SWP Vintage Sizes 018 through 105
MicroTech III
®
Unit Controller
Installation and Maintenance IM 937
Self-Contained Air Conditioning System
Group: Applied Systems
Part Number: IM 937
Date: October 2008
MEA
368-93-E
Contents
Introduction .............................................................. 3
General Description ............................................ 3
Inspection ........................................................... 3
Installation ................................................................ 4
Handling ............................................................. 4
Vibration Isolators ............................................... 4
Setting Factory-Supplied Plenum ....................... 4
Location/Service Access..................................... 4
Removing Shipping Restraints ........................... 5
Refrigerant Piping—Pressure Relief Valves ....... 5
Water Connections ............................................. 5
Duct Connections ............................................... 8
Physical Data ........................................................... 9
Dimensional Data ............................................. 10
Unit Weights ..................................................... 12
Electrical Data......................................................... 14
Field Wiring....................................................... 14
Control Center .................................................. 16
Electrical Legend .............................................. 18
Typical Wiring Schematics................................ 20
Control Panel Components ................................... 29
Control Panel Components............................... 29
High Pressure Switches.................................... 31
Low Pressure Switches .................................... 31
Compressor Motor Protector ............................ 31
Unit Options............................................................ 32
Proof of Airflow Switch...................................... 32
Frost Protection Switches ................................. 32
Clogged Filter Switch........................................ 32
Winterizing Water Coils .................................... 32
Duct High Limit ................................................. 32
Phase Fail/Under Voltage Protection................ 33
Duct Static Pressure Sensor ............................ 33
Adjustable Frequency Drive ............................. 34
Hot Gas Bypass ............................................... 34
Freezestat ........................................................ 34
Condenser Water Flow Switch......................... 35
Water Side Economizer ................................... 35
Condenser Water Head Pressure Control ....... 35
Disconnect Switch............................................ 35
Dual Power Supply........................................... 35
Electric Heat..................................................... 35
Hot Water Control ............................................ 35
Battery Pack..................................................... 35
MicroTech III Keypad Navigation.......................... 36
Using the Keypad/Display .................................... 36
Passwords........................................................ 36
Navigation Mode .............................................. 37
Edit Mode ......................................................... 37
System Check, Test, and Start ............................. 40
General ............................................................ 40
Pre Start-Up ..................................................... 40
Start-Up............................................................ 41
System Maintenance ............................................. 45
Planned Maintenance ...................................... 45
Bearing Lubrication .......................................... 45
Replacement Parts................................................. 48
Service and Warranty Procedure ......................... 49
Replacement Parts........................................... 49
Compressors.................................................... 49
All Compressors............................................... 49
Warranty Return Material Procedure ............... 50
Check, Test, and Start Procedure Form .............. 51
McQuay IM 937 3
Introduction
Introduction
General Description
McQuay Self-Contained Air Conditioning units, models SWP
018 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 III
®
self-contained unit controller is standard
equipment. For a detailed description of the MicroTech
components, input/output configurations, field wiring options
and requirements, and service procedures, refer to IM 919,
“MicroTech III Unit Controls.” For a description of operation
and information on using and programming the MicroTech III
unit controller, refer to OM 920 “MicroTech III Unit
Controls.”
Inspection
When the equipment is received, carefully check all items
against the bill of lading to ensure a complete shipment. Do
not sign the shipping receipt until all items are accounted for.
Carefully inspect all units for damage upon arrival. Report all
shipping damage to the carrier and file a claim. Before
unloading the unit, check the unit serial plate to be sure it
agrees with the power supply available.
Figure 1: Nomenclature
Vintage
D = Individual condenser circuit, 18–95 tons
E = Individual condenser circuit, 105 tons
F = Dual circuit
Nominal tons
Self-contained
Water cooled
Plenum discharge
SWP - 055 - F
4 McQuay IM 937
Installation
Installation
Handling
Units ship with a protective covering that should remain in
place while the unit is being moved to its final location.
Units are provided with lifting lugs for rigging with a crane. If
units are lifted by crane, use slings or cable to protect against
chaffing damage and use spreader bars across the top of the
cabinet to prevent any structural damage to the frame.
The unit base frame accepts dollies or Johnson bars for
transporting. Place dollies at both ends of the chassis or at one
end and use a Johnson bar at the other end for maneuvering.
Protect floor surfaces when equipment is moved across
finished flooring. Use plywood sheeting to protect surfaces
and distribute weight loading.
Vibration Isolators
All units are provided with 1" neoprene isolation pads, shipped
separately. Install pads beneath the unit, locating at each corner
and the center of each base channel. For units provided with
more than six isolator pads, evenly space the additional pads
under the front and rear base channels.
Setting Factory-Supplied Plenum
If the unit is provided with a factory plenum for field
mounting, use a forklift, slings, or other suitable lifting means.
Foam rubber gasketing is provided around the perimeter of the
unit top. Carefully set the plenum. Attach with mounting
hardware provided with the plenum.
Location/Service Access
To facilitate installation and provide service, and maintenance
access, follow the recommended clearances in Table 1.
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.
Figure 2: Recommended Service and Maintenance Clearance
IMPORTANT
Only qualified personnel familiar with local codes and
regulations and experienced with this type of equipment
should perform installation and maintenance.
Check for
concealed damage as soon as possible.
CAUTION
Sharp edges and coil surfaces can cause personal injury.
Wear protective gear and avoid contact.
WARNING
Never allow any part of the unit to fall during unloading or
moving as this can cause equipment damage, severe
personal injury, or death.
CAUTION
Do not attempt to install dollies in the center of the unit.
Units can become unstable and tip over, causing injury
CAUTION
Do not move units in an upended position.
Internal components may tear away, causing injury.
Table 1: Recommended Clearances
Location Clearance length
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"
Airflow
24"
42"
Evaporator Coil
Compressors
36"
24"
or
36"
1
AFD
Electrical Panel
Left
Side
Right
Side
Front
Back
Condenser
Cleanout
3 5 6 4 2
Motor
Airflow
24"
42"
Evaporator coil
Compressors
36"
24"
or
36"
1
AFD
Electrical panel
Left
side
Right
side
Front
Back
Condenser
cleanout
3 5 2 4 6
Motor
Independent
circuits
Dual circuits
McQuay IM 937 5
Installation
Removing Shipping Restraints
Mechanical restraints are used to secure the spring-mounted
fan during shipment. Remove the restraints and the shipping
blocks after the unit is set in its final location.
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 accommodates a 1/2" flare connection for applications
where it is necessary to connect vent piping and run it outside
the building.
Water Connections
General
Due to the variety of piping practices, follow the
recommendations of local authorities. They can supply the
installer with the proper building and safety codes required for
proper installation.
For best performance, install the piping with a minimum
number of bends and elevation changes. Size piping to
minimize system pressure drop.
Piping should contain the following:
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,
which can damage the pump and shorten unit life, from the
water before it enters the pump. Such damage is not
covered by warranty. Place the strainer far enough
upstream to prevent cavitation at the pump inlet (consult
pump manufacturer for recommendations). Using a strainer
prolongs pump life and helps maintain system
performance.
Condenser Piping
1 Units can 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 Make field piping connections to factory-provided piping,
locating them as indicated on the unit submittal drawings.
Run the piping connections 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 Make supply and return water connections at the proper
locations as indicated by the dimensional drawings. The
supply (water in) connection is always the lower
connection.
5 Units with factory-mounted water side economizer should
not require head pressure control. The economizer typically
elevates the water temperature by 5°F to 10°F before
entering the condenser. Economizer cooling takes over
when the water is too cold for compressor operation.
Mechanical cooling is locked out below 55°F EWT.
6 If entering condenser water temperatures will go below
55°F, provide head pressure control. Fan cycling and/or
modulating discharge dampers on the cooling tower are
often used, or a 3-way bypass around the tower is used to
maintain condenser water temperature. If multiple units are
in the loop, it is generally more cost effective to use cooling
tower control to maintain the temperature at >55°F.
If a field-installed water regulating valve is placed in
service with the unit condenser, install it in the water line
leaving the condenser; it should shut down to prevent water
from siphoning out of the condensers. For systems where a
constant pumping head is required, install the water
regulating valve in a bypass line around the condensers. It
then must 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 thermostatic expansion
valve operation. A minimum head pressure of 180 psi
(95°F condensing temperature) is recommended.
7 Condenser tube velocities must not exceed 10 feet per
second. Flow and velocity will be satisfactory if water
volumes do not exceed those shown in Table 2 on page 9.
WARNING
Connection plates can be used as rigging plates for the fan
section only. Do not use them for rigging the entire unit.
Unit can tip or fall and cause equipment damage, severe
personal injury, or death.
CAUTION
When refrigerant is vented to the outside of the building, install
the vent piping as recommended in ASHRAE Standard
15-1994. Failure to vent properly can result in personal injury.
6 McQuay IM 937
Installation
Figure 3: Condenser Regulating Valve (Refrigerant
Pressure Controlled)
Figure 4: Condenser Water Pressure Drop, SWP 018 to 040,
Independent Circuit
Figure 5: Condenser Water Pressure Drop, SWP 045 to 105,
Independent Circuit
Figure 6: Condenser Water Pressure Drop, SWP 018 to 095,
Dual Circuit
Figure 7: Economizer Water Pressure Drop, SWP 018 to
105
Condenser
Cooling
tower
P
40
20
10
8
6
4
3
20
40
60 80
100
200 300
Condenser Flow Rate (gpm)
Pressure Drop (ft H
2
O)
12 HP
18 HP
24 HP
28 HP
32 HP
3
6 HP
40 HP
HP = total unit compressor horsepower
60
40
20
10
8
6
4
2
80 100
200 300
400 500
Condenser Flow Rate (gpm)
Pressure Drop (ft H
2
O)
40HP
46HP
56HP
60HP
70HP
80HP
78HP
84HP
90HP
105HP
120HP
52HP
HP = total unit compressor horsepower
Condenser Flow Rate (gpm)
Pressure Drop (ft H
2
O)
60
10
40
20
6
8
4
2
10 100 500
12 HP
16 HP
24–32 HP
36–32h HP
46HP
52HP
56HP
60 HP
HP = total unit compressor horsepower
10 100 500
1
10
50
018–028
035–040
045–095
105
P16
Condenser Flow Rate (gpm)
Pressure Drop (ft H O)
2
Note: 1. Includes coil, control valves and interconnecting piping.
2. Add this P to condenser P to obtain unit P for pump selection
McQuay IM 937 7
Installation
Figure 8: Water Regulating Valve Pressure Drop, Head
Pressure Control
Figure 9: Hot Water Coil Pressure Drop, SWP 018 to 040
Figure 10: Hot Water Coil Pressure Drop, SWP 045 to 105
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. Pitch the condensate line away from
the unit with a minimum slope of 1/8" per foot.
Keep drain pans and the drain trap clean by periodic cleaning.
A cleanout is provided as standard in the trap to aid in
cleaning.
40
10
1
0.1
10
100
500
Condenser Flow Rate (gpm)
Pressure Drop (ft H
2
O)
018-040
045-095
Water Flow Rate (gpm)
Pressure Drop (ft H
2
O)
100
10
100
200
10
1
018
023-028
035
040
Water Flow Rate (gpm)
Pressure Drop (ft H
2
O)
100
10
100
200
10
1
045
105
065-095
055
8 McQuay IM 937
Installation
Duct Connections
Supply Air
To connect supply ductwork directly to the unit, first mount a
duct collar at the fan outlet, avoiding the mounting screws
located around the perimeter of the fan discharge opening. See
Figure 11. Fan discharge opening sizes are indicated on the
unit dimensional drawings. McQuay recommends a canvas
type connecting collar.
Install ductwork as shown in Figure 12. Duct take-offs that are
installed opposite to the direction of fan rotation result in an
associated system effect loss and reduced fan performance.
If a field-fabricated plenum is used, again, correctly orient duct
take-off locations to the rotation of the fan to minimize system
losses. Refer to unit dimensional drawings and Figure 11 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 are indicated on the job submittal drawing.
Figure 11: Unit Top Detail
If a field-fabricated plenum is used, again correctly orient duct
take-off locations to the rotation of the fan to minimize system
losses. Refer to unit dimensional drawings and Figure 11. for
plenum mounting size requirements. Use canvas type
connectors 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 are indicated on the job submittal drawing.
Figure 12: Discharge Duct Configurations
Return Air
Return air to the unit can be ducted or free, as follows.
Ducted return
Attach return ductwork to the 2" flange around the perimeter
of the unit’s return air opening. Refer to Figure 13. Use a
canvas-type duct connecting collar. All ductwork connected to
the unit must be of adequate size and construction for the
application. Also use a canvas-type connector where the duct
penetrates the machine room wall(s). This helps prevent
vibration generated by air movement in the duct from being
transmitted out to the occupied spaces.
Note: Do not obstruct the unit access panel located below the
return opening.
Free return
Use the mechanical equipment room as a return plenum with
no hard connection at the unit.
Note: Some building codes do not allow using the mechanical
room as a return plenum. Check applicable local codes
for each installation.
Figure 13: Back Elevation
Filters are removable from the rear of the unit or through a side filter access
door located on the piping connection side. Length increases by
approximately 3 1/2" for piping connections with water economizer option.
Mechanical access panel(s) in the back of the unit start 2" below the return
duct opening. Do not obstruct the access panel(s). All dimensions are ±0.25".
Fan
discharge
opening
Centerline of
sheet metal
screws
Unit length
Unit
depth
1.7" (typ)
1.7" (typ)
Filter Section
Economizer
Evaporator
Heater
Electrical panel
Filter Section
Economizer
Evaporator
Heater
Electrical Panel
M
2.0”
2.0” Typical
29”
D
B
K x L
Return Air Opening
Mechanical
Access
(See Notes)
(Optional)
Multi-Directional
Plenum
1” Neoprene
Isolation Pads,
Shipped Separately
McQuay IM 937 9
Physical Data
Physical Data
*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.
*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.
Table 2: SWP 018 Through SWP 105
Data
SWP model size
018 023 028 035 040 045 055 065 070 080 095 105
Compressor
Quantity 2, 3, or 4 2, 3, or 4 4 4 4 4 4 4 4 4 4, 6 6
Size See unit data plate
Evaporator coil
Face area (ft
2
) 11.8 15.3 17.7 23.3 27.7 30.7 36.1 41.5 46.3 51.1 55.9 63.2
Waterside economizer coil
Face area (ft
2
) 11.8 15.3 17.7 23.3 27.7 30.7 36.1 41.5 46.3 51.1 55.9 63.2
Max. wkg. press. (psig) 400 400 400 400 400 400 400 400 400 400 400 200
Hot water heating coil
Face area (ft
2
) 9.3 12.8 15.2 20.2 24.5 26.8 30.4 35.8 39.9 44.4 48.3 51.9
Rows 1, 2 1, 2 1, 2 1, 2 1, 2 1, 2 1, 2 1, 2 1, 2 1 1 1
Fpi 12 12 12 1212121212 12 12 12 12
Electric heat
kW 34 34 34 34 34 68 68 68 68 68 68 68
Filters
(Quantity) Size 4" depth (6) 20×20
(2) 25×20
(6) 20×20
(2) 25×20
(6) 20×20
(2) 25×20
(10)
25×20
(10)
25×20
(12)
25×20
(12)
25×20
(18)
20×20
(6) 16×20
(12) 25×20
(3) 20×20
(15) 25×20
(6) 16×20
(15) 25×20
(4) 16×20
(17) 20×25
(1) 16×25
Evaporator fan
a
a. Standard fan TSP limit is 5.5 inches of water. Consult your local McQuay sales representative for applications beyond this range.
Quantity 1 1 1 1 1 1 1 1 1 1 1 1
Size 15 18 18 20 20 22 25 25 25 27 27 33
Minimum horsepower 5 7.5 10 10 15 15 20 20 20 25 30 40
Maximum horsepower 10 15 20 20 25 30 40 40 40 50 60 60
Minimum design cfm, CV 2950 3825 4425 5825 6925 7675 9025 10375 11575 12775 13975 15800
Min. design cfm, VAV 4720 6120 7080 9320 11080 12280 14440 16600 18520 20440 22360 25280
Maximum design cfm 7080 9180 10620 13980 16620 18420 21660 24900 27780 30660 33540 37920
Condenser
Waterside wkg. press. (psig) 400 400 400 400 400 400 400 400 400 400 400 400
Min. entering temp. (°F) 55° 55° 55° 55° 55° 55° 55° 55 55° 55° 55° 55°
Minimum GPM 25 41 53 66 69 94 105 105 121 134 138 180
Maximum GPM 88 108 125 159 166 215 237 237 251 349 358 493
Table 3: Single Compressor Circuit Charge, R-407C
Compressor (hp)
Refrigerant charge per
circuit (R-407C)*
Oil charge per
circuit (oz)
69 lbs60
10 13 lbs 110
13 17 lbs 140
15 21 lbs 140
20 25 lbs 224
Table 4: Tandem Compressor Circuit Charge, R-22
Compressor (hp)
Refrigerant charge per
circuit (R-22)*
Oil charge per
circuit (oz)
69 lbs66
10 14 lbs 112
13 18 lbs 154
15 22 lbs 154
20 27 lbs 256
(2) 6 17 lbs 120
(2) 7 19 lbs 120
(2) 8 22 lbs 280
(2) 9 26 lbs 280
(2) 10 26 lbs 280
(2) 13 30 to 33 lbs 280
(2) 15 36 to 40 lbs 280
Table 4: Tandem Compressor Circuit Charge, R-22
Compressor (hp)
Refrigerant charge per
circuit (R-22)*
Oil charge per
circuit (oz)
10 McQuay IM 937
Physical Data
Dimensional Data
Table 5 contains dimensions that vary from unit to unit,
marked with letters (A, B, C, etc.) in the figures. Depth, length,
and height dimensions do not include lifting lugs, the handle,
latch, or fastener extensions. For shipping dimensions, the skid
adds 4" (102 mm) to depth, 8" (204 mm) to the length, and 4"
(102 mm) to the height.
For units with the optional plenum, the plenum can ship
separately. All openings are on the plenum are centerline. For
additional information, refer to the submittal drawing. (See
Figures 14 and 15.)
Service connections are determined when facing the front of
the unit. Left-hand connections are standard; right-hand
connections are optional. Please indicate on the unit submittal.
Unit sizes 018, 023, and 028 have a single mechanical access
panel in the bottom front and bottom back. (See Figures 16,
17, 18, and 19.)
Figure 14: Front Left Side (CW) Discharge with Optional
Multi-Directional Plenum
Figure 15: Back Left Side (CCW) Discharge with Optional
Multi-Directional Plenum
Note: *For F vintage units, subtract 1.88.
Table 5: Dimensions
Basic unit 018 023 028 035 040 045 055 065 070 080 095 105
A Depth 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 Length 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 Height 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 discharge 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 discharge 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 conn (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 16.516.516.516.816.816.816.816.817.76
R 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
"
K x L return air
Filter s ection
Economizer
Evaporator
Heater
Electrical panel
G
J
Multi-directional
plenum, optional
(Plenun can ship separately.
All openings are on the
plenum centerline.
For additional information,
see submittal drawings.)
3.25"
Outlet
0"
K x L return air
Filter s ection
Economizer
Evaporator
Heater
Electrical panel
3.25”
Outlet
9.63"
(18-95)
10.31
(105)
Multi-directional
plenum, optional
(Plenun can ship separately.
All openings are on the
plenum centerline.
For additional information,
see submittal drawings.)
McQuay IM 937 11
Physical Data
Figure 16: Unit Front Plan
Figure 17: Front Elevation
Figure 18: Back Elevation
Figure 19: Left Side
Figure 20: Discharge Plenum (optional)
Left side
piping
connections
(See Notes)
(Optional)
Right side
piping
connections
(See notes below.)
Supply
fan motor
Return air
Power
entry
3 1/8"
Disconnect
switch (optional)
MicroTech II panel
AFD (optional)
Electrical
access
Mechanical
access
D
B
76"
Power entry
7/8" pilot K.O.
Notes: Unit sizes 018, 023, and 028 have a single mechanical access panel.
M (see Dimensions table)
2. 0 "
2.0" Typical
H H
F
29"
D
B
K × L
Return air opening
Mechanical
access
(optional)
Multi-directional
plenum*
1" Neoprene isolation pads,
shipped separately
Notes: Unit sizes 018, 023, and 028 have a single mechanical access panel.
*
*
Select unit arrangement on the unit
selection. Plenum can ship separately.
All openings are on plenum center line.
For additonal information, refer to
submittal drawing.
Lifting lug
1" typ.
A/2
38.5"
(N) Water in
(N) Water out
1 1/8" ODS drain
K × L return air
(optional)
Multi-directional
plenum*
A
44.5"
(P) Hot water in
(P) Hot water out
Notes: Service connections determined when facing the front of the unit.
Left-hand standard, right-hand optional. Please indicate on the unit submittal.
*
Select unit arrangement on the unit
selection. Plenum can ship separately.
All openings are on plenum center line.
For additonal information, refer to
submittal drawing.
Plan view
Left/right elevation
Front/back elevation
Length
Dept h
H
A
B
H
3"
2" Min
3"
2" Min
Height
Height
Unit size Length (in) Depth (in) Height (in)
018 to 028 84 72 23, 29, 35, 41
035 to 040 100 72 23, 29, 35, 41
045 to 065 120 81 29, 35, 41
070 132 81 29, 35, 41
080 144 84 29, 35, 41
095 to 105 156 84 29, 35, 41
12 McQuay IM 937
Physical Data
Unit Weights
Table 6: Unit and Component Weight (lbs)
Unit weights
Unit size
018 023 028 035 040 045 055 065 070 080 095 105
Basic configuration
SWP basic unit
a
2226 2313 2318 2638 2643 3110 3279 3406 3734 4021 4246 4766
Filters
4" 30% or 65% efficiency 38 38 38 55 55 66 66 79 87 96 104 112
Evaporator coil
Heaviest coil 250 294 321 417 468 506 577 642 693 755 819 926
Water economizer coil
b
c
4 row, 12 fpi 306 338 357 458 493 520 598 648 678 723 820 927
Water weight 51 66 75 94 111 119 150 168 187 203 218 281
Hot water coil
d
c
1 row, 12 fpi 71 97 114 130 158 160 170 200 328 337 345 371
Water weight 16 20 23 28 32 37 41 49 55 59 62 62
Electric heat
34 kW 2020202020—————— —
68 kW — — — — — 40 40 40 40 40 40 40
Supply fan motors
3 hp ODP 71—————————— —
5 hp ODP 82—————————— —
7.5 hp ODP 124124————————— —
10 hp ODP 144144144144——————— —
15 hp ODP —185185185185185————— —
20 hp ODP — — 214 214 214 214 214 214 214 — — —
25 hp ODP — — — — 266 266 266 266 266 266 — —
30 hp ODP — — — — — 310 310 310 310 310 310 310
40 hp ODP ——————404404404404404404
50 hp ODP —————————452452452
60 hp ODP ——————————620620
a. Base weight includes supply fan without motor.
b. Water economizer weight includes valves and piping.
c. The values in this table do not include water weight.
d. Hot water coil weight includes valve and piping.
McQuay IM 937 13
Physical Data
Supply fan motors, continued
3 hp TEFC 72—————————— —
5 hp TEFC 85—————————— —
7.5 hp TEFC 140140————————— —
10 hp TEFC 170170170170——————— —
15 hp TEFC —235235235235235————— —
20 hp TEFC — — 300 300 300 300 300 300 300 — — —
25 hp TEFC — — — — 330 330 330 330 330 330 — —
30 hp TEFC — — — — — 390 390 390 390 390 390 390
40 hp TEFC ——————510510510510510510
50 hp TEFC —————————570570570
60 hp TEFC ——————————850850
Compressor/condenser assembly
Water weight
(4) 6 hp 43 777 777 777 777 777 777 777 777 777 777 777 777
(4) 7 hp 57 786 786 786 786 786 786 786 786 786 786 786 786
(4) 8 hp 66 1215 1215 1215 1215 1215 1215 1215 1215 1215 1215 1215 1215
(4) 9 hp 74 1272 1272 1272 1272 1272 1272 1272 1272 1272 1272 1272 1272
(3) 6 hp, (1) 10 hp 57 843 843 843 843 843 843 843 843 843 843 843 843
(2) 6 hp, (2) 10 hp 66 974 974 974 974 974 974 974 974 974 974 974 974
(1) 6 hp, (3) 10 hp 74 1115 1115 1115 1115 1115 1115 1115 1115 1115 1115 1115 1115
(4) 10 hp 95 1287 1287 1287 1287 1287 1287 1287 1287 1287 1287 1287 1287
(2) 10 hp, (2) 13 hp 106 1376 1376 1376 1376 1376 1376 1376 1376 1376 1376 1376 1376
(4) 13 hp 118 1464 1464 1464 1464 1464 1464 1464 1464 1464 1464 1464 1464
(2) 13 hp, (2) 15 hp 129 1575 1575 1575 1575 1575 1575 1575 1575 1575 1575 1575 1575
(4) 15 hp 141 1684 1684 1684 1684 1684 1684 1684 1684 1684 1684 1684 1684
(2) 15 hp, (2) 20 hp 152 1982 1982 1982 1982 1982 1982 1982 1982 1982 1982 1982 1982
(4) 20 hp 190 1970 1970 1970 1970 1970 1970 1970 1970 1970 1970 1970 1970
(6) 13 hp 167 2010 2010 2010 2010 2010 2010 2010 2010 2010 2010 2010 2010
(3) 13 hp, (3) 15 hp 178 2135 2135 2135 2135 2135 2135 2135 2135 2135 2135 2135 2135
(6) 15 hp 188 2260 2260 2260 2260 2260 2260 2260 2260 2260 2260 2260 2260
(3) 15 hp, (3) 20 hp 209 2419 2419 2419 2419 2419 2419 2419 2419 2419 2419 2419 2419
(6) 20 hp 229 2579 2579 2579 2579 2579 2579 2579 2579 2579 2579 2579 2579
Discharge plenum
23" high 551551551616616—————— —
29" high 636 636 636 711 711 862 862 862 922 1003 1064 1064
35" high 719 719 719 804 804 975 975 975 1042 1134 1203 1203
41" high 805 805 805 899 899 1090 1090 1090 1166 1269 1346 1346
a. Base weight includes supply fan without motor.
b. Water economizer weight includes valves and piping.
c. The values in this table do not include water weight.
d. Hot water coil weight includes valve and piping.
Table 6: Unit and Component Weight (lbs) (continued)
Unit weights
Unit size
018 023 028 035 040 045 055 065 070 080 095 105
14 McQuay IM 937
Electrical Data
Electrical Data
Field Wiring
General
Wiring must comply with all applicable codes and ordinances.
McQuay’s product warranty does not cover equipment failures
caused or contributed to by wiring not in accordance with
specifications. An open fuse or tripped MMP indicates a short,
ground or overload. Before replacing a fuse or restarting a
compressor or fan motor, locate the trouble and correct. Use
copper wire for all power lead terminations.
A single power terminal block is provided as standard, and
wiring within the unit is done in accordance with UL 508.
Each branch circuit within the control panel is individually
protected. 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. 24 V field connections are suitable
for Class II wiring.
Unit Disconnect
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.” Select and locate the
disconnect switch within the NEC guidelines. Location
requirements per NEC are that the disconnect is located in a
readily accessible position within sight (50 feet) of the unit. A
factory-mounted, nonfused disconnect is available.
Return Air and Outside Air Sensors
All units are provided with a return air sensor. It is connected
to the input control board and is coiled and placed behind the
access panel, to the right of the control panel of the unit for
shipment. Field install it in the return air stream for proper unit
operation. The return air sensor is connected to the unit’s input
board at location AI-2.
The outside air sensor is optional and can be ordered with the
unit. It ships loose in a package and is located on the floor of
the fan section. The outside air sensor is field wired to terminal
strip TB2. It is connected at terminals 122 and 123.
The mixed air temperature sensor is already installed at the
inlet of the unit.
Mount the sensors in areas that are exposed to representative
temperature conditions. Mount them at a position that has
good air mixing and does not have stratification. Sensors can
be mounted in the ductwork using a grommet (see Figure 21).
Figure 21: Return/Outside Air Sensor Mounting
Grommet
Sensor
Ductwork
Air flow
Table 7: Compressor Motors
Compressor hp Refrigerant
208/60/3 230/60/3 460/60/3 575/60/3
RLA LRA RLA LRA RLA LRA RLA LRA
6 R-22 14.9 156 14.9 156 7.4 75 6.0 54
R-407 14.7 156 14.7 156 7.3 75 5.8 54
7 R-22 17.6 164 17.6 164 9.6 100 7.7 78
R-407————————
8 R-22 22.1 189 22.1 189 11.0 99 8.8 74
R-407————————
9 R-22 24.8 232 24.8 232 12.4 125 9.9 100
R-407————————
10 R-22 28.4 278 28.4 278 14.2 127 11.4 100
R-407 27.5 278 27.5 278 13.8 127 11.0 100
13 R-22 32.1 350 32.1 350 16.0 158 13.1 125
R-407 32.5 350 32.5 350 16.2 158 13.0 125
15 R-22 40.1 425 40.1 425 20.0 187 16.0 148
R-407 39.6 425 39.6 425 19.8 187 15.8 148
20 R-22 65.4 360 65.4 360 32.7 180 26.2 144
R-407 65.4 425 65.4 425 32.7 187 — —
McQuay IM 937 15
Electrical Data
Table 8: Electric Heaters
SWP unit size
208 V, 60 Hz, 3 phase 230 V, 60 Hz, 3 phase 400 V, 50 Hz, 3 phase 460 V, 60 Hz, 3 ph 575 V, 60 Hz, 3 phase
kW MBh FLA kW MBh FLA kW MBh FLA kW MBh FLA kW MBh FLA
018 to 040 27.8 94 77.2 34 116 85.6 25.7 88 37.2 34 116 42.8 34 116 34.2
045 to 105 55.6 190 154.4 68 232 170.9 51.4 175 74.4 68 232 85.6 68 232 68.4
Table 9: SAF Motor Nameplate Amperage
Horsepower Type
208/60/3 230/60/3 400/50/3
a
460/60/3 575/60/3
FLA FLA FLA FLA FLA
3 High efficiency 9.9 9.0 4.5 4.5 3.4
Premium efficiency 9.3 8.2 4.1 4.1 3.1
5 High efficiency 16.1 14.0 7.0 7.0 5.3
Premium efficiency 15.7 13.6 6.8 6.8 5.2
7.5 High efficiency 25.0 21.6 10.8 10.8 8.2
Premium efficiency 22.3 20.0 10.0 10.0 7.4
10 High efficiency 33.0 28.0 14.0 14.0 11.0
Premium efficiency 29.0 25.8 12.9 12.9 10.3
15 High efficiency 44.8 40.6 20.3 20.3 16.2
Premium efficiency 43.4 37.8 18.9 18.9 14.1
20 High efficiency 61.0 50.0 25.0 25.0 20.0
Premium efficiency 57.0 49.0 24.5 24.5 18.9
25 High efficiency 74.0 62.0 31.0 31.0 24.3
Premium efficiency 70.0 61.0 30.5 30.5 24.2
30 High efficiency 86.5 75.0 37.5 37.5 30.0
Premium efficiency 83.3 72.4 36.2 36.2 29.8
40 High efficiency 117.0 102.0 51.0 51.0 40.0
Premium efficiency 110.0 96.0 48.0 48.0 38.0
50 High efficiency 140.0 124.0 62.0 62.0 49.2
Premium efficiency 137.0 120.0 60.0 60.0 47.5
60 High efficiency 154.0 144.0 72.0 72.0 57.4
Premium efficiency 160.0 140.0 70.0 70.0 56.0
a. 460/60/3 motors are used. Derate nameplate horsepower to 0.83 to obtain actual horsepower.
16 McQuay IM 937
Electrical Data
Supply Power Wiring
1 Units require three-phase power supply.
2 Allowable voltage tolerances:
a 60 Hertz
Nameplate 208 V: Min. 187 V, Max. 229 V
Nameplate 230 V: Min. 207 V, Max. 253 V
Nameplate 460 V: Min. 414 V, Max. 506 V
Nameplate 575 V: Min. 518 V, Max. 632 V
b 50 Hertz
Nameplate 400 V: Min. 342 V, Max. 418 V
3 Power lead wire sizing:
a 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
b For units with cooling capability and nonconcurrent
electric heat capability:
In the cooling mode, the loads are composed of supply
fan motor and compressors. In heating mode, the
loads are 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.
– For unit in cooling mode:
MCA = 1.25 (largest RLA or FLA) + other loads + 2
amps
– For unit in heating mode, below 50 kW
MCA = 1.25 (electric heat FLA + fan FLA) + 2 amps
– For unit in heating mode, above 50 kW
MCA = 1.25 (SAF amps) + (electric heat) + 2 amps
4 Size wires in accordance with Table 310-16 of the National
Electrical Code.
5 Size wires for a maximum of 3% voltage drop.
Lug Sizes
Note: Use copper wire only.
Control Center
All electrical controls are enclosed in a central control center
located at the front of the unit. High voltage components
include:
• Fan motor contactor, M30/M10
• Fan motor protector, MMP9, MMP10, MMP30
• Fan motor circuit breaker, CB10
• Compressor contactors, M1–M6
• Compressor protector, MMP1–MMP6
• Electric heat contactors, M11–M16
• Transformer, T1, T2, T3
• Disconnect switch, DS1–DS2
• 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 include:
• MicroTech III
®
main control board, MCB
• MicroTech III
®
expansion modules
• Duct static pressure sensor, SPS1
• Optional 2nd duct static pressure sensor, SPS2
• Optional BACnet
®
/IP communication module
• Optional BACnet MS/TP communication module
• Optional L
ONWORKS
®
communication module
Located on the face of the unit is the interactive MicroTech III
keypad/display, unit switch, system indicator light and power
indicator.
Note: IM 919 has additional layouts of the control center.
Table 10: Lug Sizes for Single Disconnect
DIsconnect size (amps) Lug size
100 #14-1/0
150 #8-3/0
250 3/0-350 MCM
400 (2) #4-250 MCM
600 (3) 3/0-500 MCM
Table 11: Lug Sizes for Power Block
Power block size (amps) Lug size
420 #2-600 MCM
760 (2) #4-500 MCM
McQuay IM 937 17
Electrical Data
Figure 22: Typical 460 Volt, 6-Compressor Control Center Layout, High and Low Voltage Compartments
18 McQuay IM 937
Electrical Data
Figure 23: A-A Section Detail, Typical 460 Volt, 6
Compressor Control Center Layout
Electrical Legend
ID Description
Standard
location
ACT3 Actuator motor, economizer Comp/cond section
AFD10 Adjustable frequency drive,
supply fan
Front assembly
CB10 Circuit breaker, supply fan Main control box
CCB1, 2 Compressor control boards,
refrig. circuits
Main control box
DAT Discharge air temperature
sensor
Discharge section
DHL Duct hi-limit Main control box
DS1 Disconnect, total unit or cond/
heat
Main control box
DS2 Disconnect, SAF/RAF/controls Main control box
F1A, B Fuse, control circuit transformer
(T1), primary
Main control box
F1C Fuse, control circuit transformer
(T1), secondary
Main control box
FB11, 12 Fuseblock, electric heat (top
bank)
Main control box
FB13, 14 Fuseblock, electric heat (bot.
bank)
Main control box
HL11A, HL11B Hi-limits, pwr, elec heaters (top
bank)
Heat section,
electric
HL12A, HL12B Hi-limits, pwr, elec heaters (bot.
bank)
Heat section,
electric
HP1–6 Hi-pressure controls, refrig On compressors
LP1–6 Low-pressure controls,
refrigeration
On compressors
M1–6, M21–26 Contactor, compressor Main control box
M9 M10 Contactor, supply fan Main control box
M30 Contactor, reversing, VFD
bypass, supply fan
IVFD bypass box
MCB Microprocessor circuit board Main control box
MJ Mechanical jumper All control boxes
MMP1–6,
MMP21–26
Manual motor protector,
compressors
Main control box
MMP9–10 Manual motor protector, supply
fan
Main control box
MP1–6 Motor protector, compr.#1–6 On compressors
OAT Outside air temperature sensor Shipped loose
PB1, 2 Power block, power distribution Main control box
PB10 Power block, supply fan Main control box
McQuay IM 937 19
Electrical Data
PC5 Pressure control, clogged filter Main control box
PC7 Pressure control, proof airflow Main control box
PB10 Power block, supply fan Main control box
PVM1, 2 Phase voltage monitor Main control box
R1–6 Relay, compressor high
pressure
Main control box
R62, 63, 65 Relay, use on specials Main control box
R70–79 Relay, use on specials Main control box
RAT Return air temperature sensor Main control box
S1 Switch, system on/off Main control box
S4 Switch, VFD bypass, on/ off Main control box
S7 Switch, local on/auto/off to
controller
Keypad
SPS1, 2 Static pressure sensors, duct/
building
Main control box
PSR1, 2 Pressure transducer, head
pressure control
Condenser section
T1 Transformer, main control (line/
115 V (ac))
Main control box
T2 Transformer, control input (115/
24 V (ac))
Main control box
T3 Transformer, control output
(115/24 V (ac))
Main control box
T4 Transformer, UV lights Main control box
TB1 Terminal block, internal Main control box
TB2 Terminal block, field, Class 2 Main control box
TB3 Terminal blocks, factory Main control box
TB4 Terminal block, field, 115 V (ac) Main control box
ID Description
Standard
location
UV Ultra-violet light(s) Coil/discharge
section
VM1 Valve motor #1, heating Heat section
ZNT1 Zone temp. sensor, setback Field installed
ID Description
Standard
location
200/ H200
1. Field wiring
3. Shielded wire/cable
4. Main control box
terminals
5. Auxilliary box
terminals
6. Field terminals
7. Plug connector
8. Wire/harness number
General Notes
2. Factory wiring
9. Wire nut/ID
WN7
20 McQuay IM 937
Electrical Data
Typical Wiring Schematics
Figure 24: Main Power
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