keypad/display. When the Tenant
Override Timer is set to a non-zero value, the unit starts and runs in the tenant override mode regardless of any scheduling features. The unit stops when the timer expires. The Tenant
Override Timer can be set from 0-300 minutes.
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Unoccupied Operation
During unoccupied operation the unit operates normally except that Min OA Pos is set to zero so that the damper is closed to the outdoor air.
Unoccupied Dehumidification
Dehumidification may be initiated in the unoccupied mode only if Dehumidification Control is set to Always instead of Occupied on the keypad. When this is the case and the humidity goes high the unit transitions in the normal manner through Start up and Recirc to Fan Only and then into the Dehumidification Mode. In this case, the UnoccSrc= parameter indicates “Unocc Dehum”.
Unoccupied Cooling (Night Setup)
Unoccupied operation is initiated if the space sensor is reliable, the space temperature is greater than the Unoccupied
Cooling Setpoint, and the Unoccupied Cooling Setpoint is set lower than its maximum setting. In this case, the unoccupied source indicates “UnoccClg”.
Unoccupied Heating (Night Setback)
Unoccupied operation is initiated if the space sensor is reliable, the space temperature is less than the Unoccupied
Heating Setpoint, and the Unoccupied Heating Setpoint is set higher than its minimum setting. In this case, the Unoccupied
Source indicates “UnoccHtg”
Internal Optimal Start
Unoccupied operation is enabled due to an internal optimal start schedule being activated. In this case, the Unoocupied
Source indicates “IntOptStrt”.
Network Optimal Start
Unoccupied operation is enabled due to a network optimal start schedule being activated. In this case, the Unoccupied
Source indicates “NetOpStrt”.
None
The Unoccupied Source is set to “None” when Unoccupied operation is inactive.
Scheduling
The Air Handling unit can be scheduled for operation by using the following three methods:
• Unit internal time scheduling functions
• External time clock function
• Network time scheduling function
Provided the unit is not locally or remotely disabled, the unit operates when any of these scheduling functions is calling for occupied operation. Conversely, the unit enters the unoccupied mode when all of these scheduling functions are calling for unoccupied operation. Therefore, any unused scheduling functions should be set for continuous unoccupied operation.
The next four sections: “Setting Controller Date and Time,”
“Internal Daily Scheduling,” “Holiday Scheduling,” and “One
Event Scheduling” describe functions related to the internal unit scheduling functions. These are followed by a section describing the optimal start function which can be use with internal scheduling and network scheduling. This is followed by two sections that describe the external time scheduling and network time scheduling functions.
Setting Controller Date and Time
The controller uses the date and time to execute its internal scheduling functions. The current time and date will not be lost if the unit is turned off for up to forty-eight hours. The clock and date are settable from the keypad. The time of day can be set by entering the hour (00-23), minute (00-59), and second (00-59) into three fields of the Current Time. Note that MicroTech III uses “military” time. The current date can be set by entering the date (00-31), month (01- 12) and year
(1999-2155) into the three fields of the Current Date.
Internal Daily Schedule
An internal Daily Schedule provides one start time and one stop time for each of the seven days of the week and for holidays. When the Occ Mode= parameter is set to “Auto/
Net”, and the unit is not disabled for other reasons, it starts and stops according to the controller internal schedule.
Holiday Scheduling
The operator may select the days when start and stop times for holidays are used by selecting a start date and an end date for up to ten periods during the year by using the holiday scheduling feature. Whenever a holiday period occurs, the controller uses the Holiday Schedule start and stop time for the period. For example, assume that Christmas Eve occurs on a Thursday. The building is shut down on both
Christmas Eve and Christmas Day, but operates normally on the weekend. This holiday period would be scheduled by setting the Holiday Schedule to the default “no schedule” values “HH:MM- HH:MM” and setting the Holiday Period to
“12/24/08 - 12/25/08.”
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Operator’s Guide
One Event Scheduling
A One-Event Schedule is provided so that one operating period can be scheduled without affecting the regular internal schedule. A start date/time and an end date/time can be set.
The unit can be scheduled to operate during a specified period by using this feature. During the specified period defined by the One Event Beginning Date/Time and One
Event Ending Date/Time parameters the unit starts up and runs continuously regardless of any other time scheduling functions. For example, assume that a space served by the unit is occupied for a special event on March 12, 2008 from
5:00 p.m. to 10:00 p.m. when the normal time scheduling has the unit shut off after 4:00 p.m. on that date. This event can be accounted for by setting the One Event Beginning Date/Time to “3/12/08 @ 17:00:00” and the One Event Ending Date/Time to “3/12/08 @ 22:00:00.”
Optimal Start
When Optimal Start is active (Optimal Start = Yes), an early start time is determined before each scheduled start. The schedule must be based on an internal schedule or a signal via a connected network that indicates time to occupancy.
The controller uses start history, outdoor air temperature and space temperature to determine when the unit should start.
The unit may start up to four hours before the scheduled occupancy time. Optimal start based on heating operates when the space temperature is below the Occupied or
Unoccupied Heating Spt by ½ the Zone Htg Deadband.
Optimal start based on cooling operates when the space temperature is above the Occupied or Unoccupied Cooling
Spt by ½ the Cooling Deadband. If space temperature is between the above two points, the unit starts at the occupancy time.
External Time Scheduling
An external time clock can be used to schedule unit operation. This is accomplished by a field supplied external time clock signal in the form of a set of dry contacts wired across terminals 101 and 102 on the unit field terminal block
TB2. In this case, all internal daily schedules should be set to
“HH:MM-HH:MM” (default setting).
Temperature Control Configurations
Temperature control is based on a Control Type that may be set to Zone, DAT, or Single Zone VAV.
When the Control Type is set to Zone temperature control, heating, compressors, and the economizer are controlled to maintain the temperature of the zone at a desired setpoint.
This configuration is used on units equipped with constant volume supply fans. Compressors and heating stages are staged to maintain space or return temperature. The number of compressors is decreased when it is too cold and increased when it is too hot subject to stage timers. The number of heat stages is decreased when it is too hot and increased when it is too cold subject to stage timers.
When the Control Type is set to DAT, heating, compressors, and the economizer are controlled to maintain the discharge air temperature at a desired setpoint. This configuration is typically used on units equipped with variable air volume supply fans.
When the Control Type is set to (single zone VAV), heating, compressors and the economizer are controlled to maintain the discharge air temperature at the desired setpoint while the variable volume supply fan is modulated to maintain the temperature of the zone at the desired heating and cooling setpoints. In heating mode the supply fan capacity is increased as the zone temperature falls and decreased as the zone temperature rises.
Heat/Cool Changeover
In general, a unit configured for discharge air temperature control either operates to deliver the cooling discharge temperature set point using economizer and/or mechanical cooling or the heating discharge air temperature set point using the heating equipment. Cooling and heating never operate simultaneously. A unit configured for zone (or space comfort) control either operates to maintain the Occupied or Unoccupied Cooling Set Point using economizer and/or mechanical cooling or the Occupied or Unoccupied Heating
Set Point using the heating equipment.
The occupied or unoccupied cooling/occupied or unoccupied heating setpoints can be set via the keypad/display or based on a signal from an optional space temperature sensor with set point adjustment capability. The following sections describe the unit heat/ cool changeover function.
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Illustrative Heat/Cool Changeover Sequence
The following is an illustration of the heat/cool changeover function.
When the control temperature is below the occupied or unoccupied heating setpoint by more than ½ the deadband
(point A), heating operation is enabled. Heating operation then remains enabled until the control temperature begins to rise and rises above the occupied or unoccupied heating setpoint by more than ½ the deadband (point B), at which point heating operation is disabled and the unit enters the fan only (or Min DAT) operating state. If the control temperature rises above the occupied or unoccupied cooling setpoint by more than ½ the deadband (point C) cooling operation is enabled. Cooling operation remains enabled until the control temperature begins to fall below the occupied or unoccupied cooling setpoint by more than ½ the deadband (point D), at which point the unit returns or fan only (or Min DAT) operating state.
Figure 12: Heat/Cool Changeover
Control Temperature
The “Control Temperature” is defined as the unit temperature input used to make the heat/cool changeover decision. This determines whether or not cooling or heating is enabled.
The user may select Space Temperature, Return Temperature,
Outdoor Air Temperature or None for DAT units. Normally either the Return or Space Temperature is selected as the control temperature. Outdoor Air Temperature may be used as the control temperature for DAT units, but not for Zone
Control units.
When the Control Temperature Source is set to None, the unit no longer “changes over” between heating and cooling in the normal manner. Instead it acts as if it is always in the
“cooling” mode of operation controlling to the discharge air cooling set point. In this case the unit operating state will vary between Cooling, Fan Only and Min DAT (heating) in order to maintain the discharge air cooling set point. The unit will only enter the Heating operating state and control to the discharge heating set point for morning warm up purposes.
The Control Temperature Source automatically reverts from
Return to Space if both of the following are true:
• The Return Air Sensor is not present and reliable
• A network or local Space Sensor is present and reliable
The Control Temperature Source automatically reverts from
Space to Return if both of the following are true:
• The space sensor is not reliable (a valid space temperature value is not provided via the network and the space temperature sensor is either in alarm or not present)
• The return air sensor is reliable (present and not in alarm)
The Control Temperature Source automatically reverts from either Outdoor Air or Mixed Air to Return if the Control
Type is Zone (Not DAT). If the return air temperature is not reliable, the control temperature may then revert to space as described above.
The Control Temperature Source automatically reverts from
Mixed Air to Outdoor Air if Unit Type is not SCU.
A Control Temperature Fault that shuts down the unit is initiated if any of the following is true.
• The return air sensor is not present and reliable and
Return Air is selected as the control temperature and a space sensor is not available.
• A network or local space sensor is not present and reliable and Space is selected as the control temperature and a return temperature sensor is not available.
• The OAT Sensor is not present and reliable and Outdoor
Air is selected as the control temperature
• The mixed air temperature sensor is not present or reliable and Mixed Air is selected as the control temperature
Occupied Temperature Set Points
When the Use Tstat set point parameter is set to No, the
Occupied Cooling Set Point and the Occupied Heating
Set Point may be set through the keypad or via a network signal. In this case these set points are changed whenever the network or keypad value changes. When the Use Tstat set point parameter is set to Yes these set points can only be adjusted through the zone thermostat. Heating and cooling set points must not overlap. The Occupied Heating Set Point must be equal to or less than the Occupied Cooling Set Point.
If a conflict occurs from values entered via the keypad or network, the Occupied Heating Set Point is automatically adjusted down to eliminate the conflict. When the Occupied
Cooling Set point is changed by more than 0.5 degrees through the wall mounted sensor, the Occupied Heating
Set Point is raised or lowered the same amount so that the difference between the Cooling and Heating set points does not change.
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OA/EWT Lockout
Heating is disabled whenever the outdoor air temperature is greater than the Outdoor Air Ambient Heating Lockout Set
Point. When the outdoor air temperature drops below the
Outdoor Air Ambient Heating Lockout Set Point by more than the Heating Lockout Differential, heating operation is re-enabled. Cooling is disabled if outdoor air temperature or entering water temperature is too low for operation. The outdoor air temperature becomes too low for operation when it drops below the Outdoor Air Ambient Cooling Lockout
Set Point. Outdoor air temperature becomes high enough for operation when it rises above the Outdoor Air Ambient
Cooling Lockout Set Point by more than the Cooling Lockout
Differential. The entering water temperature becomes too low for operation when it drops below the Minimum Entering
Water Temperature Setpoint. Entering water temperature becomes high enough for operation when it rises above the
Minimum Entering Water Temperature Setpoint by more the
Cooling Lockout Differential.
Tenant Override
The tenant-override button provided with the optional zone temperature sensor packages is used to override unoccupied operation for a pre programmed time period. This time period is set with the Tenant Override Time Increment. This value can be adjusted from 0 to 300 minutes (default is 120 minutes). When an occupant presses and releases the tenant override button on the zone temperature sensor (ZNT1), the
Tenant Override Timer is set equal to the Tenant Override
Time Increment. (The button must be held for at least 1 second but not more than 10 seconds.) The unit then starts and runs in the tenant override mode which is the same as occupied mode except that it is temporary. The Tenant
Override Timer begins timing out and the unit runs until the timer expires. If the tenant override button is pressed again while the unit is operating in tenant override mode, the
Tenant Override Timer is reset to the Tenant Override Time
Increment and the unit continues to operate. For example, assume that the Tenant Override Time Increment is 120 minutes. One press of the override button provides at least
120 minutes of unit operation. If the button is pressed again
60 minutes later, the Tenant Override Timer is reset to 120 minutes, and a total of 180 minutes of uninterrupted operation results.
NOTE:
The same operation occurs if, instead of pressing the override button on a zone temperature sensor, the
Occupancy Mode is set to “Tnt Ovrd .” Once set to “Tnt
Ovrd”, the Occupancy Mode automatically reverts to the “Auto” setting once the Tnt Ovrd Timer is set to the Tnt Ovrd Time Increment . The same operation will also occur if the network occupancy manual command it set to bypass
Zero OA Time (Morning Warm-up)
A separate Morning Warm-up operating state is not provided, but an editable ZeroOATime is used to keep the Outside Air damper closed when the unit first starts. The Minimum OA
Position is set to zero as long as the as the fan has been on for less than the ZeroOATime. This allows the Return Air type units to cool down the space with mechanical cooling or to warm up the space with the dampers closed. If the
ZeroOATime is set correctly, the OA dampers will be open only during occupied periods. When Optimum Start is used
ZeroOATime is set equal to the time to occupancy when the unit starts so that the OA dampers will open at occupancy time.
Post Heat Operation
After leaving the Recirc or Heating operating state and entering either the Fan Only or Min DAT operating state, the unit performs “post heat” operation if the Post Heat Timer is set to a non zero value. “Post heat” operation occurs within the Fan Only or MinDAT operating state. During “post heat” operation, the VAV Box Output remains open (heat) while the discharge fan capacity is forced to a minimum value (default
33% speed for VFD). By forcing the discharge fan capacity to a minimum value before the VAV Box Output closes
(cool), “post heat” operation is designed to prevent duct overpressurization by decreasing the duct pressure before the VAV boxes can close.
“Post heat” operation remains active until either the discharge fan capacity reaches the minimum value or until the Post
Heat Timer expires, whichever occurs first. When “post heat” operation ends, normal duct static pressure or position control resumes.
NOTE:
During “post heat” operation and for 120 seconds afterward, the proof of airflow input is ignored. This is to prevent nuisance Fan Fail fault alarms that may occur if the airflow switch opens during or following
“post heat” operation . The unit cannot leave the Fan
Only or Min DAT operating state while the airflow switch input is being ignored . The VAV output is only available to the field via network communications.
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Dehumidification
In the dehumidification mode, mechanical cooling is used to cool air low enough to wring moisture out of it. Hot Gas
Reheat or the standard unit heating equipment (Gas, SCR
Electric or Steam/Hot water) is used to raise the temperature of this cooled air to a desirable value.
Dehumidification Initiation
An analog sensor is mounted in the return duct, the space, or outdoor to sense relative humidity. The location is selected by setting the Sensor Location value on the keypad to Return,
Space, or OAT.
NOTE:
This setting is used to dictate which temperature sensor is used to calculate the dewpoint . OAT can only be selected for units with DAT control .
The relative humidity and a calculated dewpoint temperature are both displayed on the keypad . The calculated dewpoint temperature is based on the relative humidity and Return, Space, or OAT value depending on the location of the humidity sensor .
Humidity control is disabled if cooling is disabled for any reason. Dehumidification operation is initiated when Humidity Control is set to either relative humidity or dewpoint and that value rises above the appropriate setpoint by more than half its deadband .
Dehumidification Termination
Dehumidification is terminated if the selected variable,
Relative Humidity or Dew Point, drops below the appropriate humidity setpoint by more than half its deadband.
Dehumidification is also terminated if cooling is disabled for any reason. Other ways that dehumidification may be terminated are if Dehum Method is set to “None” on the keypad, or if the unit goes to Off Net, Off Sw, Off Alm, or
Off Man Ctrl.
When Dehumidification is terminated, all mechanical cooling is turned off except when the unit is in the Cooling state. Modulated cooling reverts to normal control when dehumidification is terminated in the Cooling state. For units with compressors, the number of cooling stages is reduced by one and control reverts to normal control when dehumidification is terminated in the Cooling state. Another compressor stage change could then occur after one Cooling
Stage Time has elapsed
Dehumidification Mechanical Cooling Control
During dehumidification, control of mechanical cooling is based on the following two editable values of the Leaving
Coil Temperature setpoint.
• Mx Lvg Coil T (Default = 52°F)
• Mn Lvg Coil T (Default = 45°F)
For compressorized units, the number of compressor stages increases when all of the following are true:
• The time since the last stage change exceeds the Clg
Stage Time
• Leaving Coil Temperature is greater than the Mx Lvg
Coil T
• The current cooling stage is less than the available number of stages
During the dehumidification mode, the number of compressor stages decreases when all of the following are true:
• The time since the last stage change exceeds the Clg
Stage Time
• Leaving Coil Temperature is less than Mn Lvg Coil T
Spt
• The current cooling stage is greater than zero
Units with modulated cooling are controlled by a PI Loop to maintain the temperature leaving the coil at the Mn Lvg
Coil T. The normal DAT Cooling Deadband and PI Loop parameters are used in this PI Loop.
MPS HGBP Valve
When the Unit Type is MPS and the unit is equipped with modulating hot gas reheat control an HGBP valve output
(MCB-DO6) is controlled to make sure hot gas is not flowing through both the hot gas bypass and hot gas reheat circuits simultaneously.
The HGBP Valve Output is On (energized) whenever Unit
State is Cooling and dehumidification operation is inactive.
The HGBP Valve Output is Off (de-energized) any other time.
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Dehumidification Reheat Control
During dehumidification control either an analog or digital
Hot Gas Reheat (HGRH) output or the standard modulating heating output is controlled to maintain the current Reheat
Setpoint. If Reheat Type software configuration parameter is set to Staged Hot Gas, then a digital HGRH output is controlled to maintain the Reheat Setpoint. If the Reheat
Type software configuration parameter is set to Modulating
Hot Gas, then an analog HGRH output is controlled to maintain the Reheat Setpoint. If the Reheat Type software configuration parameter is set to Standard Heat, then the normal heating analog output is controlled to maintain the
Reheat Setpoint.
• Cooling/Fan Only: In the Cooling and Fan Only states, a
PI Loop is used to control the HGRH valve to maintain the Discharge Air Temperature at the Dehumidification
Reheat Setpoint. The deadband for this loop is the same one used for other control of heating to maintain the
DAT Heating setpoint.
• Cooling: In the Cooling state, the Dehumidification
Reheat Setpoint equals the DAT Cooling Setpoint. For
DAT units, this is the normal DAT setpoint resulting from any reset. For Zone Control units, this setpoint is the result of a PI Loop based on the control temperature as is done in the Economizer state or with modulated cooling in the Cooling state.
• Fan Only: In the Fan Only state, the Dehumidification
Reheat Setpoint equals an editable MaxReheatSpt
(Default = 65°F) when the control temperature drops to the Occupied or Unoccupied Heating Setpoint and equals an editable MinReheatSpt (Default = 55°F) when the control temperature rises to the Occupied or
Unoccupied Cooling setpoint. The Dehumidification
Reheat Setpoint varies linearly between these two points.
This means that no matter what the Control Temperature is, including OAT, the temperature leaving the unit is at a maximum just before the unit needs to go into heating and at a minimum just before the unit needs to go into cooling. This reduces opportunity for unit to go into heating or cooling during dehumidification.
Staged HGRH Control
In the Cooling and Fan Only states, a staged output is turned on and off to control the HGRH valve to maintain the discharge air temperature at the Dehumidification Reheat
Setpoint. The deadband for this setpoint is an adjustable.
When the DAT is above the Dehumidification Reheat
Setpoint by more than half the deadband, cooling capacity is greater than 0% and the Dehumidification Reheat Timer has expired, the reheat output is turned on. When the DAT is below the Dehumidification Reheat Setpoint by more than half the deadband and the Dehumidification Reheat Timer has expired, or if the cooling capacity is 0%, the reheat output is turned off.
Modulating HGRH Control
In the Cooling and Fan Only states, a PI Loop is used to control the HGRH valve to maintain the discharge air temperature at the Dehumidification Reheat Setpoint. The PI
Loop is enabled when the unit is in the Cooling or Fan Only operating state and dehumidification becomes active.
NOTE:
When configured for modulating hot gas reheat the reheat valve is stroked open and then closed every day at 2:00 AM as long as dehumidification is inactive and the unit is not in the Cooling operating state at the time .
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Energy Recovery
Energy recovery is provided by drawing outside air across half of an enthalpy wheel and drawing exhaust air across the other half. Latent and sensible heat is transferred from the hotter, moister exhaust air to the colder dryer outside air in winter. Latent and sensible heat is transferred from the hotter more moist outside air to the cooler dryer exhaust air in summer. Control consists of starting and stopping an exhaust fan, modulating the speed of the exhaust fan, starting and stopping the enthalpy wheel, and optionally controlling the speed of the enthalpy wheel. The outdoor dampers are controlled in the normal manner. The current statuses as well as editable parameters associated with energy recovery are located in the Energy Rec Setup menu.
Enthalpy Wheel
The enthalpy wheel is turned on when all of the following are true. The speed of the enthalpy wheel is set to the maximum speed for units with a VFD controlling the speed of the enthalpy wheel.
• The exhaust fan is on
• The OA Dampers are at the minimum position
• The unit is not in the Economizer operating state
• The enthalpy wheel has not been turned off due to frost prevention (variable or constant speed wheels)
• The enthalpy wheel has not been turned off due to defrost control (constant speed wheels only)
• The wheel has not been turned off due to Variable
Effectiveness Operation
The enthalpy wheel is turned off when any of the following is true
• The exhaust fan is off
• The OA Damper Position is driven above the Minimum
OA Damper Position by more than 3%.
• Either of the frost prevention functions dictate that the wheel be off.
• The constant speed wheels defrost function dictates the wheel is to be off.
Enthalpy Wheel Frost Prevention
Two different frost protection methods are provided depending on whether or not the enthalpy wheel is controlled by a VFD. When there is a threat of frost or condensation on the enthalpy wheel, a variable speed wheel may be first slowed down and then stopped and a constant speed wheel may be stopped so that less enthalpy transfer occurs and frosting or condensation on the enthalpy wheel is avoided. In either case the frost control is based on an Intersection Point described as follows:
Condensation and frosting can occur on the enthalpy wheel when the exhaust air leaving the wheel is saturated.
This condition will occur when two lines intersect on a psychometric chart, and it will not occur when these two lines do not intersect. One of these lines is the Humidity
Ratio versus the dry bulb for saturated air. The other line is the Humidity Ratio versus the dry bulb temperature of the exhaust air leaving the enthalpy wheel. The two ends of this second straight line on a psychometric chart are the
OAT at 95% RH and the return air temperature at the return air relative humidity. One line showing frosting conditions and another line showing no frost conditions are shown on the sketch of a psychometric chart shown. A continuous calculation determines if and at what temperatures these two lines intersect. If they do intersect they intersect at two points. The higher of the two points is referred to as the
“Intersection Point”. When they do not intersect, the enthalpy wheel runs at full speed. When they do intersect, the variable speed enthalpy wheel may be slowed to its minimum speed as described above to maintain the dry bulb temperature of the exhaust air leaving the enthalpy wheel high enough to eliminate the Intersection Point and therefore the threat of frosting conditions. If slowing the wheel does not eliminate the Intersection Point after a stage time period, the wheel may be stopped. A constant speed wheel is stopped when an
Intersection Point exists.
Figure 13: Exhaust Air Psychometric Chart
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Operator’s Guide
Constant Speed Wheel Frost Prevention Control
The enthalpy wheel is stopped when both of the following are true:
• The enthalpy wheel has been on for longer than the edited Wheel Stage Time
• The exhaust air temperature leaving the enthalpy wheel is below the Intersection Point plus an edited minimum temperature difference.
• Defrost Method=ExhAir
• Enthalpy wheel is constant speed
The enthalpy wheel is turned back on when the wheel has been off due to Frosting/Condensation for longer than an edited Minimum Off Time and the exhaust air temperature leaving the enthalpy wheel is above the Intersection Point plus an edited Maximum Temperature Difference.
Variable Speed Wheel Frost Prevention Control
The enthalpy wheel VFD speed is set to a minimum wheel speed (default 5%) value when all of the following are true:
• The enthalpy wheel has been operating at maximum speed for longer than the edited Wheel Stage Time
• The exhaust air temperature leaving the enthalpy wheel is below the Intersection Point plus an edited Minimum
Temperature Difference.
• Enthalpy wheel is variable speed
To prevent Frosting/Condensation on the enthalpy wheel, the enthalpy wheel is turned off when both of the following are true:
• The exhaust air temperature leaving the enthalpy wheel is below the Intersection Point plus an edited Minimum
Temperature Difference.
• The wheel has been operating at the minimum wheel speed for longer than an edited Wheel Stage Time
The enthalpy wheel is turned on at minimum speed when both of the following are true:
• The enthalpy wheel has been off due to Frosting/
Condensation for longer than an edited Minimum Off
Time
• The exhaust air temperature leaving the enthalpy wheel is above the Intersection Point plus an edited Maximum
Temperature Difference.
The Enthalpy Wheel speed will be increased to its maximum speed when both of the following are true:
• The exhaust air temperature leaving the enthalpy wheel is above the Intersection Point plus an edited Maximum
Temperature Difference (MaxExhTDiff)
• The wheel has been operating at the minimum speed for longer than the edited Wheel Stage Time
90
Enthalpy Wheel Defrost Control (Constant Speed
Wheels Only)
In lieu of the frost prevention method described above, a constant speed enthalpy wheel can be set for a simpler timed defrost method of frost management. With this method the enthalpy wheel is stopped periodically for a defrost time duration when the outdoor air temperature is below an outdoor frost temperature threshold setpoint.
Defrost operation becomes enabled when all of the following are true:
• Defrost Method = Timed
• Energy wheel is constant speed
• OAT is less than the OA frost temperature setpoint.
• Normal wheel operation has the enthalpy wheel on
When defrost operation is enabled, the wheel is stopped for the Defrost Time (default 5 minutes) every Defrost Period
(default 60 minutes).
When the wheel is stopped due to defrost operation the wheel must be slowly rotated so that both halves of the wheel are allowed to be defrosted by the relative warm exhaust air leaving the wheel. This is accomplished by alternately turning the wheel off for the editable Defrost Off Time (default 24 seconds) and on for the editable Defrost On time (default 1 second) during defrost operation.
Enthalpy Wheel Capacity Limiting
Enthalpy wheel capacity limiting control is a means to limit the capacity of an energy wheel during part load conditions.
Normally wheels are sized for worst case winter/summer load and, therefore, at part load the wheel may be oversized.
Capacity limiting control is allowed when the energy recovery wheel leaving air temperature (ERDAT) sensor is present and reliable and the outdoor air temperature (OAT) is colder than the returning air temperature.
Capacity limiting control is not allowed during dehumidification operation or when either the wheel frost prevention or defrost operation are active.
Capacity limiting operation differs depending on whether the energy recovery wheel is constant or variable speed.
Constant Speed Wheel
The conditions that cause the energy recovery wheel to turn due to capacity limiting are different depending on the unit operation state as follows:
Fan Only
When the unit is operating in the Fan Only state, the energy recovery wheel is stopped due to capacity limiting whenever the discharge air temperature (DAT) is above the
MinDATLimit setpoint by more than ½ the discharge air heating deadband. The wheel is re-started when the DAT falls back to or below the MinDATLimit setpoint plus ½ the discharge air heating deadband.
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Operator’s Guide
Heating
When the unit is operating in the Heating state, the energy recovery wheel is stopped due to capacity limiting whenever all heating is off and the discharge air temperature (DAT) is above the discharge heating setpoint by more than ½ the discharge air heating deadband. The wheel is re-started when the DAT falls back to or below the discharge heating setpoint plus ½ the discharge air heating deadband.
Cooling
When the unit is operating in the Cooling state, the energy recovery wheel is stopped due to capacity limiting whenever the energy recovery wheel leaving air temperature (ER LAT) is above the discharge cooling setpoint by more than ½ the discharge air cooling deadband. The wheel is re-started when the ER LAT falls back to or below the discharge cooling setpoint plus ½ the discharge air cooling deadband.
Variable Speed Wheel
When the enthalpy wheel is variable speed and the Variable
Effectiveness Control PI_Loop is active the ER LAT is controlled to the current effective discharge temperature setpoint.
Exhaust Fan
A variable speed exhaust fan controlled by a VFD is provided for all Economizer units with either constant volume or VAV supply fans and on 100% Outside Air units with VAV supply fans. Either a constant volume exhaust fan or a variable speed exhaust fan controlled by a VFD may be provided on 100%
Outside Air units with constant volume supply fans.
The exhaust fan is turned on when any of the following sets of conditions is true:
All four of the following are true:
• The Exhaust Fan is controlled by a VFD
• The OA Dampers are at least open to the Minimum OA
Position
• The Minimum OA Position is greater than 0%
• The building static pressure is above the building static pressure setpoint by more than the deadband for longer than the Minimum Exhaust Fan Start Time (Default =
120 seconds)
All four of the following are true:
• The exhaust fan is controlled by a VFD
• The OA Dampers are at least open to the Minimum OA
Position
• The Minimum OA Position is greater than 0%
• The exhaust fan capacity is commanded to a value above the minimum value (Default = 5%) by a BAS for longer than the Minimum Exhaust Fan Start Time (Default =
120 seconds)
Both of the following are true:
• The exhaust fan is constant volume
• The supply fan has been commanded on for at least 4 seconds
The exhaust fan is turned off when any of the following sets of conditions is true:
All three of the following are true:
• The exhaust fan is controlled by a VFD
• The building static pressure is below the building static pressure setpoint by more than the deadband
• The exhaust fan capacity is at or below its minimum value (Default = 5%) for longer than the Min Exhaust
Fan Stop Time (Default = 120 seconds)
Both of the following are true:
• The exhaust fan is controlled by a VFD
• The exhaust fan capacity is commanded to less than or equal to its minimum value (Default = 5%) by the BAS for longer than the Minimum Exhaust Fan Stop Time
(Default = 120 seconds)
The exhaust fan is off when the supply fan is off
Whenever a variable speed exhaust fan is on, its capacity will be modulated using a VFD. The speed of the fan will be either
(1) modulated to maintain the building static pressure at a desired value or (2) set at a fixed speed provided by a Building
Automation System via a network.
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Bypass Dampers (Not Applicable for 100% OA
Units)
The bypass dampers are driven closed (Bypass Damper
Closed output is energized) whenever the OA Damper position is less than or equal to the Minimum OA Position
The Bypass dampers are driven open (Bypass Damper Open output is energized) whenever the OA Damper Position exceeds the Minimum OA Damper Position by more that 3%
Outside Air Damper Control
Minimum Outside Air Damper Control
Control of the dampers in the Economizer state is described in the Economizer Control section. The outdoor air dampers are driven open in the cooling operating state if economizer operation is enabled and to the Minimum OA Position if economizer operation is disabled. For all other operating conditions, the outdoor air dampers are set to the Minimum
OA Position. The Minimum OA Position is set to zero or closed position when the supply fan is off, the unit is in the
Recirculation state, Occupancy is set to Unocc, or the fan has been on for less than the Zero OA Time.
As a result, the OA dampers are driven closed in night setback, night setup, morning warm-up, and morning cool down situations unless economizer operation is required. In all other conditions the Minimum OA Position is equal to or below a Ventilation Limit and equal to or above a Demand
Control Ventilation limit. For CAV units, the Ventilation
Limit equals the keypad editable Vent Limit and the Demand
Control Ventilation Limit equals the keypad editable DCV
Limit. For VAV units, the Ventilation Limit varies with VFD speed between the editable Vent Limit at 100% Supply Fan speed and the editable LoFlo Vent Limit at the Min Clg Spd, as shown in
Figure 14 . For VAV units, the Demand Control
Ventilation Limit varies as the Ventilation Limit value changes so that the ratio between them remains constant.
In the example shown in
the Demand Control
Ventilation Limit would always be 1/2 the Ventilation Limit since the DCV Limit= parameter (10%) is half of the Vent
Limit= parameter (20%).
The editable parameters are to be determined when the airflow for the unit is balanced and are located in the Min OA
Set-up menu.
NOTE:
The MinClgSpd is prevented from being set equal to the Design Cooling Speed . The DCV Limit is prevented from being set greater than the Vent Limit .
If the VentLimit or the LoFloVent Limit is set to 0, the
Ventilation Limit is overridden to 0 .
Figure 14: Damper Position versus Fan Speed Chart
Cold Start Operation
A special “cold start” sequence will slow the opening of the dampers when it is cold outdoors and the unit is equipped with either Hot water/Steam or F&BP heating. This is to try to prevent nuisance freezestat trips associated with dampers opening up rapidly to minimum position before the heat has a chance to ramp up. This “cold start” sequence is initiated if the following conditions are all true:
• OAT is below the current LoDATLimit
• The unit is equipped with an Airside Economizer
• The current Unit State is beyond the Recirc
• The current Minimum Outdoor Damper Position set point is greater than 0%
• The unit is equipped with Hot water/Steam or F&BP heating
When the sequence is active the dampers will move more slowly the colder it is outdoors. The minimum and maximum ramp rates are adjustable via the keypad by navigating to the
Commission Unit/Min OA Set-up menu. The effective ramp rate will vary from the minimum 40% 100% (Minimum)
Airflow rate at OAT equal to -30°F to the maximum at OAT equal to 100°F. Once the damper position reaches a point
1% below the actual effective minimum position normal operation will begin. If the unit enters the Economizer operating state before the damper regulation begins, the regulation will begin from the current economizer position.
92 OM 920-4
Operator’s Guide
Minimum Outside Air Reset - None
If None is selected as the Min OA Reset Type, the Minimum
OA Position is set equal to the Ventilation Limit. The Demand
Control Ventilation Limit value is ignored when Min OA reset is set to None.
Minimum Outside Air Reset - Network Control
If Network is selected as the Min OA Reset Type and a valid value for the minimum position is provided via a network the
Minimum OA Position is set equal to that value. The network is only allowed to write a value that is between the Ventilation
Limit and the Demand Control Ventilation Limit current values. If Network is selected as the Min OA Reset Type and a valid value for the minimum position is not provided, the
Min OA position is set equal to the Ventilation Limit.
Minimum Outside Air Reset - External Control
If ExtV is selected as the Min OA Reset Type, the Minimum
OA Position is calculated based on an external 0-10 VDC signal. If ExtmA is selected as the Min OA Type, the
Minimum OA Position is calculated based on an external
0-20 mA signal. This calculated Minimum OA Position varies linearly from zero % at the editable minimum external signal to the maximum value at the editable maximum external signal, but it is set no lower than the Demand Control
Ventilation Limit and no higher than the Ventilation Limit.
Minimum Outside Air Reset -IAQ
If either IAQV or IAQ mA is selected as the Min OA Type, the Minimum OA Position is calculated based on a 0-10V or
0-20 mA CO2 sensor input. The CO2 level is expressed as
Parts Per Million. The minimum and maximum sensor input values (0-10V or 0-20 mA) and the corresponding minimum and maximum PPM values are user defined. This calculated
Minimum OA Position varies linearly from the Demand
Control Ventilation Limit at the “PPM @ DCV Limit” to the
Ventilation Limit at the “PPM @ VentLimit””. The “PPM @
DCV Limit” is not allow to be set equal to or greater than the
“PPM @ VentLimit”
Examples of typical Min OA reset schedules .
If IAQ VDC is selected as the Min OA Type, the Minimum
OA Position is calculated based on a 0-10V CO2 sensor input.
The CO2 level is expressed as PPM (Parts Per Million). The minimum and maximum sensor input values (0-10V) and the corresponding minimum and maximum PPM values are user changeable. This calculated Minimum OA Position varies linearly from the Demand Control Ventilation Limit at the value labeled “PPM @ DCV Limit” to the Ventilation Limit at the value labeled “PPM @ VentLimit”. The “PPM @ DCV
Limit” is not allow to be set equal to or greater than the “PPM
@ VentLimit”
Example #1 Min OA reset type = IAQ VDC
If the requirement is to have the OA damper be at its minimum (Demand Control Ventilation Limit) when the
CO2 levels are less than 800PPM and to be at its maximum
(Ventilation Limit) when the CO2 levels are greater than
1000PPM, the controller would be set up as follow:
• Vent Limit = 100%
• Lo Flow Vent Limit = 100%
• DCV Limit = 0%
• Min OA reset type = IAQ VDC
• PPM@DCV Limit = 800
• PPM@Vent Limit = 1000
• IAQ PPM = Current PPM
• Min PPM = 0 (From CO2 transducer)
• Max PPM = 2000 (From CO2 transducer)
• V/A @ Min PPM = 0 VDC
• V/A @ Max PPM = 10 VDC
In this example the Minimum OA Position would vary linearly from 0% outside air at 800PPM or less to 100% outside air at 1000PPM or greater.
Examples of typical Min OA reset schedules .
If EXT VDC is selected as the Min OA Type, the Minimum
OA Position is calculated based on an external 0-10 VDC signal. This calculated Minimum OA Position varies linearly from zero % at the changeable minimum external signal to
100% at the changeable maximum external signal, but it is set no lower than the Demand Control Ventilation Limit and no higher than the Ventilation Limit.
Example #2 Min OA reset type = EXT VDC
If the requirement is to have the OA damper be at its minimum (Demand Control Ventilation Limit) when the field supplied signal is at its minimum (0VDC) and to be at its maximum (Ventilation Limit) when the field supplied signal is at its maximum (10VDC), the controller would be set up as follow:
• Vent Limit = 100%
• Lo Flow Vent Limit = 100%
• DCV Limit = 10%
• Min OA reset type = EXT VDC
• OA@MinV/mA = 0%
• OA@MaxV/mA = 100%
• Min V/mA = 0 VDC
• Max V/mA = 10 VDC
In this example the Minimum OA Position would vary linearly from 0% outside air at 0 VDC to 100% outside air at
10 VDC.
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Operator’s Guide
Reset Temperature Limit
The user has the option of setting a low temperature limit that will override all the outdoor air reset functions described in this section except the Return Fan Capacity Override function if the discharge air temperature or entering fan temperature gets too cold as a result of the reset. The user can choose the override sensor by setting the Reset Temperature Limit to
None, DAT or EFT. When set to None the Reset Temperature
Limit function is disabled. A Reset Temperature Limit PI_
Loop will be used to reset the minimum outside air damper setpoint downward when the selected temperature input drops below the Reset Temperature Limit.
Minimum Position Control -Field Supplied Outdoor
Airflow Station Input
When the OA Flow Station parameter in the Software
Configuration Code is set to Field Station and the Field
Station parameter on the keypad is set to VDC or mA, the Minimum OA Position value is adjusted based on the measured amount of outdoor air being brought into the unit from a field supplied airflow monitoring station. If the airflow is below the desired value, the Minimum OA Position is increased and if the airflow is above the desired value,
Minimum OA Position is decreased.
The field airflow signal will be in the form of a 0-10V or 0-20 mA input. The minimum and maximum sensor input values
(0-10V or 0-20 mA) and the corresponding minimum and maximum CFM values are user editable.
NOTE:
The Minimum OA Position is reset up and down between the Ventilation Limit and the Demand
Control Ventilation Limit by a PI_Loop function to maintain the field OA CFM value at an adjustable OA
CFM Setpoint .
When the MinOAType is set to Ext or IAQ and the
Field OA Station parameter is set to VDC or mA, the
OA flow input is assigned to a specially added I/O expansion module (EXPE) position X1 . When the
MinOAType is not set to Ext or IAQ and the Field OA
Station parameter is set to VDC or mA, the OA flow input is assigned to the main control board(MCB) position X1 .
Minimum Position Control - Design Flow (RPS
Airside Economizer Units Only)
When the OA Flow Station parameter in the Unit configuration menu is set to Design Flow and the Design
Flow control flag is set to Yes, the minimum outside air damper position is controlled to maintain the minimum OA flow setpoint. Design Flow is only available when for RTU units with Airside Economizers.
When the DesignFlow control flag is set to Yes, the Minimum
OA Position value is adjusted based on the measured amount of outdoor air being brought into the unit using a PI_Loop function. If the airflow is below the desired value, the
Minimum OA Position is increased and if the airflow is above the desired value, Minimum OA Position is decreased.
94
NOTE:
The factory default for Min OA Reset is set to none however changes may be made by accessing the Min
OA Set-Up menu . Once changes have been made to the Min OA Reset type, the Apply Changes flag must be changed from no to yes in order for the controller to recognize the changes . Setting the Apply Changes flag to YES will automatically reset the controller.
0-30%OA Units
A two position 0-30% OA actuator is controlled by a modulating analog output. This actuator is driven to its fully open position, nominally 30%, when the OA damper analog output is at its maximum value and it is driven closed when the OA damper analog output is at its minimum value.
The desired minimum open position between 0% and 30% normally is set by an editable keypad menu item (Vent Limit).
If a valid value is provided via the network, that position is used as the desired minimum open position instead of the keypad value.
The two position damper is driven to the closed position when the supply fan is off (Off and Startup state), the unit is in the
Recirculation state, unoccupied operation is active, or the fan has been on for less than the Zero OA Time. As a result the
OA dampers are driven closed in night setback, night setup, morning warm-up, and morning cool down situations. The two position damper is driven to the desired minimum open position in all other conditions.
The Ventilation Limit equals the keypad editable Vent Limit and the Demand Control Ventilation Limit equals the keypad editable DCV Limit. The Vent Limit cannot be set higher than the 0-30%OAMax value. The DCV Limit cannot be set higher than the Vent Limit.
Return Fan Capacity Override (RTU Airside
Economizer Units Only)
The minimum position determined by any method below may be overridden for a variable speed return fan when the return fan speed is below the supply fan speed by more than an adjustable value. In this situation, the outdoor air damper minimum position is reset up based on the schedule shown below if normal control of the minimum position would result in a lower value. The minimum position will be controlled in the normal manner if that results in a higher value than determined by the reset schedule.
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Operator’s Guide
Table 50: Outdoor Air Damper Minimum Position Reset
Schedule
Discharge Fan
Speed – Return
Fan Speed
Outdoor Air
Damper Minimum
Position
<= 20% Min Fan
Differential
Demand Control
Ventilation Limit
Between Min and
Max Differential
>= 50% Max Fan
Differential
Linear
Interpolation
Ventilation Limit
NOTE:
If the supply fan is a constant volume fan, the
Supply Fan Speed is assumed to be 100% when the discharge fan is on . If the Min Fan Differential is set equal to the Max Fan Differential, the return fan capacity override value reverts to the Ventilation
Limit . Thiscapability is not provided for exhaust fans .
Building Static Pressure Override (Airside
Economizer Units Only)
The minimum position determined by any method described below may be overridden for a variable speed return fan or exhaust fan controlled by building static pressure when the return fan speed is at minimum or the exhaust fan has been stopped due to low building static pressure if the building pressure remains negative. If the user elects to use this function and the return fan has been at the minimum speed or the exhaust fan has been stopped for a minimum return/ exhaust fan off time (default = 120 seconds) a PI_Loop will begin modulating the Min OA Pos setpoint upward to maintain the building static pressure at the building static pressure setpoint.
100% Outside Air Damper Control, Two
Position
100% OA two position actuators are controlled by a digital output for SCU unit and by a modulating analog output for
RTU units.
• Digital Output - The OA damper is driven fully open when the digital output is On and fully closed when the digital output is Off
• Analog Output (100%OA Units) - The OA damper is driven to its 100% open position when the OA damper analog output is at its maximum value and it is driven closed when the OA damper analog output is at its minimum value
The OA damper is open during the Start Initial period, and it remains open during all operating states. The OA damper remains open after the fan is turned off until 30 seconds after the Airflow Switch digital input indicates loss of airflow. This keeps the outside air dampers open in case there is a failure or external override that keeps the fan running after it is turned off by controller logic. If the fan is turned on by bypassing the controls that have it off, the Damper Output is NOT turned on.
Airside Economizer
If a unit is equipped with a 0-100% modulating economizer, and the outdoor air is suitable for free cooling, the unit attempts to satisfy the cooling load by using outdoor air before using mechanical cooling. When the control temperature is above the Occupied or Unoccupied Cooling
Set Point by more than half the Occupied or Unoccupied
Cooling Dead Band and the discharge air temperature is above the Discharge Cooling Set Point by more than half the Discharge Cooling Dead Band, the controller enters the
Econo state. When the unit is in the Econo operating state, the outdoor air dampers are modulated as required to maintain the Discharge Cooling Set Point.
Economizer to Cooling Operating State
The transition from the Econo to Cooling operating state occurs when the economizer is unable to satisfy the cooling load and mechanical cooling is available. This will occur when the commanded economizer position indicates more than 95% open and the discharge air temperature (DAT control units) or control temperature (Zone control units) is above the applicable Cooling Setpoint by more than half the applicable Cooling Deadband for longer than the Cooling
Interstage Timer.
Waterside Economizer
If a unit is equipped with a 0-100% modulating waterside economizer, and the conditions are suitable for free cooling, the unit attempts to satisfy the cooling load by using waterside economizer before using mechanical cooling. When the control temperature is above the Cooling Enable Set Point by more than half the Cooling Enable Dead Band and the discharge air temperature is above the Discharge Cooling Set
Point by more than half the Discharge Cooling Dead Band, the controller enters the Econo state. When the unit is in the
Econo operating state, the economizer valve is modulated as required to maintain the Discharge Cooling Set Point.
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Operator’s Guide
Bypass Valve Control
This section describes the operation of an analog output used to control a valve that allows water to bypass a waterside economizer and flow directly into a condenser.
When the bypass valve is closed, all water flows through the waterside economizer before it flows through the condenser.
Figure 15: Bypass Control Diagram
When the Bypass Valve is open, all water that flows into the self-contained unit flows directly to the condenser without any water going through the waterside economizer. There are two different methods for controlling this valve; Slave Control and Bypass Control.
Slave Control
The bypass valve is linked electrically to the economizer valve so that the bypass valve closes as the economizer opens.
This provides a nearly constant flow of water through the unit regardless of the requirements of the economizer. When there is no cooling required, the bypass valve will be open and the waterside economize r valve is closed allowing water to flow through the condenser. This valve control option can be used in either a variable or constant pumping system.
Bypass Control
The bypass valve and waterside economizer valve are independently controlled. . The bypass valve to the condenser is closed in all states except the Fan only, Mechanical cooling, and Economizer. The bypass valve is open when mechanical cooling is required and the water is not flowing through the waterside economizer. When the unit is Off: Unoccupied, both the bypass valve and the waterside economizer valve are closed. No water is allowed to flow through the unit. This valve control option is typically used in variable pumping system or a constant pumping system with a bypass loop
Water Regulating Valve Control
In the Cooling state, the Water Regulating Valve stays at its last commanded position when the last compressor is turned off.
When all compressors are off and a compressor needs to be turned on, the Water Regulating Valve must be driven open long enough to prevent the compressor from being locked out due to high pressure, but not so long that it is locked out due to low pressure. The WRV Start Sequence described below is used to make sure this is the case. This is required when transitioning to the Cooling state from the Fan Only or
Economizer state.
In the Fan Only state, the Water Regulating Valve is normally closed. The WRV Start Sequence described below is initiated in the Fan Only state whenever all of the following are true:
• Cooling Status=Enabled or Off Ambient
• Airside Economizer operation is disabled or not installed
• Either of the following are true:
–
Both of the following are true:
— Control Temperature Source is something other than None
— Control Temperature > Occupied Cooling
Setpoint + ½ the cooling dead band
–
Both of the following are true:
— Control Temperature Source is set to None
—
DAT > DAT Cooling Setpoint + ½ the cooling dead band
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In the Economizer state, the Water Regulating Valve is normally closed. The WRV Start Sequence described below is initiated in the Economizer state whenever either of the following is true:
All of the following are true:
• All of the following are true:
–
Cooling Status=Enabled or Off Ambient
–
Economizer Position is greater than 95.0% for more than the Cooling Stage Time AND
– Discharge Air Temperature > DAT Cooling Setpoint
+ ½ the cooling dead band for more than the Cooling
Stage Time
• Both of the following are true:
–
Cooling enabled AND
–
Economizer Disabled
Water Pump Control
The Pump output is in the on position if any of the following are true:
• The Bypass Valve output is being driven above 0%
• The Water Regulating Valve output is being driven above 0%
• A waterside economizer is installed and the unit is in the
Economizer state
• The unit is the Cooling state
• The Unit is in the Start Initial state and Flush Mode is set to Yes
• The unit has a waterside economizer and a Freeze Fault or Freeze Problem is active
• The unit has a waterside economizer and 10 minutes have not yet passed after a Freeze Fault or Freeze
Problem has disappeared
WRV Start Sequence
The following Startup Sequence is followed when a stage up from stage zero is required and the Water Regulating Valve is closed.
The Water Regulating Valve is set to an minimum(Default =
10%)
The Entering Water Temperature (EWT) is measured after the WRV has been at its minimum position for a default of 60 seconds. An Initial WRV Position is then calculated based on the measured EWT. The Unit transitions to Cooling and the first compressor is started when the time to initial position has passed. The first compressor runs for an editable
Initial Operation Time with the WRV at the calculated initial position. Control then reverts to normal PI control.
Cooling: Multistage
Entering the Cooling Operating State
The unit enters the Cooling operating state from the Fan Only operating state when the control temperature rises above the
Occupied or Unoccupied Cooling Set Point by more than half the Cooling Dead Band and the discharge air temperature is above the discharge cooling setpoint by more than half the cooling Dead Band. The unit transitions from Cooling to Fan only when the control temperature falls below the Occupied or Unoccupied Cooling Set Point by more than half the
Occupied or Unoccupied Cooling Dead Band. The unit will also transition from the Cooling to Fan only operating state if
Cooling operation is disabled due to OA ambient lockout.
Special Procedures for Units with WRV and More
• When the unit enters Cooling, a compressor on either circuit # 1 or # 2 must start first if one is enabled because the pressure sensors are on circuits # 1 and # 2.
• If both circuits # 1 and #2 are disabled due to High
Pressure or Low Pressure alarms, the lead compressor is determined by the compressor circuit that contains the compressor with the fewest run hours.
• If both circuit # 1 and circuit # 2 are disabled, The WRV will be controlled based on the EWT and the calculated initial position.
• Control of the WRV reverts to normal PI control if either circuit # 1 or circuit # 2 is enabled and its compressor is turned on.
• All compressors are disabled if EWT drops below the minimum WRV temperature value by more than the
Outside air cooling lockout differential.
• Compressors are re-enabled if EWT rises above the minimum WRV temperature value.
Staging -DAT Control
In the Cooling state, compressor stages are turned on and off to maintain an average Discharge Air Temperature near the Discharge Cooling Setpoint. When the load is such that cooling capacity is being staged up and down between two stages, this control sequence causes the unit to operate longer at the stage that produces the discharge air temperature that is closer to the setpoint over time which results in an average discharge air temperature that is very close to the Discharge
Cooling Setpoint. This setpoint may be fixed or reset as described in the Cooling DAT Reset section. External devices such as VAV boxes maintain the desired space conditions.
The unit may be a Constant Volume unit, but it is normally a
Variable Air Volume unit. If the Discharge Air Temperature is approaching the setpoint, the number of stages continues to increase or decrease until the actual temperature gets within half the deadband. Control of cooling stages is based on two values, the Degree Time Above and the Degree Time Below the Discharge Cooling Setpoint. The difference between the actual discharge air temperature and the Discharge Cooling
Setpoint is added to one of the Degree Time values every ten seconds. If the Discharge Air Temperature exceeds Discharge
OM 920-4 97
Operator’s Guide
Cooling Setpoint, the difference is added to the Degree Time
Above value. If the Discharge Air Temperature is below the
Discharge Cooling Setpoint, the difference is added to the
Degree Time Below value. These values are limited to a maximum value of 250 to prevent remaining too long in one stage because one value or the other became very large.
When the unit enters the Cooling state the first compressor is turned on immediately. When the unit is equipped with evaporative condensing, the sump pump must be turned on before any compressor is turned on. If there is a sump pump fail condition, cooling will stay in stage 0.
With DAT staging control, there are four possible staging transitions; Stage up after stage up, stage up after stage down, stage down after stage down, and stage down after stage up.
These are described in the following paragraphs:
Stage Up After Stage Up:
If the time since the last stage change exceeds the cooling stage timer, the discharge air temperature is greater than the
Discharge Cooling Setpoint by more than half the deadband, the last stage change was a stage up, and dehumidification is not active; cooling capacity is increased by one stage
Stage Up After Stage Down:
If the time since the last stage change exceeds the cooling stage timer, the discharge air temperature is greater than the
Discharge Cooling Setpoint by more than half the deadband, the last stage change was a stage down, the Degree Time
Above value is greater than or equal to the Degree Time
Below value, and the dehumidification is not active; cooling capacity is increased one stage.
Stage Down After Stage Down:
If the time since the last stage change exceeds the cooling stage timer, the discharge air temperature is less than the
Discharge Cooling Setpoint by more than half the deadband, the last stage change was a stage down, and dehumidification is not active; cooling capacity is decreased one stage.
Stage Down After Stage Up:
If the time since the last stage change exceeds the cooling stage timer, discharge air temperature is less than the
Discharge Cooling Setpoint by more than half the deadband, the last stage change was a stage up, the Degree Time Below value is greater than or equal to the Degree Time Above value, and dehumidification is not active; cooling capacity is decreased one stage.
The Degree Time Below and Degree Time Above values change whenever a stage change occurs. If the previous stage change was a stage up and the number of stages increases again, both Degree Time Above and Degree Time Below are set to zero.
If the last stage change was a stage up and the stage decreases due to the Degree Time Below exceeding the Degree Time
Above, the Degree Time Below is reduced by an amount equal to Degree Time Above and then the Degree Time
Above is set to zero.
If the last stage change was a stage down and the stage increases due to the Degree Time Above exceeding the
Degree Time Below, the Degree Time Above is reduced by an amount equal to Degree Time Below and then the Degree
Time Below is set to zero.
Degree Time logic is not used when dehumidification is active. When dehumidification is active, cooling capacity is increased if the time since the last stage change exceeds the cooling stage timer and the Leaving Coil Temperature (LCT) is greater than the Maximum Leaving Coil Setpoint. When dehumidification is active, cooling capacity is decreased if the time since the last stage change exceeds the cooling stage timer amd the leaving coil temperature is less than the minimum leaving coil setpoint.
Average Discharge Control Method Illustration
Figure 10 is an illustration of the “Degree Time” compressor staging control method and is meant to show a variety of staging possibilities not normal unit operation. Figure 10 shows nine points on a graph of the discharge air temperature changing with time. The Cooling Interstage Timer setting is 5 minutes.
Point 1
Assume that the controller has just staged up and that DTA and DTB are zero. As a result, the discharge air temperature drops and the Cooling Interstage Timer is reset.
Point 2
DTA (Area A) equals DTB (Area B). The discharge air temperature is below the Effective Discharge Cooling Set
Point by more than half the Discharge Cooling Dead Band.
However, since the Cooling Interstage Timer has not yet expired, no staging action occurs.
Point 3
The Cooling Interstage Timer has expired. DTB
(Area B + Area C) is greater than DTA (Area A) and the discharge air temperature is below the Effective Discharge
Cooling Set Point by more than half the Discharge Cooling
Dead Band. Therefore, cooling is staged down. As a result, the discharge air temperature rises, the Cooling Interstage
Timer is reset, and DTA is subtracted from both DTA and
DTB. This zeros DTA and leaves DTB equal to Area C.
Point 4
The Cooling Interstage Timer has expired. The discharge air temperature is above the Effective Discharge
Cooling Set Point by more than half the Discharge Cooling
Dead Band. However, since DTA (Area E) is not yet equal to DTB (Area C + Area D), no staging action occurs and the discharge air temperature continues to rise.
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Operator’s Guide
Point 5
The Cooling Interstage Timer has expired. The discharge air temperature is above the Effective Discharge
Cooling Set Point by more than half the Discharge Cooling
Dead Band and DTA (Area E + Area F) is equal to DTB
(Area C + Area D). Therefore, cooling is staged up. As a result, the discharge air temperature drops, the Cooling
Interstage Timer is reset, and DTB is subtracted from both
DTB and DTA. This zeros both DTA and DTB since they are equal. Note that the elapsed time since the last stage change in
Figure 10 is 6.3 minutes.
Point 6
The Cooling Interstage Timer has expired. Because the cooling load is now increasing, the discharge air temperature does not fall below the Effective Discharge
Cooling Set Point by more than half the Discharge Cooling
Dead Band. No staging action occurs for two reasons: (1) the discharge air temperature is within the Discharge Cooling
Dead Band and (2) DTB (Area H) is not yet equal to DTA
(Area G). Even if the discharge air temperature falls below the Effective Discharge Cooling Set Point by more than half the Discharge Cooling Dead Band (as shown just after Point
6), a stage down does not occur because DTB remains less than DTA. The discharge air temperature starts rising again because the load is increasing.
Figure 16: Cooling Interstage Timer
Point 7
The discharge air temperature is again above the
Effective Discharge Cooling Set Point by more than half the
Discharge Cooling Dead Band. Since the Cooling Interstage
Timer expired at Point 6, cooling is staged up. As a result, both DTA and DTB are zeroed and the Cooling Interstage
Timer is reset. Note that DTA and DTB are both zeroed since two consecutive stage increase actions occurred. The discharge air temperature continues to rise, however, because the cooling load is still increasing. Note that the elapsed time since the last stage change in this illustration is 11.0 minutes.
Point 8
The Cooling Interstage Timer has expired. Since the discharge air temperature is still above the Effective
Discharge Cooling Set Point by more than half the Discharge
Cooling Dead Band, another stage-up occurs. As a result,
DTA (Area K) is again zeroed out (DTB remains zeroed) and the Cooling Interstage Timer is reset. The cooling load has leveled out, and the discharge air temperature drops.
Point 9 The Cooling Interstage Timer has expired at the same time that DTB (Area M) becomes equal to DTA (Area L).
Therefore, cooling is staged down, the Cooling Interstage
Timer is reset and DTA is subtracted from both DTA and
DTB. This zeros both DTA and DTB since they are equal.
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Operator’s Guide
Staging - Zone Control
In the Cooling state, compressor stages are turned on and off to maintain the control temperature close to the Occupied or
Unoccupied Cooling Setpoint. Use of the Projected Control
Temperature reduces overshoot during cool down. See the
Project Ahead section for a description of how the Project
Ahead Temperature is calculated.
When the unit enters the Cooling state or dehumidification operation begins the unit goes directly to Cooling Stage # 1 so that the first compressor is turned on immediately.
During normal cooling operation the number of compressor stages increases when the time since the last stage change exceeds the Cooling stage timer, Projected Control
Temperature is greater than the Occupied or Unoccupied
Cooling Setpoint by more than half the deadband, the Control
Temperature is greater than the Occupied or Unoccupied
Cooling Setpoint by more than half the deadband, and the
Discharge Air Temperature is greater than the minimum DAT cooling setpoint.
During normal cooling operation the number of compressor stages decreases when the time since the last stage change exceeds the cooling stage timer, the Projected Control
Temperature is less than the Occupied or Unoccupied
Cooling Setpoint by more than half the deadband, the Control
Temperature is less than the Occupied or Unoccupied Cooling setpoint by more than half the deadband.
During normal cooling operation the compressor stages also decrease when the time since the last stage change exceeds the cooling stage timer, and the discharge air temperature is less than the minimum DAT Cooling setpoint.
When Dehumidification is active, compressor stages are controlled to maintain the leaving coil temperature between the minimum leaving coil setpoint and the maximum leaving coil DAT setpoint.
During dehumidification on operation, the number of compressor stages increases if the time since the last stage change exceeds the cooling stage timer and the leaving coil temperature is greater than the Maximum Leaving Coil
Setpoint. During dehumidification operation, the number of compressor stages decreases if the time since the last stage change ecxeeds the cooling stage timer and the leaving coil temperature is less than the Minimum Leavaing Coil
Setpoint.
Project Ahead
This section describes the Projected Control Temperature used to turn on and off stages of heating and cooling for Zone
Control units. It is not used in DAT Control units.
In Zone Control cooling and heating operation, the Projected
Control Temperature, reduces overshoot as the zone temperature approaches a setpoint after startup. It does this by causing stages to stop increasing before the actual control temperature reaches the setpoint. The rate of change of the control temperature is calculated once per minute by the controller and equals the change during the last sixty seconds. This rate of change is multiplied by the Effective
Project Ahead Time and is added to the current control temperature. The rate of change may be negative or positive so the Projected Control Temperature may be higher or lower than the actual control temperature. This value, the Projected
Control Temperature, is the temperature that would exist after the Project Ahead Time passes if the control temperature were to continue to change at the same rate for the Effective
Project Ahead Time. The Effective Project Ahead Time is set equal to the Cooling Project Ahead Time when the unit is in the Cooling state. The Effective Project Ahead Time is set equal to the Heating Project Ahead Time when the unit is in the Heating state. It is set equal to zero under all other conditions causing the Projected Control Temperature to equal the actual control temperature
Cooling: Modulating
Modulating Cooling Control: Chilled Water
When the unit’s cooling type is set to chilled water and is in the Cooling operating state, or in the dehumidification operating state the chilled water valve is modulated to maintain the discharge air temperature at the Discharge
Cooling Set Point (or leaving coil temperature at the
Minimum Leaving Coil Setpoint if dehumidification is active).
Modulating Cooling Control: Face & Bypass
When the unit’s cooling type is set to Face & Bypass and is in the Cooling operating state, or in the dehumidification operating state, the chilled water valve is driven fully open and the face and bypass dampers are modulated to maintain the discharge air temperature at the Discharge Cooling Set
Point (or leaving coil temperature at the Minimum Leaving
Coil Setpoint if dehumidification is active).
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Operator’s Guide
Discharge Air Temperature Setpoint Reset -
Cooling
The Cooling DAT Setpoint may be reset for units with DAT
Cooling Control. The reset type may be set to one of the following:
• None: Discharge Cooling Spt is user adjustable
• Network: Discharge Cooling Spt is equal to the Network
DAT Clg Setpoint when it is valid
• Space: Discharge Cooling Spt is based on the Space Sensor
• Return: Discharge Cooling Spt is based on the Return Air
Sensor
• OAT: Discharge Cooling Spt is based on the Outdoor Air
Temperature
• Ext mA: Discharge Cooling Spt is determined by a 0-20 mA signal
• Ext V: Discharge Cooling Spt is determined by a 0-10 VDC signal
• Airflow: Discharge Cooling Spt is based on the airflow as indicated by the variable frequency drive speed
Reset reverts from Return to None when a Return Air Sensor opens or shorts. Reset reverts from Space to None when a
Space Sensor opens or shorts. Reset reverts from OAT to
None when an Outdoor Air Sensor opens or shorts.
When Space, Return, OAT, Airflow, Ext mA, or Ext V is selected, the Discharge Cooling Spt equals the Max Clg Spt when the selected value equals the Max Clg Spt @ value.
Similarly, the Discharge Cooling Spt equals the Min Clg Spt when the selected value equals the Min Clg Spt @ value.
When Space, Return, OAT, or Airflow is selected, the reset schedule should be set so that the DAT Cooling setpoint decreases as the selected temperature increases as shown in the graph.
Figure 17: Cooling Setpoint
When Airflow is selected, the values “Min Clg Spt @” and
“Max Clg Spt @” are entered as percentage values. When Ext mA is selected, the values “Min Clg Spt @” and “Max Clg
Spt @” are entered as mA values. When Ext VDC is selected, the values “Min Clg Spt @” and “Max Clg Spt @” are entered as VDC values.
If Ext mA or Ext V is selected as the type of reset, the Min
Clg Spt @ value may be set above the Max Clg Spt @ value to cause a decrease in the DAT setpoint as the external signal or the Min Clg Spt @ value may be set below the Max Clg
Spt @ value to cause an increase in the DAT setpoint as the external signal increase.
The Min Clg Spt @ value can be set below the Max Clg Spt
@ value for all types of reset, but it only makes sense for external reset.
When ever the Clg Reset Type or Engineering Units is changed, the Min Clg Spt @ and Max Clg Spt @ values revert to default values as follows:
• None: Min Clg Spt @=0NA, Max Clg Spt @=100NA
• Network: Min Clg Spt @=0NA, Max Clg Spt @=100NA
• Space, Return: Min Clg Spt @=73.0F, Max Clg Spt
@=71.0F
• OAT: Min Clg Spt @=90.0F, Max Clg Spt @=70.0F
• ExtmA: Min Clg Spt @=4.0mA, Max Clg Spt
@=20.0mA
• ExtVDC: Min Clg Spt @=0.0V, Max Clg Spt @=10.0V
• Airflow: Min Clg Spt @=33%, Max Clg Spt @=100%
Condenser Fan Control
RPS Units
There are up to four condenser fans per circuit. The first fan on each circuit is always turned on when any compressor on the circuit is turned on through auxiliary switches on the compressor contactors. The second two fans on each circuit (if applicable) are controlled by outputs from the Main
Controller. These are controlled via Condenser Fan Output 1 and Condenser Fan Output 2. The last fan on each circuit (if applicable) is controlled by an external refrigerant pressure switch.
Condenser Fan Output 1 is turned on when any compressor on is on and the OAT rises above the Condenser Fan A
Set Point. Condenser Fan Output 1 is turned off when all compressors are off or the OAT drops below the Condenser
Fan 1 Set Point by more than the Condenser Fan Differential
(Default = 5°F). External relays allow operation of condenser fans associated with a specific circuit only when a compressor on that circuit is on.
OM 920-4 101
Operator’s Guide
Condenser Fan Output 2 is turned on when any compressor on is on and the OAT rises above the Condenser Fan B
Set Point. Condenser Fan Output 2 is turned off when all compressors are off or the OAT drops below the Condenser
Fan 2 Set Point by more than the Condenser Fan Differential
(Default = 5°F). External relays allow operation of condenser fans associated with a specific circuit only when a compressor on that circuit is on.
Condenser Fan Output 3 is turned on when any compressor on is on and the OAT rises above the Condenser Fan 3
Set Point. Condenser Fan Output 3 is turned off when all compressors are off or the OAT drops below the Condenser
Fan 3 Set Point by more than the Condenser Fan Differential
(Default = 5°F). External relays allow operation of condenser fans associated with a specific circuit only when a compressor on that circuit is on.
The Condenser Fan default setpoints vary by unit size according to the following tables:
Table 51: 410A Condenser Fan Setpoints
Unit
Size
079
080
081
085
090
091
100
101
050
051
060
062
063
068
070
071
075
105
110
120
125
130
140
015
016
020
021
025
026
030
031
035
040
042
045
CondFanOutput1
(MCB-DO7)
CondFanOutput2
(MCB-DO8)
PC13/PC231
50
65
65
65
60
55
60
60
60
60
65
75
75
70
Setpoint Differential Setpoint Differential Setpoint Differential
70
75
70
75
5
5
5
5
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
70
70
75
75
65
65
70
60
70
70
65
70
65
60
70
75
75
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
85
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
5
—
—
—
—
—
—
—
—
—
—
—
—
—
—
90
90
90
—
—
35
35
35
—
—
—
—
—
—
—
—
—
—
—
—
5
5
5
5
5
5
5
5
5
5
5
5
5
5
80
90
85
85
85
80
85
85
85
85
80
—
—
—
5
5
5
5
5
5
5
5
5
5
5
—
—
—
90
90
90
90
90
90
90
90
90
90
90
90
90
90
35
35
35
35
35
35
35
35
35
35
35
35
35
35
Table 52: R22 Condenser Fan Setpoints
Unit
Size
045
050
060
070
075
015
018
020
025
030
036
040
080
090
105
70
65
65
60
25
40
65
65
65
0
CondFanOutput1
(MCB-DO7)
CondFanOutput2
(MCB-DO8)
CondFanOutput3
(MCB-DO6)
Setpoint Differential Setpoint Differential Setpoint Differential
60 5 — — — —
60
60
65
65
5
5
5
5
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
5
5
5
5
5
5
5
5
5
5
—
—
—
—
—
—
0
0
0
70
—
—
—
—
—
—
5
5
5
5
—
—
—
—
70
70
75
75
75
45
—
—
—
—
5
5
5
5
5
5
Table 53: R407C Condenser Fan Setpoints
Unit
Size
050
060
070
075
080
090
105
015
018
020
025
030
036
040
045
CondFanOutput1
(MCB-DO7)
CondFanOutput2
(MCB-DO8)
CondFanOutput3
(MCB-DO6)
Setpoint Differential Setpoint Differential Setpoint Differential
60
15
30
65
65
50
0
65
60
55
50
0
0
65
65
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
—
—
—
—
—
—
—
—
—
—
—
0
0
0
70
5
5
5
—
—
—
5
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
70
70
75
75
75
35
5
5
5
—
5
5
5
—
—
—
—
—
—
—
—
102 OM 920-4
Operator’s Guide
MPS Standard Condenser Fan Control
Standard Condenser Fan Control
Two, three or four condenser fans are provided. Two condenser fans are provided on 15, 17.5, 20 and 25 ton units.
Three condenser fans are provided on 26, 30 and 35 ton units.
Four condenser fans are provided on 40 and 50 ton units. The first condenser fan is always turned on when any compressor is turned on using compressor contactor auxiliary switches external to the controller.
When two condenser fans are provided, the second condenser fan (CondFanOutA) is turned on when the OAT rises above the Condenser Fan 1 Set Point. This fan is turned off when the OAT drops below the setpoint by more than the Condenser
Fan Differential (Default = 5°F).
When three condenser fans are provided, the second condenser fan is turned on when the OAT rises above the
Condenser Fan 1 Set Point and the third fan is turned on when the OAT rises above the Condenser Fan 2 Set Point.
These fans are turned off when the OAT drops below that corresponding setpoint by more than the Condenser Fan
Differential (Default = 5°F).
When four condenser fans are provided, there are two different methods for control due to a redesign of the model
040 and 050.
When the “old” four condenser fan method is used
(Condenser Control=Standard Method 1) is used, two outputs
(Condenser Fan Output1 and Condenser Fan Output 2) on the controller are used to provide three additional stages as shown in the table below. The second through fourth stages are turned on when the corresponding setpoint is exceeded by the OAT and turned off when the OAT drops below the corresponding setpoint by more than the Condenser Fan
Differential (Default = 5°F).
Table 54: Fan Staging
Operating
Fans (Stage)
1
Fan 1
(On with any compressor)
On
2
3
4
On
On
On
Fan 2
(Cond Fan
Out A)
Off
On
Off
On
Fan 3 and 4
(Cond Fan
Out B)
Off
Off
On
On
On
Condition
Any
Comp On
Cond Fan
1 Spt
Cond Fan
2 Spt
Cond Fan
3 Spt
When the “new” four condenser fan method is used
(Condenser Control=Standard Method 2), the condenser fan control is circuit specific. The first fan on each circuit is turned on using compressor contactor auxiliary switches.
The second fan on each circuit is turned on if a compressor on the circuit is on and the OAT is above the corresponding condenser fan setpoint and is turned off when the OAT drops below the corresponding setpoint by more than the Condenser
Fan Differential (Default = 5°F). Condense Fan 1 Setpoint corresponds to the second fan on Circuit 1 and Condenser Fan
2 Setpoint corresponds to the second fan on Circuit 2.
The default condenser fan setpoints vary by unit size as indicated below:
Figure 18: CondenserFan Setpoints
Unit Size
25
26
30
35
15
17
20
40 (Cond Ctrl=Std
Method 1)
50 (Cond Ctrl=Std
Method 1)
40 (Cond Ctrl=Std
Method 2)
50 (Cond Ctrl=Std
Method 2)
Condenser Fan Setpoints
Cond Fan 1 Spt
70°F/21 .11°C
70°F/21 .11°C
65°F/21 .11°C
65°F/21 .11°C
40°F/4 .44°C
40°F/4 .44°C
35°F/1 .67°C
Cond Fan 2 Spt
—
—
—
—
60°F/15 .56°C
60°F/15 .56°C
60°F/15 .56°C
Cond Fan Spt
—
—
—
—
—
—
—
25°F/-3 .89°C 45°F/7 .22°C 60°F/15 .56°C
35°F/1 .67°C
70°F/21 .11°C
70°F/21 .11°C
45°F/7 .22°C
70°F/21 .11°C
70°F/21 .11°C
55°F/12 .78°C
N/A
N/A
OM 920-4 103
Operator’s Guide
Evaporative Condensing Control (RTU)
The evaporative condensing option for rooftop units uses the heat absorbed by evaporating water as well as air drawn across a bank of tubes with refrigerant flowing through them to condense hot refrigerant to a liquid. Water is pumped from a sump beneath the condenser tubes to nozzles above the coil that spray water onto the bank of tubes. The refrigerant in the tubes is cooled and condensed as some of this water is evaporated when it strikes the hot tubes and is carried away by condenser fans. Using this method, the refrigerant can be cooled to a lower temperature than is the case with a normal finned condenser that transfers heat directly to the air.
A unit equipped with evaporative condensers cannot operate in the cooling state with the outdoor air temperature below
40°F. If the OAT Compressor Lockout Temperature on units with evaporative condensing is lowered below 40°F, it will immediately be set back up to 40°F.
The first condenser fan on each circuit is turned on and off via ModBus communications with a single VFD. The speed of these two fans is controlled via ModBus communications with the VFD. These two fans always operate at the same speed.
The second and third condenser fans on each compressor circuit are turned on and off using the two outputs on the
Main Board that are used for standard condenser fans. Relays are driven by each of these outputs so that fans associated with a circuit that is not operating will not be turned on.
Evaporative Condenser Compressor Staging Sequences
There are two cooling staging configurations available for evaporative condenser units. Both employ reciprocating compressors and so require pumpdown operation. When there is a first call for cooling on a circuit, the liquid line solenoid valve output is first energized and then as soon as the low pressure switch for that circuit closes the first compressor in the sequence is turned on. If the low pressure switch fails to close within the low pressure compressor delay timer setting the low pressure alarm for that circuit is generated.
The circuit that has the fewer run hours is the lead circuit if
Lead Circuit is set to Auto. The lead circuit is changed only when all compressors are off or at the maximum stages for the unit. If Lead Circuit is set to #1 then circuit #1 always leads if it is available. If Lead Circuit is set to #2 then circuit
#2 always leads if it is available.
The Staging Type can be set to either Standard or Alternate.
Standard
:
The two circuits are loaded up and unloaded as evenly as possible. When a stage up is required, the circuit operating at the lower stage is staged up. If both circuits are operating at the same stage, the lead circuit is staged up if it is not at its maximum stage.
When a stage down is required, the circuit operating at the higher stage is staged down if it is not at stage zero. If both circuits are operating at the same stage, the lag circuit is staged down if it is not at stage zero.
Alternate:
One circuit is loaded completely before the first compressor in the other circuit is turned on, and one circuit is unloaded completely before the other circuit begins to be unloaded.
When a stage up is required and the lead circuit is not at its maximum stage, the lead circuit is staged up.
When a stage up is required and the lead circuit is already at its maximum stage, the lag circuit is staged up. When a stage down is required and the Lag circuit is at a stage greater than zero, the lag circuit is staged down. When a stage down is required and the lag compressor is at stage zero, the lead compressor is staged down if it is not at stage zero.
A disabled circuit remains at stage zero. If the other circuit is enabled, it is staged up whenever a stage up is required, and down whenever a stage down is required. If a previously disabled circuit becomes enabled, the staging is re-aligned according to the staging tables upon the next call for stage increase or decrease. Note: During this re-alignment, the cooling stage time guaranteed on and off times must be observed as well as a minimum of 10 seconds between starting more than one compressor
When dehumidification is active staging reverts to Alternate regardless of the normal Staging Type setting. When dehumidification is not active staging is according to the
Staging Type setting.
104 OM 920-4
Operator’s Guide
Table 55:
Dehumidification Staging
Two Compressors and Six Stages (CompCfg=4 & Cond Ctrl=2 or 3)
Stage
0
1
2
3
Comp
# 1
Off
On
On
On
Circuit # 1
Liq Line Valve
# 1
Off
On
On
On
Comp # 1
Unl # 2
Off
On
On
Off
Comp # 1
Unl # 1
Off
On
Off
Off
Comp
# 2
Off
On
On
On
Liq Line Valve
# 2
Off
On
On
On
Four Compressors and Eight Stages (CompCfg=E & Cond Ctrl=2 or 3)
Circuit # 2
Comp # 2
Unl # 2
Off
On
On
Off
Circuit # 1
Stage
2
3
4
0
1
Comp
# 1
Off
On
On
On
On
Liq Line Valve
# 1
Off
On
On
On
On
Comp # 1
Unl # 2
Off
Off
Off
On*
On
Comp # 1
Unl # 1
Off
On
Off
On
Off
Comp
# 2
Off
On
On
On
On
* Note: A 20 second delay will be provided after unloading compressor #1 or #2 prior to starting Compressor #3 or Compressor #4 .
Circuit # 2
Liq Line Valve
# 2
Off
On
On
On
On
Comp # 2
Unl # 2
Off
Off
Off
On*
On
Comp # 2
Unl # 1
Off
On
Off
Off
Comp # 2
Unl # 1
Off
On
Off
On
Off
Pumpdown
Pumpdown is accomplished by closing the liquid line solenoid valve on a circuit and operating a compressor on that circuit until the circuit low pressure switch opens. The compressor pumps most of the refrigerant into the condenser and then shuts off.
When pump down is required for a circuit, the liquid line solenoid valve for that circuit is closed (its output is off) and a compressor operates until the low pressure switch opens at which time the compressor is turned off. If the low pressure switch does not open in 180 seconds, pump down is terminated by turning off the compressor and its unloaders.
If a compressor in a circuit is operating, the circuit is pumped down when the last compressor is to shut off due to normal staging, or when the pump down switch for that circuit is placed in the Pumpdown (Open) position, or when the circuit or entire unit is shutdown due to any alarm other than the High Pressure Alarm. Of course, the conditions for completing pump down are met if the low pressure alarm shuts down the circuit so no pump down occurs as a result of this alarm.
Pumpdown is also initiated if no compressors are operating in a circuit, and the Pumpdown Switch is moved from the On
(Auto) position to the Off (Pumpdown) position twice in less than 20 seconds, and the low pressure switch is closed. In this case the first compressor on the circuit is used to pump down the circuit.
If two compressors on one circuit are operating when pump down is required for that circuit, the lag compressor in that circuit is turned off immediately and the circuit is pumped down using the lead compressor.
If any unloaders on a reciprocating compressor are deenergized when that compressor is required for pump down, they are energized and the circuit is pumped down using one completely unloaded compressor.
NOTE:
A reciprocating compressor is mechanically prevented from pumping down the circuit if the oil pressure switch is open .
Sump Pump Control
The Sump Pump Output is turned on whenever the unit is in the Cooling state and the Sump Water Level Input is present (On). The Sump Pump Output is turned on before any compressor or condenser fan is turned on. The Sump
Pump Output remains on for 10 minutes (adjustable) after unit leaves the Cooling operating state before turning off as long as the Sump Water Level Input is present (On).
A Sump Water Level problem alarm is generated if the unit has been in the Cooling operation state for 5 minutes and the
Sump Water Level Input is not present (Off). If this occurs, the Sump Pump output is turned off and mechanical cooling is disabled.
To prevent problems related to Sump Water Level Switch fluctuations, there is a 5 second “to off” time on the switch.
If Dolphin= Yes, the sump pump is run every day to reduce scaling. The Sump Pump Output is turned on for one hour if all of the following are true:
• Dolphin System= Yes
• Sump Pump Output has been off for more than 24 hours but less than 120 hours.
• The OAT is greater than 35°F.
• The Sump Drain Valve is closed.
OM 920-4 105
Operator’s Guide
Sump Drain Valve Control
When the sump temperature gets too cold, the sump needs to be emptied to prevent freezing. The Sump Drain Valve
Output is used to control a sump drain valve. This output is turned on if the sump temperature drops below the Sump
Dump Setpoint, default = 35°F for more than 30 seconds.
This output is turned back off if the sump temperature rises above this setpoint by more than the Sump Dump
Differential, 2°C (hardcoded), and the unit is in the Cooling state.
If Dolphin System= Yes and the pump does not run for five days, the sump needs to be emptied. This would occur when cooling is not required and the OAT remains below 35°F.
Sump heaters are used to keep the sump temperature above
35°F when the OAT drops below that value so an additional means of turning on the Sump Drain Valve is required. In addition to the requirement that the Sump Drain Valve Output be turned on to open the valve when the sump temperature drops below 35°F, the Sump Drain Valve Output is also turned on if both of the following are true:
• Dolphin System= Yes
• The Sump Pump Output has been off for 120 hours or more.
Once on the Sump Drain Valve is turned back off as described above.
Separator Flush Valve Control
On units equipped with a Dolphin System the system
Separator needs to be flushed of its collected solids every so often. An On/Off flush valve actuator is used to flush the separator. Every 8 hours the Purge Valve Binary Output is turned on for the Separator Flush Time (default 1 minute).
Sump Temperature Control
Two configurations of evaporative condensing units are provided. One will have two condenser fan outputs per circuit (Unit Size<110), and one will have three condenser fan outputs per circuit (Unit Size≥110). The two lead condenser fans are controlled through a single VFD.
Whenever any compressor is turned on, the lead condenser fan on both circuits is turned by the Microtech III controller sending a signal to the VFD via Modbus. The lead condenser fans on both circuits are turned off when all compressors are off or they are turned off as described in paragraphs that follow when the sump temperature gets low.
Whenever any condenser fan is on, a signal is sent to the VFD to control connected fans to a setpoint. The speed setpoint is calculated based on the sump temperature.
A single Condenser Fan Output A is controlled to turn on the second condenser fan on both circuits. A single Condenser
Fan Output B is controlled to turn on the second condenser fan on both circuits. The second and third fans on the circuits are mechanically prevented from operating when no compressor on that circuit is operating. When compressors are operating on both circuits, the number of fans operating on the two circuits is the same.
The number of fans operating per circuit will increase if the time since the last change in the number of operating fans exceeds the Evap Condensing Stage Time and the sump temperature exceeds the Max Sump Temperature setpoint.
This condenser fan stage increase may occur as soon as the temperature rises above the Maximum Sump Temperature.
The temperature does not have to remain above the Maximum
Sump Temperature for longer than the stage timer.
The number of fans operating per circuit will decrease if the time since the last change in the number of operating fans exceeds the Evap Condensing Stage Time, and the sump temperature drops below the Min Sump Temperature setting.
This condenser fan stage decrease may occur as soon as the temperature drops below the Minimum Sump Temperature setting. The temperature does not have to remain below the
Minimum Sump Temperature setting for longer than the stage timer.
After the two lead condenser fans are turned off via the VFD, they are turned back on as soon as the sump temperature rises above the Maximum Sump Temperature setting. This transition from stage zero to stage one is the only transition that does not require the Stage Timer to expire.
All of the condenser fans need to be run periodically when evaporative condensing is used to prevent damage to the motors due to their high humidity environment. As indicated above, the condensing fans controlled by the VFD always run when evaporative operation is in effect so no special control of these fans is required. The fan motors controlled directly through the Condenser Fan A and Condenser Fan B outputs are turned on and off based on time on and time off. When a condenser fan output must be turned on for normal operation, the output that has been off for the longest period of time is started. When a condenser fan must be turned off for normal operation, the output that has been on for the longest period of time is turned off.
106 OM 920-4
Operator’s Guide
Heating Control
Entering Heating Operating State
The unit enters the Heating operating state from the Fan Only operating state when the control temperature falls below the
Occupied or Unoccupied Heating Set Point by more than half the Occupied or Unoccupied Heating Dead Band. The unit transitions from the Heating to Fan Only operating state when the control temperature rises above the Occupied or Unoccupied Heating Set Point by more than half the
Occupied or Unoccupied Heating Dead Band. The unit will also transition from the Heating to Fan Only operating state if heating operation is disabled due to OA ambient lockout.
Morning Warmup Control
The unit does not enter a specific morning warmup operating state to accomplish the morning warmup function. Instead the unit enters the Heating operation state when morning warmup operation is required. The dampers are held at zero percent open for Zero OA Timer after the SAF starts. The
Zero OA Timer should be set long enough to accomplish morning warmup with the dampers closed to minimize energy usage during the warmup period.
Zone Control Units
When a Zone Control Unit (Ctrl Typ=Zone) first starts in the morning it enters the Heating operating state if the Control
Temperature is below the Occupied Heating Setpoint by more that ½ the heating dead band. In this case The Occupied
Heating Setpoint is the “morning warmup setpoint”.
DAT Control Units
For Discharge Temperature Control units (Ctrl Type=DAC) there are two additional morning warmup related adjustable parameters; MWU Heating Setpoint and MWU Sensor.
When a Discharge Temperature Control unit first starts in the morning it enters the Heating operating state if the sensor selected by the MWU Sensor parameter (RAT or Space) is below the MWU Heating Setpoint by more that ½ the Heating dead band. The MWU Sensor can also be set to None. If the MWU Sensor is set to None the MWU Heating Setpoint has no effect and the unit only enters heating based on the
Occupied Setpoint in the normal manner.
Heating: Staged Zone Control
When the unit first enters the Heating operating state the unit goes directly to Stage # 1.
The number of heating stages increases when the time since the last stage change exceeds the stage time, the Projected
Control Temperature and the actual Control Temperature are less then the Occ Htg Spt (minus ½ the deadband), and the
DAT is less than the Max DAT Htg Spt.
The number of heating stages decreases when the time since the last stage change exceeds the stage time, and the Projected
Control Temperature and actual Contro Temperature are greater then the Occ Htg Spt (plus ½ the deadband).
The number of heating stages also decreases when the time since the last stage change exceeds the stage time, and the
DAT is greater than the MaxDATHtgSpt.
Heating DAT Staging or MinDAT Staging
When the unit enters the Heating or Minimum DAT states and all heating is off, the unit goes directly to Heating Stage #
1 so that the first stage of heat is turned on immediately.
The number of heating stages increases when the time since the last stage change exceeds the stage time, and DAT is less than the effective DAT setpoint (DAT staging) or the
Min DAT limit (MinDAT staging) by ½ the deadband. One exception to this is that if the current heating stage is zero, the heating stage can increase without regard to the stage timer.
The number of heating stages decreases when the time since the last stage change exceeds the stage time, and the DAT is greater than the effective DAT setpoint (DAT staging) or the
MIN DAT limit (MinDAT staging) by ½ the deadband.
The unit enters the Min DAT operating state during occupied operation when neither cooling nor heating is required based on the unit heat/cool changeover function but the discharge air temperature falls below a minimum discharge temperature limit by more than ½ the deadband. The Min DAT operating state prevents cold discharge air temperatures during what would normally be the Fan Only operating state.
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Operator’s Guide
Modulating
Entering Heating Operating State
The unit enters the Heating operating state from the Fan Only operating state when the Control Temperature falls below the Occupied or Unoccupied Heating Set Point by more than half the Occupied or Unoccupied Heating Dead Band. The unit transitions from heating to Fan only when the Control
Temperature rises above the Occupied or Unoccupied Heating
Set Point by more than half the Occupied or Unoccupied
Heating Dead Band. The unit will also transition from the
Heating to Fan Only operating state if heating operation is disabled due to OA ambient lockout. When the unit is in the Heating operating state, heating capacity is modulated to maintain the discharge air temperature at the Discharge
Heating Set Point.
There are several different modulating heating types available with this equipment. There are some differences in the control sequence depending on the heat type installed. The different types are described in the following sections.
Steam or Hot Water Heat: Face and Bypass Damper
Control
When a unit is equipped with steam or hot water with face and bypass damper heating there are two different methods used for controlling the heating arrangement. These are the
“Open Valve” and “Modulating Valve” methods and are described in the following sections.
Open Valve
When the unit enters the Heating operating state, the steam or hot water valve is driven fully open. The face and bypass dampers are then modulated to maintain the discharge air temperature at the discharge heating set point.
Modulating Valve
When the outdoor air temperature is below the F&BP changeover temperature, the Heating valve is driven to 100% open to protect the coil. The face and bypass dampers are then modulated to satisfy the heating load. When the outdoor air temperature rises above the F&B Changeover temperature by a fidderential of 2.0ºF, the face and bypass dampers are set at 100% open to the face of the coil and the Heating valve is modulated to satisfy the heating load. The default value for the changeover temperature is 37°F.
RTU Gas Heating
When a unit is equipped with modulating gas heating and is in the Heating operating state, the gas valve is modulated to maintain the discharge air temperature at the Discharge
Heating Set Point. Differences in the control of modulating gas heat are described in the following sections. On units equipped with modulating gas heat, the Discharge Heating
Set Point is limited according to a maximum heat exchanger temperature rise limit. This factory set limit varies depending on the unit burner model and can be found on the gas heat data plate attached to the unit. The controller does not allow the Discharge Heating Setpoint to be set above the current temperature entering the discharge fan (EFT) by more than this maximum heat exchanger temperature rise limit.
Min DAT
If heating is enabled and there is no heating load (normally
Fan Only operating state), the controller activates the units heating equipment as required to prevent the discharge air temperature from becoming too cool if the Min DAT Control
Flag (DAT units only) is set to yes via the Heating menu.
The unit enters the Min DAT operating state during occupied operation when neither cooling nor heating is required based on the heat/cool changeover function but the discharge temperature falls below a minimum discharge temperature limit. If the discharge air temperature falls below the this minimum discharge temperature limit by more than half the discharge heating deadband, the unit operating state changes from Fan Only to Min DAT. Note: On VAV or CAV discharge control units, the DAT cooling setpoint parameter in the Cooling menu acts as the minimum discharge temperature limit. On CAV zone control units the Min DAT
Limit parameter in the Heating menu acts as the minimum discharge temperature limit.
Typical Sequence of Operation (20-1 gas burner)
When 120V power is furnished through the system on/ off switch (S1), through the burner on/off switch (S3), and through the high limit control (FLC), terminal #6 on the flame safeguard (FSG) is powered on a call for heat.
Whenever power is restored to the flame safeguard, the flame safeguard will go through a 10 second initiation period before the prepurge period will begin. The burner air control valve will be at minimum position during off cycles. Upon a call for heat or any other time that a prepurge cycle occurs, the air control valve will be repositioned to the maximum position for prepurge and then returned to the minimum position for low fire start.
108 OM 920-4
Operator’s Guide
Upon a call for heat, the controller will close digital output
(EXPB-DO1) and energize the R20A relay. Once the normally open contacts of the R20A relay close 120V power is supplied to terminal # 6 on the FSG. The FSG then energizes its terminal #4, which powers the burner combustion air blower motor (BM) and starts the 90 second prepurge cycle. The controller will reposition the burner air valve to its maximum open position via analog output EXPBAO_X7 for prepurge.
When the burner air valve reaches the full open position switch (LS2) will ‘make’ and provide a digital input to the controller (EXPB-DI_X3). This digital input will initiate a
20 second timing period in the controller. At the completion of the timing period, the controller will begin to drive the burner air valve to its minimum (low fire) position. When the valve reaches the minimum position switch LS1 will ‘make’ and provide a digital input to the controller (EXPB-DI_X2) indicating the controller’s prepurge sequence is complete.
As soon as the FSG prepurge time expires FSG terminal #8 will energize relay R22 which will turn on a digital input to the controller (EXPB-DI-X1). As soon as this digital input is
‘made’ the controller will close digital output (EXPB-DO2) allowing the combination gas valve(s) (GV1) to be energized.
After completion of the FSG prepurge period there will be a 10 second trial for ignition during which terminal #8
(combination gas valve - GV1) and terminal #10 (ignition transformer - IT) will be energized. If flame is being detected through the flame rod (FD) at the completion of the
10 second trial for ignition period, terminal #10 (ignition transformer - IT) will be deenergized and terminal #9 (main gas valves - GV4 and GV5 depending on burner size) will be energized and the control system will be allowed to control the firing rate once the heating stage timer (default 5 minutes) has passed. After the flame has lit and been proven and the heating stage time has passed, the controller will modulate (VM1) to the required firing rate via analog output
EXPB-AO_X7. In the event the flame fails to ignite or the flame safeguard fails to detect its flame within 10 seconds, terminals #4, 8, 9, and 10 will be de-energized, thus deenergizing the burner. The FSG will then lockout and would require manual resetting. If the FSG lockout occurs, FSG terminal #3 will energize the R24 alarm input status relay which will ‘make’ a digital input to the controller (EXPB-DI_
X4). When this digital input is ‘made’ the controller will drive
VM1 to the closed position, de-energize digital output EXPB-
DO2 and the prepurge sequence will be disabled and reset. If the FSG terminal # 8 de-energizes R22 (EXPB-DI_X1) after having it turned on and the FSG is not off on safety lockout, the prepurge sequence will start over. If an attempt is made to restart the burner by resetting the FSG or if an automatic restart is initiated after flame failure the earlier described prepurge cycle with the wide open air valve will be repeated.
If the unit overheats, the high limit control (FLC) will cycle the burner, limiting furnace temperature to the limit control set point. The flame safeguard contains ‘LEDS’ (lower left corner) that will glow to indicate operation.
Typical Sequence of Operation (3-1 Gas)
When 120V power is furnished through the system on/ off switch (S1), through the burner on/off switch (S3), and through the high limit control (FLC), terminal #6 on the flame safeguard (FSG) is powered on a call for heat.
Whenever power is restored to the flame safeguard, the flame safeguard will go through a 10 second initiation period before the prepurge period will begin. The burner air control valve will be at minimum position during off cycles.
Upon a call for heat, the controller will close digital output
(EXPB-DO1) and energize the R20A relay. Once the normally open contacts of the R20A relay close, 120V power is supplied to terminal # 6 on the FSG. The FSG then energizes its terminal #4, which powers the burner combustion air blower motor (BM) and starts the FSG prepurge cycle.
After completion of the FSG prepurge period there will be a 10 second trial for ignition during which terminal #8
(combination gas valve - GV1) and terminal #10 (ignition transformer - IT) will be energized. If flame is being detected through the flame rod (FD) at the completion of the 10 second trial for ignition period, terminal #10 (ignition transformer
- IT) will be deenergized and terminal #9 (main gas valves -
GV4 and GV5) will be energized and the control system will be allowed to control the firing rate once the heating stage timer (default 5 minutes) has passed. After the flame has lit and been proven and the heating stage time has passed, the controller will modulate (VM1) to the required firing rate via analog output EXPBAO_X7. In the event the flame fails to ignite or the flame safeguard fails to detect its flame within
10 seconds, terminals #4, 8, 9, and 10 will be de-energized, thus de-energizing the burner. The FSG will then lockout and require manual resetting. If the FSG lockout occurs, FSG terminal #3 will energize the R24 alarm input status relay which will ‘make’ a digital input to the controller (EXPB-
DI_X4). When this digital input is ‘made’ the controller will drive VM1 to the closed position. If the FSG terminal 8 de-energizes relay R22 (EXPBDI_X1) after having it turned on and the FSG is not off on safety lockout the controller will drive VM1 to the closed position. If an attempt is made to reset the FSG or if an automatic restart is initiated after flame failure, the FSG prepurge cycle will be repeated. If the unit overheats, the high limit control (FLC) will cycle the burner, limiting furnace temperature to the limit control set point.
The flame safeguard contains ‘LEDS’ (lower left corner) that will glow to indicate operation.
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Operator’s Guide
Special Start Sequence for 100% Outdoor Air Units with Gas Heat
A special start sequence is used for units 100% outdoor air units with gas heat. The special start sequence applies to both Zone Control and DAT Control units. If heat is required at unit startup, the furnace enters a special burner startup sequence as the unit enters its Startup operating state. Prefiring the burner allows the gas heat pre-purge sequence to occur and the burner to fire and warm up so that tempered air is available immediately when the fans start.
Once a 100% Outdoor Air unit equipped with gas heat completes one of the start up sequences described below the gas heat operates the same for both return air units and 100% outdoor air units.
The sequence described in the following paragraphs is initiated for a 100% OA Zone Control unit any time during the Startup operating state when the Control Temperature is less than the Effective Occupied or Unoccupied Heating
Setpoint† by ½ the Occupied or Unoccupied Heating
Deadband or the OAT is less than the Min DAT Limit by the amount of the DAT Htg Deadband. The sequence described in the following paragraphs is initiated for 100% OA DAT
Control units during the startup operating state when the
Min DAT Ctrl parameter is set via the keypad and the OAT is less than the DATClgSpt by the amount of the DAT Htg
Deadband.
† The Effective Occupied or Unoccupied Heating Setpoint equals the Occupied or Unoccupied Heating Setpoint for
Zone Control units. Otherwise it equals the Morning Warmup
Heating Setpoint (DAT Control units). The special start up sequence is initiated during the Startup operating state. The fans will remain off. The main gas valve is energized so the burner starts during the Warmup Time (default = 240 seconds) and operates at low fire.
At the end of the Warmup Time, the modulating gas heating valve is set to a calculated position. This calculated position is based on the “Application Discharge Air Temperature
Setpoint”, the outdoor air temperature, and the Maximum
Temperature Rise of the gas heat exchanger using the following formula:
Gas Heat Actuator Position = 100% x (Setpoint - Outdoor Air
Temp) / Temp Rise
The Application Discharge Air Temperature Setpoint is the
Occupied or Unoccupied Heating Setpoint if the control temperature initiated the special start sequence. If the OAT initiated the special start sequence, the setpoint is the Min
DAT Limit for Zone Control units and the Eff DAT Clg Spt for DAT Control units. The Temp Rise is the Maximum
Temperature Rise of the gas heat exchanger that is entered at the factory for the specific unit. After the modulating gas heating valve is set to the calculated position, there is a HeatUpDelay (default = 60 second) to allow the heat exchanger to heat up. After this delay, since the unit is 100%
Outside Air, the unit immediately transitions from Startup
110 to the Fan Only state. As soon as the unit enters the Fan
Only state, the unit will immediately transition to either the
Heating state or the MinDAT state.
The unit remains in either the Heating or Minimum DAT operating state for the duration of the Hold Period (Default =
240 seconds). The gas heating valve does not modulate from its calculated value to allow the temperature to approach equilibrium with modulating gas heating valve at a fixed position.
The unit reverts to normal modulation of the gas heating valve when the Hold Period has elapsed since the unit entered
Heating or MinDAT.
Return Air Units
When the unit enters the Heating operating state, the controller first holds the gas valve at the minimum fire position (5% or 33% depending on the burner model) until the Heating Interstage Timer expires. Then, the controller modulates the gas valve to maintain the discharge air temperature at the Discharge Heating Set Point.
MPS Gas Heating
Sequence of Operation (Staged Control)
Low Heat Option (2 Stage Control)
The following details the sequence of operation for the low heat option.
• Unit controller calls for heat.
• Furnace DDC control module receives a call for heat.
• High limit switch is checked for safe condition.
• Proof of airflow switch is checked for combustion airflow.
• 60 second prepurge cycle starts.
• Spark ignitor is activated for 3 seconds.
• Gas valve receives a command for stage 1 of heat.
• Burner is ignited.
• Unit controller calls for stage 2 of heat.
• Furnace DDC controller receives a stage 2 heat command.
• Gas valve receives a command for stage 2 of heat.
High Heat Option (4 Stage Control)
For a unit with the optional high heat the above sequence is followed for the first two stages. For the remaining 2 stages the above procedure is repeated on the second furnace module.
OM 920-4
Operator’s Guide
Sequence of Operation (Modulating Burner)
Low Heat Option with Modulation
The following details the sequence of operation for the low heat option.
• Unit DDC controller calls for heat.
• Furnace DDC control module receives a call for heat.
• Furnace safety switches and DDC control are checked for safe conditions.
• 45 second prepurge cycle starts. Proof of airflow switch is checked for combustion airflow.
• Spark ignitor is activated.
• Gas valve receives a signal to open fully.
• Burner is ignited and runs for 20 seconds in high fire.
NOTE:
If call for heat is interrupted during this timing, the furnace will be locked in for the 20 seconds cycle .
• Gas valve and induction blower motor receives a signal to modulate burner output to match the unit discharge air temperature setting.
Discharge Air Temperature Setpoint Reset - Heating
The Heating DAT Setpoint may be reset for units with DAT
Heating Control. The Discharge Air Temperature Setpoint will never be set below the Minimum DAT Heating Setpoint or above the Maximum DAT heating Setpoint on the Heating
Reset menu. The reset type may be set to one of the following:
• None: Discharge Heating Spt is user adjustable
• Network: Discharge Heating Spt is equal to the Network
DAT Htg Setpoint when it is valid
• Space: Discharge Heating Spt is based on the Space
Sensor
• Return: Discharge Heating Spt is based on the Return
Air Sensor
• OAT: Discharge Heating Spt is based on the Outdoor Air
Temperature
• Ext mA: Discharge Heating Spt is determined by a 0-20 or 4-20 mA signal
• Ext V: Discharge Heating Spt is determined by a 0-10 or
2 - 10 VDC signal
Reset reverts from Return to None when the return air sensor opens or shorts. Reset reverts from Space to None when the space sensor opens or shorts. Reset reverts from OAT to None when the outdoor air sensor opens or shorts.
When Space, Return, OAT, Ext mA, or Ext V is selected, the Discharge Heating Spt equals the Max Htg Spt when the selected value equals the Max Htg Spt @ value. Similarly, the Discharge Heating Spt equals the Min Htg Spt when the selected value equals the Min Htg Spt @ value.
When Space, Return, or OAT is selected, the reset schedule should be set so that the DAT Heating setpoint decreases as the selected temperature increases as shown in the graph.
When Ext mA is selected, the values “Min Htg Spt @” and
“Max Htg Spt @” are entered as mA values. When Ext VDC is selected, the values “Min Htg Spt @” and “Max Htg Spt
@” are entered as VDC values.
If Ext mA or Ext V is selected as the type of reset, the Min
Htg Spt @ value may be set above the Max Htg Spt @ value to cause a decrease in the DAT setpoint as the external signal or the Min Htg Spt @ value may be set below the Max Htg
Spt @ value to cause an increase in the DAT setpoint as the external signal increase.
When ever the Clg Reset Type or Engineering Units is changed, the Min Clg Spt @ and Max Clg Spt @ values revert to default values as follows:
• None: Min Clg Spt @=0NA, Max Clg Spt @=100NA
• Network: Min Clg Spt @=0NA, Max Clg Spt @=100NA
• Space, Return: Min Clg Spt @=73.0F, Max Clg Spt
@=71.0F
• OAT: Min Clg Spt @=90.0F, Max Clg Spt @=70.0F
• ExtmA: Min Clg Spt @=4.0mA, Max Clg Spt @=20.0mA
• ExtVDC: Min Clg Spt @=0.0V, Max Clg Spt @=10.0V
An example of discharge temperature reset based on outdoor air temperature is illustrated in
Type Flag is set to “OAT” in this example). When the current outdoor air temperature is greater than or equal to the Minimum Cooling Set Point Reset Value (90°F in this example), the Discharge Cooling Set Point is set equal to the
Minimum Discharge Cooling Set Point (55°F in this example).
This is shown as Point C in
outdoor air temperature is less than or equal to the Maximum
Cooling Set Point Reset Value (70°F in this example), the
Discharge Cooling Set Point is set equal to the Maximum
Discharge Cooling Set Point (65°F in this example). This is shown as Point A in
. When the current outdoor air temperature is between the Minimum Cooling Set Point
Reset Value and the Maximum Cooling Set Point Reset Value, the Discharge Cooling Set Point varies linearly between the Minimum Discharge Cooling Set Point and Maximum
Discharge Cooling Set Point. This is shown as Point B in
.
OM 920-4 111
Operator’s Guide
Figure 19: Discharge Temperature Reset Based on
Temperature
Indoor Air Fan - On/Off Control
A supply fan is provided on every unit. That may be the only fan, but either a return fan or an exhaust fan, or fans, can be provided also. The start/stop signal and the speed signal for fans that are controlled by variable frequency drives are provided via an internal ModBus network. Constant volume supply and return fans are started and stopped through digital outputs.
Supply Fan
The supply fan is turned on when the unit enters the
Recirculation state. The supply fan is turned off when the unit transitions to the Off state, but it stays on for a
OffHtClDelayTime (Default- 120 seconds) if the unit is turned off while DX cooling or staged heating is active.
The OffHtClDelayTime function is overridden when and
Emergency Off or Duct High Limit fault is active.
Return Fan
A return fan driven by a variable frequency drive is started four seconds after the supply fan is started to reduce the amp draw peak on startup. A constant volume return fan is turned on through the same output as the supply fan. An external
Fan Delay Relay is used to provide a delay between startups if required.
Supply Fan Capacity Control (VAV)
The speed of a modulating supply fan is controlled by a
0-100% signal provided to the VFD via an internal Modbus network. Supply Fan Capacity Control for a modulating fan is controlled to either maintain the duct static pressure at a desired value or maintain a fixed speed based on a signal provided via a network.
The choice of control method, SF Cap Ctrl, may be set to
Duct Pressure or Speed via the keypad. After the supply fan is started, a speed signal of 33% is sent to the variable frequency drive for the DSPCtrlDelay (Default=30 seconds).
Control reverts to either duct pressure or speed after the fan has been on for the duration of the DSPCtrlDelay time. The
VFD speed is not controlled below the minimum SAF speed setting (default 33%) while the fan is operating.
NOTE:
Units supplied with Daikin MD2, MD3, and MD6 drives will have a user editable maximum supply fan hertz setpoint (default 60 Hz) located in the SAF Set
Up menu . This parameter can be changed when job site conditions require the speed of the drive to be above 60 Hz .
Duct Static Pressure Control
The supply air fan speed is controlled by a VFD. The control parameter for the fan speed is the duct static pressure setpoint. If the duct static pressure is below the duct static pressure setpoint by more than ½ the deadband, the fan speed will increase. Likewise if the duct static pressure is above the duct static pressure setpoint by more than ½ the deadband the fan speed will decrease. Example - if the duct static pressure setpoint is 1.2" and the deadband is 0.1",the duct static pressure must reach 1.14 before the fan will increase in speed. The Duct Static Pressure setpoint may be set through the keypad or via a network signal. The active setpoint is changed whenever either of these values changes so it equals whichever value was changed most recently.
Speed/Network
When speed control is selected, the fan operates at the larger of its minimum speed or a value provided via a connected network or the keypad/display.
Single Zone VAV Control (1ZnVAV)
When space temperature control is selected, the supply fan
VFD is controlled with a PI_Loop to maintain the Control
Temperature input at the Occupied or Unoccupied Cooling
Setpoint or Occupied or Unoccupied Heating Setpoint. This control choice is designed for DAC control type and will be used in applications where the unit will act as a single
VAV box to control space temperature. Cooling and heating discharge air temperature control and outside air damper control will function in the normal manner as with VAV units.
112 OM 920-4
Operator’s Guide
Cooling/Economizer
When the Unit State is Cooling or Econo the Single Zone
VAV Control PI_Loop will be set for direct acting control to modulate the supply fan VFD to maintain the Control
Temperature at the Occupied Cooling Setpoint. As the
Control Temperature rises, the VFD speed will be increased and as the Control Temperature falls, the VFD speed will be decreased. An adjustable Minimum Cooling Speed and Maximum Cooling Speed value limits the range of modulation of the VFD.
Heating
When the Unit State is Heating the Single Zone VAV Control
PI_Loop will be set to reverse acting control to modulate the supply fan VFD to maintain the Control Temperature at the Occupied Heating Setpoint. As the Control Temperature falls, the VFD speed will be increased and as the Control
Temperature rises, the VFD speed will be decreased. An adjustable Minimum Heating Speed and Maximum Heating
Speed value limits the range of modulation of the VFD
Fan Only/MinDat
When the Unit State is FanOnly or MinDat, the supply fan speed will be held fixed at the speed the VFD was operating upon entering the FanOnly or MinDat state. This will be either the Minimum Cooling Speed or the Minimum Heating
Speed depending on the state the unit enters FanOnly/MinDat from
Building Static Pressure Control (BSP)
Building static pressure supply fan control is available on
100% OA units that have the Control Type set to Zone or
DAC. Building static pressure supply fan control is not available if the Control Type set to 1ZnVAV (2). When BSP is selected as the SAF capacity control method, the supply fan
VFD is controlled to maintain a building static pressure input at a building static pressure setpoint using a PI Loop.
A BSP Input parameter allows for selecting No or Yes for supply fan building static pressure control. If BSP Input is set to No then no monitoring or control based on BSP is possible.
All menu items related to BSP control are removed from the
HMI in this case. If BSP Input is set to Yes then the building static pressure input is available for control and monitoring purposes.
Carbon Dioxide Control (CO
2
)
CO
2
supply fan control is available on 100% OA units that have the Control Type set to Zone or DAC.
CO
2
supply fan control is not available if the Control Type set to 1ZnVAV. When CO
2
is selected as the SAF capacity control method, the supply fan VFD is controlled based on a
CO
2
input. The supply fan speed varies linearly between the
Minimum PPM Speed and the Maximum PPM Speed value as the PPM input varies from the Minimum SAF PPM and the
Maximum SAF PPM value. A CO
2
Input parameter allows for selecting None, VDC or mA as the type of input for the CO
2 sensor in this case.
If CO
2
Input is set to None then no monitoring or control based on CO
2
is possible. All menu items related to CO
2 control and scaling are removed from the HMI in this case.
If CO
2
Input is set to VDC then the CO
2
input is available for control and/or monitoring purposes and the sensor scaling parameters are in terms of volts DC. If CO
2
Input is set to mA then the CO
2
input is available for control and/or monitoring purposes and the sensor scaling parameters are in terms of milliamps.
Airflow Control (CFM)
Airflow supply fan control is available on 100% OA units that have the Control Type set to Zone or DAC. Airflow supply fan control is not available if the Control Type set to 1ZnVAV.
When CFM is selected as the SAF capacity control method, the supply fan VFD is controlled to maintain a CFM input at a
Minimum Outside Air CFM Setpoint using a PI Loop.
A CFM Input parameter allows for selecting None, VDC or mA as the type of input for the CFM sensor in this case.
If CFM Input= is set to None then no monitoring or control based on CFM is possible. All menu items related to CFM control and scaling are removed from the HMI in this case.
If CFM Input is set to VDC then the CFM input is available for control and/or monitoring purposes and the sensor scaling parameters are in terms of volts DC. If CFM Input is set to mA then the CFM input is available for control and/or monitoring purposes and the sensor scaling parameters are in terms of milliamps.
OM 920-4 113
Operator’s Guide
Modulating Return and Exhaust Fan Control (RTU,
MPS)
Four different approaches may be used to maintain the building static pressure at acceptable levels. An analog signal is provided to the VFD to control return or exhaust fan to:
• Maintain the speed of a return fan based on supply fan speed (Fan Tracking)
• Maintain the building static pressure at a desired value
• Maintain a fixed speed based on a signal provided by a
Building Automation System via a network.
• Vary the speed of an exhaust fan based on OA Damper position.
Any of the first three methods may be selected for a return fan. Building Static Pressure, Speed, or OA Damper may be selected for an exhaust fan.
When the unit is in the Off or Startup state, the variable frequency drive for the return or exhaust is driven to 0%.
After the return or exhaust fan is started, a speed signal of 5% for exhaust fan or 33% for return fan is sent to the variable frequency drive for the BSPCtrlDelay (Default=30 seconds) and the VFD will increase its speed to 5% (or 33%). Control reverts to one of the methods below after the fan has been on for the BSPCtrlDelay. The VFD speed is not controlled below
5% (or 33%) while the fan is operating.
During non-Off states when the outdoor air damper is closed, the speed of the return fan is set equal to the supply fan speed.
Under these conditions, the return fan is set to 100% if the supply fan is a constant volume fan. To provide a “bumpless transfer” when the outdoor air damper opens the return fan will start to control building static pressure from its speed when the damper was closed. Exhaust fans do not use this feature.
NOTE:
Units supplied with Daikin MD2, MD3, and MD6 drives will have a user editable maximum return fan/ exhaust fan hertz setpoint (default 60 Hz) located in the RF/EF Set Up menu . This parameter can be changed when job site conditions require the speed of the drive to be above 60 Hz .
Fan Tracking Control
For units with variable frequency drives, the return fan may be controlled such that the return fan speed tracks up and down with the supply fan speed. The user defines the position of the return fan with respect to the supply fan for minimum and maximum positions. When the supply fan is between the minimum and maximum positions, the fan varies proportionally between its minimum and maximum values. There are four adjustable parameters to define this relationship. They are:
Supply Fan (DF) Value Return Fan (RF) Value
Supply Fan Max Return Fan @ Supply Fan Max
Supply Fan Min Return Fan @ Supply Fan Min
To set the four parameters described above, the airflow and return vane positions are adjusted until maximum airflow and proper indoor conditions are met. The supply fan is controlled normally as the VAV boxes are adjusted to obtain maximum airflow. The return fan is adjusted using the Remote RF/EF setting on the keypad. The user then uses the key to set the
Supply Fan Max values and Return Fan @ Supply Fan Max to the observed values. The process is repeated at minimum airflow to set Supply Fan Min and Return Fan @ Supply Fan
Min values.
Building Static Pressure Control
A PI control loop is used to modulate the variable frequency drive of the exhaust fans to maintain a measured building static pressure at a setpoint. The BSP Gain, Project Ahead
Time, and Sample Time are editable via the keypad
The Building Static Pressure setpoint may be set through the keypad or via a network signal. The active setpoint is changed whenever either of these values changes so it equals whichever value was changed most recently.
Speed/Network Control
Single zone VAV control is available when the unit Control
Type is Single Zone VAV (1ZnVAV). When single zone VAV control is selected as the SAF capacity control method, the supply fan VFD or ECM motor is controlled with a PI_Loop to maintain the Control Temperature input at the Occupied
Cooling Setpoint or Occupied Heating Setpoint. This option is designed for discharge control applications where the unit will act as a single VAV box to control space temperature.
OAT is not allowed as the Control Temperature when SAF capacity control method is set to 1ZnVAV. Cooling and heating discharge air temperature control and outside air damper control will function in the normal manner as with
VAV units.
NOTE:
Single zone VAV control of SAF is not available when the Control Temperature Source is set to None .
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Exhaust Fan - Speed Control
The exhaust fan is turned on when the OA Dampers are at least open to the Minimum Exhaust OA Position (default
5%), the SAF capacity is above the Minimum Exhaust SAF capacity (default 10%), and the Remote Exhaust Fan capacity is commanded to a value above the minimum value (Default
= 5%) by a BAS for longer than the Minimum Exhaust Fan
On Time (Default = 120 seconds).
The exhaust fan is turned off when the Supply Fan is turned off when the Remote Exhaust Fan capacity is commanded to less than or equal to its minimum value (Default = 5%) for longer than the MinExhStopTime (Default = 120 seconds).
Modulating Propeller Exhaust- OA Damper Control
When the unit is equipped with a modulating propeller exhaust fan arrangement and the Return/Exhaust Fan
Capacity Control Method is set to OA Damper, the exhaust fan is turned on at an adjustable outdoor air damper position
(default 40%), and is turned back off when the dampers are below this setting for more that the minimum exhaust stop time (Default = 120 seconds). When on the fan is modulated linearly between the minimum exhaust fan speed and 100% as the dampers vary between the Exhaust On OA Position and the Exhaust Maximum OA Position.
Exhaust Fan - Building Static Pressure Control
An exhaust fan, or fans, driven by a variable frequency drive is started based on building static pressure. A constant volume exhaust fan is turned on through the same output as the supply fan. An external Fan Delay Relay is used to provide a delay between startups if required.
A VAV exhaust fan is turned on when the OA Dampers are at least open to the Minimum Exhaust OA Position (default
5%), the SAF capacity is above the Minimum Exhaust SAF capacity (default 10%), and the building static pressure is above the building static pressure setpoint by more than the deadband for longer than the Minimum Exhaust Fan Start
Time (Default = 120 seconds).
A VAV exhaust fan is turned off when the supply fan is turned off or when the building static pressure is below the building static pressure setpoint by more than the deadband, or the OA Dampers are open less than the Minimum Exhaust
OA Position (default 5%), or the SAF capacity is below the Minimum Exhaust SAF capacity (default 10%), and the Exhaust Fan capacity is at or below its minimum value
(Default = 5%) for longer than the Min Exhaust Fan Stop
Time (Default = 120 seconds).
Exhaust Fan - Speed Control
When speed control is selected, the fan operates at the larger of its minimum speed or a value provided via a connected network or the keypad/display.
The exhaust fan is turned on when the OA Dampers are at least open to the Minimum Exhaust OA Position (default
5%), the SAF capacity is above the Minimum Exhaust SAF capacity (default 10%), and the Remote Exhaust Fan capacity is commanded to a value above the minimum value (Default
= 5%) by a BAS for longer than the Minimum Exhaust Start
Time (Default = 120 seconds)
The exhaust fan is turned off when the supply fan is turned off when the Remote Exhaust Fan capacity is commanded to less than or equal to its minimum value (Default = 5%) for longer than the Minimum Exhaust Stop Time (Default = 120 seconds).
Staged Exhaust (MPS Units) Exhaust Fan - OA
Damper Control
When the Return Fan Type is set to 1StgExh, 2StgExh or
3StgExh and the Return/Exhaust Fan Capacity Control
Method is set to OA Damper, one, two or three exhaust fans are turned on and off based on the outdoor air damper position. Refer to the following table for the number of fans versus unit size.
Table 56:
Fan Configuration
MPS Unit Size
15
18
20
25
30
35
40
50
Number of Fans
1
1
2
2
2
2
3
3
The default exhaust fan On and Off values are as follows:
Table 57: Fan Settings
Action
Exh Fan Stg 1 On
Exh Fan Stg 1 Off
Exh Fan Stg 2 On
Exh Fan Stg 2 Off
Exh Fan Stg 3 On
Exh Fan Stg 3 Off
Default OA Setting
40%
30%
55%
40%
70%
50%
Adjustable Range
0–100%
0–100%
0–100%
0–100%
0–100%
0–100%
OM 920-4 115
Operator’s Guide
Troubleshooting
Fan Failure Codes
HLL = Hall Sensor Error
First occurrence:
Power fluctuations may be responsible.
Corrective:
Reset the failure; re-start the motor and observe it. If applicable, filter out the source of the disturbing voltage .
Repeated occurrence:
Question:
Do other fans show the same failure?
Yes:
Systematically search for voltage peaks .
No:
It seems to be a hardware problem of the fan . Fan need to be replaced .
TFEI = Electronics Interior Overheated
First occurrence:
Too high ambient temperature may be responsible .
Question:
• Could ambient temperature have been too high?
• Is it possible to connect the fan to EC Control in order to display the temperature? If so, is the
displayed temperature within the expected temperature range?
Corrective:
If the displayed temperature is above 95°C (the electronics switches off at 105°C,) double-check the ambient temperature in each operating mode .
Reset the failure; re-start the motor and observe it .
Repeated occurrence:
Question:
Do other fans show the same failure?
Yes:
Systematically search for the cause of excessive ambient temperature . Perhaps use a data logger or read out the electronics temperature via EC Control .
No:
It seems to be a hardware problem of the fan . Fan need to be replaced .
TFM = Motor Overheated
First occurrence:
Excessive ambient temperature may be responsible .
Question:
• Could ambient temperature have been too high? Or is the motor overloaded?
• Is it possible to connect the fan to EC Control in order to display the motor temperature?
• Is the displayed temperature within the expected temperature range?
Corrective:
If the displayed temperature is too high:
• Double-check the motor temperature in each operating mode.
• Check of the fan load: Measure the input power at max. load/ operating point and compare the
measured value with nominal data on the label . Is there any discrepancy?
• Reset the failure; re-start the motor and observe it.
Repeated occurrence:
Question:
Do other fans show the same failure?
Yes:
systematically search for the cause of excessive ambient temperature . Perhaps use a data logger or read out the electronics temperature via EC Control .
No:
It seems to be a hardware problem of the fan . Fan need to be replaced .
116 OM 920-4
Operator’s Guide
TFE = Power Mod Overheated
First occurrence:
Excessive ambient temperature may be responsible .
Question:
• Do other fans (temporarily) show the same failure within the arrangement? Could ambient temperature
have been too high? Or is the motor overloaded?
• Is it possible to connect the fan to EC Control in order to display the temperature?
• Is the displayed temperature within the expected temperature range?
Corrective:
If the displayed temperature is too high:
• Check the module temperature during operation in each operating mode (Tmodule <110°C;
switching-off temperature 115°C)
• Check the fan load and supply voltage: Measure the input power at max. load/ operating point and
compare the measured value with nominal data on the label . Is there any discrepancy?
• Reset the failure; re-start the motor and observe it.
Repeated occurrence:
Question:
Do other fans show the same failure?
Yes:
No:
Systematic search for the reason of too high ambient temperature, overload, overvoltage or low voltage . Perhaps use a data logger .
It seems to be a hardware problem of the fan . Fan need to be replaced .
BLK = Locked Motor
First occurrence:
Question:
• Is it possible that the motor was locked by an obstruction or ice?
• Do other fans show the same behaviour?
Corrective:
Remove the reason for blocking . Caused by ice: activate the shake-loose functionality (starting with
ModBus 5) or increase the starting phase control factor .
Repeated occurrence:
Question:
Does increasing the starting phase control factor improve the situation?
No:
It seems to be a hardware problem of the fan . Fan need to be replaced .
SKF = Communication Error
First occurrence:
Power fluctuations may be responsible.
Corrective:
Reset the failure; re-start the motor and observe it. If applicable, filter out the source of the disturbing signal .
Repeated occurrence:
Question:
Do other fans show the same failure?
Yes: systematic search for peaks of disturbance voltage
No:
It seems to be a hardware problem of the fan . Fan need to be replaced .
OM 920-4 117
Operator’s Guide
PHA = Phase failure
UzLow = DC-Link Undervoltage
UzHigh = DC-Link Overvoltage
UeHigh = Mains Overvoltage
UeLow = Mains Undervoltage
Question:
Can the main voltage be measured at any spot; a data logger may be helpful .
No:
Measure the voltage at the power supply input of the concerned fan .
Corrective:
• Reset the failure; re-start the motor and observe it.
• If applicable, filter out the source of disturbing signal.
Repeated occurrence:
Question:
• Do other fans show the same failure?
• How often does the failure occur?
• Get big electrical consumer loads switched at the same time when the failure occurs in the
surrounding area?
• Are compressors or large asynchronous motors applied within the arrangement?
Yes:
Systematic search for external disturbance voltage peaks; If applicable, usage of data logger for a longer period and analysis of the measured values .
• Are the voltage values within the specified range?
No:
It seems to be a hardware problem of the fan . Fan need to be replaced .
118 OM 920-4
Daikin Training and Development
Now that you have made an investment in modern, efficient Daikin equipment, its care should be a high priority. For training information on all Daikin HVAC products, please visit us at www.DaikinAppliedcom and click on training, or call 540-248-9646 and ask for the Training Department.
Warranty
All Daikin equipment is sold pursuant to its standard terms and conditions of sale, including Limited
Product Warranty. Consult your local Daikin Representative for warranty details. Refer to Form
933-430285Y. To find your local Daikin Representative, go to www.DaikinApplied.com.
Aftermarket Services
To find your local parts office, visit www.DaikinApplied.com or call 800-37PARTS (800-377-2787).
To find your local service office, visit www.DaikinApplied.com or call 800-432-1342.
This document contains the most current product information as of this printing. For the most up-to-date product information, please go to www.DaikinApplied.com.
Products manufactured in an ISO Certified Facility.
Daikin Applied
800.432.1342
www.DaikinApplied.com
© 2013 Daikin Applied
04/13
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Table of contents
- 4 Introduction
- 4 Getting Started
- 5 Using the Keypad/Display
- 7 Manual Control
- 7 Rapid Start
- 7 Service Timers
- 6 Edit Mode
- 6 Navigation Mode
- 6 Passwords
- 8 Keypad/Display Menu Structure
- 17 Menu Descriptions
- 17 Quick Menu
- 67 Trending Menus
- 67 Points 1-8 (Fixed)
- 67 Points 9-24 (From List)
- 68 Points 25-27 (With IDs)
- 68 Points 28-30 (With IDs)
- 69 Trending Selection Lists
- 64 Unit Configuration
- 63 BMS Communications Menu
- 62 Unit Maintenance
- 55 Service Menus
- 55 Timer Settings Menu
- 60 Modbus Status Menu
- 60 D3 Status Menu
- 61 Sensor Offsets Menu
- 52 Manual Control
- 50 Alarm Configuration Menu
- 50 Alarm Limits Menu
- 50 Alarm Output Config Menu
- 51 Alarm Delays Menu
- 29 Commission Unit
- 29 Unit Setup
- 29 Timer Settings Menu
- 31 SAF Set-up
- 34 RF/EF Set-Up
- 36 Heat/Cool Changeover Set-Up
- 37 Cooling Set-Up
- 38 Econo Set-up
- 40 Min OA Set-Up Menu
- 43 Heating Set-Up Menu
- 45 Dehum Set-Up
- 46 Energy Recovery Set-up
- 48 Head Pressure Set-Up Menu
- 49 Evap Cond Set-Up Menu
- 27 Date/Time/Schedules Menu
- 27 Time/Date
- 26 Dehumidification Menu
- 25 Heating Menu
- 25 Min OA Damper Menu
- 24 Economizer Menu
- 24 Cooling Menu
- 24 RF/EF Control Menu
- 23 SAF Spd Control Menu
- 23 Flow Status Menu
- 22 Temperatures Menu
- 21 Occupancy Menu
- 19 View/Set Unit Menus
- 19 Unit Status Settings
- 71 Alarms
- 71 About this Unit
- 71 Alarms
- 71 Alarm Clearing
- 72 Warnings
- 72 Problems
- 74 Faults
- 76 Operator’s Guide
- 76 Determining Unit State
- 76 Off Operating State
- 76 Start Up Operating State
- 116 Troubleshooting
- 116 Fan Failure Codes
- 77 Recirculating Operating State
- 77 Fan Only
- 77 Min DAT
- 77 Heating
- 77 Economizer
- 78 Mechanical Cooling
- 78 Determining Unit Status
- 78 Determining Control Mode
- 79 Determining Cooling Status
- 79 Determining Heat Status
- 80 Determining Economizer Status
- 80 Determining Cooling Capacity
- 80 Determining Supply Air Fan Capacity
- 80 Determining RF/EF Capacity
- 82 Determining Occupancy Mode
- 82 Determining Occupancy Source
- 83 Unoccupied Operation
- 83 Scheduling
- 84 Temperature Control Configurations
- 84 Heat/Cool Changeover
- 85 Control Temperature
- 87 Dehumidification
- 89 Energy Recovery
- 92 Outside Air Damper Control
- 95 100% Outside Air Damper Control, Two Position
- 95 Airside Economizer
- 95 Economizer to Cooling Operating State
- 95 Waterside Economizer
- 96 Bypass Valve Control
- 97 Water Pump Control
- 97 Cooling: Multistage
- 100 Cooling: Modulating
- 101 Discharge Air Temperature Setpoint Reset - Cooling
- 101 Condenser Fan Control
- 107 Heating Control
- 108 Modulating
- 108 RTU Gas Heating
- 108 Min DAT
- 110 MPS Gas Heating
- 112 Indoor Air Fan - On/Off Control