Compressor
078 = 6.5 ton, single
090 = 7.5 ton, single
120 = 10 ton, single
125 = 10 ton, tandem
150 = 12.5 ton, tandem
180 = 15 ton, tandem
240 = 20 ton, tandem
Introduction
DANGER
The use of unauthorized components, accessories or devices
may adversely affect the operation of the condensing unit and
may also endanger life and property.
The manufacturer disclaims any responsibility for such loss or
injury and the manufacturer’s warranty does not cover any
damage or defect to the air conditioner caused by the
attachment or use of any components, accessories or devices
(other than those authorized by the manufacturer) into, onto or
in conjunction with the condensing unit.
This manual contains the installation and operating
instructions for your split condensing unit. There are a few
precautions that should be taken to derive maximum
satisfaction from it. Improper installation can result in
unsatisfactory operation or dangerous conditions.
Read this manual and any instructions packaged with separate
equipment required to make up the system prior to installation.
Give this manual to the owner and explain its provisions. The
owner should retain this manual for future reference.
Nomenclature
Hazard Identification Information
DANGER
Dangers indicate a hazardous situation which will result in
death or serious injury if not avoided.
WARNING
Warnings indicate potentially hazardous situations, which can
result in property damage, severe personal injury, or death if
not avoided.
CAUTION
Cautions indicate potentially hazardous situations, which can
result in personal injury or equipment damage if not avoided.
Note: For larger size units (greater than 20 ton), refer to Catalog 222.
Checking Product Received
Upon receiving the unit, inspect it for any damage from
shipment. Claims for damage, either shipping or concealed,
should be filed immediately with the shipping company. Check
the unit model number, electrical characteristics, and
accessories to determine if they are correct.
McQuay IM 9623
Introduction
Standard Unit Features
CABINET — Galvanized steel with a durable powder paint
finish. Stamped louvered panels offer 100% protection for the
condenser coil.
COMPRESSOR — Hermetically sealed scroll compressors.
Compressors are mounted on rubber-in-shear pads to reduce
vibration and noise.
CONDENSER COIL — Constructed with copper tubes and
aluminum fins mechanically bonded to the tubes for maximum
heat transfer capabilities. All coil assemblies are leak tested at
450 psig internal pressure.
REFRIGERANT CONNECTIONS — Field piping
connections are made through a fixed panel. This allows
complete access or removal of access panels after piping
connections have been made.
CRANKCASE HEATER — Standard, all models.
LOW AMBIENT CONTROL — A pressure sensitive fan
cycling control to allow unit operation to 0°F is standard.
SERVICE VALVES — Standard on liquid lines and vapor
lines.
SERVICE ACCESS — The control box, as well as the
compressor and other refrigerant controls, is accessible
through access panels. It may be opened without affecting the
normal operation of the unit.
Condenser fan motors are accessible by removing wire grilles.
FILTER DRIER — Field supplied.
SIGHT GLASS — Optional, field supplied.
TRANSFORMER — Step down type, line to 24 volts.
CONTACTOR — The contactor is an electrical switch which
operates the compressor and condenser fans.
HIGH PRESSURE CONTROL — Opens the contactor
circuit on high refrigerant pressure; manual reset.
LOW PRESSURE CONTROL — Stops compressor
operation in the event of loss of refrigerant.
CONDENSER FAN MOTOR (Direct Drive) — Ball bearing
1075 RPM motors are mounted to minimize vibration and
noise problems.These are permanent split capacitor types and
require the same capacitance for both run and start.
TESTING — All units are run tested at the factory prior to
shipment. Units are shipped with a holding pressure of
nitrogen.
Volt and phase208/230-1460-1575-1
Full load amps (each)2.21.31.0
System characteristics
Unit full load amps
Minimum circuit ampacity91.042.031.0
Maximum fuse size (amps) or HACR circuit
breaker ampacity
Disconnect size2006060
Note: 1 Each Compressor
2
Conditions at 45° suction and 95° ambient
3
Local codes take precedent over recommended fuse size
1
1
2
3
33.317.912.8
23912580
81.637.827.1
1255040
RCS
20F
RCS
Figure 7: Control Box Example – RCS 10F Through 20F
McQuay IM 9629
Introduction
Installation
Crankcase Heaters
These units are equipped with a crankcase heater that is factory
wired to operate whenever the main power supply to the unit is
“on” and compressors are “off.” Before starting the equipment
after prolonged shutdown or at the time of initial spring startup, be sure that the circuits to the condensing units are closed
for at least 24 hours.
Order Parts
When reporting shortages or damaged parts, or when ordering
repair parts, give the complete unit model and serial numbers
which are stamped on the unit rating plate.
Standard Items
The condensing unit consists of a completely assembled
package which includes a compressor pack, condenser coils,
fans, fan motors, outdoor control box, factory wiring, factory
tubing and fittings.
Corrosive Environment
• A good liquid cleaner may be used several times a year to
remove matter that will not wash off with water.
Several different types of protective coatings are offered in
some areas. These coatings may provide some benefit, but the
effectiveness of such coating materials cannot be verified by
the equipment manufacturer.
Installation General
The condensing unit should be installed outdoors. It should be
located as near as possible to the evaporator section to keep
connecting refrigerant tubing lengths to a minimum. The unit
must be installed to allow a free air flow to the condenser coils.
Figure 8: Clearances RCS 06F – 20F Service Clearances
The metal parts of this unit may be subject to rust or
deterioration if exposed to a corrosive environment. This
oxidation could shorten the equipment's useful life. Corrosive
elements include salt spray, fog or mist in seacoast areas,
sulphur or chlorine from lawn watering systems, and various
chemical contaminants from industries such as paper mills and
petroleum refineries.
If the unit is to be installed in an area where contaminants are
likely to be a problem, special attention should be given to the
equipment location and exposure.
• Avoid having lawn sprinkler heads spray directly on the unit
cabinet.
• In coastal areas, locate the unit on the side of the building
away from the waterfront.
• Shielding provided by a fence or shrubs may give some
protection, based on clearances recommended in this book.
Regular maintenance will reduce the buildup of contaminants
and help to protect the unit's finish.
DANGER
Disconnect all power to unit before starting maintenance.
Failure to do so can cause electrical shock resulting in severe
personal injury or death.
• Frequent washing of the cabinet, fan blade and coil with
fresh water will remove most of the salt or other
contaminants that build up on the unit.
• Regular cleaning and waxing of the cabinet with a good
automobile polish will provide some protection.
If several units are installed adjacent to each other, take care to
avoid recirculation of air from one condenser to another. In all
installations, adequate space must be provided for installation
and servicing.
The unit must not be connected to any duct work. Do not
locate unit under a roof drip; if necessary, install gutters, etc.,
to prevent water runoff onto the unit. To prevent air
recirculation, it is recommended that the unit not be installed
under an overhang. However, if this is necessary, allow a
minimum of 60 inches above the unit for air discharge.
Rooftop Installation
If rooftop installation is required, make certain that the
building construction is adequate for the weight of the unit.
(Refer to physical data chart.) Before placing the unit on the
roof, make certain that the nylon rigging slings are of
sufficient length to maintain equilibrium of the unit when
lifting. Under no circumstances should the unit be lifted by
only one corner for rooftop installation.
Slab Installation
Condensing units should be set on a solid level foundation.
When installed at ground level, the unit should be placed on a
6 inch cement slab. If the pad is formed at the installation site,
do not pour the pad tight against the structure, otherwise
vibration will be transmitted from the unit through the pad.
Do not use oxygen to purge lines or pressure system for leak
test. Oxygen reacts violently with oil, which can cause an
explosion resulting in severe personal injury or death.
Note: The condensing unit is shipped with a holding charge of
dry nitrogen which must be purged from the unit before
evacuation.
Once located, the condensing unit is ready to be
interconnected with the evaporator using ONLY refrigeration
grade dehydrated tubing.The following should be considered
when connecting the tubing.
1 Pitch vapor line toward the compressor approximately
1/2 in. every 10 feet to facilitate oil return.
2 It is recommended that the sight glass, filter drier and
liquid line solenoid valve be installed in the liquid line
just prior to the evaporator.
3 Silver solder (such as silfos, Easy Flow, etc.) should be
used for all refrigerant joints.
4 Thoroughly clean all joints before fluxing. DO NOT
USE ACID FLUX.
5 When fluxing, limit the application of paste to the
minimum and always apply flux to the male portion of
the connection.
6 Vapor lines should be insulated to prevent condensate
drip. Use insulation of at least 3/8 inch wall thickness.
The insulation should be installed on the tubing prior to
making the sweat connections.
7 Insulate the liquid line whenever the heat pickup or
transfer can affect the subcooling.
8 Care should be taken to avoid transmission of noise or
vibration to building structure.
Typical Piping Recommendations
The following will be of help in accomplishing a successful
installation.
1 Size liquid line for no more than 10°F loss which
corresponds to approximately 3 psig pressure drop.
2 Size vapor lines for no more than 2°F loss which
corresponds to approximately 3 psig pressure drop.
3 Install sight glass, filter drier and solenoid valve in liquid
line adjacent to evaporator. Filter drier should be
between the condensing unit and sight glass.
4 Pitch all horizontal vapor lines downward in the
direction of flow (1/2" to 10 ft. run).
5 When making up refrigerant piping, take every
precaution to prevent dirt and moisture from entering the
piping.
6 Locate the condensing unit and evaporator(s) as close
together as possible to minimize piping runs.
7 Liquid or vapor lifts not to exceed 60 ft.
8 To prevent suction line breakage due to vibration and to
prevent tubing noise transmission into the conditioned
space, the suction clamp must be installed after tubing is
brazed as illustrated in Figure 10.
Figure 10: Suction Clamp
Table 7: Refrigerant Piping Data
EQUIVALENT LENGTH (FT.) [m] OF STRAIGHT TYPE “L”
TUBING FOR NONFERROUS VALVES/FITTINGS (BRAZED)
Tub e
Solenoid
Size,
O.D.
1/270 [21.3]
5/8 72 [21.9]
3/4 75 [22.9]
7/8 78 [23.8]
1 1/8
1 3/8
1 5/8
2 1/8
Valve
Angle
Valve
8.3
[2.5]
10.4
[3.2]
12.5
[3.8]
14.6
[4.4]
18.8
[5.7]
22.9
[7.0]
27.1
[8.3]
35.4
[10.8]
Short
Radius
Ell
1.6 [0.5] 1.0 [0.3] 1.0 [0.3] 3.1 [0.9]
1.9 [0.6] 1.2 [0.4] 1.2 [0.4] 3.6 [1.1]
2.1 [0.7] 1.4 [0.4] 1.4 [0.4] 4.2 [1.3]
2.4 [0.7] 1.6 [0.5] 1.6 [0.5] 4.8 [1.5]
3.0 [0.9] 2.0 [0.6] 2.0 [0.6] 6.0 [1.8]
3.6 [1.1] 2.4 [0.7] 2.4 [0.7] 7.2 [2.2]
4.2 [1.3] 2.8 [0.8] 2.8 [0.8] 8.4 [2.6]
5.3 [1.6] 3.5 [1.1]
Long
Radius
Ell
Tee
Line
Flow
10.7
[3.3]
Tee
Branch
Flow
10.7 [3.3]
Table 8: Recommended Vapor and Liquid Line Sizes for
Various Lengths of Run
RECOMMENDED VAPO R AND LIQUID LINE SIZES FOR
VARIOUS LENGTHS OF RUN
EQUIVALENT
LENGTH TO
EVAPORATOR
(FEET)
0” to 15” 5/8 5/8 1 3/8 1 3/8
16” to 50” 5/8 5/8 1 3/8 1 3/8
51” to 100” 5/8 5/8 1 3/8 1 3/8
101” to 150” 5/8 5/8 1 5/8 1 5/8
LIQUID LINE
O.D. SIZES
(INCHES)
120 125 120 125
VAP OR LINE O.D.
SIZES (INCHES)
Note: Line length between condenser and evaporator (suction
and liquid) not to exceed 150' equivalent length.
12McQuay IM 962
Introduction
Figure 11: Liquid Line Pressure Drop Per 100 Feet
Equivalent Length (Type L Copper Tubing)
Note:
1
When evaporator coil is above condenser, the pressure
drop due to vertical lift (.5 PSIG per foot of lift) must be
added to the pressure drop derived from this curve.
2 Size liquid line for no more than 10°F loss
(approximately 30 PSIG total pressure drop).
3 Do not oversize liquid line. Oversized liquid lines add
significantly to the amount of refrigerant required to
charge the system.
4 The maximum recommended velocity with solenoid
valves or other quick closing devices in the liquid line is
300 FPM.
1
The minimum velocity line (700 fpm) is recommended
for cooling only units with vertical or horizontal run
refrigerant lines.
2 For suction pressure drop (PSIG), multiply percent (%)
loss by 1.18.
Figure 13: Typical Drain Piping
Figure 14: Coil Above Condensing Unit
Figure 12: Suction Line System Capacity Loss In Percent
Per 100 Feet Equivalent Length (Type L Copper Tubing)
Figure 15: Coil Below Condensing Unit
Note:
McQuay IM 96213
Introduction
Electrical Wiring
Note: Field wiring must comply with the National Electric Code
(CEC in Canada) and any local ordinance that may
apply.
Electrical Power
It is important that proper electrical power is available at the
unit. Voltage must not vary more than 10% from that stamped
on the rating plate. (See Electrical Data Table on Page 6 for
minimum and maximum voltage.) Interphase voltage variation
on three-phase units must not be more than 3%. Contact local
power company for correction of improper voltage or phase
unbalance.
IMPORTANT: Models equipped with scroll compressors
must be phased correctly for proper compressor rotation. If the
compressor is noisy or if suction and discharge pressures do
not appear normal, reverse any two power leads to the unit.
Extended run time in reverse rotation will damage the
compressor and lead to premature failure.
Power Wiring
Power wiring should be run in grounded rain-tight conduit.
See Electrical Data Table for wire ampacity and proper wire
size.
WARNING
After completing wiring, check all electrical connections,
including factory wiring within the unit. Make sure all
connections are tight. Replace and secure all electrical box
covers and access doors before leaving the unit or turning on
power to the unit. Failure to do so can cause a fire or electrical
shock resulting in property damage, personal injury or death.
Table 9: Field Wire Size for 24 Volt Thermostat
SOLID COPPER WIRE –AWG
10
10
10
12
14
16
3.0
10
10
12
12
14
16
2.5
10
12
12
14
16
18
2.0
Thermostat
Load Amps
50100150200250300
Length of Run -Feet (1)
(1) Wire length equals twice the run distance.
WARNING
This unit must be permanently grounded. A ground lug is
provided near the contactor for a ground wire. Failure to do so
can cause a fire or electrical shock resulting in property
damage, severe personal injury or death.
Grounding
A grounding lug is provided in control box for a ground wire.
Wire Routing
POWER WIRING MUST BE RUN IN CONDUIT. Conduit
must be run through the connector panel below the service
cover and attached to the bottom of the control box.
If low (extra-low in Canada) voltage control wire is run in
conduit with power supply, Class I insulation is required. If run
separate, Class II is required. Low voltage wiring may be run
through the insulated bushing provided in the 7/8" hole in the
connector panel, then route to the control box.
Grounding also may be accomplished by grounding the power
line conduit to the unit.
Thermostat
An appropriate thermostat should be mounted on an inside
wall in a location where it will not be affected by the sun or
drafts, from open doors or other sources. Install, level, and
after installation check the thermostat calibration and
recalibrate if necessary. Refer to thermostat manufacturer's
information for additional installation, checkout and operation
instructions.
14McQuay IM 962
Figure 16: Typical Field Wiring Connections
Introduction
Table 10: Copper Wire Size (1% Voltage Drop)
COPPER WIRE GAUGE* COPPER WIRE
GAUGE (75°C INSULATION)
DISTANCE IN FEET
100 150200250300
Circuit Ampacity
40
45
50
60
70
80
90
100
110
125
4
6
3
4
3
4
2
4
2
3
1
3
1/0
2
1/0
2
2/0
1
2/0
1
3
2
2
1
1/0
1/0
2/0
2/0
3/0
3/0
2
1
1
1/0
2/0
2/0
3/0
3/0
4/0
4/0
1
1/0
1/0
2/0
3/0
3/0
4/0
4/0
250
250
Leak Testing
Pressurize line set and coil through service fittings with dry
nitrogen to 150 psig maximum. Leak test all joints using liquid
detergent. If a leak is found, recover pressure and repair.
WARNING
Do not use oxygen to purge lines or pressure system for leak
test. Oxygen reacts violently with oil, which can cause an
explosion resulting in severe personal injury or death.
Note: Quantiites based on 110°F liquid and 45°F vapor
Liquid Tube
(oz) [g]
Vapor (oz.) [g]
McQuay IM 96215
Introduction
Tools Required for Installing &
Servicing R410A Models
Manifold Sets:
• Up to 800 PSIG High side
• Up to 250 PSIG Low Side
• 550 PSIG Low Side Retard
Manifold Hoses:
• Service Pressure Rating of 800 PSIG
Recovery Cylinders:
• 400 PSIG Pressure Rating
• Dept. of Transportation 4BA400 or BW400
CAUTION
R410A systems operate at higher pressures than R22
systems. Do not use R22 service equipment or components on
R410A equipment
Specification Of R410A:
Application: R410A is not a drop-in replacement for R22;
equipment designs must accommodate its higher pressures. It
cannot be retrofitted into R22 condensing units.
Physical Properties: R410A has an atmospheric boiling point
of 62.9°F and its saturation pressure at 77°F is 224.5 psig.
Composition: R410A is an azeotropic mixture of 50% by
weight difluoromethane (HFC32) and 50% by weight
pentafluoroethane (HFC125).
Pressure: The pressure of R410A is approximately 60%
(1.6 times) greater than R22. Recovery and recycle
equipment, pumps, hoses and the like need to have design
pressure ratings appropriate for R410A. Manifold sets need to
range up to 800 psig high-side and 250 psig low-side with a
550 psig low-side retard. Hoses need to have a service pressure
rating of 800 psig. Recovery cylinders need to have a 400 psig
service pressure rating. DOT 4BA400 or BW400.
Quick Reference Guide For R410A
• R410A refrigerant operates at approximately 60% higher
pressure (1.6 times) than R22. Ensure that servicing
equipment is designed to operate with R410A.
• R410A refrigerant cycles are pink in color.
• R410A, as with other HFC's is only compatible with POE
oils.
• Vacuum pumps will not remove moisture from oil.
• R410A systems are to be charged with liquid refrigerants.
Prior to March 1999, R410A refrigerant cylinders had a dip
tube. These cylinders should be kept upright for equipment
charging. Post March 1999 cylinders do not have a dip tube
and should be inverted to ensure liquid charging of the
equipment.
• Do not install a suction line filter drier in the liquid line.
• A liquid line filter drier is standard on every unit. Only
manufacturer approved liquid line filter driers can be used.
These filter driers are rated for minimum working pressure
of 600 psig.
• Desiccant (drying agent) must be compatible for POE oils
and R410A.
Replacement Units
To prevent failure of a new condensing unit, the existing
evaporator tubing system must be correctly sized and cleaned
or replaced. Care must be exercised that the expansion device
is not plugged. For new and replacement units, a liquid line
filter drier should be installed and refrigerant tubing should be
properly sized. Test the oil for acid. If positive, a suction line
filter drier is mandatory.
IMPORTANT: WHEN REPLACING AN R22 UNIT WITH
AN R410A UNIT, EITHER REPLACE THE LINE SET OR
ENSURE THAT THE EXISTING LINE SET IS
THOROUGHLY CLEANED OF ANY OLD OIL OR
DEBRIS.
Combustibility: At pressures above 1 atmosphere, mixture of
R410A and air can become combustible. R410A and air
should never be mixed in tanks or supply lines, or be
allowed to accumulate in storage tanks. Leak checking
should never be done with a mixture of R410A and air.
Leak checking can be performed safely with nitrogen or a
mixture of FR410A and nitrogen.
16McQuay IM 962
Evaporator Coil
REFER TO EVAPORATOR COIL MANUFACTURER'S
INSTALLATION INSTRUCTIONS.
IMPORTANT: The manufacturer is not responsible for the
performance and operation of a mismatched system, or for a
match listed with another manufacturer's coil.
CAUTION
Only use evaporators approved for use on R410A systems.
Use of existing R22 evaporators can introduce mineral oil to
the R410A refrigerant forming two different liquids and
decreasing oil return to the compressor. This can result in
compressor failure.
Introduction
Evacuation and Charging
The evacuation of any system component that has been
exposed to atmosphere or lost its charge is essential before
charging. Never attempt to operate a system while it is under a
vacuum.
Note: The condensing unit is shipped with a holding charge of
dry nitrogen which must be purged from the unit before
evacuation.
1
Since the condensing unit itself must be evacuated, open
the vapor, discharge and liquid shut-off valves.
2 Use a refrigeration type vacuum pump capable of
evacuation in the 500 micron range.
3 Connect the vacuum pump to the service manifold
assembly with a pressure gauge that will read 30 inches
vacuum. Connect the service manifold to the vapor line
service port. (“Low” shown on label.)
4 With an accurate scale, 1/2 oz., set refrigerant tank up so
its weight can be measured while in a position to charge
liquid. (Unit must be off.) Energize liquid line solenoid
valve by wiring valve to 24V power supply (or open by
manual stem if applicable).
5 Connect to the liquid line service port. (“High” shown on
label.) Shut off tank and evacuate the system. The
pressure gauge should read at least 29.5" of vacuum.
6 Triple evacuate the system.
7 The refrigerant system will now be free of non-
condensables.
8 Remove vacuum pump from 3way valve.
9 Install refrigerant tank (liquid charging) to liquid line
service valve.
10 Before tightening, purge tank and service valve hose.
11 Note weight of refrigerant tank.
12 De-energize liquid line solenoid valve. Open refrigerant
tank valve. Allow pressure in tank and unit to equalize.
13 Close off service valve to liquid line service port and
note weight of refrigerant tank.
14 Position tank for gas charging.
15 Rewire liquid line solenoid to thermostat control. Close
main disconnect switch and turn thermostat to lowest
setting.
16 Charge unit per Table 11 and Table 12.
17 Adjust refrigerant charge to obtain pressures indicated in
the temperature/pressure charging charts beginning on
page 20.
18 Note weight of refrigerant tank.
19 When system has stabilized, check superheat at the
suction line service valve. The actual line temperature
should be 8° to 20°F higher than the saturation
temperature corresponding to the vapor pressure. If
superheat is measured at evaporator, the actual line
temperature should be 6° to 10° higher than the
saturation temperature corresponding to the vapor
pressure.
20 Close service ports on vapor and liquid valves. Remove
service gauges.
21 Replace service port caps and valve stem caps. These
caps must be replaced to prevent leaks.
22 Record total charge quantity on rating plate.
Final Leak Testing
After the unit has been properly evacuated and charged, a
halogen leak detector should be used to detect leaks in the
system. All piping within the condensing unit, evaporator, and
interconnecting tubing should be checked for leaks. If a leak is
detected, the refrigerant should be recovered before repairing a
the leak. The Clean Air Act prohibits releasing refrigerant into
the atmosphere.
Table 13: Charging Hints
SYMPTOM POSSIBLE CAUSE REMEDY
High head pressure
Low head pressure Short of refrigerant. Check for leak, add charge.
Low vapor & hot compressor Short of refrigerant. Check for leak—add refrigerant.
Excessive sweating Low indoor airflow.
McQuay IM 96217
Air flow to or from condenser restricted or
dirty condenser.
Faulty condenser fan or motor.Replace.
Overcharge of refrigerant.Reduce charge.
Air in system. Evacuate and recharge.
Low evaporator air flow.Increase blower speed, check filters.
Increase speed of air handler blower or
reduce restriction—replace air filter.
Introduction
Table 14: Pre-Start Check
Accessories Installation
1 Remove clamp securing suction line ext. tube (if
applicable).
2 Remove connector panel “A”.
3 Remove suction line ext. tube by sweating at reducer/
suction line “B” (reducer required on some models and
remains on suction line). Remove excess braze material
from surface.
4 Slide service valve “C” onto reducer/suction line “B” (do
NOT braze at this time).
5 Install connector panel “A”.
6 Install bracket “D”.
7 Braze valve.
Louvers
1 Remove two screws from top panel where louver will
install.
2 Slide top of louver panel under lip of the top panel and
slide into place.
3 Attach with four screws provided.
Figure 17: Optional Service Valve Installation
18McQuay IM 962
Introduction
Maintenance and Operation
• All access panels must be in place when unit is in operation.
• For maximum efficiency, the condenser coil must be kept
clean. Periodic inspections, depending on local conditions
are recommended. If it is necessary to clean the condenser
coil, use a common garden hose.
• Never operate the unit without filters installed in the air
handler.
Crankcase Heaters
All units are equipped with crankcase heaters that are factory
wired to operate whenever the main power supply to the unit is
“on” and compressors are “off”. Before starting the equipment
after prolonged shutdown or at the time of initial start-up, be
sure that the circuits to the condensing units are closed for at
least 24 hours.
Contactor
The contactor is an electrical switch which operates the
compressor and condenser fans. Relay activates contactor
when safety circuit is made.
High Pressure Switch (HPC)
Opens the contactor circuit on high refrigerant pressure Manual Reset - check for cause of tripping before putting unit
back in service.
WARNING
Do not wire around the high pressure switch. 15 ton unit
compressors are not provided with internal pressure relief
means. Failure to follow this warning can cause an explosion
resulting in personal injury or death.
Low Pressure Switch (LPC)
Acts as safety against loss of refrigerant.
Relay (R)
Energizes the compressor contactor when safety circuit is
made.
Replacement Parts
To find your local McQuay Certified Parts Distributor, go to
www.mcquay.com and select Parts Locator.
Charge Information
Refer to the appropriate charge chart beginning on page 20.
Wiring Diagrams
Refer to the appropriate wiring diagram beginning on page 26.
Troubleshooting
Refer to the troubleshooting chart beginning on page 15.
McQuay IM 96219
Introduction
Charging Charts
Figure 18: 6-1/2 Ton Charging Charts
20McQuay IM 962
Figure 19: 7-1/2 Ton Charging Chart
Introduction
McQuay IM 96221
Introduction
Figure 20: 10 Ton Charging Chart
22McQuay IM 962
Figure 21: 12 Ton Charging Chart
Introduction
McQuay IM 96223
Introduction
Figure 22: 15 Ton Charging Chart
24McQuay IM 962
Figure 23: 20 Ton Charging Chart
Introduction
McQuay IM 96225
Introduction
Wiring Diagrams
Figure 24: Typical Wiring Schematic - RCS 06F-10F
26McQuay IM 962
Figure 25: Typical Wiring Schematic - RCS 11F-20F
COMPONENT CODE
CCCOMPRESSOR CONTACTOR
CCH CRANKCASE HEAT ER
COMP COMPRESSOR
CTCONTROL TRANSFORMER
DISC DIS CO NN ECT SWITC H
F CFAN MOTOR CON TACTOR
FCC FAN CYCLE CONTROL
GND GROUND
HRHEATER RELAY AS NEEDED
H PCHIG H PR E S SU RE CO N T ROL
L PCLOW PR E S S U RE CO N TRO L
MSMETAL STRIP
OFM OUTDOOR FAN MOTOR
RCRUN CAPACITOR
RRELAY
T BT ER MINAL BLOC K
THTHERMOSTAT HEATING
TDCTIME DELAY CONTROL
THM MOTOR SAFETY TH ERMOSTAT
TORTH ERMAL OV ERLOAD RE LAY
WIRE NUT
NOT ES :
1. RE PLACEMENT WIRE & FUSES
MUST BE SAME TYPE & SIZE
AS ORIG INA L.
2. UNIT MUST BE PERMANENTLY
GROUNDED AND CONFOR M
TO N.E. C. AND LOCAL CODES.
3. MAXIMUM IN RUSH VA NOT TO
EXCE ED 92 VA.
4. MINIMUM WIRE SIZE BASE D
ON 75 DEGREES C INSU LATION
COPPER WIRE.
WIRING INFORMATION
1. LINE VOLTAGE
FACTORY STANDAR D
FACTOR Y OPTION
FIELD INSTALLED
2. LOW VOLTAGE
FACTORY STANDAR D
FA
CTORY OPTION
FIELD INSTALLED
3. R E PLACEMENT WIRE
MUST BE THE SAME SIZE AND TY PE OF
INSULATION AS ORIGINAL (105°C MIN.)
WARNING
CABINET MUST BE PERMANENTLY
GROUNDED AND CONFORM TO I.E.C.,
N. E.C. (C.E. C.-CANADA) AND LOCAL .
CODES AS APPLICABLE.
90-42663-08-03
WIRING SCHEMATIC
CONDE NSING UNIT
208-230,
460, 575, 3 PH, 50 & 60 Hz
380, 3 PH, 60 Hz
W IR E COL O R CO DE
BK — BLACKO — ORANGE
B R — BROWNP R — PURPLE
BL — BLUER — RE D
G —GREENW — WHITE
GY— GRAYY — YELLOW
AH
SUPPLY FAN
Introduction
McQuay IM 96227
Introduction
Replacement Parts
When contacting McQuay for service or replacement parts,
provide the model number, serial number, and unit part
number of the unit as stamped on the serial plate attached to
the unit. For questions regarding wiring diagrams, provide the
number on the specific diagram. If replacement parts are
required, include the date of unit installation, the date of
failure, an explanation of the malfunction, and a description of
the replacement parts required.
Scroll Compressor
All McQuay Rooftop products include a first-year parts only
warranty. The warranty period extends 12 months from startup or 18 months from date of shipment, whichever comes first.
Labor to install these parts is not included with this warranty.
Compressors are considered a part and are included in this
standard warranty.
All Compressors
Replacement compressors for McQuay Rooftop Units can be
obtained from the McQuay Service Parts department.
4 Contact the McQuay Parts Department for compressor
availability.
5 Send a completed parts order form to the McQuay Parts
Department.
6 The Parts Department processes the order and the
compressors are shipped from our Dayton, OH
warehouse via ground transportation. If next-day air is
required, indicate this on the parts order form and a
freight charge will be billed to your account. Air freight
costs are not covered under the McQuay warranty.
7 After the failed compressor is replaced, return it to
McQuay International with a Return Goods Tag
attached, which you will receive in the mail. It must be
attached to the compressor. The Return Goods Tag has
instructions on where to send the compressor. If the
compressor is not returned, you will be billed for the
replacement compressor.
8 Consideration may be given at this time to a compressor
teardown analysis, depending on the history of failures.
In-Warranty Return Material Procedure
Material other than compressors may not be returned except by
permission of authorized factory service personnel of McQuay
International at Minneapolis, Minnesota.
A “return goods” tag will be sent to be included with the
returned material. Enter the information as called for on the tag
in order to expedite handling at out factories and issuance of
credits. All parts shall be returned to the factory designated on
the return goods tag, transportation charges prepaid.
The return of the part does not constitute an order for
replacement. A purchase order for the replacement part must
be entered through your nearest McQuay representative. The
order should include the component's part number and
description and the model and serial numbers of the unit
involved.
If it is determined that the failure of the returned part is due to
faulty material or workmanship within the standard warranty
period, credit will be issued on the customer's purchase order.
28McQuay IM 962
Introduction
To comply with the terms of McQuay Warranty, complete and return this Equipment
Warranty Registration Form within 10 days to McQuay, Warranty Department.
Check, test, and start procedure for RoofPak roof mounted air conditioners with or without heat recovery and roof
mounted air handlers.
Please see the following page "Quality Assurance Survey Report" and list any additional comments that could affect the operation of this unit; e.g.,
shipping damage, failed components, adverse installation applications, etc. If additional comment space is needed, write the comment(s) on a
separate sheet, attach it to the Survey Report and return it to the Warranty Department with the above completed Warranty Registration form.
RETURN COMPLETED EQUIPMENT WARRANTY REGISTRATION FORM TO:
McQuay International Warranty Department, 13600 Industrial Park Boulevard, Minneapolis, MN 55441
Quality Assurance Survey Report
To whom it may concern:
Please review the items below upon receiving and installing our product. Mark N/A on any item that does not apply to the product.
9. How would you rate the serviceability of the product?
10. How would you rate the overall quality of the product?
11. How does the quality of McQuay products rank in relation to competitive products?
Comments:
Please list any additional comments which could affect the operation of this unit; i.e., shipping damage, failed components, adverse installation
applications, etc. If additional comment space is needed, write the comment(s) on a separate sheet, attach the sheet to this completed Quality
Assurance Survey Report, and return it to the Warranty Department with the completed preceding “Equipment Warranty Registration Form”.
RETURN COMPLETED QUALITY ASSURANCE SURVEY REPORT TO:
McQuay International Warranty Department, 13600 Industrial Park Boulevard, Minneapolis, MN 55441
McQuay IM 96231
McQuay Training and Development
Now that you have made an investment in modern, efficient McQuay equipment, its care should be a high priority.
For training information on all McQuay HVAC products, please visit us at www.mcquay.com and click on training,
or call 540-248-9646 and ask for the Training Department.
Warranty
All McQuay equipment is sold pursuant to its standard terms and conditions of sale, including Limited Product
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.
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.