GeneSys Air-Cooled Screw Compressor Chiller

GeneSys   Air-Cooled Screw Compressor Chiller
CONTROL PANEL OPERATING MANUAL
WATER-COOLED SCREW CHILLER
MICROTECH III CONTROLLER
D–EOMWC00A07-16EN
-2-
Table of Contents
INTRODUCTION .......................................... 2
OPTIONAL REMOTE USER INTERFACE
CONTROLLER OPERATING LIMITS:.... 3 ......................................................................... 54
CONTROLLER FEATURES ....................... 3 START-UP AND SHUTDOWN .................. 56
GENERAL DESCRIPTION .......................... 4
TEMPORARY SHUTDOWN ............................ 56
EXTENDED (SEASONAL) S HUTDOWN .......... 57
OPERATION COMMANDS LAYOUT ................ 4
CONTROLLER DESCRIPTION .......................... 5 BASIC CONTROL SYSTEM
HARDWARE STRUCTURE ............................... 5 DIAGNOSTIC............................................... 59
SYSTEM ARCHITECTURE ............................... 7
CONTROLLER MAINTENANCE ............ 61
CONTROL NETWORK DETAILS ....................... 8
APPENDIX .................................................... 62
SEQUENCE OF OPERATION .................... 9
DEFINITIONS................................................ 62
CONTROLLER OPERATION................... 12
MASTER/SLAVE .......................................... 64
MICROTECH III INPUTS/OUTPUTS............... 12
EXTENSION I/O COMPRESSOR #1 TO #3 ...... 13
I/O EXV CIRCUIT #1 TO #3......................... 13
EXTENSION I/O FAN MODULE CIRCUIT #2 . 14
EXTENSION I/O FAN MODULE CIRCUIT #3 . 14
EXTENSION I/O UNIT HEAT PUMP .............. 14
SETPOINTS................................................... 15
UNIT FUNCTIONS ...................................... 18
CALCULATIONS ........................................... 18
UNIT MODEL ............................................... 18
UNIT ENABLE .............................................. 18
UNIT MODE SELECTION .............................. 18
UNIT CONTROL STATES .............................. 19
UNIT STATUS .............................................. 20
ICE MODE START DELAY ............................ 20
EVAPORATOR PUMP CONTROL ................... 20
CONDENSER P UMP CONTROL...................... 21
CONDENSATION CONTROL.......................... 22
LEAVING WATER TEMPERATURE (LWT)
RESET .......................................................... 23
UNIT CAPACITY CONTROL .......................... 25
UNIT CAPACITY OVERRIDES ....................... 27
CIRCUIT FUNCTIONS .............................. 29
CALCULATIONS ........................................... 29
CIRCUIT CONTROL LOGIC ........................... 29
CIRCUIT STATUS ......................................... 30
COMPRESSOR CONTROL.............................. 31
PRESSURE CONDENSATION CONTROL.......... 33
EXV CONTROL ........................................... 34
LIQUID INJECTION ....................................... 35
ALARMS AND EVENTS ............................ 36
SIGNALING ALARMS ................................... 36
CLEARING ALARMS .................................... 36
DESCRIPTION OF ALARMS ........................... 36
UNIT EVENTS .............................................. 38
CIRCUIT STOP ALARMS ............................... 38
CIRCUIT EVENTS ......................................... 42
ALARM LOGGING ........................................ 44
USING THE CONTROLLER..................... 45
NAVIGATING ............................................... 46
2
D–EOMWC00A07-16EN
Introduction
This manual provides setup, operating, troubleshooting and maintenance information for the
DAIKIN Water Cooled Chillers listed below with 1, 2 and 3 circuits using Microtech III
Controller.
HAZARD IDENTIFICATION INFORMATION
!
DANGER
Dangers indicate a hazardous situation which will result in death or serious injury if not avoided.
!
WARNING
Warnings indicate potentially hazardous situations, which can result in property damage, severe
personal injury, or death if not avoided.
!
CAUTION
Cautions indicate potentially hazardous situations, which can result in personal injury or
equipment damage if not avoided.
Software Version: This manual covers EWWD G-EWLD G-EWWD I-EWLD I-EWWD JEWLD J-EWWQ B units. The unit’s software version number can be viewed by selecting the
“About Chiller” menu item accessible without password. Then, pressing the MENU key will
return to the Menu screen.
!
WARNING
Electric shock hazard: can cause personal injury or equipment damage. This equipment must be
properly grounded. Connections to, and service of, the MicroTech III control panel must be
performed only by personnel who are knowledgeable in the operation of this equipment .
!
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 control panel before performing any service work. Never unplug any cables, circuit
board terminal blocks, or power plugs while power is applied to the panel.
NOTICE
This equipment generates, uses, and can radiate radio frequency energy and, if not
installed and used in accordance with this instruction manual, can cause interference to
radio communications. Operation of this equipment in a residential area can cause
harmful interference, in which case the user will be required to correct the interference at
the user’s own expense. Daikin disclaims any liability resulting from any interference or
for the correction thereof.
-3-
Controller Operating Limits:
Operation (IEC 721-3-3):

Temperature -40...+70 °C



Restriction LCD -20… +60 °C
Restriction Process-Bus -25….+70 °C
Humidity < 90 % r.h (no condensation)

Air pressure min. 700 hPa, corresponding to max. 3,000 m above sea level
Transport(IEC 721-3-2):


Temperature -40...+70 °C
Humidity < 95 % r.h (no condensation)

Air pressure min. 260 hPa, corresponding to max. 10,000 m above sea level.
Controller Features
Readout of the following temperature and pressure readings:

Entering and leaving chilled water temperature




Saturated evaporator refrigerant temperature and pressure
Saturated condenser refrigerant temperature and pressure
Outside air temperature
Suction line, and discharge line temperatures  calculated superheat for discharge and suction
lines
Oil pressure

Automatic control of primary and standby chilled water pumps. The control will start one of the
pumps (based on lowest run-hours) when the unit is enabled to run (not necessarily running on a
call for cooling) and when the water temperature reaches a point of freeze possibility.
Two levels of security protection against unauthorized changing of setpoints and other control
parameters.
Warning and fault diagnostics to inform operators of warning and fault conditions in plain
language. All events and alarms are time and date-stamped for identification of when the fault
condition occurred. In addition, the operating conditions that existed just prior to an alarm
shutdown can be recalled to aid in isolating the cause of the problem.
Twenty-five previous alarms and related operating conditions are available.
Test mode allows the service technician to manually control the controllers’ outputs and can be
useful for system checkout.
Building Automation System (BAS) communication capability via LonTalk, Modbus, or
BACnet standard protocols for all BAS manufacturers.
Pressure transducers for direct reading of system pressures. Preemptive control of low
evaporator pressure conditions and high discharge temperature and pressure to take corrective
action prior to a fault trip.
D-EOMWC00A07-16EN
3
-4-
General Description
The control panel is located on the front of the unit at the compressor end. There are three
doors. The control panel is behind to left-hand door. The power panel is behind the middle
and right-hand doors.
General Description
The MicroTech III control system consists of a microprocessor-based controller and a
number of extension modules, which vary depending on the unit size and conformation. The
control system provides the monitoring and control functions required for the controlled,
efficient operation of the chiller.
The operator can monitor all critical operating conditions by using the screen located on the
main controller. In addition to providing all normal operating controls, the MicroTech III
control system will take corrective action if the chiller is operating outside of its normal
design conditions. If a fault condition develops, the controller will shut a compressor, or the
entire unit, down and activate an alarm output. .
The system is password protected and only allows access by authorized personnel. Except
that some basic information is viewable and alarms can be cleared without a password. No
settings can be changed.
Operation Commands Layout
Figure 1, Operation Commands
Unit On/Off Switch
#2 Compressor
On/Off Switch
4
D–EOMWC00A07-16EN
#1 Compressor
On/Off Switch
Heat/Cool Switch
-5-
Figure 2, Operation Commands
Unit On/Off Switch
#2 Compressor On/Off Switch
#1 Compressor On/Off Switch
Unit On/Off Switch
Heat Pump Switch
#1 Compressor On/Off Switch
Controller Description
Hardware Structure
The MicroTech III control system for water cooled screw chillers consists of a main unit controller
with a number of extension I/O modules attached depending on the chiller size and configuration.
Up to two optional BAS communication modules may be included on request.
An optional Remote Operator Interface panel may be included, connected with up to nine units.
The Advanced MicroTech III controllers used on water cooled screw chillers are not
interchangeable with previous MicroTech II controllers.
D-EOMWC00A07-16EN
5
-6-
Figure 3, hardware structure
Remote Operator Interface
MicroTech III Unit Controller
BACnet/
MSTP
BACnet/IP
Communication Cards
AWC
MODbus
LON
Extension I/O Modules
6
D–EOMWC00A07-16EN
-7-
System Architecture
The overall controls architecture uses the following:
 One Microtech III main controller
 I/O extension modules as needed depending on the configuration of the unit
 Optional BAS interface as selected
Figure 4, System Architecture
D-EOMWC00A07-16EN
7
-8-
Control network details
Peripheral Bus is used to connect I/O extensions to the main controller.
Controller/
Extension Module
Unit
Comp. #1
EEXV #1
Comp. #2
EEXV #2
Fan#2
Comp. #3
EEXV #3
Fan#3
HP
Siemens Part Number
POL687.70/MCQ
POL965.00/MCQ
POL94U.00/MCQ
POL965.00/MCQ
POL94U.00/MCQ
POL945.00/MCQ
POL965.00/MCQ
POL94U.00/MCQ
POL945.00/MCQ
POL925.00/MCQ
Addres
s
n/a
2
3
4
5
6
7
8
9
25
Usage
Used on all configurations
Used when configured for
2
Used when configured for
3
Heat Pump Option
Communication modules
Any of the following modules can be connected directly to the left side of the main
controller to allow a BAS interface to function.
Module
BacNet/IP
Lon
Modbus
BACnet/MSTP
8
D–EOMWC00A07-16EN
Siemens Part Number
POL908.00/MCQ
POL906.00/MCQ
POL902.00/MCQ
POL904.00/MCQ
Usage
Optional
Optional
Optional
Optional
-9-
Sequence of Operation
Figure 5, Unit Sequence of Operation (see Figure 9 for circuit sequence of operation)
AWS Chiller Sequence of Operation in Cool Mode
Unit power up
Unit in Off state
No
Is unit enabled?
Yes
Yes
The chiller may be disabled via the unit switch, the remote switch, the keypad
enable setting, or the BAS network. In addition, the chiller will be disabled if all
circuits are disabled, or if there is a unit alarm. If the chiller is disabled, the unit
status display will reflect this and also show why it is disabled.
If the unit switch is off, the unit status will be Off:Unit Switch. If the chiller is
disabled due to network command, the unit status will be Off:BAS Disable. When
the remote switch is open, the unit status will be Off:Remote Switch. When a unit
alarm is active, the unit status will be Off:Unit Alarm. In cases where no circuits
are enabled, the unit status will be Off:All Cir Disabled. If the unit is disabled via
the Chiller Enable set point, the unit status will be Off:Keypad Disable.
Low ambient lockout will prevent the chiller from starting even if it is otherwise
enabled. When this lockout is active, the unit status will be Off:Low OAT Lock.
Is low ambient lockout
active?
No
If the chiller is enabled, then the unit will be in the Auto state and the evaporator
water pump output will be activated.
Evaporator pump output on
No
The chiller will then wait for the flow switch to close, during which time the unit
status will be Auto:Wait for flow.
Is flow present?
Yes
After establishing flow, the chiller will wait some time to allow the chilled water loop
to recirculate for an accurate reading of the leaving water temperature. The unit
status during this time is Auto:Evap Recirc.
Wait for chilled water loop to
recirculate.
Keep pump output on while
chiller is enabled and either
running or ready to run.
No
Is there enough load to
start chiller?
The chiller is now ready to start if enough load is present. If the LWT is not higher
than the Active Setpoint plus the Start Up Delta T, the unit status will be Auto:Wait
for load.
If the LWT is higher than the Active Setpoint plus the Start Up Delta T, the unit
status will be Auto. A circuit can start at this time.
Yes
D-EOMWC00A07-16EN
9
- 10 -
Yes
The first circuit to start is generally the available circuit with the least number of
starts. This circuit will go through its start sequence at this point.
Start first circuit.
The first circuit will be loaded and unloaded as needed in an attempt to satisfy the
load by controlling LWT to the Active Setpoint.
Load/unload as needed to
satisfy load.
No
Is more capacity
needed to satisfy load?
No
If a single circuit is not enough to satisfy the load, additional circuits will need to be
started. An additional circuit will be started when all running compressors are
loaded to a specific capacity and the LWT is higher than the Active Setpoint plus
the Stage Up Delta T.
Yes
A minimum time must pass between the starting of circuits. The time remaining
can be viewed on the HMI if the minimum password level is active.
Has the stage up time
delay expired?*
The second circuit will go through its start sequence at this point.
Yes
Note that a third circuit can be started if available. The two preceding conditions
must again be satisfied after starting the second circuit before starting the third
circuit.
Start next circuit. *
All running circuits will now be loaded/unloaded as needed to satisfy the load.
When possible, they will load balance so that running circuits are providing nearly
equal capacity.
Load/unload as needed to
satisfy load.*
No
Can less circuits handle
the load?*
As the load drops off, the circuits will unload accordingly. If the LWT drops below
the Active Setpoint minus the Stage Down Delta T, one circuit will shut off. If all
running circuits are unloaded below a minimum value, this can also result in one
circuit shutting off.
A minimum time must pass between the shutting down of circuits. The time
remaining can be viewed on the HMI if the minimum password level is active.
Yes
Shut down one circuit. *
The next circuit to shut off is generally the one with the most run hours.
* The points highlighted are considered only in 2 or 3 circuits units
10
D–EOMWC00A07-16EN
- 11 -
Figure 6, Circuit Sequence of Operation
AWS Sequence of Operation - Circuits
Unit power up
When the circuit is in the Off state the EXV is closed, compressor is off, and all fans
are off.
Circuit is in Off state
No
Is circuit is enabled to
start?
Yes
The circuit must be enabled before it can run. It may be disabled for several
reasons. When the circuit switch is off, the status will be Off:Circuit Switch.
If the BAS has disabled the circuit, the status will be Off:BAS Disable. If the circuit
has an active stop alarm then the status will be Off:Cir Alarm. If the circuit has
been disabled via the circuit mode set point, the status will be Off:Cir Mode
Disable.
Yes
No
A minimum time must pass between the previous start and stop of a compressor
and the next start. If this time has not passed, a cycle timer will be active and the
circuit status will be Off:Cycle Timer.
Are compressor cycle
timers active?
No
If the compressor is not ready due to refrigerant in the oil, the circuit cannot start.
The circuit status will be Off:Refr In Oil.
Is compressor oil sump
ready?
Yes
If the compressor is ready to start when needed, the circuit status will be
Off:Ready.
Circuit is ready to start
No
Is circuit commanded to
start?
Yes
When the circuit begins to run, the compressor will be started and the EXV, fans,
and other devices will be controlled as needed. The normal circuit status at this
time will be Run.
Run circuit
No
Is circuit commanded to
shut down?
Yes
Pumpdown circuit
D-EOMWC00A07-16EN
When the circuit is commanded to shut down, a normal shut down of the circuit will
be performed. The circuit status during this time will be Run:Pumpdown. After
the shut down is completed, the circuit status will normally be Off:Cycle Timer
initially.
11
- 12 -
Controller Operation
MicroTech III Inputs/Outputs
The chiller may be equipped with one up to three compressors.
Analog Inputs
#
Description
Signal Source
Expected Range
AI1
Evaporator Entering Water Temp
NTC Thermister (10K@25°C)
-50°C – 120°C
AI2
Evaporator Leaving Water Temp
NTC Thermister (10K@25°C)
-50°C – 120°C
AI3
X1
Condenser Entering Water Temp
Condenser Leaving Water Temp
NTC Thermister (10K@25°C)
NTC Thermister (10K@25°C)
-50°C – 120°C
-50°C – 120°C
X4
LWT Reset
4-20 mA Current
1 to 23 mA
X7
Demand Limit
4-20 mA Current
1 to 23 mA
X8
Unit Current
4-20 mA Current
1 to 23 mA
Analog Outputs
Output Signal
Range
X5
#
Condenser Pump VFD
Description
0-10VDC
0 to 100% (1000 steps resolution)
X6
Condenser Bypass Valve
0-10VDC
0 to 100% (1000 steps resolution)
Digital Inputs
#
Description
DI1
Unit PVM
DI2
Evaporator Flow Switch
DI3
Signal Off
Signal On
Fault
No Fault
No Flow
Flow
Double Set Point/ Mode Switch
Cool mode
Ice mode
DI4
External Alarm
Remote off
Remote on
DI5
Unit Switch
Unit off
Unit on
DI6
Emergency Stop
Unit off/rapid stop
Unit on
X2
X3
Current Limit Enable
Condenser Flow Switch
Disabled
No Flow
Enabled
Flow
Output OFF
Output ON
Pump Off
Digital Outputs
#
Description
DO1
Evaporator Water Pump #1
DO2
Unit Alarm
DO3
Cooling Tower Out 1
Fan Off
Pump On
Alarm Active
(Flashing= circuit
alarm)
Fan On
DO4
Cooling Tower Out 2
Fan Off
Fan On
DO5
Cooling Tower Out 3
Fan Off
Fan On
DO6
Cooling Tower Out 4
Fan Off
Fan On
Alarm not Active
DO7
12
DO8
Evaporator Water Pump #2
Pump Off
Pump On
DO9
Condenser Water Pump
Pump Off
Pump On
D–EOMWC00A07-16EN
- 13 -
Extension I/O Compressor #1 to #3
Analog Inputs
#
Description
Signal Source
Expected Range
X1
Discharge Temperature
NTC Thermister (10K@25°C)
-50°C – 120°C
X2
Evaporator Pressure
Ratiometric (0,5-4,5 Vdc)
0 to 5 Vdc
X3
Oil Pressure
Ratiometric (0,5-4,5 Vdc)
0 to 5 Vdc
X4
Condenser Pressure
Ratiometric (0,5-4,5 Vdc)
0 to 5 Vdc
X7
Motor Protection
PTC Thermistor
n/a
Output Signal
Range
Analog Outputs
#
Description
Not Needed
Digital Inputs
#
Description
Signal Off
Signal On
X6
Starter Fault
Fault
No fault
X8
Circuit Switch
Circuit Off
Circuit On
DI1
High Pressure Switch
Fault
No fault
Digital Outputs
EU. Configuration
#
Description
Output Off
Output On
DO1
Start Compressor
Compressor Off
Compressor On
DO2
Circuit Alarm
Circuit Alarm Off
Circuit Alarm On
DO3
Load #2 Circuit
DO4
Unload #2 Circuit / Liquid Injection
DO5
Load #1 Circuit
Load 2 Circuit Off
Unload 2 Circuit Off /
Liquid Injection Off
Load 1 Circuit Off
Load 2 Circuit On
Unload 2 Circuit On /
Liquid Injection On
Load 1 Circuit On
DO6
Unload #1 Circuit
Unload 1 Circuit Off
Unload 1 Circuit On
X5
Turbo Slide
Turbo Slide Off
Turbo Slide On
I/O EXV Circuit #1 to #3
Analog Inputs
#
X1
X2
Description
Evaporator Leaving Water Temp
(*)
Suction Temperature
Signal Source
Expected Range
NTC Thermister 10K@25°C)
-50°C – 120°C
NTC Thermister 10K@25°C)
-50°C – 120°C
Output Signal
Range
X3
Analog Outputs
#
Description
Not Needed
Digital Inputs
#
Description
Signal Off
Signal On
DI1
Evaporator Flow Switch (Circuit)
No Flow
Flow
Output Off
Liquid Line Solenoid Valve
Off
Output On
Liquid Line Solenoid
Valve On
Digital Outputs
#
Description
DO1
Liquid Line Solenoid Valve
D-EOMWC00A07-16EN
13
- 14 -
Stepper Motor Output
#
M1+
M1M2+
M2-
Description
EXV Stepper Coil 1
EXV Stepper Coil 2
Extension I/O Fan Module Circuit #2
Digital Outputs
#
Description
Output Off
Output On
DO1
Circuit #2 Fan Step #1 Fan Off Fan On
DO2
Circuit #2 Fan Step #2 Fan Off Fan On
Fan Off
Fan Off
Fan On
Fan On
DO3
Circuit #2 Fan Step #3 Fan Off Fan On
Fan Off
Fan On
DO4
Circuit #2 Fan Step #4 Fan Off Fan On
Fan Off
Fan On
Extension I/O Fan Module Circuit #3
Digital Outputs
#
Description
Output Off
Output On
DO1
Circuit #3 Fan Step #1 Fan Off Fan On
DO2
Circuit #3 Fan Step #2 Fan Off Fan On
Fan Off
Fan Off
Fan On
Fan On
DO3
Circuit #3 Fan Step #3 Fan Off Fan On
DO4
Circuit #3 Fan Step #4 Fan Off Fan On
Fan Off
Fan Off
Fan On
Fan On
Extension I/O Unit Heat Pump
Digital Inputs
14
#
Description
Signal Off
Signal On
DI1
Cool Heat Switch
Cooling Mode
Heating Mode
D–EOMWC00A07-16EN
- 15 -
Setpoints
The following parameters are remembered during power off, are factory set to the Default
value, and can be adjusted to any value in the Range column.
Read and write access to these set points is determined by the Global HMI (Human Machine
Interface) Standard Specification.
Table 1, Setpoint Value and Range
Description
Unit
Manufacturing Location
Default
Ft/Lb
SI
Range
Not Selected
Not Selected, Europe, USA
Disabled
Disabled, Enabled
Local
Cool
Unit Enable
Control source
Available Modes
44 F
44 F
113°F
113 °F
25 F
5 F
2.7 F
7 °C
7 °C
45 °C
45 °C
-4 °C
2,7 °C
1.5 °C
Local, Network
COOL
COOL/w GLYCOL
COOL/ICE w GLYCOL
ICE w/GLYCOL
HEAT/COOL
HEAT/COOL w GLYCOL
HEAT/ICE w GLYCOL
TEST
See section 0
See section 0
§
§
20 to 38F / -8 to 4 °C
0 to 10 F / 0 to 5 °C
0 to 3 F / 0 to 1,7 °C
2 F
1 °C
0 to 3 F / 0 to 1,7 °C
1 F
0,5 °C
0 to 3 F / 0 to 1,7 °C
Max Pulldown
3 F/min
0.5-5.0 F /min / 0,3 to 2,7 °C/min
Max Pullup
3 °F/min
1,7
°C/min
1,7
°C/min
Cool LWT 1
Cool LWT 2
Heat LWT 1
Heat LWT 2
Ice LWT
Startup Delta T
Shut Down Delta T
Stage Up Delta T (between
compressors)
Stage Down Delta T (between
compressors)
Evap Recirc Timer
30
Evap Control
LWT Reset Type
Max Reset
Start Reset Delta T
Soft Load
Starting Capacity Limit
Soft Load Ramp
Demand Limit
Current @ 20mA
Current limit Set Point
# of Circuits
Ice Cycle Delay
Condenser Water Temp Setpoint
Condensation Control value
Condensation Analog Output type
Tower 1 Setpoint
Tower 2 Setpoint
Tower 3 Setpoint
Tower 4 Setpoint
Tower 1 Differential
Tower 2 Differential
Tower 3 Differential
Tower 4 Differential
Vfd Min Speed
D-EOMWC00A07-16EN
#1 Only
None
10 F
10 F
5 °C
5 °C
Disable
40%
20 min
Disable
800 Amp
800 Amp
2
12
95 °F
35 °C
Cond In
None
95 °F
35 °C
98,6 °F
37 °C
102,2 °F
39 °C
105,8 °F
41 °C
2.7 °F/1.5 °C
2.7 °F/1.5 °C
2.7 °F/1.5 °C
2.7 °F/1.5 °C
10%
0.5-5.0 F /min / 0,3 to 2,7 °C/min
0 to 300 seconds
#1 Only, #2 Only, Auto,
#1 Primary, #2 Primary
None, 4-20mA, Return
0 to 20 F / 0 to 10 °C
0 to 20 F / 0 to 10 °C
Disable, Enable
20-100%
1-60 minutes
Disable, Enable
0 to 2000 Amp = 4 to 20 mA
0 to 2000 Amp
1-2-3
1-23 hours
69,8 to 140 °F / 21 to 60 °C
Cond In, Cond Out, Press
None, Vfd, Bypass Valve
69,8 to 140 °F / 21 to 60 °C
69,8 to 140 °F / 21 to 60 °C
69,8 to 140 °F / 21 to 60 °C
69,8 to 140 °F / 21 to 60 °C
0,2 to 9 dF / 0,1 to 10 dK
0,2 to 9 dF / 0,1 to 10 dK
0,2 to 9 dF / 0,1 to 10 dK
0,2 to 9 dF / 0,1 to 10 dK
0 to 100%
15
- 16 -
Description
Default
Unit
Vfd Max Speed
Byp valve Min Opening
Byp valve Max Opening
Vfd/ Byp valve PID prop gain (kp)
Vfd/ Byp valve PID deriv time (Td)
Vfd/ Byp valve PID integ time (Ti)
Clear Ice Delay
SSS Communication
PVM
Ft/Lb
SI
100%
0%
95%
10.0
1.0 s
600.0 s
No
No
Multi Point
Noise Reduction
Noise Reduction Start Time
Noise Reduction End Time
Noise Reduction Condenser Offset
Evap LWT sensor offset
Evap EWT sensor offset
Start-start timer
Disabled
21:00
6:00
5 °C
10.0 F
0°F
0°C
0°F
0°C
10 min
Compressor – Global
Stop-start timer
Pumpdown Pressure
Pumpdown Time Limit
Light Load Stg Dn Point
Load Stg Up Point
Stage Up Delay
Stage Down Delay
Stage Delay Clear
Max # Comps Running
Sequence # Cir 1
Sequence # Cir 2
Sequence # Cir 3
Liquid Injection Activation
Liquid Line Solenoid Valves
Low Evap Pressure-Unload
Low Evap Pressure-Hold
High Oil Press Delay
High Oil Press Differential
Low Oil Level Delay
High Discharge Temperat.
Low Pressure Ratio Delay
Start Time Limit
Evaporator Water Freeze
Evaporator Flow Proof
Evap Recirculate Timeout
Ft/Lb
Range
0 to 100%
0 to100%
0 to100%
0 to 50
0 to 180s
0 to 600s
No, Yes
No, Yes
Single Point, Multi Point ,
None(SSS)
Disabled, Enabled
18:00 – 23:59
5:00 – 9:59
0.0 to 25.0 F
-5.0 to 5.0°C / -9.0 to 9.0°F
-5.0 to 5.0°C / -9.0 to 9.0°F
6-60 minutes
SI
5 min
14,3 PSI
100 kPa
120 sec
50%
50%
5 min
3 min
No
2
1
1
1
185°F
85°C
Disable
23.2 PSI
160 kPa
27.5 PSI
180 kPa
30 sec
35 PSI
250 kPa
120 sec
110 °C
230 F
90 sec
60 sec
2,2 °C
36 F
15 sec
3 min
3-20 minutes
10 to 40 PSI / 70 to 280 kPa
0 to 180 sec
20 to 50%
50 to 100%
0 to 60 min
3 to 30 min
No, Yes
1-3
1-4
1-4
1-4
75 to 90°C
Disable, Enable
See section 0
See section 0
10-180 sec
0-60 PSI / 0 to 415 kPa
10 to 180 sec
150 to 230 °F / 65 to 110 °C
30-300 sec
20 to 180 sec
See section 0
5 to 15 sec
1 to 10 min
The following set points exist individually for each circuit:
Description
Circuit mode
Capacity Control
Capacity
Economizer En Cap
Clear Cycle Timers
EXV control
EXV position
Service Pumpdown
Evap pressure offset
Cond pressure offset
Oil pressure offset
Suction temp offset
Discharge temp offset
16
D–EOMWC00A07-16EN
Default
Range
Ft/Lb
SI
Enable
Disable, Enable, Test
Auto
Auto, Manual
0%
0 to 100%
40%
40% to 75%
Off
Off,On
Auto
Auto, manual
See note 2 below table
0% to 100%
Off
Off,On
0PSI
0kPa -14.5 to 14.5 PSI /-100 to 100 kPa
0PSI
0kPa -14.5 to 14.5 PSI /-100 to 100 kPa
0PSI
0kPa -14.5 to 14.5 PSI /-100 to 100 kPa
0°F
0°C
-5.0 to 5.0 deg
0°F
0°C
-5.0 to 5.0 deg
- 17 -
Fan 1 Setpoint
Fan 2 Setpoint
Fan 3 Setpoint
Fan 4 Setpoint
Fan 1 Differential
Fan 2 Differential
Fan 3 Differential
Fan 4 Differential
Vfd Min Speed
Vfd Max Speed
Vfd PID prop gain (kp)
Vfd PID deriv time (Td)
Vfd PID integ time (Ti)
95 °F
35°C
98,6 °F
37°C
102,2 °F
39°C
105,8 °F
41°C
2.7 °F
1.5 °C
2.7 °F
1.5 °C
2.7 °F
1.5 °C
2.7 °F
1.5 °C
10%
100%
10.0
1.0 s
600.0 s
69.8 to 140 °F / 21 to 60 °C
69.8 to 140 °F / 21 to 60 °C
69.8 to 140 °F / 21 to 60 °C
69.8 to 140 °F / 21 to 60 °C
0.2 to 9 dF / 0.1 to 10 dK
0.2 to 9 dF / 0.1 to 10 dK
0.2 to 9 dF / 0.1 to 10 dK
0.2 to 9 dF / 0.1 to 10 dK
0 to 45%
55 to 100%
0 to 50
0 to 180s
0 to 600s
Auto Adjusted Ranges
Some settings have different ranges of adjustment based on other settings.
Cool LWT 1 and Cool LWT 2
Available Mode Selection
Range Imp. Range SI
Without Glycol
40 to 60oF
4 to 15 °C
With Glycol
25 to 60oF
-4 to 15 °C
Evaporator Water Freeze
Available Mode Selection
Range Imp.
Range SI
Without Glycol
36 to 42oF
2 to 6 °C
With Glycol
0 to 42oF
-18 to 6 °C
Low Evaporator Pressure - Hold
Available Mode Selection
Range Imp.
Range SI
Without Glycol
28 to 45
195 to 310 kPa
PSIG
With Glycol
0 to 45 PSIG 0 to 310 kPa
Low Evaporator Pressure - Unload
Available Mode Selection
Range Imp.
Range SI
Without Glycol
26 to 45 Psig 180 to 310 kPa
With Glycol
0 to 45 Psig
0 to 410 kPa
D-EOMWC00A07-16EN
17
- 18 -
Unit Functions
Calculations
LWT Slope
LWT slope is calculated such that the slope represents the change in LWT over a time frame
of one minute with at least five samples per minute for both evaporator and condenser.
Pulldown Rate
The slope value calculated above will be a negative value as the water temperature is
dropping. For use in some control functions, the negative slope is converted to a positive
value by multiplying by –1.
Unit Model
The unit model can be selected between the four available for this application. Depending on
the model temperature ranges and refrigerant type are selected automatically.
Unit Enable
Enabling and disabling the chiller is accomplished using set points and inputs to the chiller.
The unit switch, remote switch input, and Unit Enable Set Point all are required to be on for
the unit to be enabled when the control source is set to local. The same is true if the control
source is set to network, with the additional requirement that the BAS request must be on.
Unit is enabled according to the following table.
NOTE: An x indicates that the value is ignored.
Unit
Switch
Off
x
x
On
x
On
Control
Source Set
Point
x
x
x
Local
Network
Network
Remote
Switch Input
Unit Enable
Set Point
BAS
Request
Unit
Enable
x
x
Off
On
x
On
x
Off
x
On
x
On
x
x
x
x
Off
On
Off
Off
Off
On
Off
On
All of the methods for disabling the chiller, discussed in this section, will cause a normal
shutdown (pumpdown) of any running circuits.
When the controller is powered up, the Unit Enable Set Point will be initialized to ‘off’ if the
Unit Status After Power Failure Set Point is set to ‘off’.
Unit Mode Selection
The operating mode of the unit is determined by setpoints and inputs to the chiller. The
Available Modes Set Point determines what modes of operation can be used. This setpoint
also determines whether the unit is configured for glycol use. The Control Source Set Point
determines where a command to change modes will come from. A digital input switches
between cool mode and ice mode if they are available and the control source is set to local.
The BAS mode request switches between cool mode and ice mode if they are both available
and the control source is set to network.
18
D–EOMWC00A07-16EN
- 19 -
The Available Modes Set Point must only be changed when the unit switch is off. This is
to avoid changing modes of operation inadvertently while the chiller is running.
Unit Mode is set according to the following table.
NOTE: An “x” indicates that the value is ignored.
Control Source
Set Point
x
x
Local
Local
Network
Network
x
Local
Local
Network
Network
Mode
Input
x
x
Off
On
x
x
x
x
x
x
x
HP
Switch
x
x
x
x
x
x
x
Off
On
x
x
BAS
Request
x
x
x
x
Cool
Ice
x
x
x
Cool
Heat
Local
Off
Off
x
Local
On
Off
x
Local
Local
x
x
On
On
x
x
Network
x
x
Cool
Network
x
x
Ice
Network
x
x
Heat
x
x
x
Available Modes
Set Point
Cool
Cool w/Glycol
Cool/Ice w/Glycol
Cool/Ice w/Glycol
Cool/Ice w/Glycol
Cool/Ice w/Glycol
Ice w/Glycol
Cool/Heat
Cool/Heat
Cool/Heat
Cool/Heat
Cool/Ice w/Glycol/
Heat
Cool/Ice w/Glycol/
Heat
Cool w/Glycol/Heat
Cool w/Glycol/Heat
Cool/Ice w/Glycol/
Heat
Cool/Ice w/Glycol/
Heat
Cool/Ice w/Glycol/
Heat
Test
Unit Mode
Cool
Cool
Cool
Ice
Cool
Ice
Ice
Cool
Heat
Cool
Heat
Cool
Ice
Cool
Heat
Cool
Ice
Heat
Test
Glycol Configuration
If the Available Modes Set Point is set to an option w/Glycol, then glycol operation is
enabled for the unit. Glycol operation must be disabled only when the Available Modes
Set Point is set to Cool.
Unit Control States
The unit will always be in one of three states:

Off – Unit is not enabled to run.

Auto – Unit is enabled to run.

Pumpdown – Unit is doing a normal shutdown.
The unit will be in the Off state if any of the following are true:
 A manual reset unit alarm is active
 All circuits are unavailable to start (cannot start even after any cycle timers have
expired)
 The unit mode is ice, all circuits are off, and the ice mode delay is active
The unit will be in the Auto state if any of the following are true:
 Unit enabled based on settings and switches
 If unit mode is ice, the ice timer has expired
 No manual reset unit alarms are active
 At least one circuit is enabled and available to start
The unit will be in Pumpdown until all running compressors finish pumping down if any
of the following are true:
 Unit is disabled via settings and/or inputs in section 0
D-EOMWC00A07-16EN
19
- 20 -
Unit Status
The displayed unit status is determined by the conditions in the following table:
Enum
0
Status
Auto
1
Off:Ice Mode Timer
2
3
4
5
6
Off:All Cir Disabled
Off:Unit Alarm
Off:Keypad Disable
Off:Remote Switch
7
Off:BAS Disable
8
9
10
Off:Unit Switch
Off:Test Mode
Auto:Noise Reduction
11
Auto:Wait for load
12
Auto:Evap Recirc
13
Auto:Wait for flow
14
Auto:Pumpdown
15
Auto:Max Pulldown
16
Auto:Unit Cap Limit
17
Auto:Current Limit
18
19
Off:Config Changed,
Reboot
Off:Set Mfg Location
Conditions
Unit State = Auto
Unit State = Off, Unit Mode = Ice, and Ice Delay =
Active
Unit State = Off and all compressors unavailable
Unit State = Off and Unit Alarm active
Unit State = Off and Unit Enable Set Point = Disable
Unit State = Off and Remote Switch is open
Unit State = Off, Control Source = Network, and BAS
Enable = false
Unit State = Off and Unit Switch = Disable
Unit State = Off and Unit Mode = Test
Unit State = Auto and Noise Reduction is active
Unit State = Auto, no circuits running, and LWT is
less than the active set point + startup delta
Unit State = Auto and Evaporator State = Start
Unit State = Auto, Evaporator State = Start, and Flow
Switch is open
Unit State = Pumpdown
Unit State = Auto, max pulldown rate has been met or
exceeded
Unit State = Auto, unit capacity limit has been met or
exceeded
Unit State = Auto, unit current limit has been met or
exceeded
Unit State = Off and Unit Enable Set Point = Disable
Unit State = Off and Unit Enable Set Point = Disable
Ice Mode Start Delay
An adjustable start-to-start ice delay timer will limit the frequency with which the chiller
may start in Ice mode. The timer starts when the first compressor starts while the unit is
in ice mode. While this timer is active, the chiller cannot restart in Ice mode. The time
delay is user adjustable.
The ice delay timer may be manually cleared to force a restart in ice mode. A set point
specifically for clearing the ice mode delay is available. In addition, cycling the power
to the controller will clear the ice delay timer.
Evaporator Pump Control
Three evaporator pump control states for control of the evaporator pumps:



Off - No pump on.
Start – Pump is on, water loop is being recirculated.
Run – Pump is on, water loop has been recirculated.
The control state is Off when all of the following are true:
 Unit state is Off
 LWT is higher than the Evap Freeze set point or LWT sensor fault is active
 EWT is higher than the Evap Freeze set point or EWT sensor fault is active
20
D–EOMWC00A07-16EN
- 21 -
The control state is Start when any of the following are true:
 The unit state is auto
 LWT is less than the Evap Freeze set point minus 0.6 °C and LWT sensor fault
isn’t active
 EWT is less than the Evap Freeze set point minus 0.6 °C and EWT sensor fault
isn’t active
The control state is Run when the flow switch input has been closed for a time greater
than the Evaporator Recirculate set point.
Pump Selection
The pump output used is determined by the Evap Pump Control set point. This setting
allows the following configurations:





#1 only – Pump 1 will always be used
#2 only – Pump 2 will always be used
Auto – The primary pump is the one with the least run hours, the other is used
as a backup
#1 Primary – Pump 1 is used normally, with pump 2 as a backup
#2 Primary – Pump 2 is used normally, with pump 1 as a backup
Primary/Standby Pump Staging
The pump designated as primary will start first. If the evaporator state is start for a time
greater than the recirculate timeout set point and there is no flow, then the primary pump
will shut off and the standby pump will start. When the evaporator is in the run state, if
flow is lost for more than half of the flow proof set point value, the primary pump will
shut off and the standby pump will start. Once the standby pump is started, the flow loss
alarm logic will apply if flow cannot be established in the evaporator start state, or if
flow is lost in the evaporator run state.
Auto Control
If auto pump control is selected, the primary/standby logic above is still used. When the
evaporator is not in the run state, the run hours of the pumps will be compared. The
pump with the least hours will be designated as the primary at this time.
Condenser Pump Control
There are three condenser pump control states for control of the condenser pump:
 Off
 Start – Pump is on, water loop is being recirculated
 Run – Pump is on, water loop has been recirculated
The control state is Off when any of the following are true:
 Unit state is Off
 LWT is higher of Evap Freeze set point or LWT sensor fault is active
 EWT is higher of Evap Freeze set point or EWT sensor fault is active
The control state is Start when any of the following are true:
 The unit state is auto
 LWT is lower than (Evap Freeze set point - 0.6 °C ) and LWT sensor fault is
not active or EWT is lower than (Evap Freeze set point – 0.6 °C) and EWT
sensor fault is not active.
The control state is Run when the flow switch input has been closed for a time greater
than the loop Recirculate set point.
D-EOMWC00A07-16EN
21
- 22 -
Condensation Control
Three condensation control modes are available:



Cond In – the condensation control measure is the condenser entering water
temperature
Cond Out - the condensation control measure is the condenser leaving water
temperature
Pressure - the condensation control measure is the gas pressure referred to
condenser saturated temperature
The Condenser control mode is determined by the Condensation Control Value set
point.
Within these control modes, the application manages the outputs for the control of
condensation devices:
 n.4 on/off signals, always available
 n.1 modulating 0-10V signal, whose availability is determined by the
Condensation Analog Output type set point.
Cond In/Cond Out condensation control
If the Condensation Control Value Set Point is set to Cond In or Cond Out options, then
Tower fan #1..4 control is enabled for the unit.
According to Tower fan #1..4 set point and differential default values listed in the Unit
Set Points table, the following graph summarizes the activation and deactivation
conditions for Towers fan.
The Tower fan # (# = 1..4) control states are:
 Off
 On
The Tower fan # control state is Off when any of the following are true:
 Unit state is Off
 Tower fan # state is Off and EWT (Cond In) or LWT (Cond Out) is lower than
Tower fan # Set point
 Tower fan # state is On and EWT (Cond In) or LWT (Cond Out) is lower than
Tower fan # Set point – Tower fan # Diff.
The Tower fan # control state is On when all of the following are true:
 The unit state is auto
22
D–EOMWC00A07-16EN
- 23 -

EWT (Cond In) or LWT (Cond Out) is equal or higher than Tower fan # Set
point
If the Condensation Control Value Set Point is set to Cond In or Cond Out options and
Cond Aout type Set Point is set to Vfd or Byp Valve options, a 0-10V signal is also
enabled for the unit to regulate a modulating condensation device by mean of a PID
controller.
According to Vfd/Byp Valve default values listed in the Unit Set Points table, the
following graph is an example of the modulating signal behavior in case of a control
supposed to be purely proportional.
In this case, the analog output varies across the regulation band calculated as Condenser
Water Temp Set Point ± 100/kp, where kp is the control proportional gain, and centered
on the Condenser Water Temp Set Point.
Pressure condensation control
Refer to Circuit Functions.
Leaving Water Temperature (LWT) Reset
LWT Target
The LWT Target varies based on settings and inputs and is selected as follows:
Control Source
Set Point
Local
Local
Network
Local
Local
Network
Local
Local
Network
Network
Local
D-EOMWC00A07-16EN
Mode
Input
OFF
ON
X
OFF
ON
X
OFF
ON
x
x
x
HP
Switch
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
BAS
Request
X
X
COOL
X
X
X
x
x
COOL
ICE
x
Available Modes
Set Point
COOL
COOL
COOL
COOL w/Glycol
COOL w/Glycol
COOL w/Glycol
COOL/ICE w/Glycol
COOL/ICE w/Glycol
COOL/ICE w/Glycol
COOL/ICE w/Glycol
ICE w/Glycol
23
Base LWT Target
Cool Set Point 1
Cool Set Point 2
BAS Cool Set Point
Cool Set Point 1
Cool Set Point 2
BAS Cool Set Point
Cool Set Point 1
Ice Set Point
BAS Cool Set Point
BAS Ice Set Point
Ice Set Point
- 24 -
Network
Local
Local
Network
x
OFF
ON
X
OFF
ON
ON
x
x
X
X
HEAT
ICE w/Glycol
HEAT
HEAT
HEAT
BAS Ice Set Point
Heat Set Point 1
Heat Set Point 2
BAS Heat Set Point
Leaving Water Temperature (LWT) Reset
The base LWT target may be reset if the unit is in Cool or Heat mode and it is
configured for a reset. The type of reset to be used is determined by the LWT Reset
Type set point.
When the active reset increases, the Active LWT Target is changed at a rate of
0.05 °C (0.1°F) every 10 seconds. When the active reset decreases, the Active LWT
Target is changed all at once.
After resets are applied, the LWT target can never exceed a value of 15°C (60°F).
Reset Type – None
The Active Leaving Water variable is set equal to the current LWT set point.
Reset Type – Return
The Active Leaving Water variable is adjusted by the return water temperature.
Return Reset
LWT set Point+Max Reset
(54)
Active
LWT
(oF)
Max Reset
(10)
LWT Set Point
(44)
0
Start Reset Delta T
Evap Delta T (oF)
The active set point is reset using the following parameters:
1. Cool LWT set point
2. Max Reset set point
3. Start Reset Delta T set point
4. Evap Delta T
Reset varies from 0 to Max Reset set point as the Evaporator EWT – LWT (Evap delta t)
varies from the Start Reset Delta T set-point to 0.
4-20 mA External Signal Reset
The Active Leaving Water variable is adjusted by the 4 to 20 mA reset analog input.
Parameters used:
1. Cool LWT set point
2. Max Reset set point
3. LWT Reset signal
Reset is 0 if the reset signal is less than or equal to 4 mA. Reset is equal to the Max
Reset Delta T set point if the reset signal equals or exceeds 20 mA. The amount of reset
will vary linearly between these extremes if the reset signal is between 4 mA and 20
mA. An example of the operation of 4-20 reset in Cool mode follows.
24
D–EOMWC00A07-16EN
- 25 -
4-20 mA Reset - Cool Mode
(54)
Active
LWT
(oF)
Max Reset
(10)
Cool LWT Set
Point (44)
0
4
20
Reset Signal (mA)
Unit Capacity Control
Unit capacity control is performed as described in this section.
Compressor Staging in Cool Mode
The first compressor on the unit is started when evaporator LWT is higher than the
target plus the Startup Delta T set point.
An additional compressor is started when Evaporator LWT is higher than the target plus
the Stage Up Delta T set point.
When multiple compressors are running, one will shut down if evaporator LWT is lower
than the target minus the Stage Down Delta T set point.
The last compressor running will shut down when the evaporator LWT is lower than the
target minus the Shut Down Delta T set point.
Compressor Staging in Heat Mode
The first compressor on the unit is started when condenser LWT is lower than the target
minus the Startup Delta T set point.
An additional compressor is started when condenser LWT is lower than the target minus
the Stage Up Delta T set point.
When multiple compressors are running, one will shut down if condenser LWT is higher
than the target plus the Stage Down Delta T set point.
The last compressor running will shut down when the condenser LWT is higher than the
target plus the Shut Down Delta T set point.
Stage Up Delay
A minimum amount of time will pass between compressors starting, which is defined by
the Stage Up Delay set point. This delay will only apply when at least one compressor
is running. If the first compressor starts and quickly fails on an alarm, another
compressor will start without this minimum time passing.
Required Load For Stage Up
An additional compressor will not be started until all running compressors are at a
capacity higher than the Load Stage Up set point, or running in a limited state.
Light Load Stage Down in Cool Mode
When multiple compressors are running, one will shut down if all running compressors
are at a capacity lower than the Load Stage Down set point and the evaporator LWT is
less than the target plus the Stage Up Delta T set point. A minimum amount of time will
D-EOMWC00A07-16EN
25
- 26 -
pass between compressors stopping as a result of this logic, which is defined by the
Stage Down Delay set point.
Light Load Stage Down in Heat Mode
When multiple compressors are running, one will shut down if all running compressors
are at a capacity lower than the Load Stage Down set point and the condenser LWT is
greater than the target minus the Stage Up Delta T set point. A minimum amount of
time will pass between compressors stopping as a result of this logic, which is defined
by the Stage Down Delay set point.
Maximum Circuits Running
If the number of compressors running is equal to the Max Circuits Running set point, no
additional compressors will be started.
When multiple compressors are running, one will shut down if the number of
compressors running is more than the Max Circuits Running set point.
Compressor Staging in Ice Mode
The first compressor will start when evaporator LWT is higher than the target plus the
Startup Delta T set point.
When at least one compressor is running, the other compressors will start only when
evaporator LWT is higher than the target plus the Stage Up Delta T set point.
All compressors will be staged off when evaporator LWT is less than the target.
Stage Up Delay
A fixed stage up delay of one minute between compressor starts is used in this mode.
When at least one compressor is running, the other compressors will start as quickly as
possible with respect to the stage up delay.
Staging Sequence
This section defines which compressor is the next one to start or stop. In general,
compressors with fewer starts will normally start first, and compressors with more run
hours will normally stop first. Compressor staging sequence can also be determined by
an operator defined sequence via setpoints.
Next To Start
The next compressor to start must meet the following requirements:
Lowest sequence number of those compressors available to start
 if sequence numbers are equal, it must have the least starts
 if starts are equal, it must have least run hours
 if run hours are equal, it must be the lowest numbered compressor
Next To Stop
The next compressor to shut down must meet the following requirements:
Lowest sequence number of the compressors that are running

if sequence numbers are equal, it must have the most run hours

if run hours are equal, it must be the lowest numbered compressor
Compressor Capacity Control In Cool Mode
In Cool mode, evaporator LWT is controlled to within 0.2 °C (0.4 °F)of the target under
constant flow conditions by controlling capacity of the individual compressors.
Compressors are loaded with a fixed step scheme. The rate of capacity adjustment is
determined by the time between capacity changes. The farther away from the target, the
faster compressors will be loaded or unloaded.
26
D–EOMWC00A07-16EN
- 27 -
The logic projects ahead to avoid overshoot, such that the overshoot does not cause the
unit to shut off due to evaporator LWT dropping below the target minus the Shutdown
Delta T set point while there is still a load on the loop at least equal to the minimum unit
capacity.
Capacity of the compressors is controlled so that when possible their capacities are
balanced.
Circuits that are running in manual capacity control or running with active capacity
limiting events are not considered in the capacity control logic.
The compressor capacities are adjusted one at a time while maintaining a capacity
imbalance that does not exceed 12.5%.
Load/Unload Sequence
This section defines which compressor is the next one to load or unload.
Next To Load
The next compressor to load meets the following requirements:
Lowest capacity of the running compressors that can load up

if capacities are equal, it must have the highest sequence number of the
compressors that are running

if the sequence numbers are equal, it must have the least run hours

if run hours are equal, it must have the most starts

if starts are equal, it must be the highest numbered compressor
Next To Unload
The next compressor to unload must meet the following requirements:
Highest capacity of the running compressors
 if capacities are equal, it must have the lowest sequence number of the compressors
that are running
 if sequence numbers are equal, it must have the most run hours
 if run hours are equal, it must have the least starts
 if starts are equal, it must be the lowest numbered compressor
Compressor Capacity Control In Ice Mode
In Ice mode, running compressors are loaded up simultaneously at the maximum
possible rate that allows for stable operation of the individual circuits.
Unit Capacity Overrides
Unit capacity limits can be used to limit total unit capacity in Cool mode only. Multiple
limits may be active at any time, and the lowest limit is always used in the unit capacity
control.
Soft load, demand limit, and network limit use a deadband around the actual limit value,
such that unit capacity increase is not allowed within this deadband. If unit capacity is
above the deadband, capacity is decreased until it is back within the deadband.



For 2 circuit units, the deadband is 7%.
For 3 circuit units, the deadband is 5%.
For 4 circuit units, the deadband is 4%.
Soft Load
Soft Loading is a configurable function used to ramp up the unit capacity over a given
time. The set points that control this function are:
 Soft Load – (ON/OFF)
 Begin Capacity Limit – (Unit %)
D-EOMWC00A07-16EN
27
- 28 -

Soft Load Ramp – (seconds)
The Soft Load Unit Limit increases linearly from the Begin Capacity Limit set-point to
100% over the amount of time specified by the Soft Load Ramp set-point. If the option
is turned off, the soft load limit is set to 100%.
Demand Limit
The maximum unit capacity can be limited by a 4 to 20 mA signal on the Demand Limit
analog input at the unit controller. This function is only enabled if the Demand Limit set
point is set to ON.
As the signal varies from 4 mA up to 20 mA, the maximum unit capacity changes by
steps of 1% from 100% to 0%. The unit capacity is adjusted as needed to meet this
limit, except that the last running compressor cannot be turned off to meet a limit lower
than the minimum unit capacity.
Network Limit
The maximum unit capacity can be limited by a network signal. This function is only
enabled if the unit control source is set to network. The signal will be received through
the BAS interface on the unit controller.
As the signal varies from 0% up to 100%, the maximum unit capacity changes from 0%
to 100%. The unit capacity is adjusted as needed to meet this limit, except that the last
running compressor cannot be turned off to meet a limit lower than the minimum unit
capacity.
Current Limit
Current Limit control is enabled only when the current limit enable input is closed.
Unit current is calculated based on the 4-20 mA input that receives a signal from an
external device. The current at 4 mA is assumed to be 0, and the current at 20 mA is
defined by a set point. As the signal varies from 4 to 20 mA, the calculated unit current
varies linearly from 0 amps to the amp value defined by the set point.
The current limit uses a deadband centered around the actual limit value, such that unit
capacity increase is not allowed when current is within this deadband. If unit current is
above the deadband, capacity is decreased until it is back within the deadband. The
current limit deadband is 10% of the current limit.
Maximum LWT Pulldown Rate
The maximum rate at which the leaving water temperature can drop is limited by the
Maximum Rate set point, only when the LWT is less than 60°F (15°C).
If the pulldown rate is too fast, the unit capacity is reduced until the rate is less than the
Maximum Pulldown Rate set point.
High Water Temperature Capacity Limit
If the evaporator LWT exceeds 18 °C (65F), compressor load will be limited to a
maximum of 75%. Compressors will unload to 75% or less if running at greater than
75% load when the LWT exceeds the limit. This feature is to keep the circuit running
within the capacity of the condenser coil.
A dead-band placed below the limit set-point will be used to increase function stability.
If the actual capacity is in the band, unit loading will be inhibited.
28
D–EOMWC00A07-16EN
- 29 -
Circuit Functions
Calculations
Refrigerant Saturated Temperature
Refrigerant saturated temperature is calculated from the pressure sensor readings for
each circuit. A function provides the converted value of temperature to match values
published data for R134a
-within 0.1 C for pressure inputs from 0 kPa to 2070kPa,
-within 0.2 C for pressure inputs from -80 kPa to 0 kPa.
Evaporator Approach
The evaporator approach is calculated for each circuit. The equation is as follows:
Evaporator Approach = LWT – Evaporator Saturated Temperature
Suction Superheat
Suction superheat is calculated for each circuit using the following equation:
Suction superheat = Suction Temperature – Evaporator Saturated Temperature
Discharge Superheat
Discharge superheat is calculated for each circuit using the following equation:
Discharge superheat = Discharge Temperature – Condenser Saturated
Temperature
Oil Differential Pressure
Oil Differential Pressure is calculated for each circuit with this equation:
Oil Differential Pressure = Condenser Pressure - Oil Pressure
Maximum Saturated Condenser Temperature
The maximum saturated condenser temperature calculation is modeled after the
compressor operational envelope. Its value is 68.3°C basically but it can change when
saturated evaporator temperature decreases below 0°C.
High Saturated Condenser – Hold Value
High Cond Hold Value = Max Saturated Condenser Value – 2.78C
High Saturated Condenser – Unload Value
High Cond Unload Value = Max Saturated Condenser Value – 1.67C
Condenser Saturated Temperature Target
The saturated condenser temperature target is calculated to maintain the proper pressure
ratio, to keep the compressor lubricated and to have the maximum circuit performances.
The calculated target value is limited to a range defined by the Condenser Saturated
Temperature Target min and max set points. These set points simply cut off the value to
a working range, and this range can be limited to a single value if the two set points are
set to the same value.
Circuit Control Logic
Circuit Availability
A circuit is available to start if the following conditions are true:
 Circuit switch is closed
 No circuit alarms are active
 Circuit Mode set point is set to Enable
 BAS Circuit Mode set point is set to Auto
 No cycle timers are active
 Discharge Temperature is at least 5°C higher than Oil Saturated Temperature
D-EOMWC00A07-16EN
29
- 30 -
Starting
The circuit will start if all these conditions are true:
 Adequate pressure in the evaporator and condenser (see No Pressure At Start Alarm)
 Circuit Switch is closed
 Circuit Mode set point is set to Enable
 BAS Circuit Mode set point is set to Auto
 No cycle timers are active
 No alarms are active
 Staging logic requires this circuit to start
 Unit state is Auto
 Evaporator pump state is Run
Circuit Startup Logic
Circuit startup is the time period following the starting of the compressor on a circuit.
During the startup, the low evaporator pressure alarm logic is ignored. When the
compressor has been running at least 20 seconds and the evaporator pressure rises above
the low evaporator pressure unload set point, the startup is complete.
If the pressure does not rise above the unload set point and the circuit has been running
longer than the Startup Time set point, then the circuit is turned off and an alarm
triggered. If the evaporator pressure drops below the absolute low pressure limit then
the circuit is turned off and the same alarm triggered.
Stopping
Normal Shutdown
A normal shutdown requires the circuit to pumpdown before the compressor is turned
off. This is done by closing the EXV, and closing the liquid line solenoid (if present)
while the compressor is running.
The circuit will do a normal shutdown (pumpdown) if any of the following are true:
 Staging logic requires this circuit to stop
 Unit State is Pumpdown
 A pumpdown alarm occurs on the circuit
 Circuit switch is open
 Circuit Mode set point is set to Disable
 BAS Circuit Mode set point is set to Off
The normal shutdown is complete when any of the following are true:
 Evaporator Pressure is less than the Pumpdown Pressure set point
 Service Pumpdown set point is set to Yes and Evaporator Pressure is less than
5 psi
 Circuit has been pumping down for longer than the Pumpdown Time Limit setpoint
Rapid Shutdown
A rapid shutdown requires the compressor to stop and the circuit to go to the Off state
immediately.
The circuit will do a rapid shutdown if either of these conditions occurs at any time:
 Unit State is Off
 A rapid stop alarm occurs on the circuit
Circuit Status
The displayed circuit status is determined by the conditions in the following table:
Enum
30
Status
0
Off:Ready
1
Off:Stage Up Delay
D–EOMWC00A07-16EN
Conditions
Circuit is ready to start when needed.
Circuit is off and cannot start due to stage up delay.
- 31 -
2
Off:Cycle Timer
3
Off:Keypad Disable
4
Off:Circuit Switch
5
Off:Oil Heating
6
Off:Alarm
7
Off:Test Mode
8
EXV Preopen
9
Run:Pumpdown
10
Run:Normal
11
Run:Disc SH Low
12
Run:Evap Press Low
13
Run:Cond Press High
Circuit is off and cannot start due to active cycle timer.
Circuit is off and cannot start due to keypad disable.
Circuit is off and circuit switch is off.
Circuit is off and Discharge Temperature – Oil
Saturated Temperature at gas pressure <= 5°C
Circuit is off and cannot start due to active circuit alarm.
Circuit is in test mode.
Circuit is in preopen state.
Circuit is in pumpdown state.
Circuit is in run state and running normally.
Circuit is running and cannot load due to low discharge
superheat.
Circuit is running and cannot load due to low evaporator
pressure.
Circuit is running and cannot load due to high
condenser pressure.
Compressor Control
The compressor will run only when the circuit is in a run or pumpdown state. This
means the compressor should not be running any time the circuit is off or during
preopening the EXV.
Cycle Timers
A minimum time between starts of the compressor and a minimum time between
shutdown and start of the compressor will be enforced. The time values are set by
global circuit set points.
These cycle timers are enforced even through cycling of power to the chiller.
These timers may be cleared via a setting on the controller.
Compressor Run Timer
When a compressor starts, a timer will start and run as long as the compressor runs.
This timer is used in the alarm log.
Compressor Capacity Control
After starting, the compressor will be unloaded to the minimum physical capacity and
no attempt to increase compressor capacity is made until the differential between
evaporator pressure and oil pressure meets a minimum value.
After the minimum differential pressure is met, compressor capacity is controlled to
25%.
Compressor capacity will always be limited to a minimum of 25% while it is running,
except for the time after compressor start when the differential pressure is being built
and except when changes to capacity are performed as needed to meet unit capacity
requirements (see unit capacity control section).
Capacity will not be increased above 25% until discharge superheat has been at least
12°C for a time of at least 30 seconds.
Manual capacity control
The capacity of the compressor can be controlled manually. Manual capacity control is
enabled via a set point with choices of auto or manual. Another set point allows setting
the compressor capacity from 25% to 100%.
The compressor capacity is controlled to the manual capacity set point. Changes will be
made at a rate equal to the maximum rate that allows stable circuit operation.
Capacity control reverts back to automatic control if either:
 the circuit shuts down for any reason
D-EOMWC00A07-16EN
31
- 32 -

capacity control has been set to manual for four hours
Slide Control Solenoids (Asymmetric compressors)
This section applies to the following compressor models (asymmetric):
Model
F3AS
F3AL
F3BS
F3BL
F4AS
F4AL
Name plate
HSA192
HSA204
HSA215
HSA232
HSA241
HSA263
The required capacity is achieved by controlling one modulating slide and one nonmodulating slide. The modulating slide can control 10% to 50% of the total compressor
capacity, infinitely variable. The non-modulating slide can control either 0% or 50% of
the total compressor capacity.
Either the load or the unload solenoid for the non-modulating slide is on any time the
compressor is running. For compressor capacity from 10% up to 50%, the nonmodulating slide unload solenoid is on to keep that slide in the unloaded position. For
capacity from 60% to 100%, the non-modulating slide load solenoid is on to keep that
slide in the loaded position.
The modulating slide is moved by pulsing of the load and unload solenoids to achieve
the required capacity.
An additional solenoid is controlled to assist in moving the modulating slide in certain
conditions. This solenoid is activated when the pressure ratio (condenser pressure
divided by evaporator pressure) is less than or equal to 1.2 for at least
5 seconds. It is deactivated when pressure ratio is more than 1.2.
Slide Control Solenoids (Symmetric compressors)
This section applies to the following compressor models (asymmetric):
Model
F4221
F4222
F4223
F4224
F3216
F3218
F3220
F3221
F3118
F3120
F3121
F3122
F3123
Name plate
HSA205
HSA220
HSA235
HSA243
HSA167
HSA179
HSA197
HSA203
HSA3118
HSA3120
HSA3121
HSA3122
HSA3123
The required capacity is achieved by controlling one modulating slide. The modulating
slide can control 25% to 100% of the total compressor capacity, infinitely variable.
The modulating slide is moved by pulsing of the load and unload solenoids to achieve
the required capacity.
32
D–EOMWC00A07-16EN
- 33 -
Capacity Overrides – Limits of Operation
The following conditions override automatic capacity control when the chiller is in
COOL mode. These overrides keep the circuit from entering a condition in which it is
not designed to run.
Low Evaporator Pressure
If the Low Evaporator Pressure Hold event is triggered, the compressor will not be
allowed to increase in capacity.
If the Low Evaporator Pressure Unload event is triggered, the compressor will begin
reducing capacity.
The compressor will not be allowed to increase in capacity until the Low Evaporator
Pressure Hold event has cleared.
See the Circuit Events section for details on triggering, reset, and unloading action.
High Condenser Pressure
If the High Condenser Pressure Hold event is triggered, the compressor will not be
allowed to increase capacity.
If the High Condenser Pressure Unload event is triggered, the compressor will begin
reducing capacity.
The compressor will not be allowed to increase in capacity until the High Condenser
Pressure Hold event has cleared.
See the Circuit Events section for details on triggering, reset, and unloading action.
Pressure condensation control
If the Condensation Control Value Set Point is set to Press option, then Fan steps #1..4
control is enabled for each enabled circuit.
According to Fan steps set point and differential default values listed in the Circuit Set
Points table, the following graph summarizes the activation and deactivation conditions
for fan steps.
The Fan step# (# = 1..4) control states are:
 Off
 On
The Fan step # control state is Off when any of the following are true:
 Unit state is Off
 Fan step# state is Off and the Saturated Condenser Temperature corresponding
to the current Condenser Pressure is lower than Fan step # Set point.
 Fan step # state is On the Saturated Condenser Temperature corresponding to
the current Condenser Pressure is lower than Fan step# Set point – Fan step#
Diff.
D-EOMWC00A07-16EN
33
- 34 -
The Tower # control state is On when all of the following are true:
 The unit state is auto
 The Saturated Condenser Temperature corresponding to the current Condenser
Pressure is equal or higher than Fan step# Set point
If the Condensation Control Value Set Point is set to Press option and Cond Aout type
Set Point is set to Vfd option, a 0-10V signal is also enabled for the circuit to regulate a
modulating condensation device by mean of a PID controller.
According to Vfd default values listed in the Circuit Set Points table, the following
graph represents the modulating signal behavior in case of a control supposed to be
purely proportional.
In this example, the analog output varies across the regulation band calculated as
Condenser Saturated Temp Set Point ± 100/kp, where kp is the control proportional
gain, and centered on the Condenser Saturated Temp Set Point.
EXV Control
The control is able to support different valve models from different vendors. When a
model is selected, all the operational data for that valves are set including phase and
hold currents, total steps, motor speed and extrasteps.
The EXV is moved at a rate which depends on the valve model, with a total range of
steps. Positioning is determined as described in the following sections, with adjustments
made in increments of 0.1% of the total range.
Preopen Operation
The EXV control includes a preopen operation that is used only when the unit has
optional liquid line solenoids. The unit is configured for use with or without liquid line
solenoids via a set point.
When a circuit start is required, the EXV opens before the compressor starts. The
preopen position is defined by a set point. The time allowed for this preopen operation
is at least enough time for the EXV to open to the preopen position based on the
programmed movement rate of the EXV.
Startup Operation
When the compressor starts (if no liquid line solenoid valve is installed), the EXV will
start to open to an initial position that allows a safe start up. The value of LWT will
determine if it is possible to enter the normal operation. If it is higher than 20°C (68 °F)
34
D–EOMWC00A07-16EN
- 35 -
then a pressostatic (constant pressure) control will start to keep the compressor into the
envelope. It goes in normal operation as soon as the suction superheat drops below a
value equal to the suction superheat setpoint.
Normal Operation
Normal operation of the EXV is used when the circuit has completed startup operation
of the EXV and is not in a slide transition conditions.
During normal operation, the EXV controls suction superheat to a target that can vary in
a pre-defined range
The EXV controls the suction superheat within 0.83°C (1.5°F) during stable operating
conditions (stable water loop, static compressor capacity, and stable condensing
temperature).
The target value is adjusted as needed to maintain discharge superheat within a range
from 15°C (27 °F) to 25 °C (45°F).
Maximum Operating Pressures
The EXV control maintains the evaporator pressure in the range defined by the
maximum operating pressure.
If the leaving water temperature is higher than 20°C (68°F) at startup or if the pressure
becomes higher than 350.2 kPa (50.8 psi) during normal operations, then a pressostatic
(constant pressure) control will be started to keep the compressor in the envelope.
Maximum operating pressure 350.2 kPa (50.8 psi). It switches back to normal operation
as soon as the suction superheat drops below a pre-defined value.
Response to Compressor Capacity Change
The logic will consider transition from 50% to 60% and from 60% to 50% as special
conditions. When a transition is entered the valve opening will change to adapt to the
new capacity, this new calculated position will be kept for 60 seconds. The valve
opening will be increased during 50% to 60% transition and decreased in 60% to 50%
transition.
Purpose of this logic is to limit liquid flood back when changing from 50% to 60% if the
capacity increases above 60% due to slides movement.
Manual Control
The EXV position can be set manually. Manual control can only be selected when the
EXV state is Pressure or Superheat control. At any other time, the EXV control set
point is forced to auto.
When EXV control is set to manual, the EXV position is equal to the manual EXV
position setting. If set to manual when the circuit state transitions from run to another
state, the control setting is automatically set back to auto. If EXV control is changed
from manual back to auto while the circuit state remains run, the EXV state goes back to
the normal operations if possible or to pressure control to limit maximum operating
pressure.
Transitions Between Control States
Whenever EXV control changes between Startup Operation, Normal Operation, or
Manual Control, the transition is smoothed by gradually changing the EXV position
rather than changing all at once. This transition prevents the circuit from becoming
unstable and resulting in a shutdown due to alarm trip.
Liquid Injection
Liquid injection is activated when the circuit is in a run state and the discharge
temperature rises above the Liquid Injection Activation set point.
Liquid injection is turned off when the discharge temperature decreases below the
activation set point by a differential of 10°C.
D-EOMWC00A07-16EN
35
- 36 -
Alarms and Events
Situations may arise that require some action from the chiller or that should be logged
for future reference. A condition that requires a shutdown and/or lockout is an alarm.
Alarms may cause a normal stop (with pumpdown) or a rapid stop. Most alarms require
manual reset, but some reset automatically when the alarm condition is corrected. Other
conditions can trigger what is known as an event, which may or may not cause the
chiller to respond with a specific action in response. All alarms and events are logged.
Signaling Alarms
The following actions will signal that an alarm has occurred:
1. The unit or a circuit will execute a rapid or pumpdown shutoff.
2. An alarm bell icon  will be displayed in the upper right-hand corner of all
controller screens including the optional remote user interface panel’s screens.
3. An optional field supplied and wired remote alarm device will be activated.
Clearing Alarms
Active alarms can be cleared through the keypad/display or a BAS network. Alarms are
automatically cleared when controller power is cycled. Alarms are cleared only if the
conditions required to initiate the alarm no longer exist. All alarms and groups of alarms
can be cleared via the keypad or network via LON using nviClearAlarms and via
BACnet using the ClearAlarms object
To use the keypad, follow the Alarm links to the Alarms screen, which will show Active
Alarms and Alarm Log. Select Active Alarm and press the wheel to view the Alarm Li st
(list of current active alarms). They are in order of occurrence with the most recent on
top. The second line on the screen shows Alm Cnt (number of alarms currently active)
and the status of the alarm clear function. Off indicates that the Clear function is off and
the alarm is not cleared. Press the wheel to go to the edit mode. The Alm Clr (alarm
clear) parameter will be highlighted with OFF showing. To clear all alarms, rotate the
wheel to select ON and enter it by pressing the wheel.
An active password is not necessary to clear alarms.
If the problem(s) causing the alarm have been corrected, the alarms will be cleared,
disappear from the Active Alarm list and be posted in the Alarm Log. If not corrected,
the On will immediately change back to OFF and the unit will remain in the alarm
condition.
Remote Alarm Signal
The unit is configured to allow field wiring of alarm devices. Refer to unit onboard
documentation for field wiring information.
Description of Alarms
Phase Volts Loss/GFP Fault
Alarm description (as shown on screen): UnitOffPhaseVoltage
Trigger: PVM set point is set to Single Point and PVM/GFP input is low
Action Taken: Rapid stop all circuits
Reset: Auto reset when PVM input is high or PVM set point does not equal single
point for at least 5 seconds.
36
D–EOMWC00A07-16EN
- 37 -
Evaporator Flow Loss
Alarm description (as shown on screen): UnitOffEvapWaterFlow
Trigger:
1: Evaporator Pump State = Run AND Evaporator Flow Digital Input = No Flow
for time > Flow Proof Set Point AND at least one compressor running
2: Evaporator Pump State = Start for time greater than Recirc Timeout Set Point
and all pumps have been tried
Action Taken: Rapid stop all circuits
Reset:
This alarm can be cleared at any time manually via the keypad or via the BAS clear
alarm signal.
If active via trigger condition 1:
When the alarm occurs due to this trigger, it can auto reset the first two times each
day, with the third occurrence being manual reset.
For the auto reset occurrences, the alarm will reset automatically when the
evaporator state is Run again. This means the alarm stays active while the unit
waits for flow, then it goes through the recirculation process after flow is detected.
Once the recirculation is complete, the evaporator goes to the Run state which will
clear the alarm. After three occurrences, the count of occurrences is reset and the
cycle starts over if the manual reset flow loss alarm is cleared.
If active via trigger condition 2:
If the flow loss alarm has occurred due to this trigger, it is always a manual reset
alarm.
Evaporator Water Freeze Protect
Alarm description (as shown on screen): UnitOffEvapWaterTmpLo
Trigger: Evaporator LWT or EWT drops below evaporator freeze protect set point.
If the sensor fault is active for either LWT or EWT, then that sensor value cannot
trigger the alarm.
Action Taken: Rapid stop all circuits
Reset: This alarm can be cleared manually via the keypad or via the BAS clear
alarm signal, but only if the alarm trigger conditions no longer exist.
Evaporator Water Temperatures Inverted in Cool Mode
Alarm description (as shown on screen): UnitOffEvpWTempInvrtd
Trigger: Evap EWT < Evap LWT - 1 deg C AND at least one circuit is running
AND EWT sensor fault not active AND LWT sensor fault not active] for 30
seconds
Action Taken: Pumpdown stop on all circuits
Reset: This alarm can be cleared manually via the keypad.
Leaving Evaporator Water Temperature Sensor Fault
Alarm description (as shown on screen): UnitOffEvpLvgWTemp
Trigger: Sensor shorted or open
Action Taken: Rapid stop all circuits
Reset: This alarm can be cleared manually via the keypad, but only if the sensor is
back in range.
D-EOMWC00A07-16EN
37
- 38 -
External Alarm
Alarm description (as shown on screen): UnitOffExternalAlarm
Trigger: External Alarm/Event input is open for at least 5 seconds and external
fault input is configured as an alarm.
Action Taken: Pumpdown stop on all circuits.
Reset: Auto clear when digital input is closed.
Emergency Stop Alarm
Alarm description (as shown on screen): UnitOffEmergencyStop
Trigger: Emergency Stop input is open.
Action Taken: Rapid stop of all circuits.
Reset: This alarm can be cleared manually via the keypad if the switch is closed.
Unit Events
The following unit events are logged in the event log with a time stamp.
Entering Evaporator Water Temperature Sensor Fault
Event description (as shown on screen): UnitOffEvpEntWTemp
Trigger: Sensor shorted or open
Action Taken: Pumpdown stop on all circuits.
Reset: Auto reset when sensor is back in range.
Unit Power Restore
Event description (as shown on screen): UnitPowerRestore
Trigger: Unit controller is powered up.
Action Taken: none
Reset: none
External Event
Alarm description (as shown on screen): UnitExternalEvent
Trigger: External Alarm/Event input is open for at least 5 seconds and external
fault is configured as an event.
Action Taken: None
Reset: Auto clear when digital input is closed.
Circuit Stop Alarms
All circuit stop alarms require shutdown of the circuit on which they occur. Rapid stop
alarms do not do a pumpdown before shutting off. All other alarms will do a
pumpdown.
When one or more circuit alarms are active and no unit alarms are active, the alarm
output will be switched on and off on 5 second intervals.
Alarm descriptions apply to all circuits, the circuit number is represented by ‘N’ in the
description.
Phase Volts Loss/GFP Fault
Alarm description (as shown on screen): C# OffPhaseVoltage
Trigger: PVM input is low and PVM set point = Multi Point
Action Taken: Rapid stop circuits
Reset: Auto reset when PVM input is high or PVM set point does not equal multi
point for at least 5 seconds.
Low Evaporator Pressure
Alarm description (as shown on screen): Co#.LowEvPr
38
D–EOMWC00A07-16EN
- 39 -
Trigger: [Freezestat trip AND Circuit State = Run] OR Evaporator Press < -10 psi
Freezestat logic allows the circuit to run for varying times at low pressures. The
lower the pressure, the shorter the time the compressor can run. This time is
calculated as follows:
Freeze error = Low Evaporator Pressure Unload – Evaporator Pressure
Freeze time = 70 – 6.25 x freeze error, limited to a range of 20-70 seconds
When the evaporator pressure goes below the Low Evaporator Pressure Unload set
point, a timer starts. If this timer exceeds the freeze time, then a freezestat trip
occurs. If the evaporator pressure rises to the unload set point or higher, and the
freeze time has not been exceeded, the timer will reset.
The alarm cannot trigger if the evaporator pressure sensor fault is active.
Action Taken: Rapid stop circuit
Reset: This alarm can be cleared manually if the evaporator pressure is above –10
psi.
Low Pressure Start Fail
Alarm description (as shown on screen): C# OffStrtFailEvpPr
Trigger: Circuit state = start for time greater than Startup Time set point.
Action Taken: Rapid stop circuit
Reset: This alarm can be cleared manually via the Unit Controller keypad
Mechanical Low Pressure Switch
Alarm description (as shown on screen): C# Cmp1 OffMechPressLo
Trigger: Mechanical Low Pressure switch input is low
Action Taken: Rapid stop circuit
Reset: This alarm can be cleared manually via the Unit Controller keypad if the
MLP switch input is high.
High Condenser Pressure
Alarm description (as shown on screen): Co#.HighCondPr
Trigger: Condenser Saturated Temperature > Max Saturated Condenser Value for
time > High Cond Delay set point.
Action Taken: Rapid stop circuit
Reset: This alarm can be cleared manually via the Unit Controller keypad
Low Pressure Ratio
Alarm description (as shown on screen): C# Cmp1 OffPrRatioLo
Trigger: Pressure ratio < calculated limit for a time > Low Pressure Ratio Delay
set point after circuit startup has completed. The calculated limit will vary from 1.4
to 1.8 as the compressor’s capacity varies from 25% to 100%.
Action Taken: Normal shutdown of circuit
Reset: alarm can be cleared manually via the Unit Controller keypad
Mechanical High Pressure Switch
Alarm description (as shown on screen): C# Cmp1 OffMechPressHi
Trigger: Mechanical High Pressure switch input is low AND Emergency Stop
Alarm is not active.
(opening emergency stop switch kills power to MHP switches)
Action Taken: Rapid stop circuit
Reset: This alarm can be cleared manually via the Unit Controller keypad if the
MHP switch input is high.
D-EOMWC00A07-16EN
39
- 40 -
High Discharge Temperature
Alarm description (as shown on screen): C# Disc Temp High
Trigger: Discharge Temperature > High Discharge Temperature set point AND
compressor is running. Alarm cannot trigger if discharge temperature sensor fault
is active.
Action Taken: Rapid stop circuit
Reset: This alarm can be cleared manually via the Unit Controller keypad.
High Oil Pressure Difference
Alarm description (as shown on screen): C# Cmp1 OffOilPrDiffHi
Trigger: Oil Pressure Differential > High Oil Pressure Differential set point for a
time greater than Oil Pressure Differential Delay.
Action Taken: Rapid stop circuit
Reset: This alarm can be cleared manually via the Unit Controller keypad.
Oil Level Switch
Alarm description (as shown on screen): Oil Level Low N
Trigger: Oil level switch open for a time greater than Oil level switch Delay while
compressor is in the Run state.
Action Taken: Rapid stop circuit
Reset: This alarm can be cleared manually via the Unit Controller keypad.
Compressor Starter Fault
Alarm description (as shown on screen): C# Cmp1 OffStarterFlt
Trigger:
If PVM set point = None(SSS): any time starter fault input is open
If PVM set point = Single Point or Multi Point: compressor has been running for at
least 14 seconds and starter fault input is open
Action Taken: Rapid stop circuit
Reset: This alarm can be cleared manually via the Unit Controller keypad.
High Motor Temperature
Alarm description (as shown on screen): C# Cmp1 OffMotorTempHi
Trigger:
Input value for the motor temperature is 4500 ohms or higher.
Action Taken: Rapid stop circuit
Reset: This alarm can be cleared manually via the Unit Controller keypad after
input value for motor temperature has been 200 ohms or less for at least 5 minutes.
No Pressure Change After Start
Alarm description (as shown on screen): C# OffNoPressChgStart
Trigger: After start of compressor, at least a 1 psi drop in evaporator pressure OR
5 psi increase in condenser pressure has not occurred after 15 seconds
Action Taken: Rapid stop circuit
Reset: This alarm can be cleared manually via the Unit Controller keypad.
No Pressure At Startup
Alarm description (as shown on screen): C# OffNoPressAtStart
Trigger: [Evap Pressure < 5 psi OR Cond Pressure < 5 psi] AND Compressor start
requested AND circuit does not have a fan VFD
Action Taken: Rapid stop circuit
Reset: This alarm can be cleared manually via the Unit Controller keypad.
40
D–EOMWC00A07-16EN
- 41 -
CC Comm Failure #
Alarm description (as shown on screen): C# OffCmpCtrlrComFail
Trigger: Communication with the I/O extension module has failed. Section
‘Control network details’ indicates the expected type of module and the address
for each module.
Action Taken: Rapid stop of affected circuit
Reset: This alarm can be cleared manually via the keypad when communication
between main controller and the extension module is working for 5 seconds.
FC Comm Failure Circuit 2
Alarm description (as shown on screen): C2 OffFnCtlrComFail
Trigger: Condensation Control Value Set Point is set to Press option, Circuit 2 is
enabled and communication with the I/O extension module has failed. Section
‘Control network details’ indicates the expected type of module and the address
for the module.
Action Taken: Rapid stop of circuit 2
Reset: This alarm can be cleared manually via the keypad when communication
between main controller and the extension module is working for 5 seconds.
FC Comm Failure Circuit 3
Alarm description (as shown on screen): C3 OffFnCtlrComFail
Trigger: Condensation Control Value Set Point is set to Press option, Circuit 3 is
enabled and communication with the I/O extension module has failed. Section
‘Control network details’ indicates the expected type of module and the address
for the module.
Action Taken: Rapid stop of circuit 3
Reset: This alarm can be cleared manually via the keypad when communication
between main controller and the extension module is working for 5 seconds.
EEXV Comm Failure #
Alarm description (as shown on screen): C# OffEXVCrtlrComFail
Trigger: Communication with the I/O extension module has failed. Section
‘Control network details’ indicates the expected type of module and the address
for each module. Alarm on Circuit #3 will be enabled if Number of Circuits set
point > 2; alarm on Circuit #4 will be enabled if Number of Circuits set point > 3.
Action Taken: Rapid stop of affected circuit
Reset: This alarm can be cleared manually via the keypad when communication
between main controller and the extension module is working for 5 seconds.
Heat Pump Comm Failure
Alarm description (as shown on screen): HeatPCtrlrCommFail
Trigger: Heating mode is enabled and communication with the I/O extension
module has failed. Section ‘Control network details’ indicates the expected type
of module and the address for the module.
Action Taken: Pumpdown stop on all circuits
Reset: This alarm can be cleared manually via the keypad when communication
between main controller and the extension module is working for 5 seconds.
Evaporator Pressure Sensor Fault
Alarm description (as shown on screen): C# Cmp1 OffEvpPress
Trigger: Sensor shorted or open
Action Taken: Rapid stop circuit
Reset: This alarm can be cleared manually via the keypad, but only if the sensor
is back in range.
D-EOMWC00A07-16EN
41
- 42 -
Condenser Pressure Sensor Fault
Alarm description (as shown on screen): C# Cmp1 OffCndPress
Trigger: Sensor shorted or open
Action Taken: Rapid stop circuit
Reset: This alarm can be cleared manually via the keypad, but only if the sensor
is back in range.
Oil Pressure Sensor Fault
Alarm description (as shown on screen): C# Cmp1 OffOilFeedP
Trigger: Sensor shorted or open
Action Taken: Normal shutdown of circuit
Reset: This alarm can be cleared manually via the keypad, but only if the sensor
is back in range.
Suction Temperature Sensor Fault
Alarm description (as shown on screen): C# Cmp1 OffSuctTemp
Trigger: Sensor shorted or open
Action Taken: Normal shutdown of circuit
Reset: This alarm can be cleared manually via the keypad, but only if the sensor
is back in range.
Discharge Temperature Sensor Fault
Alarm description (as shown on screen): C# Cmp1 OffDischTmp
Trigger: Sensor shorted or open
Action Taken: Normal shutdown of circuit
Reset: This alarm can be cleared manually via the keypad, but only if the sensor
is back in range.
Motor Temperature Sensor Fault
Alarm description (as shown on screen): C# Cmp1 OffMtrTempSen
Trigger: Sensor shorted or open
Action Taken: Rapid stop circuit
Reset: This alarm can be cleared manually via the keypad, but only if the sensor
is back in range.
Circuit Events
The following events limit operation of the circuit in some way as described in the
Action Taken column. The occurrence of a circuit event only affects the circuit on which
it occurred. Circuit events are logged in the event log on the unit controller.
Low Evaporator Pressure - Hold
Event description (as shown on screen): EvapPress Low Hold
Trigger: This event is not enabled until the circuit startup is complete and the unit
mode is Cool. Then, while running, if evaporator pressure <= Low Evaporator
Pressure Hold set point the event is triggered. The event is not to be triggered for
90 seconds following the capacity change of the compressor from 50% to 60%.
Action Taken: Inhibit loading.
Reset: While still running, the event will be reset if evaporator pressure > (Low
Evaporator Pressure Hold SP + 2psi). The event is also reset if the unit mode is
switched to Ice, or the circuit is no longer in the run state.
Low Evaporator Pressure - Unload
Event description (as shown on screen): C# UnloadEvapPress
42
D–EOMWC00A07-16EN
- 43 -
Trigger: This event is not enabled until the circuit startup is complete and the unit
mode is Cool. Then, while running, if evaporator pressure <= Low Evaporator
Pressure Unload set point the event is triggered. The event is not to be triggered
for 90 seconds following the capacity change of the compressor from 50% to 60%
(for Asymmetric compressors only).Action Taken: Action Taken: Unload the
compressor by decreasing the capacity by one step every 5 seconds until the
evaporator pressure rises above the Low Evaporator Pressure Unload set point.
Reset: While still running, the event will be reset if evaporator pressure > (Low
Evaporator Pressure Hold SP + 2psixxx). The event is also reset if the unit mode
is switched to Ice, or the circuit is no longer in the run state.
High Condenser Pressure - Hold
Event description (as shown on screen): C# InhbtLoadCndPr
Trigger: While the compressor is running and unit mode is Cool, if saturated
condenser temperature >= High Saturated Condenser Hold Value, the event is
triggered.
Action Taken: Inhibit loading.
Reset: While still running, the event will be reset if saturated condenser
temperature < (High Saturated Condenser Hold Value – 10oF). The event is also
reset if the unit mode is switched to Ice, or the circuit is no longer in the run state.
High Condenser Pressure - Unload
Event description (as shown on screen): C# UnloadCondPress
Trigger: While the compressor is running and unit mode is Cool, if saturated
condenser temperature >= High Saturated Condenser Unload Value, the event is
triggered.
Action Taken: Unload the compressor by decreasing the capacity by one step
every 5 seconds until the evaporator pressure rises above the High Condensing
Pressure Unload set point.
Reset: While still running, the event will be reset if saturated condenser
temperature < (High Saturated Condenser Unload Value – 10oF). The event is
also reset if the unit mode is switched to Ice, or the circuit is no longer in the run
state.
Failed Pumpdown
Event description (as shown on screen): C# FailedPumpdown
Trigger: Circuit state = pumpdown for time > Pumpdown Time set point
Action Taken: Shutdown circuit
Reset: N/A
Power Loss While Running
Event description (as shown on screen): C# PwrLossRun
Trigger: Circuit controller is powered up after losing power while compressor
was running
Action Taken: N/A
Reset: N/A
D-EOMWC00A07-16EN
43
- 44 -
Alarm Logging
When an alarm occurs, the alarm type, date, and time are stored in the active alarm
buffer corresponding to that alarm (viewed on the Alarm Active screens) also in the
alarm history buffer (viewed on the Alarm Log screens). The active alarm buffers hold
a record of all current alarms.
A separate alarm log stores the last 25 alarms to occur. When an alarm occurs, it is put
into the first slot in the alarm log and all others are moved down one, dropping the last
alarm. In the alarm log, the date and time the alarm occurred are stored, as well as a list
of other parameters. These parameters include unit state, LWT, and EWT for all alarms.
If the alarm is a circuit alarm, then the circuit state, refrigerant pressures and
temperatures, EXV position, compressor load, number of fans on, and compressor run
time are also stored.
44
D–EOMWC00A07-16EN
- 45 -
Using the Controller
The Unit Controller Operation
Figure 7, Unit Controller
Alarm Button
Menu Button
Back Button
Navigation Wheel
Display
The keypad/display consists of a 5-line by 22 character display, three buttons (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 and will jump from a link to the next set of parameters.
Figure 8, Typical Screen
6
View/Set Unit 3
Status/Settings

Set Up


Temperature
Date/Time/Schedule

Generally, each line contains a menu title, a parameter (such as a value or a setpoint), or
a link (which will have an arrow in the right of the line) to a further menu.
The first line visible on each display includes the menu title and the line number to
which the cursor is currently “pointing”, in the above case 3. The left most position of
the title line includes an “up” arrow to indicate there are lines (parameters) “above” the
currently displayed line; and/or a “down” arrow to indicate there are lines (parameters)
“below” the currently displayed items or an “up/down” arrow to indicate there are lines
“above and below” the currently displayed line. The selected line is highlighted.
Each line on a page can contain status only information or include changeable data fields
(setpoints). 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
D-EOMWC00A07-16EN
45
- 46 -
box around it. When the line contains a changeable value and the cursor is at that line,
the entire line is highlighted.
Or a line in a menu may be a link to further menus. This is often referred to as a jump
line, meaning pushing the navigation wheel will cause a “jump” to a new menu. 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.
NOTE - Only menus and items that are applicable to the specific unit configuration are
displayed.
This manual includes information relative to the operator level of parameters; data and
setpoints necessary for the every day operation of the chiller. There are more extensive
menus available for the use of service technicians.
Navigating
When power is applied to the control circuit, the controller screen will be active and display the
Home screen, which can also be accessed by pressing the Menu Button The navigating wheel is
the only navigating device necessary, although the MENU, ALARM, and BACK buttons can
provide shortcuts as explained later.
Passwords
The home screen has eleven lines:

Enter Password, links to the Entry screen, which is an editable screen So pressing
the wheel goes to the edit mode where the password (5321) can be entered. The first
(*) will be highlighted, rotate the wheel clockwise to the first number and set it by
pressing the wheel. Repeat for the remaining three numbers.
The password will time out after 10 minutes and is cancelled if a new password is
entered or the control powers down.

Other basic information and links are shown on the Main Menu page for ease of
usage and includes Active setpoint, Evaporator Leaving Water Temperature, etc.
The About Chiller link connect to a page were is possible to see the software
version.
Figure 9, Password Menu
Main Menu
Enter Password
Unit Status=
1/11

Auto
Active Setpt=
xx.x°C
Evap LWT=
Unit Capacity=
xx.x°C
xxx.x%
Unit Mode=
Cool
Time Until Restart
>
Alarms
>
Scheduled Maintenance >
About Chiller
46
D–EOMWC00A07-16EN
>
- 47 -
Figure 10, Password Entry Page
Enter Password
Enter1/1
****
Entering an invalid password has the same effect as continuing without 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 in the Extended
Menus.
Navigation Mode
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.
Pushing the wheel acts as an “Enter” button.
Three types of lines exist:
Menu title, displayed in the first line as in

Figure 10.

Link (also called Jump) having an arrow (  ) in the right of the line and used to link
to the next menu.

Parameters with a value or adjustable setpoint.
For example, “Time Until Restart” jumps from level 1 to level 2 and stops there.
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.
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 counterclockwise 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.
D-EOMWC00A07-16EN
47
- 48 -
A parameter with an “R” is read only; it is giving a value or description of a condition.
An “R/W indicates a read and/or write opportunity; a value can be read or changed
(providing the proper password has been entered).
Example 1: Check Status, for example -is the unit being controlled locally or by
an external network? We are looking for the Unit Control Source Since this a
unit status parameter, start at Main Menu and select View/Set Unit and press the
wheel to jump to the next set of menus. There will be an arrow at the right side of
the box, indicating that a jump to the next level is required. Press the wheel to
execute the jump.
You will arrive at the Status/ Settings link. There is an arrow indicating that this line is a link to a
further menu. Press the wheel again to jump to the next menu, Unit Status/Settings.
Rotate the wheel to scroll down to Control Source and read the result.
Example 2; Change a Set point, the chilled water set point for example. This parameter is
designated as Cool LWT Set point 1 and is a unit set parameter. From the Main Menu select
View/Set Unit. The arrow indicated that this is link to a further menu.
Press the wheel and jump to the next menu View/Set Unit and use the wheel to scroll down to
Temperatures. This again has an arrow and is a link to a further menu. Press the wheel and jump
to the Temperatures menu, which contains six lines of temperatures set points. Scroll down to
Cool LWT 1 and press the wheel to jump to the item change page. Rotate the wheel to adjust the
set point to the desired value. When this is done press the wheel again to confirm the new value.
With the Back button it will be possible to jump back to the Temperatures menu where the new
value will be displayed.
Example 3; Clear an Alarm,. The presence of a new alarm is indicated with a Bell ringing on
the top right of the display. If the Bell is frozen one or more alarm had been acknowledged but
are still active. To view the Alarm menu from the Main Menu scroll down to the Alarms line or
simply press the Alarm button on the display. Note the arrow indicating this line is a link. Press
the wheel to jump to the next menu Alarms There are two lines here; Alarm Active and Alarm
Log. Alarms are cleared from the Active Alarm link. Press the wheel to jump to the next screen.
When the Active Alarm list is entered scroll to the item AlmClr which is set to off by default.
Change this value to on to acknowledge the alarms. If the alarms can be cleared then the alarm
counter will display 0 otherwise it will display the number of alarm still active. When the alarms
are acknowledged the Bell on the top right of the display will stop to ring if some of the alarms
are still active or will disappear if all the alarms are cleared.
48
D–EOMWC00A07-16EN
- 49 -
Figure 11, Home Page, Main Menu Parameters and Links
Home Page
Enter Password
Continue W/O Password
Main Menu
View/Set – Unit
View/Set – Circuit
Unit Status *
Active Setpoint *
Evap Leaving Water Temp *
Evap Entering Water Temp *
Unit Capacity *
Unit Current
Softload Limit Value
Network Limit Value
Demand Limit Value
Unit Mode *
Control Source *
Current Limit Setpoint


R
R
R
R
R
R
R
R
R
R
R/W
R/W
Time Until Restart
Scheduled Maintenance
Alarms



About This Chiller

View/Set Unit
Status/Settings
Set-Up
Temperatures
Date/Time/Schedules
Power Conservation
LON Setup
BACnet IP Setup
BACnet MSTP Setup
Modbus Setup
AWM Setup





Design Conditions
Alarm Limits


Menu Password

View/Set Circuit

Status/Settings
Compressor


Time Until Restart
Compressor 1 Cycle Time Remaining
Compressor 2 Cycle Time Remaining
Compressor 3 Cycle Time Remaining
Compressor 4 Cycle Time Remaining
*
*
*
*
R
R
R
R



Alarms
Alarm Active
Alarm Log
Scheduled Maintenance
Next Maintenance Month/Year *
Service Support Reference *
About This Chiller
Model Number *
G. O. Number *
Unit Serial Number *
Starter Model Number(s) *
Starter Serial Number(s) *
Firmware Version *
Application Version *
Application GUID *
HMI GUID *
Note: Parameters with an “*” are available without entering a password.
D-EOMWC00A07-16EN
49
R/W
R
R
R
R
R
R
R
R
R
R
- 50 -
Figure 12, Navigation, Part A
View/Set Unit
Status/Settings
Set-Up
Temperatures
Condenser
Date/Time/Schedules
Power Conservation
LON Setup
BACnet IP Setup
BACnet MSTP Setup
Modbus Setup
AWM Setup











Design Conditions
Alarm Limits


Menu Password

View/Set Circuit

Status/Settings
Compressor


Time Until Restart
Compressor 1 Cycle Time
Remaining 2 Cycle Time
Compressor
Remaining 3 Cycle Time
Compressor
Remaining 4 Cycle Time
Compressor
Remaining
Alarms
Alarm Active
Alarm Log
Scheduled Maintenance
Next Maintenance
Month/Year
Service
Support
Reference
About This Chiller
Model Number
G. O. Number
Unit Serial Number
Starter Model Number(s)
Starter Serial Number(s)
Firmware Version
Application Version
Application GUID
HMI GUID
OBH GUID
R
R
R
R



R/W
R
R
R
R
R
R
R
R
R
R
R
Date/Time/Schedules
Actual Time
Actual Date
Time Zone
DLS Enable
DLS Start Month
DLS Start Week
DLS End Month
DLS End Week
Enable Quiet Mode
Quiet Mode Start Hr
Quiet Mode Start Min
Quiet Mode End Hr
Quiet Mode End Min
Quiet Mode Cond Offset
50
D–EOMWC00A07-16EN
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Status/Settings (view/set
unit)UUnitunitunit)
Unit
Status
Chiller Enable
Control Source
Next Circuit On
Chiller Enable Setpoint Network
Chiller
Mode Setpoint Network
Cool
Setpoint - Network
Capacity Limit Setpoint Network
Stage
Up Delay Remaining
Stage Down Delay
Remaining
Clear
Stage Delays
Ice Setpoint - Network
Ice Cycle Time Remaining
Evaporator Pump 1 Run
Hours
Evaporator
Pump 2 Run
Hours
Remote Service Enable
R
R
R
R
R
R
R
R
R
R
R/W
R
R
R
R
R/W
Set-Up (view/set unit)
Available Modes
Start Up DT
Shut Down DT
Stage Up DT
Stage Down DT
Max Pulldown Rate
Stage Up Delay
Chiller Status After Power
Failure
Ice Cycle Delay
R
R
R
R
R
R
R
R
R
Temperatures (view/set
unit) Leaving Water Temp
Evap
Evap Entering Water Temp
Evaporator Delta T
Active Set Point
Outside Air Temperature
Cool LWT Setpoint 1
Cool LWT Setpoint 2
Ice LWT Setpoint
R
R
R
R
R
R/W
R/W
R/W
Condenser
Cond LWT
Cond EWT
Cond Target
VFD
VFD Speed
Speed
Valve
Valve Opening
Opening
Tower Setpt 1
Tower Setpt 1
Tower Setpt 2
Tower Setpt 2
Tower Setpt 3
Tower
Tower Setpt
Setpt 3
4
Tower
Tower Setpt
Diff 1 4
Tower Diff 1
2
3
Tower Diff 2
4
Tower Diff 3
VDF
Tower
Diff
1
TowerMin
DiffSpeed
4
VDF Min Speed
VDF Min
MaxSpeed
Speed
Valve Min Open
peed Max Open
Valve
Prop Gain Vfd
Der Time Vfd
Int Time Vfd
Prop Gain Vlv
Der Time Vlv
Int Time Vlv
R
R
R/W
R
R
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
- 51 -
Note: Parameters with an “*” are available without entering a password.
D-EOMWC00A07-16EN
51
- 52 -
Figure 2, Navigation, Part B
View/Set Unit
Status/Settings
Set-Up
Temperatures
Condenser
Date/Time/Schedules
Power Conservation
LON Setup
BACnet IP Setup
BACnet MSTP Setup
Modbus Setup
AWM Setup











Design Conditions
Alarm Limits


Menu Password

View/Set Circuit

Status/Settings
Compressor



R
R
R
R
Time Until Restart
Compressor 1 Cycle Time
Remaining 2 Cycle Time
Compressor
Remaining 3 Cycle Time
Compressor
Remaining 4 Cycle Time
Compressor
Remaining
Alarms
Alarm Active
Alarm Log



Scheduled Maintenance
Next Maintenance Month/Year
Service Support Reference
About This Chiller
Model Number
G. O. Number
Unit Serial Number
Starter Model Number(s)
Starter Serial Number(s)
Firmware Version
Application Version
Application GUID
HMI GUID
OBH GUID
52
R/W
R
R
R
R
R
R
R
R
R
R
R
D–EOMWC00A07-16EN
Power Conservation (view/set unit)
Unit Capacity
Unit Current
Demand Limit Enable
Demand Limit Value
Current @ 20mA
Current Limit Setpoint
Setpoint Reset
Max Reset
Start Reset DT
Soft Load Enable
Soft Load Ramp
Starting Capacity
R
R
R/W
R
R
R
R/W
R/W
R/W
R/W
R/W
R/W
LON Setup (view/set unit)
Neuron ID
Max Send Time
Min Send Time
Receive Heartbeat
LON BSP
LON App Version
R
R/W
R/W
R/W
R
R
BACnet IP Setup (view/set unit)
Apply Changes
Name
Dev Instance
UDP Port
DHCP
Actual IP Address
Actual Mask
Actual Gateway
Given IP Address
Given Mask
Given Gateway
Unit Support
NC Dev 1
NC Dev 2
NC Dev 3
BACnet BSP
R/W
R/W
R/W
R/W
R/W
R
R
R
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R
BACnet MSTP Setup (view/set
unit) Changes
Apply
Name
Dev Instance
MSTP Address
Baud Rate
Max Master
Max Info Frm
Unit Support
Term Resistor
NC Dev 1
NC Dev 2
NC Dev 3
BACnet BSP
BACnet
MSTP
R/W
Setup
R/W
(view/set
R/W
unit)
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R
Modbus Setup (view/set unit)
Apply Changes
Address
Parity
Two Stop Bits
Baud Rate
Load Resistor
Response Delay
Comm LED Time Out
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
- 53 -
Figure 3, Navigation, Part C
View/Set Unit
Status/Settings
Set-Up
Temperatures
Condenser
Date/Time/Schedules
Power Conservation
LON Setup
BACnet IP Setup
BACnet MSTP Setup
Modbus Setup
AWM Setup











Design Conditions
Alarm Limits


Menu Password

View/Set Circuit

Status/Settings
Compressor


Time Until Restart
Compressor 1 Cycle Time
Remaining 2 Cycle Time
Compressor
Remaining 3 Cycle Time
Compressor
Remaining
Compressor 4 Cycle Time
Remaining
Alarms
Alarm Active
Alarm Log
Scheduled Maintenance
Next Maintenance Month/Year
Service Support Reference
About This Chiller
Model Number
G. O. Number
Unit Serial Number
Starter Model Number(s)
Starter Serial Number(s)
Firmware Version
Application Version
Application GUID
HMI GUID
OBH GUID

R
R
R
R



R/W
R
AWM Setup (view/set unit)
Apply Changes
DHCP
Actual IP Address
Actual Mask
Actual Gateway
Given IP Address
Given Mask
Given Gateway
AWM BSP
Design Conditions (view/set
unit) Entering Water Temp @
Evap
Design
Evap
Leaving Water Temp @
Design
Alarm Limits (view/set unit)
Low Pressure Hold Setpoint
Low Pressure Unload Setpoint
R
R
R/W
Status/Settings (view/set
circuit)
Status Circuit 1
Circuit Status
Circuit Mode
Circuit Capacity
R
R/W
R



Status Circuit 2
Status Circuit 3
Status Cricuit 4
Compressor (view/set circuit)
Compressor 1 Circuit 1
Run Hours
Number Of Starts
Active Alar
Acknowledge All
Alarm Log (Alarms)
Alarm Entry 1
…
Alarm Entry 50
Note: Parameters with an “*” are available without entering a password.
D-EOMWC00A07-16EN
R
R
Menu Password (view/set
unit)
Password Disable
Alarm Active (Alarms)
Active Alarm 1
R
R
R
R
R
R
R
R
R
R
R/W
R/W
R
R
R
R/W
R/W
R/W
R
53
R
R
R
R
R
R/W
R
R
R
- 54 -
Optional Remote User Interface
The optional remote user interface is a remote control panel that mimics operation of the controller
located on the unit. Up to eight AWS units can be connected to it and selected on the screen. It
provides HMI (Human Machine Interface) within a building, the building engineer’s office for
example, without going outdoors to the unit.
It can be ordered with the unit and shipped loose as a field installed option. It can also be ordered
anytime after chiller shipment and mounted and wired on the job as explained on the following page.
The remote panel is powered from the unit and no additional power supply is required.
All viewing and setpoint adjustments available on the unit controller are available on the remote
panel. Navigation is identical to the unit controller as described in this manual.
The initial screen when the remote is turned on shows the units connected to it. Highlight the desired
unit and press the wheel to access it. The remote will automatically show the units attached to it, no
initial entry is required.
Menu Button
Alarm Button
w/Flashing Red
Alarm Light
54
Back Button
Push and Roll
Navigating Wheel
D–EOMWC00A07-16EN
- 55 -
D-EOMWC00A07-16EN
55
- 56 -
Start-up and Shutdown
NOTICE
Daikin service personnel or factory authorized service agency
must perform initial start-up in order to activate warranty.
!
CAUTION
Most relays and terminals in the unit control center are powered when S1 is closed
and the control circuit disconnect is on. Therefore, do not close S1 until ready for
start-up or the unit may start unintentionally and possibly cause equipment damage.
Seasonal Start-up
1. Double check that the discharge shutoff valve and the optional compressor suction
butterfly valves are open.
2. Check that the manual liquid-line shutoff valves at the outlet of the subcooler coils
and the oil separator oil return line shutoff valves are open.
3. Check the leaving chilled water temperature setpoint on the MicroTech III controller
to be sure it is set at the desired chilled water temperature.
4. Start the auxiliary equipment for the installation by turning on the time clock, and/or
remote on/off switch, and chilled water pump.
5. Check to see that pumpdown switches Q1 and Q2 (and Q3) are in the "Pumpdown
and Stop" (open) position. Throw the S1 switch to the "auto" position.
6. Under the "Control Mode" menu of the keypad, place the unit into the automatic
cool mode.
7. Start the system by moving pumpdown switch Q1 to the "auto" position.
8. Repeat step 7 for Q2 (and Q3).
Temporary Shutdown
Move pumpdown switches Q1 and Q2 to the "Pumpdown and Stop" position. After the
compressors have pumped down, turn off the chilled water pump.
!
CAUTION
Do not turn the unit off using the "Override Stop" switch, without first moving Q1 and
Q2 (and Q3) to the "Stop" position, unless it is an emergency, as this will prevent the
unit from going through a proper shutdown/pumpdown sequence.
!
CAUTION
The unit has a one-time pumpdown operation. When Q1 and Q2 are in the
"Pumpdown and Stop" position the unit will pump down once and not run again
until the Q1 and Q2 switches are moved to the auto position. If Q1 and Q2 are in
the auto position and the load has been satisfied, the unit will go into one-time
pumpdown and will remain off until the MicroTech III control senses a call for
cooling and starts the unit.
!
CAUTION
Water flow to the unit must not be interrupted before the compressors pump down
to avoid freeze-up in the evaporator. Interruption will cause equipment damage.
56
D–EOMWC00A07-16EN
- 57 -
CAUTION
!
If all power to the unit is turned off, the compressor heaters will become
inoperable. Once power is resumed to the unit, the compressor and oil separator
heaters must be energized a minimum of 12 hours before attempting to start the
unit.
Failure to do so can damage the compressors due to excessive accumulation of
liquid in the compressor.
Start-up After Temporary Shutdown
1. Insure that the compressor and oil separator heaters have been energized for at least
12 hours prior to starting the unit.
2. Start the chilled water pump.
3. With System switch Q0 in the "on" position, move pumpdown switches Q1 and Q2
to the "auto" position.
4. Observe the unit operation until the system has stabilized.
Extended (Seasonal) Shutdown
1. Move the Q1 and Q2 (and Q3) switches to the manual pumpdown position.
2. After the compressors have pumped down, turn off the chilled water pump.
3. Turn off all power to the unit and to the chilled water pump.
4. If fluid is left in the evaporator, confirm that the evaporator heaters are operational.
5. Move the emergency stop switch S1 to the "off" position.
6. Close the compressor discharge valve and the optional compressor suction valve (if
so equipped) as well as the liquid line shutoff valves.
7. Tag all opened compressor disconnect switches to warn against start-up before
opening the compressor suction valve and liquid line shutoff valves.
8. If glycol is not used in the system, drain all water from the unit evaporator and
chilled water piping if the unit is to be shutdown during winter and temperatures
below -20F can be expected. The evaporator is equipped with heaters to help
protect it down to -20F. Chilled water piping must be protected with field-installed
protection. Do not leave the vessels or piping open to the atmosphere over the
shutdown period.
9. Do not apply power to the evaporator heaters if the system is drained of fluids as
this can cause the heaters to burn out.
Start-up After Extended (Seasonal) Shutdown
1. With all electrical disconnects locked and tagged out, check all screw or lug-type
electrical connections to be sure they are tight for good electrical contact.
!
DANGER
LOCK AND TAG OUT ALL POWER SOURCES WHEN CHECKING
CONNECTIONS. ELECTRICAL SHOCK WILL CAUSE SEVERE PERSONAL
INJURY OR DEATH.
2. Check the voltage of the unit power supply and see that it is within the 10%
tolerance that is allowed. Voltage unbalance between phases must be within 3%.
3. See that all auxiliary control equipment is operative and that an adequate cooling
load is available for start-up.
4. Check all compressor flange connections for tightness to avoid refrigerant loss.
Always replace valve seal caps.
D-EOMWC00A07-16EN
57
- 58 -
5. Make sure system switch Q0 is in the "Stop" position and pumpdown switches Q1
and Q2 are set to "Pumpdown and Stop", throw the main power and control
disconnect switches to "on." This will energize the crankcase heaters. Wait a
minimum of 12 hours before starting up unit. Turn compressor circuit breakers to
"off" position until ready to start unit.
6. Open the optional compressor suction butterfly as well as the liquid line shutoff
valves, compressor discharge valves.
7. Vent the air from the evaporator water side as well as from the system piping. Open
all water flow valves and start the chilled water pump. Check all piping for leaks
and recheck for air in the system. Verify the correct flow rate by taking the pressure
drop across the evaporator and checking the pressure drop curves in the installation
manual, IMM AGSC-2.
8. The following table gives glycol concentrations required for freeze protection.
Table 2, Freeze Protection
Temperature
F (C)
Percent Volume Glycol Concentration Required
For Freeze Protection
For Burst Protection
Ethylene Glycol Propylene Glycol Ethylene Glycol Propylene Glycol
16
18
11
12
25
29
17
20
33
36
22
24
39
42
26
28
44
46
30
30
48
50
30
33
52
54
30
35
56
57
30
35
60
60
30
35
20 (6.7)
10 (-12.2)
0 (-17.8)
-10 (-23.3)
-20 (-28.9)
-30 (-34.4)
-40 (-40.0)
-50 (-45.6)
-60 (-51.1)
Notes:
1. These figures are examples only and cannot be appropriate to every situation. Generally, for an
extended margin of protection, select a temperature at least 10F lower than the expected lowest ambient
temperature. Inhibitor levels should be adjusted for solutions less than 25% glycol.
2. Glycol of less than 25% concentration is not recommended because of the potential for bacterial growth
and loss of heat transfer efficiency.Field Wiring Diagram
Field wiring diagram is generated for each unit and is part of the unit onboard documentation.
Refer to this document for a complete explanation of the field wirings for this chillers.
58
D–EOMWC00A07-16EN
- 59 -
Basic Control System Diagnostic
MicroTech III controller, extension modules and communication modules are equipped
with two status LED (BSP and BUS) to indicate the operational status of the devices.
The meaning of the two status LED is indicated below.
Controller LED
BSP LED
Solid Green
Solid Yellow
Solid Red
Flashing Yellow
Flashing Red
Flashing Red/Green
(*) Contact Service.
BUS LED
OFF
OFF
OFF
OFF
OFF
OFF
Mode
Application running
Application loaded but not running (*)
Hardware Error (*)
Application not loaded (*)
BSP Error (*)
Application/BSP update
Extension Module LED
BSP LED
Solid Green
Solid Red
Flashing Red
BUS LED
Solid Green
Solid Yellow
Solid Red
Mode
BSP running
Hardware Error (*)
BSP Error (*)
Communication running, I/O working
Communication running, parameter missing (*)
Communication down (*)
(*) Contact Service.
Communication Module LED
BSP LED
Solid Green
Solid Yellow
Solid Red
Flashing Red
Flashing Red/Green
(*) Contact Service.
Mode
BPS running, communication with controller
BSP running, no communication with controller (*)
Hardware Error (*)
BSP Error (*)
Application/BSP update
BUS LED status vary depending on the module.
LON module:
BuS LED
Solid Green
Solid Yellow
Solid Red
Flashing Yellow
D-EOMWC00A07-16EN
Mode
Ready for Communication. (All Parameter loaded, Neuron
configured). Doesn't indicate a communication with other
devices.
Startup
No Communication to Neuron (internal error, could be solved
by downloading a new LON application)
Communication not possible to the Neuron. The Neuron must
be configured and set online over the LON Tool.
59
- 60 -
Bacnet MSTP:
BuS LED
Solid Green
Solid Yellow
Solid Red
Mode
Ready for Communication. The BACnet Server is started. It
doesn't indicate a active communication
Startup
BACnet Server down. Automatically a restart after 3 seconds
are initiated.
Bacnet IP:
BuS LED
Solid Green
Solid Yellow
Solid Red
Mode
Ready for Communication. The BACnet Server is started. It
doesn't indicate a active communication
Startup. The LED stays yellow until the module receives a IP
Address, therefore a link must be established.
BACnet Server down. Automatic restart after 3 seconds is
initiated.
Modbus
BuS LED
Solid Green
Solid Yellow
Solid Red
60
Mode
All Communication running
Startup, or one configured channel not communicating to the
Master.
All configured Communications down. Means no
communication to the Master. The timeout can be configured.
In case that the timeout is zero the timeout is disabled.
D–EOMWC00A07-16EN
- 61 -
Controller maintenance
The controller requires to maintain the installed battery. Every two years it’s required to
replace the battery. Battery model is: BR2032 and it is produced by many different
vendors.
To replace the battery remove the plastic cover of the controller display using a screw
driver as shown in the following picture:
Be careful to avoid damages to the plastic cover. The new battery shall be placed in the
proper battery holder which is highlighted in the following picture, respecting the
polarities indicated into the holder itself.
D-EOMWC00A07-16EN
61
- 62 -
Appendix
Definitions
Active Setpoint
The active setpoint is the setting in effect at any given moment. This variation occurs on
setpoints that can be altered during normal operation. Resetting the chilled water
leaving temperature setpoint by one of several methods, such as return water
temperature, is an example.
Active Capacity Limit
The active setpoint is the setting in effect at any given moment. Any one of several
external inputs can limit a compressor’s capacity below its maximum value.
BSP
The BSP represents the operative system of the MicroTech III controller.
Condenser Saturated Temperature Target
The saturated condenser temperature target is calculated by first using the following
equation:
Sat condenser temp target raw = 0.833(evaporator sat temp) + 68.34
The “raw” value is the initial calculated value. This value is then limited to a range
defined by the Condenser Saturated Temperature Target minimum and maximum
setpoints. These setpoints simply cut off the value to a working range, and this range
can be limited to a single value if the two setpoints are set to the same value.
Dead Band
The dead band is a range of values surrounding a setpoint such that a change in the
variable occurring within the dead band range causes no action from the controller. For
example, if a temperature setpoint is 6.5 °C (44F) and it has a dead band of 1°C ( 2
°F), nothing will happen until the measured temperature is less than 5.5°C (42F) or
more than 7.5°C (46F).
DIN
Digital input, usually followed by a number designating the number of the input.
Error
In the context of this manual, “Error” is the difference between the actual value of a
variable and the target setting or setpoint.
Evaporator Approach
The evaporator approach is calculated for each circuit. The equation is as follows:
Evaporator Approach = LWT – Evaporator Saturated Temperature
Evap Recirc Timer
A timing function, with a 30-second default, that holds off any reading of chilled water
for the duration of the timing setting. This delay allows the chilled water sensors
(especially water temperatures) to take a more accurate reading of the chilled water
system conditions.
EXV
Electronic expansion valve, used to control the flow of refrigerant to the evaporator,
controlled by the circuit microprocessor.
62
D–EOMWC00A07-16EN
- 63 -
High Saturated Condenser – Hold Value
High Cond Hold Value = Max Saturated Condenser Value – 2.7 °C (5 °F)
This function prevents the compressor from loading whenever the pressure approaches
within 2.7 °C (5 °F) of the maximum discharge pressure. The purpose is to keep the
compressor online during periods of possibly temporary elevated pressures.
High Saturated Condenser – Unload Value
High Cond Unload Value = Max Saturated Condenser Value – 1.6 °C (3°F)
This function unloads the compressor whenever the pressure approaches within 1.6 °C
(3°F) of the maximum discharge pressure. The purpose is to keep the compressor online
during periods of possibly temporary elevated pressures.
Light Load Stg Dn Point
The percent load point at which one of two operating compressors will shut off,
transferring the unit load to the remaining compressor.
Load Limit
An external signal from the keypad, the BAS or a 4-20 ma signal that limits the
compressor loading to a designated percent of full load. Frequently used to limit unit
power input.
Load Balance
Load balance is a technique that equally distributes the total unit load among the running
compressors on a unit or group of units.
Low Pressure Unload Setpoint
The psi evaporator pressure setting at which the controller will unload the compressor
until a preset pressure is reached.
Low Pressure Hold Setpoint
The psi evaporator pressure setting at which the controller will not allow further
compressor loading.
Low/High Superheat Error
The difference between actual evaporator superheat and the superheat target.
LWT
Leaving water temperature. The “water” is any fluid used in the chiller circuit.
LWT Error
Error in the controller context is the difference between the value of a variable and the
setpoint. For example, if the LWT setpoint is 6.5 °C (44F) and the actual temperature
of the water at a given moment is 7.5°C (46F), the LWT error is +1°C (+2°F).
LWT Slope
The LWT slope is an indication of the trend of the water temperature. It is calculated by
taking readings of the temperature every few seconds and subtracting them from the
previous value, over a rolling one minute interval.
ms
Milli-second
Maximum Saturated Condenser Temperature
The maximum saturated condenser temperature allowed is calculated based on the
compressor operational envelope.
Offset
Offset is the difference between the actual value of a variable (such as temperature or
pressure) and the reading shown on the microprocessor as a result of the sensor signal.
D-EOMWC00A07-16EN
63
- 64 -
Refrigerant Saturated Temperature
Refrigerant saturated temperature is calculated from the pressure sensor readings for
each circuit. The pressure is fitted to an R-134a temperature/pressure curve to determine
the saturated temperature.
Soft Load
Soft Loading is a configurable function used to ramp up the unit capacity over a given
time period, usually used to influence building electrical demand by gradually loading
the unit.
SP
Setpoint
SSS
Solid state starter as used on screw compressors.
Suction Superheat
Suction superheat is calculated for each circuit using the following equation:
Suction Superheat = Suction Temperature – Evaporator Saturated Temperature
Stage Up/Down Accumulator
The accumulator can be thought of as a bank storing occurrences that indicate the need
for an additional fan.
Stageup/Stagedown Delta-T
Staging is the act of starting or stopping a compressor or fan when another is still
operating. Startup and Stop is the act of starting the first compressor or fan and stopping
the last compressor or fan. The Delta-T is the “dead band” on either side of the setpoint
in which no action is taken.
Stage Up Delay
The time delay from the start of the first compressor to the start of the second.
Startup Delta-T
Number of degrees above the LWT setpoint required to start the first compressor.
Stop Delta-T
Number of degrees below the LWT setpoint required for the last compressor to stop.
VDC
Volts, Direct current, sometimes noted as vdc.
Master/Slave
In this section will be described the Master Slave (MS) control logic and all scenarios
where this function can be applied. MS control consists in a common management of
more chillers interconnected between them through the serial communication Konnex,
where a chiller defined Master gets the control of all other chillers defined Slaves.
All schemes present in this section provide only a principle diagram of the
hydraulic connection
Master Slave Overview
Master Slave function allows to control multi-chiller plant with a maximum of 4
chillers, 1 Master + 3 Slaves, connected in parallel in the water circuit. Temperature
control is always performed on the base of the common leaving water temperature read
by the Master chiller.
64
D–EOMWC00A07-16EN
- 65 -
BUILDING
T
MASTER
SLAVE 1
SLAVE 2
SLAVE 3
The MS function is able to manage individually several plants. The main difference that
identifies every plant type is mainly in the number and in the connection method of the
water pumps. The MS never can provide a speed modulation signal for one or more
water pumps.
-
Plant 1 : Single Common Pump
The simplest plant that Master Slave function can manage is composed by a single
common pump installed on the water manifold that provided the water flow for all
chillers of the network. The pump enable is obtained putting in parallel the enable
contacts of the evaporator water pump of each chiller. First chiller enabled to start by the
Master will activate the common pump. With this plant type all chillers are always
crossed by the water flow even if they are still.
-
Plant 2 : Single Chiller Pump
In the second plant type every chiller of the Master Slave network is equipped with a
pump. The pump can be installed directly on the unit or in the pipe of the single chiller
and it avoids the water flow in the evaporator if the chiller is in off state. Every pump
will be commanded only by the chiller to which is connected.
- Plant 3 : Double Chiller Pump
Third plant type is an extension of the previous plant. As standard every chiller can
control two evaporator water pumps: primary and standby. This function is maintained
also in Master Slave. Every pair of pumps is connected to the related chiller that will
manage them rotation according to the local settings.
-
Plant 4. Chiller with sectioned evaporator
In the last plant type every chiller has the evaporator sectioned by a two way valve that
avoids the water flowing if the chiller is not running. The number of pumps and valves
has to be the same of number of chillers, as every pump and every valve is associated to
a specific chiller. Like in the Single Chiller Pump plant every chiller will enable its
valve and its pump. No standby pump can be managed in this plant type.
In this case it is advisable to connect the evaporator water pump enable provided by the
chiller to the valve and consequently the feedback of total opening of the valve to the
enable of the pump. In this way should be avoided all problems of over-pressure due to a
simultaneous starting of the pump and of the valve
D-EOMWC00A07-16EN
65
- 66 -
BUILDING
BUILDING
MASTER
MASTER
SLAVE 1
SLAVE 1
SLAVE 2
SLAVE 2
SLAVE 3
SLAVE 3
Single Common Pump
Single Chiller Pump
BUILDING
MASTER
BUILDING
SLAVE 1
MASTER
SLAVE 2
SLAVE 1
SLAVE 2
SLAVE 3
SLAVE 3
Double Chiller Pump
Chiller with sectioned evaporator
Electrical Connection
In the following section are reported all electrical connections necessary for the correct
operation of the Master Slave function.
All schemes present in this section provide only a principle diagram of the
electrical connection
Process Bus
The following diagram shows how have to be connected the chillers between them to
establish the Master Slave Network. Starting from first chiller connect in parallel all
terminals PB [CE+ / CE-] of each controllers, accessible on the customer terminal board.
Refer to the table for the enumeration of the terminals.
66
D–EOMWC00A07-16EN
- 67 -
MASTER
CE- CE+
SLAVE 2
SLAVE 1
CE- CE+
SLAVE 3
CE- CE+
CE- CE+
Common leaving water temperature sensor
Common leaving water temperature sensor has to be connected to the chiller Master
through the customer terminal block (Master/Slave Temperature Sensor). Refer to the
table for the enumeration of the terminals.
Pumps Connection
Different types of pump connections are available depending on the plant type where the
Master Slave function is used.
1. Single Common Pump
In the plant type Single Common Pump, where a unique pump provides all water flow,
all enable pump contacts of each chiller have to be connected in parallel so that it is
possible to provide a unique enabling contact for the common pump. The pump contact
of each chiller is available on the customer terminal block (Evaporator Pump #1 start).
Refer to the table for the enumeration of the terminals.
MASTER
SLAVE 1
SLAVE 2
SLAVE 3
Ev. Pump #1
Ev. Pump #1
Ev. Pump #1
Ev. Pump #1
PUMP
For the water cooled unit with water inversion, remember that in heat mode the
user side pump is not the evaporator pump but the condenser pump. For this
reason will be necessary use the terminal Condenser Pump #1 start to control the
common pump
2. Single Chiller Pump
In the plant type Single Chiller Pump, every pump have to be connected to the related
unit. The enabling contact is available on the customer terminal block (Evaporator Pump
#1 start). Refer to the table for the enumeration of the terminals.
MASTER
SLAVE 1
SLAVE 2
SLAVE 3
Ev. Pump #1
Ev. Pump #1
Ev. Pump #1
Ev. Pump #1
PUMP
PUMP
PUMP
PUMP
3. Double Chiller Pump
In the plant type Double Chiller Pump, every pair of pump have to be connected to the
related chiller. The enabling contact are available in the customer terminal block
(Evaporator Pump#1 start / Evaporator Pump#2 start). Refer to the table for the
enumeration of the terminals.
D-EOMWC00A07-16EN
67
- 68 -
MASTER
Ev. Pump #1
SLAVE 1
Ev. Pump #2
PUMP 1
PUMP 2
Ev. Pump #1
SLAVE 2
Ev. Pump #2
PUMP 2
PUMP 1
Ev. Pump #1
PUMP 1
SLAVE 3
3
Ev. Pump #2
PUMP 2
Ev. Pump #1
PUMP 1
Ev. Pump #2
PUMP 2
4. Chiller with sectioned evaporator
In the plant where the evaporator is sectioned by a two way valve, connect the valve to
the pump enable provided by the chiller and the pump to the total opening feedback of
the valve. The enabling contact is available in the customer terminal block (Evaporator
Pump#1 start). Refer to the table for the enumeration of the terminals.
MASTER
SLAVE 1
SLAVE 2
SLAVE 3
Ev. Pump #1
Ev. Pump #1
Ev. Pump #1
Ev. Pump #1
VALVE
PUMP
VALVE
PUMP
VALVE
PUMP
VALVE
PUMP
Master Slave Operation
Master Slave configuration
The basic configuration of the Master Slave function requires the set of three
parameters available in the unit configuration menu.
Setpoint/SubMenu
M/S Address
Default
Range
Standalone
Standalone
Master
Slave 1
Slave 2
Slave 3
Description
Define if the chiller works as standalone or if
belongs to Master Slave network.
Standalone: Current unit does not belong to
the Master Slave network
Master: Current unit is defined Master
Slave 1: Current unit is defined Slave 1
Slave 2: Current unit is defined Slave 2. This
address can be assigned only if the parameter
M/S Num Of Unit = 3 or 4
Slave 3: Current unit is defined Slave 3. This
address can be assigned only if the parameter
M/S Num Of Unit = 4
Example:
If in a network there are 3 chillers then them
have to be addressed like : Master - Slave 1 Slave 2. Any other addressing will generate a
configuration alarm
M/S Num Of Unit
M/S Sns Type
68
2
2,3,4
NTC10K NTC10K,
PT1000
D–EOMWC00A07-16EN
Indicate the number of chiller belonging to
Master Slave network. This parameter have
to be set only in the chiller Master, in all
Slave units it can be let at default value as
ignored.
Define the sensor type used to measure the
common leaving water temperature.
This parameter have to be set only in the
- 69 -
chiller Master, in all Slave units it can be let
at default value as ignored.
System enable
The startup and shutdown of all system can be performed applying the normal enabling
commands (Local/Remote switch, HMI command, enable by Modbus/BACNet/Lon) to
the master unit.
All other slaves unit maintain however their local enabling. When a slave is locally not
enable, the master will consider it as not ready unit and will not send it starting
commands.
Since that the master loses his its local enabling (used as system enable), it is present in
the menu the parameter
Master Enable that allows to disable the Master. Disable the Master unit means that it
will not use for the thermoregulation but it will continue to acquire the common leaving
water temperature and it will continue to send the activation command to the slave units.
System setpoint
Temperature control in the MS is performed on the base of the common evaporator
leaving water temperature respect the target value set in the Master chiller. This setpoint
is global for all system and it is sent by the Master to all Slaves through the serial
communication.
Like in the single chiller, every function to modify the target value (LWT Reset, Double
setpoint, changes by Modbus/BACNet/Lon) can be applied to the Master to modify the
global temperature target.
On the Slave chillers the parameter Active Setpt (refer to section) always will
display the target received by the master except when the unit is in alarm
communication or the function Disconnect Mode 0 is active.
System Operating Mode: Cool/Heat/Ice
All units belonging to the Master Slave network always have to work with same
operating mode. Since that in all units the operating mode is local, master chiller does
not send its operating mode, it is very important verify that the changeover Cool, Heat,
Ice always will be performed in all unit.
For the water cooled chiller remember that the Master Slave cannot manage the
Pursuit mode.
Operation with a communication alarm
All Slave units communicate through a serial communication with the Master unit. If
during the normal functioning occurs a communication failure between Master and
Slave the system continue to run with the followings behavior:
-
The Slave unit that has lost the communication with the Master starts to operate
as a Standalone unit following all local settings
-
The Master unit detects that there is a communication error with a Slave and if
present enable the Standby Chiller
D-EOMWC00A07-16EN
69
- 70 -
If the Master unit loses the communication with all units of the network then all chiller
will work in standalone mode
Master Slave Options
Chiller Priority
Startup and shutdown of each chiller is managed by the Master based on the conditions
reported in the table below
Conditions
1st
2nd
3rd
4th
5th
Next Chiller to start
Highest priority
Lowest number of starts
Lowest running hours
Lowest address
-
Next Chiller to stop
Lowest priority
Lowest load
Highest running hours
Highest number of starts
Lowest address
First condition is related to the priority defined for each chiller. The priority default
values are all 1, i.e. all unit have the same priority. A value of 1 indicates highest
priority, a value of 4 indicates lowest priority. The priority values can be modified on
the Master chiller (refer to section).
Standby Chiller
Master Slave function allows to define one of the chillers belonging to the network as
standby chiller. The standby chiller is normally off and becomes operating only when
one of the following conditions occurs:
1. At least one chiller is in alarm state.
2. At least one of the Slave chillers is in communication alarm with the Master
chiller.
3. At least one chiller is not enabled.
4. The function Temperature Compensation is enabled and the water temperature
setpoint is not reached with the system at full load.
In the following is explained step by step how to set all parameters changeable through
the menu to configure the standby chiller according to the local requirements.
Step 1 : Selection of the standby chiller.
Setpoint/SubMenu
Standby Chiller
70
Default
No
Range
No
Auto
Master
Slave 1
Slave 2
Slave 3
D–EOMWC00A07-16EN
Description
No = There are not standby chiller in the Master
Slave network
Auto = One of the chillers of the Master Slave
network will be always assigned as standby chiller.
The rotation of the standby chiller will be performed
according to the configuration set through the
parameters Rotation Type and Interval Time
Master = Master chiller is always set as standby
chiller
Slave 1 = The Slave 1 chiller is always set as
standby chiller
- 71 -
Slave 2 = The Slave 2 chiller is always set as
standby chiller
Slave 3 = The Slave 3 chiller is always set as
standby chiller
Step 2 : Define rotation type of the standby chiller.
Define the rotation type of the standby chiller make sense only if the parameter
Standby Chiller is set as Auto
Setpoint/SubMenu
Rotation Type
Range
Description
Time,
Sequenc
e
Time = The next Standby chiller will be the chiller with most
running hours at the moment of the changeover
Sequence = The next standby chiller will be the next according to
the following sequences:
- network with one slave: Master  Slave 1  Master
- network with tow slaves: Master  Slave 1  Slave 2 
Master
- network with three slaves: Master  Slave 1  Slave 2
 Slave 3  Master
Step 3 : Interval time for rotation of the Standby Chiller.
Define the interval time for rotation of the Standby Chiller make sense only if the
parameter Standby Chiller is set as Auto
Setpoint/SubMenu
Interval Time
Default
Description
1…365
Define the interval time (expressed in
day) for the rotation of the standby
chiller.
Switch Time
00:00:00 00:00:00…23:59:59 Define the time within the day when will
be performed the switch of the standby
chiller
Step 4 : Enable of Temperature Compensation function
Choose if enable the temperature compensation function
Setpoint/Sub
-Menu
Tmp Cmp
7 Days
Range
Default
No
Range
No,Yes
Description
No = The standby chiller becomes
operating only in the following case:
1.
At least one
chiller is in alarm state.
2.
At least one
of the Slave chillers is in
communication alarm with the
Master chiller.
3.
At least one
chiller is not enabled.
Yes = The standby chiller becomes
operating in all previous cases and also if
the all other chillers are running at the
D-EOMWC00A07-16EN
71
- 72 -
Tmp
Time
Comp
120 min 0…600
maximum capacity and the water
temperature setpoint is not reached for at
least a specific time defined by the
parameter Tmp Comp Time
Time constant in which the system has to
be at maximum capacity and the setpoint
not reached before that the standby chiller
will be enabled.
Step 5 : Reset
The reset command can be used to force the rotation of the standby chiller.
Setpoint/SubMenu
Standby Reset
Default
Range
Off Off, Reset
Description
Off = No Action
Reset = Force a rotation of the standby
chiller and reset the timer for rotation
Disconnect Mode
For each unit belonging to the Master Slave is possible activate the function Disconnect
Mode through the menu. This function allows to disconnect temporary the unit from the
network and manage it like if this unit has been configured as Standalone.
-
If a slave unit is in Disconnect mode then the master considers this unit as not
available.
- If the master unit is in Disconnect mode then also all other slave units are forced
to work in Disconnect mode.
This function can be used to easily perform maintenance operation of one or more
chillers of the network.
72
D–EOMWC00A07-16EN
- 73 -
This page has been left intentionally free
D-EOMWC00A07-16EN
73
- 74 -
This page has been left intentionally fre
74
D–EOMWC00A07-16EN
This page has been left intentionally fre
The present publication is drawn up by of information only and does not constitute an offer binding upon Daikin Applied Europe
S.p.A.. Daikin Applied Europe S.p.A. has compiled the content of this publication to the best of its knowledge. No express or
implied warranty is given for the completeness, accuracy, reliability or fitness for particular purpose of its content, and the products
and services presented therein. Specification are subject to change without prior notice. Refer to the data communicated at t he
time of the order. Daikin Applied Europe S.p.A. explicitly rejects any liability for any direct or indirect damage, in the broadest
sense, arising from or related to the use and/or interpretation of this publication. All content is copyrighted by
Daikin Applied Europe S.p.A..
DAIKIN APPLIED EUROPE S.p.A.
Via Piani di Santa Maria, 72 - 00072 Ariccia (Roma) - Italia
Tel: (+39) 06 93 73 11 - Fax: (+39) 06 93 74 014
http://www.daikinapplied.eu
Was this manual useful for you? yes no
Thank you for your participation!

* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project

Download PDF

advertising