McQuay Self-Contained Air Conditioning System

McQuay Self-Contained Air Conditioning System
Installation and Maintenance
IM708-1
Group: Applied Systems
Part Number: IM708
Date: March 2003
Self-Contained Air Conditioning System
Type SWP Vintage Sizes 18D thru 95D, 105E
MEA
368-93-E
© 2001 McQuay International
Table of Contents
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
General Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Inspection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Nomenclature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SWP-055-D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3
3
3
3
3
Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Low Pressure Switches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Compressor Motor Protector . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Proof of Airflow Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Frost Protection Switches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Clogged Filter Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
27
27
27
27
27
Unit Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Physical Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Duct High Limit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Phase Fail/Under Voltage Protection . . . . . . . . . . . . . . . . . . . . . .
Duct Static Pressure Sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Mounting instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Building Static Pressure Sensor . . . . . . . . . . . . . . . . . . . . . . . . . . .
Building pressurization applications . . . . . . . . . . . . . . . . . . . .
Freezestat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Condenser Water Flow Switch . . . . . . . . . . . . . . . . . . . . . . . . . . .
Water Side Economizer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Condenser Water, Head Pressure Control. . . . . . . . . . . . . . . . . . .
Variable Inlet Vanes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Adjustable Frequency Drive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Disconnect Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Dual Power Supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Battery Pack . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Electric Heat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Hot Water Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Dimensional Data . . . . . . . . . . . . . . . . . . . . . . . . . 11
System Check, Test and Start . . . . . . . . . . . . . . . 31
Handling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Vibration Isolators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Setting Factory Supplied Plenum. . . . . . . . . . . . . . . . . . . . . . . . . . .
Location/Service Access . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removal of Shipping Restraints . . . . . . . . . . . . . . . . . . . . . . . . . . .
4
4
4
4
4
Refrigerant Piping . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Pressure Relief Valves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Water Connections . . . . . . . . . . . . . . . . . . . . . . . . . 6
General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Condenser Piping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Condensate Drain Connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Duct Connections . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Supply Air. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Return Air . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Unit Weights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Field Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Unit Disconnect . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Return Air and Outside Air Sensor. . . . . . . . . . . . . . . . . . . . . . . . .
Supply Power Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Lug Sizes For Single Disconnect or Power Block . . . . . . . . . . . . .
14
14
14
16
16
Control Center . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Electrical Legend . . . . . . . . . . . . . . . . . . . . . . . . . 18
Typical Wiring Schematics . . . . . . . . . . . . . . . . . . 19
Figure 19. Power Schematic . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 20. Input Schematic, Discharge Air Control (DAC). . . . . . .
Figure 21. Input Schematic, Zone or Space
Comfort Control (SCC) 21
Figure 22. Output Schematic, Actuator Control . . . . . . . . . . . . . .
Figure 23. Output Schematic, Auxiliary Fan Start/Stop Control . .
Figure 24. Output Schematic, Actuator Control . . . . . . . . . . . . . .
Figure 25. Output Schematic, Compressor Control
(4 Compressors/4, 5 or 6 Stage) . . . . . . . . . . . . . . . . . . . . .
Figure 26. Output Schematic, Compressor Control
(6 Compressors / 6 Stage) . . . . . . . . . . . . . . . . . . . . . . . . . .
19
20
General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Pre Start-up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Start-up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
General. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fan start-up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Compressor start-up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Economizer start-up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Hot water start-up. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Expansion valve superheat adjustment . . . . . . . . . . . . . . . . .
Refrigerant Charge. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Variable air volume (VAV) start-up . . . . . . . . . . . . . . . . . . . .
Rpm changes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Drive sheave alignment and belt tension . . . . . . . . . . . . . . . .
Final control settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Maintaining control parameter records . . . . . . . . . . . . . . . . .
28
28
28
28
28
29
29
29
29
30
30
30
30
30
30
30
30
31
31
31
31
32
32
32
32
32
33
34
34
34
35
35
System Maintenance . . . . . . . . . . . . . . . . . . . . . . . 36
22
23
24
25
26
Standard Controls . . . . . . . . . . . . . . . . . . . . . . . . . 27
High Pressure Switches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Preventative Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Motor Bearings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Replacement Parts . . . . . . . . . . . . . . . . . . . . . . . . 37
Service and Warranty Procedure . . . . . . . . . . . . . 38
In Warranty Return Material Procedure . . . . . . . . . . . . . . . . . . . . . 38
Replacement Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Product Warranty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Check, Test and Start Procedure Form . . . . . . . . 39
© 2003 McQuay International. All rights reserved throughout the world.
2
IM708-1
Introduction
General Description
Table 1. Self-contained unit operation manual literature
Models SWP018 through 105 are factory assembled, refrigerant charged and tested, water cooled packaged air conditioning units designed for ducted applications.
Each unit contains multiple hermetic compressors, water
cooled condensers, multi-circuit evaporator, thermal expansion valves, interconnecting refrigerant piping, forward
curved or airfoil centrifugal fan, belt drive, fan motor, pleated
filters and all necessary operating and safety controls.
All rigging, installation, power and control wiring external to
the unit, and condenser water and condensate piping are the
responsibility of the installer.
The MicroTech II self-contained unit controller is standard
equipment. For a detailed description of the MicroTech II
components, input/output configurations, field wiring
options and requirements, and service procedures, refer to
Bulletin No. IM 710, "MicroTech II Self-contained Unit
Controller." For a description of operation and information
on using and programming the MicroTech II unit controller,
refer to the appropriate operation manual (see Table 1).
UNIT CONTROL
CONFIGURATION
Variable Air Volume (VAV)
Discharge Air Control (DAC)
OPERATION MANUAL
BULLETIN NUMBER
OM711
Constant Air Volume
Space Comfort Control (SCC)
OM712
Constant Air Volume
Discharge Air Control (DAC)
OM711
Inspection
When the equipment is received, all items should be carefully checked against the bill of lading to insure a complete
shipment. The shipping receipt should not be signed until all
items have been accounted for. All units should be carefully
inspected for damage upon arrival. All shipping damage
should be reported to the carrier and a claim filed. The unit
serial plate should be checked before unloading the unit to be
sure that it agrees with the power supply available.
Nomenclature
SWP-055-D
Self-contained
Water cooled
Plenum discharge
IM708-1
Vintage
Nominal tons
3
Installation
Note:
Installation and maintenance are to be performed
only by qualified personnel who are familiar with
local codes and regulations, and experienced with
this type of equipment.
CAUTION
Sharp edges and coil surfaces are a potential injury hazard.
Avoid contact with them.
Handling
Units are shipped with a protective covering which should
remain in place while the unit is being moved to its final
location.
Note:
Check for concealed damage as soon as possible.
Never allow any part of the unit to fall during unloading or
moving as this may result in serious damage. Units are provided with lifting lugs for rigging with a crane. If units are
lifted by crane, protection against chaffing damage by slings
or cable must be provided and spreader bars must be used
across the top of the cabinet to prevent any structural damage
to the frame.
The unit base frame will accept dollies or Johnson bars for
transporting the unit. Furniture dollies can be placed at both
ends of the chassis or at one end and a Johnson bar used at
the other end for maneuvering.
Setting Factory Supplied Plenum
If the unit is provided with a factory plenum for field mounting, a forklift, slings or other suitable lifting means is
required. Foam rubber gasket is provided around the perimeter of unit top. Carefully set plenum. Attach with mounting
hardware provided with the plenum.
Location/Service Access
For good installation, service, and maintenance access the
following recommended clearances should be followed.
Minimum clearances required by local, state, or federal
codes, such as the NEC take precedence over those listed
below. Clearance is required to allow room for side filter
access, mechanical cleaning of the condenser tubes and
economizer coil, access to expansion valves and other control components and to allow for possible fan shaft or compressor removal.
Unit front - 42"
Unit rear - 24"
Motor location; right side - 36"
Piping location; left side or right side - 36"
Side without motor or piping -24"
Figure 1.Recommended Service and Maintenance
Clearance
CAUTION
Airflow
Do not attempt to install dollies in the center of the unit.
Units can become unstable and tip over causing injury
CAUTION
Units must not be moved in an upended position. Internal
components may tear away causing injury.
Floor surfaces must be protected when equipment is moved
across finished flooring. Plywood sheeting may be used to
protect surfaces and distribute weight loading.
24"
Back
Evaporator Coil
Left
Side
24"
or
36"
Condenser
Cleanout
Motor
Compressors
1
AFD
3
5
6
4
2
Electrical Panel
36"
Right
Side
Front
42"
Vibration Isolators
All units are provided with 1” neoprene isolation pads,
shipped separately. Pads are to be installed beneath the unit
and located at each corner and the center of each base channel. For units provided with more than six (6) isolator pads,
evenly space the additional pads under the front and rear
base channels.
4
Removal of Shipping Restraints
Mechanical restraints are used to secure the spring mounted
fan during shipment. Restraints and shipping blocks must be
removed after unit has been set in its final location.
IM708-1
Refrigerant Piping
Pressure Relief Valves
All units have individual refrigerant circuits and each circuit
is provided with a spring loaded relief valve. The valve is set
to open when refrigerant pressure reaches 400 psig. The
relief valve will accommodate a 1/2" flare connection for
IM708-1
applications where it is necessary to connect vent piping and
run it outside the building.
CAUTION
When refrigerant is vented to the outside of the building,
the vent piping should be installed as recommended in
ASHRAE Standard 15-1994.
5
Water Connections
General
Due to the variety of piping practices, it is advisable to follow the recommendations of local authorities. They can supply the installer with the proper building and safety codes
required for a safe and proper installation.
The piping should be installed with a minimum number of
bends and elevation changes for best performance. Piping
should contain:
1. Vibration eliminators to reduce vibration and noise
transmission to the building.
2. Shutoff valves to isolate the unit from the piping system
during unit servicing.
3. Manual or automatic air vent valves at the high points of
the system.
4. Some means of maintaining adequate system water
pressure (e.g., expansion tank or regulating valve).
5. Temperature and pressure indicators located at the unit
to aid in servicing.
6. A strainer or some means of removing foreign matter
from the water before it enters the pump. It should be
placed far enough upstream to prevent cavitation at the
pump inlet (consult pump manufacturer for recommendations). The use of a strainer will prolong pump life
and help maintain system performance.
7. Size piping to minimize system pressure drop.
Condenser Piping
1.
Units may be specified with water and condensate connections on either the left or right side of the unit.
2. All condensers are factory piped for a common condenser water supply and a common condenser water
return connection.
3. Field piping connections are made to factory provided
piping located as indicated on the unit submittal drawings. The piping connections are run to the outside of
the unit cabinet. Connections are located behind a factory mounted shipping cover. All connections are copper sweat connections as indicated on unit dimensional
drawings.
4. Supply and return water connections must be made at
the proper locations as indicated by the dimensional
drawings. Supply (water in) connection is always the
lower connection.
6
5.
6.
7.
Units with factory mounted water side economizer
should not require head pressure control. The economizer will typically elevate the water temperature by 5
to 10°F before entering the condenser, allowing suitable
condenser water temperatures whenever the tower supply temperature is 50°F or higher. Mechanical cooling is
locked out below 55°F EWT.
Head pressure control must be provided if entering condenser water temperatures will go below 55°F. Fan
cycling and/or modulating discharge dampers on the
cooling tower are often used, or a 3-way bypass around
the tower to maintain condenser water temperature.
Cooling tower control to maintain the temperature at
>55°F is generally more cost effective if multiple units
are in the loop.
If the water regulating valve is placed in service with the
unit condenser, it should be installed in the water line
leaving the condenser and should shut down to prevent
water from siphoning out of the condensers. For systems where a constant pumping head is required, the
water regulating valve may be installed in a bypass line
around the condensers. It must then open on falling discharge pressure.
These typical systems, depending on the specific application, must maintain a constant condensing pressure
regardless of temperature conditions and must provide
adequate head pressure for proper thermal expansion
valve operation. A minimum head pressure of 180 psi
(95°F condensing temperature) is recommended.
Condenser tube velocities must not exceed 10 feet per
second.
Figure 2.Condenser Regulating Valve
(refrigerant pressure controlled)
IM708-1
Figure 3.Condenser water pressure drop
SWP018 - SWP040
Figure 5.Economizer water pressure drop,
SWP018-SWP105
03
01 5-04
8- 0
02
8
04
509
10
5
5
24
H
28 P
H
32 P
36 HP
40 HP
HP
50
Pressure Drop (ft H2O)
Pressure Drop (ft H2 O)
12
H
18
H
P
P
40
20
10
8
10
6
4
1
3
20
40
80 100
60
200
300
10
Condenser Flow Rate (gpm)
Note:
500
c Includes coil, control valves and interconnecting
Note:
HP = total unit compressor horsepower.
100
Condenser Flow Rate (gpm)
piping.
d Add this∆P to condenser ∆P to obtain unit ∆P
Figure 4.Condenser water pressure drop
SWP045 - SWP105
for pump selection.
P
H
H
56 P
H
P
60
H
70 P
H
80 P
H
P
46
40
H
40
Figure 6.Water regulating valve pressure drop.
Head pressure control
52
P
60
1
90 84 78
0H 05H
H HP HP
P
P
P
4
0
04
95
-0
04
5
6
8-
8
10
Pressure Drop (ft H2O)
10
01
20
12
Pressure Drop (ft H2O)
40
1
2
80
100
200
300
400
500
Condenser Flow Rate (gpm)
Note:
HP = total unit compressor horsepower.
0.1
10
100
500
Condenser Flow Rate (gpm)
IM708-1
7
Figure 7.Hot water coil pressure drop, SWP018 SWP040
Figure 8. Hot water coil pressure drop, SWP045 SWP105
100
Pressure Drop (ft H 2O)
Pressure Drop (ft H 2O)
01
8
02
303 028
5
04
0
04
055
065
10 5-0
5 95
100
10
10
1
1
10
100
Water Flow Rate (gpm)
200
10
100
200
Water Flow Rate (gpm)
Condensate Drain Connection
The condensate drain connection is 1-1/8" O.D.S. copper
and is located on the same end of the unit as the condenser
water connections. The drain is internally trapped at the factory requiring no external trap. The condensate line should
be pitched away from the unit with a minimum slope of 1/8"
per foot.
Drain pans and the drain trap should be kept clean by periodic cleaning. A cleanout is provided as standard in the trap
to aid in cleaning.
8
IM708-1
Duct Connections
Supply Air
Return Air
For connection of supply ductwork directly to the unit, a
duct collar must first be mounted at the fan outlet, avoiding
the mounting screws located around the perimeter of the fan
discharge opening. See Figure 9. Fan discharge opening
sizes are indicated on the unit dimensional drawings. When
connecting ductwork to the unit, a canvas type connecting
collar is recommended.
Ductwork should be ducted as shown in Figure 10. Duct
take-offs which go opposite to the direction of fan rotation
will result in an associated system effect loss and reduced
fan performance.
If a field fabricated plenum is used, duct take-off locations
should again be correctly oriented to the rotation of the fan to
minimize system losses. Refer to unit dimensional drawings
and Figure 9. for plenum mounting size requirements. Canvas type connectors are recommended at the duct connection
to the plenum.
Units are also available with a factory provided discharge
plenum. Supply duct connections to the plenum opening(s)
should include a canvas type connector. Plenum opening
sizes and locations will be indicated on the job submittal
drawing.
Return air to the unit can be arranged in two ways.
1. Ducted return
Return ductwork may be attached to the 2" flange around the
perimeter of the unit's return air opening. Refer to Figure 11.
A canvas type duct connecting collar is recommended. All
ductwork connected to the unit should be of adequate size
and construction for the application. A canvas type connector is also recommended where the duct penetrates the
machine room wall(s). This will prevent vibration generated
by air movement in the duct from being transmitted out to
the occupied spaces.
Note:
Do not obstruct unit access panel located below the
return opening.
2. Free return
The mechanical equipment room may be used as a return
plenum with no hard connection at the unit.
Note:
Some building codes do not allow the use of the
mechanical room as a return plenum. Applicable
local codes should be checked for each installation.
Figure 11.Back Elevation
(Optional)
Multi-Directional
Plenum
(See Notes)
Figure 9.Unit top detail
29
2.0
KxL
Return Air Opening
Typical
2.0
D
M
B
Mechanical
Access
(See Notes)
1 Neoprene
Isolation Pads,
Shipped Separately
Figure 10.Discharge duct configurations
IM708-1
9
Physical Data
Table 2. SWP 018 Through SWP 105
SWP Model Size
Data
018
023
028
035
040
045
2, 3, 4
3, 4
4
4
4
Face Area (Ft.2)
11.8
15.3
17.7
23.3
27.7
30.7
Rows
4, 6
12
4, 6
12
4, 6
12
4, 6
12
4, 6
12
4, 6
12
11.8
15.3
17.7
23.3
27.7
4
12
4
12
4
12
4
12
4
12
400
400
400
400
Face Area (Ft.2)
9.3
12.8
15.2
Rows
1, 2
12
1, 2
12
1, 2
12
34
34
34
055
065
070
080
095
105
4
4
4
4, 6
6
36.1
41.5
46.3
51.1
55.9
63.2
6
12
6
12
6
12
6
12
6
12
6
12
30.7
36.1
41.5
46.3
51.1
55.9
63.2
4
12
4
12
4
12
4
12
4
12
4
12
4
12
400
400
400
400
400
400
400
200
20.2
24.5
26.8
30.4
35.8
39.9
44.4
48.3
51.9
1, 2
12
1, 2
12
1, 2
12
1, 2
12
1, 2
12
1, 2
12
1
12
1
12
1
12
34
34
68
68
68
68
68
68
68
Compressor
Quantity
Size
4
4
See Unit Data Plate
Evaporator Coil
Fpi
Waterside Economizer
Coil
Face Area (Ft.2)
Rows
Fpi
Maximum Working
Pressure (psig)
Hot Water Heating Coil
Fpi
Electric Heat
Kw
Filters
(Quantity) Size 4” Depth
(4) 16x20
(6) 20x20 (6) 20x20 (6) 20x20
(6) 16x20 (3) 20x20 (6) 16x20
(17) 20x25
(10) 25x20 (10) 25x20 (12) 25x20 (12) 25x20 (18) 20x20
(2) 25x20 (2) 25x20 (2) 25x20
(12) 25x20 (15) 25x20 (15) 25x20
(1) 16x25
Evaporator Fana
1
15
5
10
2950
4720
7080
1
18
7.5
15
3825
6120
9180
1
18
10
20
4425
7080
10620
1
20
10
20
5825
9320
13980
1
20
15
25
6925
11080
16620
1
22
15
30
7675
12280
18420
1
25
20
40
9025
14440
21660
1
25
20
40
10375
16600
24900
1
25
20
40
11575
18520
27780
1
27
25
50
12775
20440
30660
1
27
30
60
13975
22360
33540
1
33
40
60
15800
25280
37920
Waterside Working
Pressure (psig)
400
400
400
400
400
400
400
400
400
400
400
400
Minimum Entering
Temperature (F)
55°
55°
55°
55°
55°
55°
55°
55
55°
55°
55°
55°
Minimum GPM
25
88
41
108
53
125
66
159
69
166
94
215
105
237
105
237
121
251
134
349
138
358
180
493
Quantity
Size
Minimum Horsepower
Maximum Horsepower
Minimum Design cfm, CV
Minimum Design cfm, VAV
Maximum Design cfm
Condenser
Maximum GPM
a.
Standard fan TSP limit is 5.5 inches of water. Consult your local McQuay sales representative for applications beyond this range.
Table 3. Compressor circuit charge
COMPRESSOR
(HP)
*REFRIGERANT
CHARGE PER
CIRCUIT (R-22)
OIL CHARGE
PER CIRCUIT
(OZ.)
6
9 lbs.
66
10
14 lbs.
112
13
18 lbs.
128
15
22 lbs.
256
20
27 lbs.
256
*Charge quantities listed are average. Actual charge quantity is dependent on
individual unit evaporator coil circuiting. Actual charge quantities are stamped
on each unit nameplate.
10
IM708-1
Dimensional Data
Figure 12. Left Side Front (CW) Discharge with 0ptional
Multi-Directional Plenum
G
Figure 13. Left Side Back (CCW) Discharge with
0ptional Multi-Directional Plenum
J
9.63"
(18-95)
10.31
(105)
(Optional)
Multi-Directional
Plenum
(See Notes)
Electrical Panel
Heater
Evaporator
Economizer
Electrical Panel
Filter Section
K x L Return Air
Heater
Evaporator
Economizer
K x L Return Air
Filter Section
(Optional)
Multi-Directional
Plenum
(See Notes)
3.25
3.25
Outlet
19.0"
19.0"
Outlet
Inlet
Q
A
R
A
8.75
14.75
Inlet
A22
Note: Select unit arrangement on the unit selection.
Plenum can be shipped separately. All openings are on plenum centerline. For additional information refer to submittal drawing.
Table 4.
018
023
028
035
040
045
055
065
070
080
095
105
A
BASIC UNIT
Depth
ab
72.00
72.00
72.00
72.00
72.00
81.00
81.00
81.0
81.00
84.00
84.00
96.00
B
Lengtha b
84.00
84.00
84.00
100.00
100.00
120.00
120.00
120.0
132.00
144.00
156.00
156.00
D
Heighta b
82.00
82.00
82.00
82.00
82.00
82.00
82.00
88.0
88.00
88.00
88.00
96.00
F
Fan Disch.
18.62
21.88
21.88
24.75
24.75
27.25
31.25
31.25
31.25
34.25
34.25
47.25
G
Fan Disch. ⊥ To Shaft
15.88
18.88
18.88
24.75
24.75
27.25
31.25
31.25
31.25
34.25
34.25
34.94
H
Fan Discharge Location
32.69
31.06
31.06
37.62
37.62
46.38
44.38
44.38
50.38
54.88
60.88
54.40
J
Fan Discharge Location
22.50
18.81
18.81
20.12
20.12
21.06
21.32
21.32
21.32
23.82
23.82
33.76
K
Return Opening Height
41.44
41.44
41.44
51.44
51.44
51.44
51.44
62.20
62.20
62.20
62.20
70.20
L
Return Opening Length
80.00
80.00
80.00
96.00
96.00
116.00
116.00
116.00
128.00
140.00
152.00
152.00
M
Base of Return Opening
28.62
28.62
28.62
28.62
28.62
28.62
28.62
23.87
23.87
23.87
23.87
23.87
N
Water Out/In (ODS)
2-1/8
2-1/8
2-1/8
2-5/8
2-5/8
2-5/8
3-1/8
3-1/8
3-1/8
3-1/8
3-1/8
3-1/8
P
1 Row HW Donn (ODS)
1-5/8
1-5/8
1-5/8
1-5/8
1-5/8
1-5/8
1-5/8
1-5/8
2-1/8
2-1/8
2-1/8
2-1/8
P
2 Row HW Conn (ODS)
1-5/8
1-5/8
1-5/8
1-5/8
1-5/8
2-1/8
2-1/8
2-1/8
2-1/8
—
—
—
Q
Condenser Outlet
16.5
16.5
16.5
16.5
16.5
16.5
16.8
16.8
16.8
16.8
16.8
17.76
Condenser Inlet
10.5
10.5
10.5
10.5
10.5
10.8
10.8
10.8
10.8
10.8
10.8
11.75
R
a.
b.
IM708-1
Dimensions do not include lifting lugs, handle, latch, or fastener extensions.
For shipping dimensions add 4" (102mm) to depth, 8" (204mm) to length, and 4" (102mm) to height.
11
Figure 14. Unit Front Plan
Figure 17. Left Side
Return Air
(Optional)
Right Side
Piping
Connections
(See Notes)
Left Side
Piping
Connections
(See Notes)
Power
Entry
3-1/8"
Supply
Fan Motor
Figure 15. Front Elevation
AFD (Optional)
MicroTech II Panel
Disconnect
Switch (Optional)
Power Entry
7/8" Pilot K.O.
Figure 18. Discharge Plenum (Optional)
P la n V ie w
D
D e p th
Electrical
Access
72"
Mechanical
Access
Service connections determined when facing the front of the
unit. Left-hand standard, right-hand optional. Please indicate on
the unit submittal.
Note:
Unit sizes 018, 023 and 028 have a single mechanical access
panel in bottom front and bottom back.
Figure 16. Back Elevation
H
F
M u lti- D ir e c t io n a l
P le n u m ( O p t io n a l)
(S e e N o te s , P a g e 1 1 )
H
2 9 ”
H
B
3 ”
Table 5. Discharge Plenum
Unit Size
Length (in.)
Depth (in.)
Height (in.)
018D-028D
84
72
23, 29, 35, 41
035D-040D
100
72
23, 29, 35, 41
045D-065D
120
81
29, 35, 41
070D
132
81
29, 35, 41
080D
144
84
29, 35, 41
095D-105D
156
84
29, 35, 41
2 .0 ” T y p ic a l
K x L
R e tu r n A ir O p e n in g
D
H e ig h t
A
2 ” M in
Note:
L e ft/R ig h t E le v a tio n
2 ” M in
H e ig h t
B
H
F r o n t/B a c k E le v a tio n
3 ”
L e n g th
2 .0 ”
M
B
M e c h a n ic a l A c c e s s
(S e e N o te s )
12
1 ” N e o p re n e
Is o la tio n P a d s ,
S h ip p e d S e p a r a te ly
IM708-1
Unit Weights
Table 6. Unit and Component Weight in lbs.
Unit Weights
018
023
028
035
040
Unit Size
045
055
065
070
080
095
105
2226
2313
2318
2638
2643
3110
3279
3406
3734
4021
4246
4766
38
38
38
55
55
66
66
79
87
96
104
112
250
206
294
238
321
257
417
333
468
368
506
395
577
-
642
-
693
-
755
-
819
-
926
-
306
51
338
66
357
75
458
94
493
111
520
119
598
150
648
168
678
187
723
203
820
218
927
281
71
16
97
20
114
23
130
28
158
32
160
37
170
41
200
49
328
55
337
59
345
62
371
62
20
-
20
-
20
-
20
-
20
-
40
40
40
40
40
40
40
71
82
124
144
72
85
140
170
-
124
144
185
140
170
235
-
144
185
214
170
235
300
-
144
185
214
170
235
300
-
185
214
266
235
300
330
-
185
214
266
310
235
300
330
390
-
214
266
310
404
300
330
390
510
-
214
266
310
404
300
330
390
510
-
266
310
404
452
330
390
510
570
-
310
404
452
620
390
510
570
850
310
404
452
620
390
510
570
850
368
538
699
-
538
699
843
-
699
843
974
-
699
843
974
1115
1263
-
843
974
1115
1263
-
1263
1404
1549
1709
1867
-
1263
1404
1549
1709
1867
-
1263
1404
1549
1709
1867
1982
1549
1709
1867
1982
-
1709
1867
1982
2096
-
1709
1867
1982
2096
2265
2479
2693
2914
3135
2265
2479
2693
2914
3135
551
636
719
805
551
636
719
805
551
636
719
805
616
711
804
899
616
711
804
899
862
975
1090
862
975
1090
862
975
1090
922
1042
1166
1003
1134
1269
1064
1203
1346
1064
1203
1346
Basic Configuration
SWP basic unita
Filters
4" 30% or 65% efficiency
Evaporator Coil
6 Row, 12 fpi
4 Row, 12 fpi
Water Economizer Coilb c
4 Row, 12 fpi
Water weight
Hot Water Coild c
1 Row, 12 fpi
Water weight
Electric Heat
34 KW
68 KW
Supply Fan Motors
3 HP ODP
5 HP ODP
7.5 HP ODP
10 HP ODP
15 HP ODP
20 HP ODP
25 HP ODP
30 HP ODP
40 HP ODP
50 HP ODP
60 HP ODP
3 HP TEFC
5 HP TEFC
7.5 HP TEFC
10 HP TEFC
15 HP TEFC
20 HP TEFC
25 HP TEFC
30 HP TEFC
40 HP TEFC
50 HP TEFC
60 HP TEFC
Compressor/Condenser Assembly
Water Weight
(2) 6HP
26
(3) 6HP
35
(4) 6HP
43
(3) 6HP, (1) 10HP
57
(2) 6HP, (2) 10HP
66
(1) 6HP, (3) 10HP
74
(4) 10HP
95
(2) 10HP, (2) 13HP
106
(4) 13HP
118
(2) 13HP, (2) 15HP
129
(4) 15HP
141
(2) 15HP, (2)20HP
152
(4) 20HP
190
(6) 13HP
167
(3) 13HP, (3)15HP
178
(6) 15HP
188
(3) 15HP, (3) 20HP
209
(6) 20HP
229
Discharge Plenum
23” High
29” High
35” High
41” High
a.
b.
c.
d.
IM708-1
214
266
310
404
300
330
390
510
Base Weight includes supply fan without motor.
Water economizer weight includes valves and piping.
The values in this table do not include water weight.
Hot water coil weight includes valve and piping.
13
Field Wiring
General
Return Air and Outside Air Sensors
Wiring must comply with all applicable codes and ordinances. The product warranty may be voided if wiring is not
in accordance with specifications. An open fuse indicates a
short, ground or overload. Before replacing a fuse or restarting a compressor or fan motor, the trouble must be found and
corrected. Copper wire is recommended for all power lead
terminations. Contact factory for information concerning
aluminum wire power lead terminations.
A single power terminal block is provided as standard and
wiring within the unit is done in accordance with the
National Electric Code. All branch circuits within the control
panel are individually fused. A single field supplied disconnect is required or a unit mounted nonfused disconnect can
be ordered with the unit.
A 7/8” knockout is located on the right-hand unit upright for
locating unit power entry. 24V field connections are suitable
for Class II wiring.
All units are provided with a return air sensor. The outside
air sensor is optional and can be ordered with the unit. The
return air sensor is connected to the input control board and
is coiled up and placed in the control box of the unit for shipment. The return air sensor must be field installed in the
return air stream for proper unit operation. The outside air
sensor is shipped loose in a package and is located on the
floor of the fan section. The mixed air temperature sensor is
already installed at the inlet of the unit.
The sensors must be mounted in areas that are exposed to
representative temperature conditions. The sensor should be
mounted at a position that has good air mixing and does not
have stratification. The sensor can be mounted in the ductwork using a grommet, see Figure 19.
Figure 19. Return/Outside Air Sensor Mounting
Unit Disconnect
Sensor
Disconnecting means are addressed by Article 440 of the
National Electric Code (NEC) which requires “disconnecting means capable of disconnecting air conditioning and
refrigerant equipment including motor-compressors, and
controllers, from the circuit feeder.” The disconnect switch
should be selected and located within the NEC guidelines.
Location requirements per NEC are that the disconnect be
located in a readily accessible position within sight (50 feet)
of the unit.
A factory mounted nonfused disconnect is available.
Grommet
Ductwork
The return air sensor is connected to the unit’s input board at
location AI4, see IM710. The outside air sensor is field
wired to terminal strip TB2. The sensor is to be connected at
terminals 124 and 125.
Table 7. Compressor Motors
208/60/3
Compressor
HP
RLA
230/60/3
LRA
RLA
400/50/3
LRA
RLA
460/60/3
LRA
RLA
575/60/3
LRA
RLA
LRA
6
17.9
156.0
16.2
156.0
8.1
70.0
8.1
70.0
6.5
54.0
10
31.2
239.0
28.2
239.0
14.1
125.0
14.1
125.0
11.3
80.0
13
35.6
350.0
32.0
350.0
16.0
158.0
16.0
158.0
12.8
125.0
15
42.1
425.0
38.0
425.0
19.0
187.0
19.0
187.0
15.2
148.0
20
74.0
360.0
67.2
360.0
33.6
180.0
33.6
180.0
26.2
144.0
Table 8. Electric Heaters
SWP UNIT SIZE
14
208V/60HZ/3PH
kW
MBH
FLA
230V/60HZ/3PH
kW
MBH
FLA
400V/50HZ/3PH
kW
MBH
FLA
460V/60HZ/3PH
kW
MBH
FLA
575V/60HZ/3PH
kW
MBH
FLA
018 - 040
27.8
94
77.2
34
116
85.6
25.7
88
37.2
34
116
42.8
34
116
34.2
045 - 105
55.6
190
154.4
68
232
170.9
51.4
175
74.4
68
232
85.6
68
232
68.4
IM708-1
Table 9. SAF Motor Nameplate Amp Table
Horsepower
3
5
7.5
10
15
20
25
30
40
50
60
a.
IM708-1
208/60/3
230/60/3
400/50/3a
460/60/3
575/60/3
FLA
FLA
FLA
FLA
FLA
High Efficiency
9.9
9.0
4.5
4.5
3.4
Premium Efficiency
9.3
8.2
4.1
4.1
3.1
High Efficiency
16.1
14.0
7.0
7.0
5.3
Premium Efficiency
15.7
13.6
6.8
6.8
5.2
High Efficiency
25.0
21.6
10.8
10.8
8.2
Premium Efficiency
22.3
20.0
10.0
10.0
7.4
High Efficiency
33.0
28.0
14.0
14.0
11.0
Premium Efficiency
29.0
25.8
12.9
12.9
10.3
High Efficiency
44.8
40.6
20.3
20.3
16.2
Premium Efficiency
43.4
37.8
18.9
18.9
14.1
High Efficiency
61.0
50.0
25.0
25.0
20.0
Premium Efficiency
57.0
49.0
24.5
24.5
18.9
High Efficiency
74.0
62.0
31.0
31.0
24.3
Premium Efficiency
70.0
61.0
30.5
30.5
24.2
High Efficiency
86.5
75.0
37.5
37.5
30.0
Premium Efficiency
83.3
72.4
36.2
36.2
29.8
High Efficiency
117.0
102.0
51.0
51.0
40.0
Premium Efficiency
110.0
96.0
48.0
48.0
38.0
High Efficiency
140.0
124.0
62.0
62.0
49.2
Premium Efficiency
137.0
120.0
60.0
60.0
47.5
High Efficiency
154.0
144.0
72.0
72.0
57.4
Premium Efficiency
160.0
140.0
70.0
70.0
56.0
TYPE
460/60/3 motors are used. Derate nameplate horsepower to 0.83 to obtain actual horsepower.
15
Supply Power Wiring
1.
2.
a.
b.
3.
a.
b.
4.
5.
Units require three-phase power supply.
Allowable voltage tolerances:
60 Hertz
Nameplate 208V: Min.187V, Max. 229V
Nameplate 230V: Min.207V, Max. 253V
Nameplate 460V: Min.414V, Max. 506V
Nameplate 575V: Min.518V, Max. 632V
50 Hertz
Nameplate 400V: Min. 342V, Max. 418V
Power lead wire sizing:
For units with cooling capability (all concurrent loads)
with or without hot water heating and circuits with
motor loads only:
MCA = 1.25 (largest motor RLA or FLA) + other loads
+ 2 amps.
For units with cooling capability and nonconcurrent
electric heat capability:
In the cooling mode, the loads will be composed of supply fan motor and compressors. In heating mode, the
loads will be composed of supply fan motor and electric
heater. The MCA is calculated for unit running in either
mode; the highest value obtained is used for the MCA.
(1)For unit in cooling mode:
MCA = 1.25 (largest RLA or FLA) + other loads + 2
amps.
(2)For unit in heating mode:
MCA = 1.25 (electric heat FLA + Fan FLA) + 2 amps.
Size wires in accordance with Table 310-16 or 310-19 of
the National Electrical Code.
Wires should be sized for a maximum of 3% voltage
drop.
Lug Sizes For Single Disconnect or
Power Block
Table 10. Single Disconnect
UNIT
VOLTAGE
SIZE (AMPS)
018-028
208/230
225
018-028
400/460
100
018-028
575
100
035-040
208/230
225
035-040
400/460
150
035
575
100
040
575
150
045
208/230
400
045
400/460
150a
045
575
150
055-070
208/230
400
055-070
400/460
250
055-070
575
150
080-095
208/230
600
080-095
400/460
250
080-095
575
250
095-105 (6 Comp)
208/230
N/A
095-105 (6 Comp)
400/460
250
095-105 (6 Comp)
575
250
a.
Disconnect is 250 amps with electric heat.
Table 11. Lug Sizes For Single Disconnect
DISCONNECT SIZE
LUG SIZE
100
#6-2/0
150
#2-3/0
225
#3-300 MCM
250
#4-350 MCM
400
250 MCM-500 MCM
600
250 MCM-350 MCM
Table 12. Lug Sizes For Power Block
UNIT
VOLTAGE
LUG SIZE
018-045
ALL
#6-400 MCM
055-105
400/460/575
#6-400 MCM
055-105
208/230
1/0-600 MCM
Note: Use copper wire only.
16
IM708-1
Control Center
All electrical controls are enclosed in a central control center
located at the front of the unit. The control center is divided
into two separate compartments, high and low voltage. The
lower compartment houses the high voltage components and
can be accessed through the “Electrical Access" panels indicated on the dimensional drawing. Behind these access panels are hinged dead front panels for further operator safety.
High voltage components include:
1. Fan Motor Contactor, M30
2. Fan Motor Overload, OL10
3. Fan Motor Fuse, FB10
4. Compressor Contactors, M1-M6
5. Compressor Fuses, FB1-FB6
6. Electric Heat Contactors, M11-M16
7. Transformer, T1, T2, T3
8. Disconnect Switch, DS1-DS2
9. Power Block, PB1-PB2
If the optional disconnect switch is provided, the switch handle is visible and accessible without removing any safety or
access panels.
Low voltage components are located in the upper left compartment, and include:
1. MicroTech II™ Main Control Board, MCB
2. Duct Static Pressure Sensor, SPS1
3. Optional 2nd Duct Static Pressure Sensor, SPS2
4. Optional BACnet®/IP Communication Module
5. Optional BACnet MS/TP Communication Module
6. Optional LONWORKS® Communication Module*
7. Compressor Control Board, CCB #1
8. Compressor Control Board, CCB #2
(6 compressor units only)
Located on the face of the unit is the interactive MicroTech
II keypad/display, unit switch, system indicator light and
power indicator.
Note:
IM710 has additional layout of the control center.
Figure 20. Typical Control Center Layout High and Low Voltage Compartments
LonWorks Communication Module*
BACnet Communication Module
Adjustable Frequency
Drive (Optional)
Disconnect Switch
Phase Voltage
(Optional)
Monitor
Power Block
Transformer, Control Output, 24V, T3
Transformer, Control Output, 24V, T2
Duct Static Pressure Sensor
Transformer, Main Control, 115V, T1
* Unit controller is LONMARK® certified with the LONWORKS communication module.
IM708-1
17
Electrical Legend
Designation
ACT1
Description
ACTUATOR,VARIABLE INLET VANES
Standard Location
SUPPLY FAN SECTION
CONDENSER VALVE
WATERSIDE ECONO
VALVE
MAIN CONTROL
Designation
OAE
Description
OUTSIDE AIR ENTHALPY
Standard Location
EXTERNAL
ACT2
ACT3
ACTUATOR,BYPASS VALVE
ACTUATOR,WATERSIDE ECONOMIZER
OAT
OL10
OUTSIDE AIR TEMP. SENSOR
OVERLOAD RELAY--SUPPLY FAN
EXTERNAL
MAIN CONTROL
AFD10
ADJUST.FREQUENCY DRIVE--SUPPLY FAN
PB1
MAIN CONTROL
MAIN CONTROL
PB2
POWER BLOCK--TOTAL UNIT OR
COMPR/HEAT
POWER BLOCK--SAF/RAF/CONTROLS
CCB1,2
COMPR#1-6
COMPR CONTROL BOARDS--REFRIG. CIRCUITS
COMPRESSORS #1--6
PC5
PRESSURE CONTROL--CLOGGED FILTER
FAN SECTION
DISCHARGE AIR TEMP. SENSOR
DUCT HI-LIMIT
DISCONNECT--TOTAL UNIT OR COND/HEAT
COMPRESSOR SECTION
NEAR FAN INLET
FAN SECTION
MAIN CONTROL
DAT
DHL
DS1
PC7
PM1
PSR1,2
PRESSURE CONTROL--PROOF AIRFLOW
PHONE MODEM
PRESSURE SENSOR,REFRIGERANT
DS2
EWT
F1
DISCONNECT--SAF/RAF/CONTROLS
ENT. COND. WATER SENSOR
FUSE--CONTROL CIRCUIT
MAIN CONTROL
COND. WATER INLET
MAIN CONTROL
PVM1
PVM2
R11
FB10
FUSEBLOCK--SUPPLY FAN
MAIN CONTROL
R12
FB11,12
FB1--6
FB8
FP1-6
FS1
GRD
HL13-14
FUSEBLOCKS--ELECTRIC HEAT
FUSEBLOCKS--COMPRESSOR #1-6
FUSEBLOCK--MAIN TRANSFORMER
FROST PROTECTION--REFRIG. CIRCUITS
FREEZESTAT CONTROL
GROUND
HI-LIMITS, PWR, ELEC HEATERS
R1-6
R18
R67
RAE
RAT
S1
S4,5
HP1-6
HI-PRESSURE CONTROLS, REFRIG
S7
SWITCH--LOCAL ON/OFF TO CONTROLLER
MAIN CONTROL
HTR-11,12
HTR-15,16
HTR1-6
ELECTRIC HEATERS
ELECTRIC HEATERS
CRANKCASE HEATERS
S8
S9
SD1
SWITCH--COOL ENABLE
SWITCH--HEAT
SMOKE DETECTOR--SUPPLY FAN
MAIN CONTROL
MAIN CONTROL
EXTERNAL
HUM1
LP1-6
HUMIDSTAT SENSOR
LO-PRESSURE CONTROLS, REFRIG
SD2
SPS1,2
SMOKE DETECTOR--RETURN FAN
STATIC PRESSURE SENSORS--DUCT/BLDG
EXTERNAL
MAIN CONTROL
LWT
LEAVING COND. WATER SENSOR
T1
CONTACTOR--SUPPLY FAN
CONTACTORS--ELECTRIC HEAT CONTROL
CONTACTORS--ELECTRIC HEAT SAFETY
CONTACTORS--ELECTRIC HEAT CONTROL
CONTACTORS--COMPR#1-6
CONTACTORS--ELECTRIC HEAT SAFETY
CONTACTOR--INVERTER BYPASS
MIXED AIR TEMP SENSOR
MICROPROCESSOR CIRCUIT BOARD #1
MECHANICAL JUMPERS
T2
T3
TB10
TB2
TB3
TB4
TB5
TB6
TB8
VM1
TRANSFORMER--MAIN CONTROL
(LINE/115V)
TRANSFORMER--CONTROL INPUT 24V
TRANSFORMER--CONTROL OUTPUT 24V
TERMINAL BLOCK-TERMINAL BLOCK--24V-FACTORY/FIELD
TERMINAL BLOCK--24VTERMINAL BLOCK--24V-COMPRESSOR
TERMINAL BLOCK--115V-FACTORY/FIELD
TERMINAL BLOCK--115V/24V FACTORY
TERMINAL BLOCK-VALVE MOTOR #1--HEATING
MAIN CONTROL
M10
M11,12
M13,14
M15,16
M1-6
M17,18
M30
MAT
MCB1
MJ
MP1-6
MOTOR PROTECTOR--COMPR#1-6
VM5
VALVE MOTOR #5--COOLING
NB1
NEUTRAL BLOCKS
MAIN CONTROL
MAIN CONTROL
MAIN CONTROL
EVAP. COIL
BT/DT COIL
ALL CONTROL BOX
ELECTRIC HEAT
JCT.BOX
ON COMPRESSORS
#1-6
DX COIL
DX COIL
ON COMPRESSORS
#1-6
EXTERNAL
ON COMPRESSORS
#1-6
COND. WATER OUTLET
MAIN CONTROL
MAIN CONTROL
MAIN CONTROL
MAIN CONTROL
MAIN CONTROL
MAIN CONTROL
MAIN CONTROL
BEHIND FILTERS
MAIN CONTROL
ON TEMINAL
BLOCKS
ON COMPRESSORS
#1-6
MAIN CONTROL
PHASE VOLTAGE MONITOR
PHASE VOLTAGE MONITOR
RELAY--ELECTRIC HEAT STAGE 1 HW/S
CLOSE
RELAY--ELECTRIC HEAT STAGE 2 HW/S
OPEN
RELAYS--HI-PRESSURE
RELAY--COOL ENABLE
RELAY--ENABLE SUPPLY FAN
RETURN AIR ENTHALPY
RETURN AIR TEMP. SENSOR
SWITCH--SYSTEM ON/OFF
SWITCHES--INVERTER BYPASS
FAN SECTION
MAIN CONTROL
LIQ. SHUTOFF
VALVES
MAIN CONTROL
MAIN CONTROL
MAIN CONTROL
WF1
ZNT1
CONDENSER WATER FLOW SWITCH
ZONE TEMP. SENSOR--SETBACK
1.
TERMINAL
3.
FIELD WIRING TERMINAL
200
MAIN CONTROL
MAIN CONTROL
MAIN CONTROL
MAIN CONTROL
MAIN CONTROL
MAIN CONTROL
MAIN CONTROL
MAIN CONTROL
MAIN CONTROL
NEAR HOT WATER
INLET
NEAR CHILLED
WATER
NEAR CONDENSER
FIELD INSTALLED
WIRE NUMBER
6.
WIRE CONNECTOR
7.
OPTION BLOCK
PLUG IN CONNECTOR
8.
18
MAIN CONTROL
MAIN CONTROL
MAIN CONTROL
EXTERNAL
EXTERNAL
MAIN CONTROL
MAIN CONTROL
TERMINAL P.C. BOARD FACTORY WIRED
4.
9.
MAIN CONTROL
FIELD WIRING
2.
5.
MAIN CONTROL
M/J
MECHANICAL JUMPER
IM708-1
Typical Wiring Schematics
Figure 21. Power Schematic
IM708-1
19
Figure 22. Input Schematic, Discharge Air Control (DAC)
20
IM708-1
Figure 23. Input Schematic, Zone or Space Comfort Control (SCC)
IM708-1
21
Figure 24. Output Schematic, Actuator Control
22
IM708-1
Figure 25. Output Schematic, Auxiliary Fan Start/Stop Control
IM708-1
23
Figure 26. Output Schematic, Actuator Control
24
IM708-1
Figure 27. Output Schematic, Compressor Control (4 Compressors/4, 5 or 6 Stage)
IM708-1
25
Figure 28. Output Schematic, Compressor Control (6 Compressors / 6 Stage)
26
IM708-1
Standard Controls
High Pressure Switches
Proof of Airflow Switch
The high pressure switch (HP1-HP6) is a single pole pressure activated device that opens on a pressure rise. When the
switch opens it de-energizes the compressor circuit, shutting
down the compressor. The MicroTech II controller will display an alarm condition. Once the cause of the fault has been
identified and corrected, the unit may be manually reset
through the MicroTech II keypad/display interface. The control is attached to a Shrader fitting and is located at the compressor. To check the control, shut off water flow to the
condensers and observe the cutout point on a high pressure
gauge. The high pressure control should open at 360 psig
and close at 300 psig. After testing the high pressure control
check the pressure relief device for leaks.
A positive proof of airflow switch (PC7) is provided with all
units. The switch is factory set to close at 0.2 inches of water
column. The switch has a field adjustable set point range of
0.05 to 5.0 inches of water column. Turn adjustment screw
clockwise to decrease differential pressure setting. Turn
adjustment screw counterclockwise to increase differential
pressure setting. In a constant volume system, if the fan system is energized and the minimum pressure setting of the
switch has not been reached, the unit will be shut down and a
loss of airflow alarm indicated at the MicroTech II controller.
For variable air volume units, the unit will shutdown due to
loss of airflow only if the airflow switch is open AND the
duct static pressure is less than half the duct static pressure
setpoint. Once the reason for the fault has been corrected, the
unit can be manually reset through the MicroTech II keypad/display interface. PC7 is located in the fan section on the
motor side.
Low Pressure Switches
The low pressure switch (LP1-LP6) is a single pole pressure
activated device which closes on a pressure rise. It senses
evaporator pressure and is factory set to close at 60 psig and
open at 35 psig. Compressor operation is not allowed until
the switch closes. The low pressure switch is an automatic
reset control. If the condition occurs on any one compressor
three times in a 24-hour period, the alarm will have to be
manually reset through the MicroTech II keypad/display
interface to restart the compressor. The low pressure switch is
attached to a Shrader fitting and is located at the compressor.
Compressor Motor Protector
All compressors are thermally protected. All 10 horsepower
and larger compressors use a solid state protection device
(MP1 - MP6) located in the compressor junction box. Whenever the protection system opens the compressor is shut
down for a period of 10 minutes and an alarm indication is
made at the MicroTech II controller.
All 6 horsepower compressors have in-line protection. The
control automatically resets when the alarm condition is
removed and the time delay is satisfied.
If the condition occurs on any one compressor three times in
a 24-hour period, the alarm will have to be manually reset
through the MicroTech II keypad/display interface to restart
the compressor.
IM708-1
Frost Protection Switches
A frost protection switch (FP1-FP6) is used on each refrigerant circuit to protect against evaporator coil freeze up. The
frost protection switches are normally closed and open on a
drop in temperature. When a frosting condition is sensed the
compressor circuit is shutdown until the condition has been
removed. The frost protection control is an automatic reset
control. If the condition occurs on any one compressor three
times in a 24 hour period, the alarm will have to be manually
reset through the MicroTech II keypad/display interface to
restart the compressor. The MicroTech II control will indicate
a warning when a frost condition exists. The temperature sensors are located on a return bend for each refrigerant circuit.
Clogged Filter Switch
A clogged filter switch (PC5) is provided to indicate when
unit filters are to be changed. The switch is factory set to
close at 1.0 inches of H2O. The switch has a field adjustable
set point range of 0.05 to 5.0 inches of H2O. Turn adjustment
screw clockwise to decrease differential pressure setting.
Turn adjustment screw counterclockwise to increase differential pressure setting. When the filter pressure differential
exceeds the switch setpoint, a clogged filter indication is
made at the MicroTech II controller. The unit is allowed to
continue operation. PC5 is located in the fan section on the
motor side.
27
Unit Options
Duct High Limit
A duct high limit (DHL) pressure control is provided as standard with all units having variable air volume control. The
duct high limit is intended to protect the ductwork, etc. from
over pressurization caused by tripped fire dampers or a control failure. When the duct pressure exceeds the setting of the
control, the unit is de-energized via the MicroTech II controller and an alarm condition indicated. After the reason for
trip has been identified and corrected, the control can be
reset via the MicroTech II keypad/display interface.
The duct high limit is factory installed including sensing tubing, and preset for a 3.0" wc trip point. The control can be
readjusted in the field to match the specific ductwork of a
project. The switch has a field adjustable set point range of
0.05 to 5.0 inches of H2O. Turn adjustment screw clockwise
to decrease differential pressure setting. Turn adjustment
screw counterclockwise to increase differential pressure setting. DHL is located in the fan section on the motor side.
Phase Fail/Under Voltage Protection
The monitor is a microprocessor controlled device which
provides protection against three-phase electrical motor loss
due to low voltage, phase loss, voltage unbalance and phase
reversal. The microprocessor constantly monitors the threephase line voltages and detects these harmful power line
conditions. Whenever any of these conditions occur, the
SWP controls are deactivated and remain deactivated until
power line conditions return to an acceptable level. Trip and
reset delays have been provided to prevent nuisance tripping
due to rapid power fluctuations. The trip and reset delays are
field adjustable. The monitor also provides a variable line
voltage adjustment.
3.
The sensing tube should be located in a nonturbulent
flow area of the duct. Keep several duct widths away
from take-off points, bends or neck downs.
Mounting instructions
See Figure 29.
1.
2.
3.
Drill hole in duct at remote sensing point and install a
rubber grommet. Insert sensing tube 1/8" into the duct
and securely clamp tubing to the duct, being sure not to
stress or kink the tubing. The end of the sensing tube
must be smooth and cut straight across. An angle cut
will affect operation.
Clamp a second tube to the outside of the duct at the
location of the sensing point.
Run both tubes along the ductwork and back to the unit.
The tubing may be routed to the pressure sensor (SPS1)
by drilling two holes through the unit upright post. A
grommet must be used at each hole to protect the tubing
and seal the cabinet.
Note: To avoid confusion between "high" and "low" tubing,
it is recommended that two different tubing colors be
used and that this information be recorded, along with
the sensing point location, on the master building blueprints.
4.
Connect tubing to the high and low ports on the sensor.
Figure 29. Mounting
Duct Static Pressure Sensor
All units provided with variable air volume control include a
factory mounted static pressure sensor (SPS1). The unit can
also have an optional second static pressure sensor, SPS2.
The sensor is factory wired and requires field installation of
1/8" I.D. sensor tubing to the selected duct location.
Note:
1.
2.
28
Be sure that tubing complies with local code requirements. Flame retardant plastic or metal tubing may
be required. Carefully select the ductwork sensing
point for the pressure sensor. Improper location of
the sensing point will result in unsatisfactory operation of the entire variable air volume system. The following guidelines should be adhered to:
Position sensors near the end of long duct runs so all terminal box take-offs along the run will have adequate
static pressure to operate.
The end of the sensing tube must be perpendicular to the
airflow in order to sense only static pressure.
Building Static Pressure Sensor
If a unit has direct building static pressure control capability,
static pressure taps must be field installed and connected to
pressure sensor SPS1 in the unit. This sensor is located on
the control panel.
The two static pressure sensing taps must be carefully
located and installed. Improper location or installation of the
sensing taps will cause unsatisfactory operation. Following
are pressure tap location and installation recommendations
for both building envelope and lab, or "space within a
space," pressure control applications. The installation must
comply with local code requirements.
IM708-1
CAUTION
Fragile sensor fittings.
May damage pressure sensor.
If tubing must be removed from a pressure sensor
fitting, use care. Do not wrench the tubing back
and forth to remove or the fitting may break off.
Building pressurization applications
1.
2.
3.
4.
5.
6.
7.
Install a tee fitting with a leak-tight removable cap in
each tube near the sensor. This will facilitate connecting
a manometer or pressure gauge if testing is required.
Locate the building pressure (HI) tap in the area that
requires the closest control. Typically, this is a ground
level floor that has doors to the outside.
Locate the building tap so that it is not influenced by
any source of moving air (velocity pressure). These
sources may include air diffusers or outside doors.
Connect the tube to the 1/4 inch HI fitting on sensor
SPS1. Check that the sensor does not support the weight
of the tubing; use tube clamps or some other means.
Locate the reference pressure (LO) tap on the roof. Keep
it away from the condenser fans, waIls, or anything else
that may cause air turbulence. Mount it high enough
above the roof so that it is not affected by snow. If the
reference tap is not connected to the sensor, unsatisfactory operation will result.
Use an outdoor static pressure tap (Dwyer A306 or
equivalent) to minimize the adverse effects of wind.
Place some type of screen over the sensor to keep out
insects. Loosely packed cotton works well.
Route the outdoor tap tube out of the main control panel
through a small field-cut opening in the edge of the control wiring raceway cover. Cut this "mouse hole" in the
vertical portion of the edge. Seal the penetration to prevent water from entering. Connect the tube to the 1/4
inch LO fitting on sensor SPS1.
Freezestat
A non-averaging type freezestat (FS1) is provided to protect
hydronic coils from subfreezing temperatures. If the unit has
an economizer coil the control is mounted on the entering
face of the economizer coil. If the unit does not have an
economizer coil the control will be mounted on the leaving
face of the hot water coil. Upon sensing a hazardous temperature, the unit will shut down, open hydronic control valves
and send an alarm indication via the MicroTech II controller.
The freezestat has a field adjustable setpoint range of 35°F to
45°F. The setpoint may be changed by turning the adjustment screw until pointer is opposite the desired cutout point.
IM708-1
The adjustment screw is accessible at the bottom of the control or at the top when the cover is removed.
Condenser Water Flow Switch
A flow switch (WF1) is available to verify flow to the unit
condenser before compressor operation is allowed. The flow
switch is factory installed in the unit next to the condenser
piping connections. If a loss of condenser water flow is
sensed, the cooling will be locked out via the MicroTech II
controller. When flow is restored, the unit will automatically
reset.
The factory settings for the water flow switch N.O. contacts
are as follows:
Unit Size
Close
Ft. wc
018D-040D 3.0
045D-105D 4.5
Adj.
Range
+0.0
-0.5
+0.0
-0.5
Open
Ft. wc
1.5
3.0
Adj.
Range
+0.5
-0.5
+0.5
-0.5
Water Side Economizer
A completely factory installed, piped and controlled water
side economizer system is available on any constant or variable air volume system. Whenever the entering water temperature is more than 5-7°F (adjustable at the MicroTech II
keypad/display) below the mixed air temperature to the unit,
the control valves modulate to provide cooling directly from
the tower water. The economizer system can be used to provide 100% of the cooling demand or supplement mechanical
cooling by precooling the return air. The economizer system
consists of a water coil and two, two-way control valves. The
unit's MicroTech II controller will modulate the control
valves to satisfy the cooling demand whenever the entering
water is suitable. When the control valves are in the 90%
open position, the unit's compressors will be allowed to be
staged on to satisfy the cooling load. When the entering
water temperature is no longer suitable, the economizer control valve will close and the unit will be on 100% mechanical
cooling.
Two valve control arrangements are available from the factory. The first maintains full flow through the unit condensers at all times. This control arrangement is used for systems
with constant pumping systems. For installations with a variable pumping system, the control valves will be sequenced
such that flow is removed from the unit whenever cooling is
not required. A mechanical clutch is provided on each valve
to manually close or open the valves.
The economizer system is factory piped and the coil takes
advantage of the same drain pan and condensate connection.
Air may be vented from the economizer coil by using the
uppermost clean out plug. The torque requirement for the
cleanout plugs is 10 inch-lb.
29
Condenser Water, Head Pressure
Control
An optional condenser head pressure control valve is available on units without water side economizer. This option
permits operation with entering water temperatures as low as
40°F. The valve is a two-way regulating valve controlled via
MicroTech II to maintain refrigerant head pressure.
Variable Inlet Vanes
An optional variable inlet vane assembly is available for unit
sizes 018-040 for variable air volume applications. The
assembly consists of inlet funnels with integral sets of leveractuated radial vanes, one assembly for each side of the fan.
The vanes, upon opening, direct air in the direction of wheel
rotation.
The vanes rotate 90 degrees from closed to full open in
response to the factory installed actuator motor. The actuator
is controlled by the unit's MicroTech II controller. The inlet
vanes operate in unison and are properly adjusted and tested
before the unit leaves the factory. The start-up contractor
must check the adjustments and retighten all bolts and ball
joints to insure that shipping and handling has not caused
misalignment.
Adjustable Frequency Drive
As an option an adjustable frequency drive (AFD), is available for airflow modulation. A manually activated bypass
contactor is provided to allow system operation in the event
of drive service.
Static pressure is controlled by the unit mounted MicroTech
II controller. Indication of current airflow is available at the
MicroTech II controller. Static pressure is sensed by one or
two factory mounted duct sensors. The installer provides and
installs the sensor tubing from unit mounted sensor(s) to duct
location(s). The static pressure setpoint is keypad adjustable
through the MicroTech II DDC controller.
30
All variable air volume units include field adjustable duct
high limit safety control to protect ductwork from excessive
duct pressure.
Disconnect Switch
A factory mounted, nonfused main circuit interrupter for disconnecting the main electrical power is available. The switch
is located at the front of the unit on the control panel and is
accessible without unit penetration. The lug size information
is provided in Table 11 and Table 12 on page 16.
Dual Power Supply
The dual power block is an option for the power supply. This
allows the fan motor and control circuit to be isolated from
the compressor circuit. If the unit has the optional electric
heat it will be circuited with the compressors.
Electric Heat
Optional electric heat is available. Heat is controlled by the
unit's MicroTech II unit controller to maintain setpoint. The
heaters are factory installed and wired including branch fusing and all safety controls.
Hot Water Control
A factory mounted, 1 or 2 row hot water coil is available,
with or without factory mounted control valve. The hot
water control valve is controlled by the unit's MicroTech II
controller to provide morning warm-up heat or heat for constant volume application.
Battery Pack
An optional unit mounted battery pack is available. If the
electrical power fails, the battery pack provides power to
drive the actuator on the economizer valve and the bypass
valve closed, when valves are independently controlled.
IM708-1
System Check, Test and Start
8.
WARNING
Electric shock hazard. Failure to bond the
frame of this equipment to the building electrical ground by use of the grounding terminal provided or other acceptable means may
result in electric shock. Disconnect electric
power before servicing equipment.
9.
10.
11.
General
Only qualified personnel should perform the start-up and
service of this equipment. A representative of the owner or
the operator should be present during start-up to receive
instruction in the operation, care and adjustment of the unit.
For proper warranty coverage, put the unit through a check,
test and start-up procedure. The completed check test and
start form (supplied with each unit) must be signed and
returned to McQuay International.
Note:
Always open power disconnect switch before opening service panels.
Pre Start-up
1.
2.
3.
4.
5.
6.
7.
Check that the unit is completely and properly installed
with ductwork connected. Check that all construction
debris is removed and filters are clean.
With all electrical disconnects open, check all electrical
connections to be sure they are tight. Although all factory connections are tight before shipment, some loosening may have resulted from shipping vibration.
Check all compressor valve connections for tightness to
avoid refrigerant loss at start-up. Although all factory
connections are tight before shipment, some loosening
may have resulted from shipping vibration. Refer to
Table 13 for proper valve torque values.
Check tightness of setscrews in bearings, drives, and fan
wheels. If retightening is needed, make certain fan
wheels are centered between the inlet openings and setscrews are torqued per Table 14 .
Check that the fan rotates freely. Check belt tension and
alignment.
Check that the unit condenser water connections and
condensate drain connections have been made.
Before attempting to operate the unit, review the control
layout description to become familiar with the control
locations. Review all equipment service literature and
the unit wiring diagrams supplied with each unit.
Review optional controls to determine which are
included in the unit.
IM708-1
12.
13.
14.
15.
Check that the return air temperature sensor and
optional space temperature sensor, if used, have been
installed in the return air duct and that the wiring terminations have been made at the unit Input Board.
Check that entering and leaving condenser water temperature sensors are mounted.
Check that the optional duct static pressure sensor is
connected to the duct with appropriate tubing. The unit
may have one optional static pressure sensor, SPS1. The
other option would be that or SPS1 and SPS2.
Check the voltage of the unit power supply and see that
it is within the ±10% tolerance that is allowed. Phase
voltage unbalance must be within ±2%.
Check the unit power supply wiring for adequate
ampacity and a minimum insulation rating of 75°C.
Verify that all mechanical and electrical inspections
have been completed per local codes.
Open the compressor suction and discharge shutoff
valves until backseated. Always replace valve seal caps.
The following must be done only for units with 20 hp
compressors. Making sure unit switch S7 is in the
"OFF" position, throw the main power disconnect to
"ON." This will energize the crankcase heaters. Wait a
minimum of 24 hours before starting up the unit.
Table 13. Valve Torques
COUPLING
NUT SIZE
INCH
GAGE PORT
CAP TORQUE
LBS-FT
STEM CAP
TORQUE
LBS-FT
COUPLING
NUT TORQUE
LBS-FT
1.00
7±1
32±2
55+5
1.25
7±1
32±2
90+10
1.75
7±1
45±3
205+15
Table 14. Setscrew Torque
SETSCREW DIAMETER
TORQUE MIN. (FT.-LBS.)
#10
4.3
1/4”
10.0
5/16”
20.0
3/8”
25.0
Start-up
General
All units are factory tested to for proper field operation.
1. Close disconnect switch with switch S7 in the "OFF"
position. Allow crankcase heaters to operate for 24
hours.
2. Power should now be supplied to the MicroTech II controller and the LEDs on MCB1 should follow the normal startup sequence.
31
3.
Set internal MicroTech II time clock or external time
clock if used.
4. Set cooling setpoint to a value which will provide a full
call for cooling.
5. Start the auxiliary equipment for the installation such as
water pumps, cooling towers, etc.
Fan start-up
1.
Place the unit into the "FAN ONLY" mode through the
keypad:
System summary:
Control Mode:
Off
Auto
Heat/Cool
Heat only
Cool only
Fan only
2.
Turn switch S7 to "ON". The supply air fan should start
and run.
Observe fan rotation. If fan is rotating backward,
reverse two legs of the main unit supply power. Unit
compressors are factory “phased” to match the supply
fan. Do not reverse internal fan motor power leads as
this will result in the compressor being out of phase. If
fan does not run:
Check the control circuit fuse F1.
Check control transformer fuse FB7.
Verify that the fan overload is not tripped.
Check the fan motor power fuses.
Trace the circuits.
3.
a.
b.
c.
d.
e.
Compressor start-up
With the supply air fan operational, prepare for compressor
operation. Note: The unit is shipped with the refrigeration
service valves closed. Backseat (open) the suction, discharge
and liquid line valves and replace service caps.
Connect service gauges and crack valves off the backseat
position (one turn forward). Verify that the unit has not lost
its refrigerant charge due to shipping damage or leaks. The
20 hp compressor have crankcase heaters that need to be verified they are operating. These should operate at least 24
hours before starting compressors.
1. Set Cooling Control Setpoint, menu 13, to a value which
will provide a call for full cooling.
2. Place unit into the “COOL ONLY” mode through keypad/display.
3. If desired, the MicroTech internal control timers can be
reduced to 20 seconds. The amount of time it operates in
this “Fast” mode can be entered through the keypad:
Setup/Service
Timer setting
Service
Note:
32
"Fast" timers should only be used to verify
sequencing of compressors during start-up. The
timer must be returned to "Normal" for proper unit
operation.
Do not allow compressors to come on repeatedly in the
"Fast" timer mode as this may damage compressors and/or
will indicate "Motor Protector Failure" under compressor
alarms.
The compressors should now start. Start compressors one at
a time, beginning with compressor number 1. Facing the
unit, from left to right, compressors are numbered #1, #3, #4
and #2.
If the compressor motor hums but does not run, verify that
the unit is getting three phase power.
The compressors should run continuously. If a compressor
cycles on the low pressure switch:
a. Verify that the circuit is not low on charge.
b. Check for low airflow.
c. Check for clogged filters.
d. Check for restricted ductwork.
e. Check for very low mixed air temperatures to the unit.
f. Verify that all the distributor tubes, expansion valve and
liquid line components are feeding the evaporator coil.
g. Verify that all fan section access panels are in place.
h. Verify that the suction service valves and the liquid line
service valves are completely open.
i. Verify that all sensor inputs are connected.
Economizer start-up
The economizer is modulated to maintain the cooling setpoint. With entering water temperature more than 3°F below
the mixed air return to the unit, place the water sensor in a
cold bath if supply water to the unit is too warm, and the unit
calling for cooling, observe that the economizer control
valve modulates open. Readjust control setting or remove
the sensor from the bath and observe that the economizer
control valve drives closed.
Hot water start-up
The hot water valve is modulated to maintain the discharge
heating setpoint. To verify the hot water valve operation,
adjust the heating setpoint through the keypad:
Temperatures
Zone heating
OCC HTG SPT
Set the heating setpoint to a temperature greater than the
control temperature plus the dead band. Note the cooling setpoint must be higher than the heating setpoint. With the heating setpoint set properly the hot water valve should modulate
open. To close the hot water valve adjust the heating setpoint
below the control temperature minus the dead band. After
testing the hot water valve, return the heating setpoint to its
proper setting.
Expansion valve superheat adjustment
It is very important that superheat is set properly. It should
be between 10°F and 12°F under full load conditions. Lower
entering air conditions, lower airflow rates and higher condensing temperatures reduce the load on the expansion
valve. Under reduced load conditions, the superheat could be
IM708-1
as low as 6°F to 8°F. Insufficient superheat will cause liquid
floodback to the compressor and possible liquid slugging.
Excessive superheat will reduce system performance and
shorten compressor life. Verify that the sensing bulb is properly located and securely strapped to the refrigerant line. See
Figure 30. Turn the adjusting stem clockwise to increase
superheat. Adjust the stem (maximum one turn at a time) and
observe the superheat. Allow up to 30 minutes for the system
to rebalance at the final setting.
Refrigerant Charge
Units are shipped with a full operating charge of refrigerant
and oil. However, in the event of a leak in the system, some
added charge may be required. If an undercharged situation
occurs, any of the following may be experienced:
1. If a circuit is slightly undercharged, bubbles will show
in the sightglass.
2. If a circuit is moderately undercharged, it may trip on its
frost protection sensor.
3. If the circuit is severely undercharged, it may trip on its
low pressure safety.
If any of these conditions occur, first identify and correct the
source of the leak and then follow the charging procedure
described below.
Using the liquid line sight-glass as the sole means of metering additional refrigerant charge into a self-contained unit, or
any AC unit, will not always provide the desired result.
Depending on the load conditions experienced by the equipment during the charging process, adding refrigerant until
the sight-glass is clear of all bubbles may over charge the
system and cause future operating issues. The better way to
charge a circuit is to use liquid sub-cooling and suction line
superheat as indicators, using the following procedure:
1. Verify that superheat is set per the System Check, Test
& Start procedures in this manual.
2. Measure the discharge pressure reading and convert it to
a discharge temperature.
3. Measure and record the circuit's liquid line temperature.
4. Measure and record the entering condenser water temperature using the MicroTech II display.
5. Calculate liquid subcooling: subcooling = discharge
temperature - liquid line temperature
6. If the calculated subcooling value is less than 8ºF, refrigerant needs to be added.
7. Monitoring discharge pressure and liquid line temperature, add refrigerant until the discharge temperature
minus the liquid line temperature is equal to 8ºF ± 2ºF.
If the system is running at light load conditions, subcooling should be at the low end of the range. If the sys-
IM708-1
8.
tem is running near design conditions, subcooling
should be near the upper end of the range.
Verify that superheat is still in the prescribed range.
Following this method should prevent over charging of
the circuit.
Figure 30. Water and Refrigerant Piping Schematic
RELIEF
VALVE
ISOLATION FILTER
VALVE
DRIER
SIGHT
GLASS
ISOLATION
VALVE
RECEIVER
EQUALIZER
CONDENSER
CAPILLARY
SUCTION
DISCHARGE
VALVE
VALVE
COMPRESSOR NO. 1
RELIEF
VALVE
EVAPORATOR
EXPANSION
VALVE
A- A
ISOLATION FILTER
VALVE
DRIER
SIGHT
GLASS
ISOLATION
VALVE
RECEIVER
EQUALIZER
CONDENSER
CAPILLARY
SUCTION
DISCHARGE
VALVE
VALVE
COMPRESSOR NO. .2
RELIEF
VALVE
EVAPORATOR
EXPANSION
VALVE
A- A
ISOLATION FILTER
VALVE
DRIER
SIGHT
GLASS
ISOLATION
VALVE
RECEIVER
EQUALIZER
CONDENSER
CAPILLARY
SUCTION
DISCHARGE
VALVE
VALVE
COMPRESSOR NO. 3
RELIEF
VALVE
EVAPORATOR
EXPANSION
VALVE
A- A
ISOLATION FILTER
VALVE
DRIER
SIGHT
GLASS
ISOLATION
VALVE
RECEIVER
EQUALIZER
CONDENSER
CAPILLARY
SUCTION
DISCHARGE
VALVE
VALVE
COMPRESSOR NO. 4
LOW
WATER FLOW SWITCH
EVAPORATOR
EXPANSION
VALVE
A- A
BYPASS
VALVE
WATER SENSORS
HIGH
E.S.
WATER
COIL
CONDENSER
WATER
OUT
CONDENSER
WATER
IN
MODERATING
VALVE
SUCTION
LINE
CAPILLARY
EXPANSION
VALVE
BULB
12'
30°
SECTION A - A
33
Variable air volume (VAV) start-up
Enter the duct static pressure setpoint value and parameters
through the keypad:
Air/Water Flow
Duct static pressure
Ducts tsp SPT
When the appropriate number of VAV terminal boxes are
opened by setting down their respective thermostats, the vanes
should go to the maximum airflow. Upon closing enough VAV
boxes by setting their respective thermostats up, the inlet
vanes should go to the minimum airflow position.
RPM changes
All units are provided with fixed pitch sheaves selected for
the specified operating conditions. If a new fan rpm selection
is required a new sheave selection will need to be field
installed. Adjust belt tension as described below.
Drive sheave alignment and belt tension
Drive sheave alignment should be checked using the fourpoint method shown in Figure 30. When measuring from the
straight edge to the belt, the dimensions A, B, C and D must
be equal for correct alignment.
Check drive for adequate run-in belt tension. Use the following procedure to determine proper belt tension:
Step 1. Measure span length (t) as shown in Figure 31.
34
Step 2. From Figure 31, the deflection height (h) is always
1/64" per inch of span length (t). For example, a 32"
span length would require a deflection of 32/64" or
1/2".
Step 3. Determine the minimum and maximum recommended pounds force using Table 14. Find the minimum recommended deflection force for the belt
section and type based upon the small sheave diameter. For intermediate sheave diameters and/or drive
ratio combinations, the minimum force may be interpolated.
Step 4. Using a spring scale, apply a perpendicular force to
any one of the belts at the midpoint of the span as
shown in Figure 31. Compare this value with the
values found in Step 3.
a. If the value is below the minimum, the belts are
too loose and should be tightened.
b.If the value is higher, the belts are too tight and
tension should be decreased.
When new belts are installed, the initial tension will drop.
Check tightness of all setscrews on the fan hub, bearing
sleeves and retighten belts after 48 hours of operation.
Note:
If after all tension adjustments, the belts slip or
squeal when starting, increase tension slightly and
replace the belts if they are worn or glazed.
IM708-1
Final control settings
Figure 32. Belt Tension
When all of the start-up procedures have been completed, set
the individual control parameters for operation.
1. Unit switch S7 to AUTO.
2. Heating/Cooling control parameters set as required.
3. Alarm limits set as required.
4. Night setback parameters set as required.
5. Duct static pressure, building static pressure, as
required.
6. Economizer control parameters set as required.
7. Control timers set as required.
8. Date and time set as required.
9. Operating schedule set as required.
10. Holiday schedule set as required.
Note:
See Operation manual per Table 1 on page 3, for the
keypad menu structure.
Maintaining control parameter records
Table 15. Recommended Pounds Force Per Belt
BELT
SECTION
A
After the unit has been checked, tested and started and the
final control parameters are set, the final settings should be
recorded and kept on file. This file should be updated whenever changes are made to the control parameters. This will
facilitate any required analysis and troubleshooting of the
system operation.
Figure 31. Drive Alignment
B
BX
FIELD SUPPPLIED STRAIGHTEDGE
A
B
C
D
5VX
IM708-1
SMALL SHEAVE
DIA. (IN)
MINIMUM
3.0 - 3.6
3.00
4.25
3.8 - 4.8
3.5
5.00
5.0 - 7.0
4.00
5.50
3.4 - 4.2
4.00
5.50
4.4 - 5.6
5.13
7.13
5.8 - 8.6
6.38
8.75
3.4 - 5.6
6.50
9.13
4.4 - 5.6
6.50
9.13
5.8 - 8.6
7.38
10.13
4.7 - 6.7
10.00
15.00
7.1 - 10.8
12.88
18.75
11.8 - 16.0
15.00
22.00
MAXIMUM
35
System Maintenance
7.
WARNING
Installation and maintenance are to be performed only by qualified personnel who are
familiar with local codes and regulations, and
are experienced with this type of equipment.
WARNING
Moving machinery and electrical power hazards. May cause severe personal injury or
death.
Disconnect and lock off power before servicing
equipment.
.
WARNING
Sharp edges are inherent to sheet metal
parts, screws, clips and similar items. May
cause personal injury.
8.
9.
10.
11.
12.
13.
14.
15.
Check refrigerant sightglass. Check for refrigerant leaks
if sightglass is not solid with steady-state full load operation of unit. (Note: A partially full sightglass is not
uncommon at part load conditions. Check for proper
superheat.)
Check for blockage of condensate drain. Clean condensate pan as needed.
Check power and control voltages.
Check running amperage.
Check operating temperatures and pressures.
Check and adjust temperature and pressure controls.
Check and adjust linkages.
Check operation of all safety controls.
Lubricate door latch mechanisms.
Motor Bearings
Fan motors should have grease added after every 2,000
hours of operation. Re-lubricate while motor is warm and at
a standstill. Remove and clean upper and lower grease plugs,
insert grease fitting into upper hole adding a small amount of
clean grease with a low pressure gun. Run motor for five
minutes before replacing plugs.
Note:
Specific greasing instructions are to be found on a
tag attached to the motor. If special lubrication
instructions are shown on the motor nameplate,
they will supersede all other instructions.
Exercise caution when servicing equipment.
CAUTION
Preventative Maintenance
Preventative maintenance is the best way to avoid unnecessary expense and inconvenience. Have this system inspected
at regular intervals by a qualified service technician. The
required frequency of inspections will depend on installation
and operating duty. Routine maintenance should cover the
following items:
1. Tighten all belts, setscrews, and wire connections. (See
Table 14 on page 31.)
2. Clean evaporator or economizer coils mechanically or
with cold water, if necessary. Usually any fouling is
only matted on the entering air face of the coil and can
be removed by brushing.
3. Clean condenser and economizer tubes on a periodic
basis. Condenser and economizer coils can be cleaned
chemically or mechanically. Tubing should be kept clean
to maintain system performance.
4. Lubricate motor and fan shaft bearings.
5. Align or replace belts as needed.
6. Replace filters as needed.
36
Bearing overheating potential. Can cause damage to the equipment.
Do not over-lubricate. Use only a high grade mineral
grease with a 200°F safe operating temperature.
Refer to unit lubrication instruction label for specific
lubricants
Table 16. Lubricants recommended for fan shaft ball
MANUFACTURER
Texaco Lubricants Company
PRODUCT NAME
Premium RB
TEMP. RANGE
°F
°C
-30 to 300 -34 to 149
Keystone Ind. Lubricants
81EP-2
0 to 250
Mobil Oil Corporation
Mobilith SCH100
-40 to 350 -40 to 177
-18 to 121
Chevron U.S.A. Inc.
SRI-2
-20 to 325 -29 to 163
Exxon Company, U.S.A.
Ronex MP
-40 to 300 -40 to 149
Shell Oil Company
Alvania No. 2
-20 to 240 -29 to 116
bearings
Note:Temperature ranges over 225°F are shown for lubricants only. High temperature applications are not suitable for standard air handler components.
IM708-1
Replacement Parts
Description
McQuay Part
Number
Zone temperature sensor with tenant override
111048101
Outside air temperature sensor (OAT)
060004703
Airflow proving switch (PC7)
060015801
Discharge air temperature sensor (DAT)
170047822
Return air temperature sensor (RAT)
1700474-02
Freeze stat (FS1)
072502001
Filters
Part Number
Unit Size
Filter Size
Qty
018-028
20 x 20
20 x 25
035-040
2"-35%
4"-35%
4"-65%
4"-85%
6
2
072407703
072407704
072402303
072402304
072405703
072405704
072407603
072407604
20 x 25
10
072407704
072402304
072405704
072405704
045-055
20 x 25
12
072407704
072402304
072405704
072405704
065
20 x 20
18
072407703
072402303
072405703
072407603
070
16 x 20
20 x 25
6
12
072407701
072407704
072402301
072402304
072405701
072405704
072407601
072407604
080
20 x 20
20 x 25
3
15
072407703
072407704
072402303
072402304
072405703
072405704
072407603
072407604
095
16 x 20
20 x 25
6
15
072407701
072407704
072402301
072402304
072405701
072405704
072407601
072407604
16 x 20
16 x 25
20 x 25
4
1
17
072407701
072407702
072407704
072402301
072402302
072402304
072405701
072405702
072405704
072407601
072407602
072407604
105
IM708-1
37
Service and Warranty Procedure
Warranty
Consult your local McQuay Representative for warranty
details. Refer to Form 933-43285Y. To find your local
McQuay Representative, go to www.mcquay.com.
Warranty Return Material Procedure
Defective material may not be returned without permission
of authorized factory service personnel of McQuay International in Minneapolis, Minnesota, (763) 553-5330. A
"Return Goods" tag must be included with the returned
material. Enter the required information to expedite handling
and prompt issuance of credits. All parts must be returned to
the appropriate McQuay facility, designated on the "Return
Goods" tag. Transportation charges must be prepaid.
The return of the part does not constitute an order for
replacement. Therefore, a purchase order must be entered
through the nearest McQuay representative. The order
38
should include part number, model number, and serial number of the unit involved.
Credit will be issued on customer's purchase order following
an inspection of the return part and upon determination that
the failure is due to faulty material or workmanship during
the warranty period.
Replacement Parts
When writing to McQuay for service or replacement parts,
refer to the model number and serial number of the unit as
stamped on the serial plate attached to the unit. If replacement parts are required, mention the date of installation of
the unit and date of failure, along with an explanation of the
malfunctions and a description of the replacement parts
required.
IM708-1
Check, Test and Start Procedure Form
Compressorized Equipment Warranty Registration Form:
This form must be filled out and returned to McQuay, Warranty
Department, within 10 days in order to comply with the terms of
McQuay Warranty.
Check, Test and Start Procedure for SWP/SWT (Self-contained Air Conditioning Systems)
Job Name:
McQuay G.O. No.:
Installation Address:
City:
State:
Purchasing Contractor:
City:
State:
Unit Model No.:
Serial No.:
Compressor No. 2 Serial No.
Compressor No. 1 Serial No.
Compressor No. 3 Serial No.
Compressor No. 4 Serial No.
Compressor No. 5 Serial No.
Compressor No. 6 Serial No.
Mark N/A on all items not applying to the type of the unit. See IM Bulletin for more information. Any additional comments
may be made on a separate sheet of paper and attached to this form.
INITIAL CHECK
A.
B.
C.
D.
E.
F.
G.
H.
I
J.
K.
L.
M.
N.
O.
P.
Q.
R.
S.
T.
Is any shipping damage visible?
Is unit installed level?
Is unit positioned to provide adequate free area for service and operation?
Are fan drives properly aligned and belts adjusted?
Does fan turn freely?
Tightened all setscrews on pulleys, bearings and fans?
Have the Condenser Water Temperature Sensors been located correctly?
Has the Installing Contractor installed the Return Air Temperature Sensor
in the Return Air stream?
Has the Installing Contractor installed the high & low Static Pressure Sensor
tubing in the ductwork?
Does electrical service correspond to unit nameplate?
Adequate disconnect and circuit protectors installed?
Is the unit adequately grounded?
Are all electrical power connections tight?
Have the compressor heaters operated continuously for 24 hours prior to start up?
Does all electrical wiring conform to unit electrical diagram?
Does all field wiring conform to electrical diagrams?
Are all service valves open?
Have all the shipping hold-down plates securing the fan frame been removed?
Unit with ducted return, has the low side tubing for PC5 (dirty filter switch) been
Installed?
Are all the cleanout plugs installed (condenser, condensate trap & optional
waterside economizer)?
IM708-1
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
No
Yes
No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
No
No
No
No
Yes
No
Yes
No
39
START-UP
A.
B.
C.
D.
E.
F.
G.
H.
I.
Does the unit start & perform per sequence of operation as stated in IM Bulletin?
Does the fan rotate in the right direction?
Condenser inlet water temperature
Deg. F _____
Condenser outlet water temperature
Deg. F. _____
Number of Compressors Operating
Deg. F. _____
Return air temperature
Deg. F. _____
Mixed air temperature
Deg. F. _____
Supply air temperature
Deg. F. _____
Compressor Readings:
Compressor
#1
Reading
Compressor
#2
Compressor
#3
Compressor
#4
Yes
Yes
No
No
Compressor
#5
Compressor
#6
Suction Pressure, psig
Discharge Pressure, psig
Superheat Setting @ TXV
Bulb, Deg. F
Compressor RLA (name
plate)
Current, Line L1, amps
Current, Line L2, amps
Current, Line L3, amps
J.
Electrical Heat Readings (When installed):
FLA
amps (nameplate)
68KW Heat, 230v or 208v Only
Reading
@ Contactor M11
@ Contactor M12
@ Contactor M15
@ Contactor M16
Current, Line Ll, amps
Current, Line L2, amps
Current, Line L3, amps
40
IM708-1
K.
Fan Motor Current Per Phase:
FLA:
amps
Variable Frequency Drive:
L.
Fan Speed:
M.
N.
Unit Voltage across each phase:
Unit Current per phase:
amps
amps
amps
% Speed /
Hertz
rpm at above frequency
volts
amps
volts
amps
volts
amps
CONTROL CHECK
A.
Compressor Low and High Pressure Cut-outs:
Comp. No. 1
Comp. No. 2
Low Press Cut-out, psig
Low Press Cut-in, psig
High Press Cut-out, psig
Comp. No. 5
Comp. No. 3
Comp. No. 4
Comp. No. 6
Low Press Cut-out, psig
Low Press Cut-in, psig
High Press Cut-out, psig
GENERAL
A.
B.
C.
D.
Are all control lines secure to prevent excessive vibration and wear?
Are all gauge ports shut off, valve caps and packings tight after start-up?
Are VAV boxes set to keep a minimum airflow of 40% of design?
Do the Economizer, Water Regulating, and Hot Water valves rotate freely?
Performed By:
Signature:
Yes
Yes
Yes
Yes
No
No
No
No
Title:
Date of Start-up:
RETURN COMPLETED FORM TO:
McQuay International
Warranty Department
13600 Industrial Park Boulevard
Minneapolis, MN 55441
Comments:
IM708-1
41
This document contains the most current product information as of this printing. For the most up-to-date
product information, please go to www.mcquay.com.
© 2002 McQuay International • www.mcquay.com • 800-432-1342
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