Carrier 50ZH024-060 User Manual
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Installation, Start-Up and Service Instructions
50ZH024-060
Packaged Heat Pump Units
NOTE: Read the entire instruction manual before starting the
installation.
TABLE OF CONTENTS
SAFETY CONSIDERATIONS.....................................................1
INTRODUCTION..........................................................................2
RECEIVING AND INSTALLATION..........................................2
Check Equipment......................................................................2
IDENTIFY UNIT................................................................2
INSPECT SHIPMENT........................................................2
Provide Unit Support................................................................2
SLAB MOUNT ...................................................................2
GROUND MOUNT ............................................................2
Provide Clearances....................................................................2
Place Unit..................................................................................2
Select and Install Ductwork .....................................................2
INSTALL FLANGES FOR DUCTWORK CONNEC-
TIONS (50ZH060 ONLY)..................................................6
CONVERTING HORIZONTAL DISCHARGE UNITS TO
DOWNFLOW (VERTICAL) DISCHARGE......................6
Provide for Condensate Disposal.............................................6
Install Electrical Connections...................................................7
HIGH-VOLTAGE CONNECTIONS..................................7
ROUTING POWER LEADS INTO UNIT........................8
CONNECTING GROUND LEAD TO UNIT
GROUND ............................................................................8
ROUTING CONTROL POWER WIRES..........................8
ACCESSORY ELECTRIC HEAT WIRING .....................8
SPECIAL PROCEDURES FOR 208-V OPERATION .....8
PRE-START-UP ............................................................................9
START-UP.....................................................................................9
Check for Refrigerant Leaks..................................................10
LOCATE AND REPAIR REFRIGERANT LEAKS AND
CHARGE THE UNIT AS FOLLOWS: ...........................10
Start-Up Cooling Section and Make Adjustments ................10
CHECKING COOLING CONTROL OPERATION .......10
COMPRESSOR ROTATION ...........................................10
Refrigerant Charge..................................................................10
NO CHARGE....................................................................10
LOW CHARGE COOLING .............................................10
TO USE THE COOLING CHARGING CHART............10
HEATING MODE CHARGE...........................................11
Indoor Airflow and Airflow Adjustments..............................11
FOR 208/230-V.................................................................12
FOR 460-V MOTORS......................................................12
Unit Controls...........................................................................12
HIGH-PRESSURE RELIEF VALVE...............................12
LOSS OF CHARGE SWITCH.........................................12
COMPRESSOR OVERLOAD..........................................12
Sequence of Operation............................................................12
FAN OPERATION............................................................12
COOLING..........................................................................14
HEAT PUMP HEATING..................................................14
DEFROST..........................................................................15
ELECTRIC RESISTANCE HEATING............................15
MAINTENANCE.........................................................................15
Air Filter..................................................................................16
Unit Top Removal (Outdoor-Coil Side)................................16
Indoor Blower and Motor.......................................................16
Outdoor Coil, Indoor Coil, and Condensate Drain Pan........16
Outdoor Fan............................................................................17
Electrical Controls and Wiring...............................................18
Refrigerant Circuit..................................................................18
Indoor Airflow........................................................................18
Metering Devices....................................................................18
Lubrication..............................................................................18
Liquid Line Strainer................................................................18
High Flow Valves...................................................................19
TROUBLESHOOTING...............................................................22
START-UPCHECKLIST............................................................23
NOTE TO INSTALLER—Before installation, READ THESE
INSTRUCTIONS CAREFULLY AND COMPLETELY. Also,
make sure the User’s Manual and Replacement Guide are left with
the unit after installation.
C00155
Fig. 1—Unit 50ZH
SAFETY CONSIDERATIONS
Installation and servicing of air-conditioning equipment can be
hazardous due to system pressure and electrical components. Only
trained and qualified workers should install, repair, or service
air-conditioning equipment.
Untrained workers can perform basic maintenance functions of
cleaning coils and filters. All other operations should be performed
by trained service people. When working on air-conditioning
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
Book 1 4
Tab 6 8
PC 101 Catalog No. 535-00080 Printed in U.S.A. Form 50ZH-5SI Pg 1 7-03 Replaces: 50ZH-4SI
equipment, pay attention to precautions in the literature, tags, and
labels attached to the unit, and other safety precautions that may
apply.
Follow all safety codes. Wear safety glasses and work gloves. Use
quenching cloth for unbrazing operations. Have fire extinguisher
available for all brazing operations.
Before performing service or maintenance operations on
system, turn off main power to unit and install lockout tag.
Turn off accessory heater power switch if applicable. Electrical shock can cause serious injury or death.
Recognize safety information. This is the safety-alert symbol .
When you see this symbol in instructions or manuals, be alert to
the potential for personal injury.
Understand the signal words DANGER, WARNING, CAUTION,
and NOTE. These words are used with the safety-alert symbol.
DANGER identifies the most serious hazards which will result in
severe personal injury or death. WARNING signifies a hazard
which could result in personal injury or death. CAUTION is used
to identify unsafe practices which would result in minor personal
injury or product and property damage. NOTE is used to highlight
suggestions which will result in enhanced installation, reliability,
or operation.
These instructions cover minimum requirements and conform to
existing national standards and safety codes. In some instances,
these instructions exceed certain local codes and ordinances,
especially those that may not have kept up with changing residential construction practices. We require these instructions as a
minimum for a safe installation.
INTRODUCTION
50ZH heat pump units are fully self-contained and designed for
outdoor installation (See Fig. 1). As shown in Fig. 2-4, units are
shipped in a horizontal-discharge configuration for installation on
a ground-level slab. All units can be field-converted to downflow
discharge configurations for rooftop applications with a fieldsupplied plenum.
RECEIVING AND INSTALLATION
Step 1—Check Equipment
IDENTIFY UNIT
The unit model number and serial number are stamped on the unit
identification plate. Check this information against shipping papers. Verify that unit voltage and amperage listed on unit rating
plate agree with power supplied for equipment.
INSPECT SHIPMENT
Inspect for shipping damage while unit is still on shipping pallet.
If unit appears to be damaged or is torn loose from its securing
points, have it examined by transportation inspectors before
removal. Forward claim papers directly to transportation company.
Manufacturer is not responsible for any damage incurred in transit.
Check all items against shipping list. Immediately notify the
nearest Carrier Air Conditioning office if any item is missing.
To prevent loss or damage, leave all parts in original packages
until installation.
Step 2—Provide Unit Support
SLAB MOUNT
Place the unit on a rigid, level surface, suitable to support the unit
weight. A concrete pad or a suitable fiberglass mounting pad is
recommended. The flat surface should extend approximately 2-in.
beyond the unit casing on the 2 sides. The duct connection side and
condensate drain connection sides should be flush with the edge of
the flat surface.
A 6-in. wide gravel apron should be used around the flat surface to
prevent airflow blockage by grass or shrubs. Do not secure the unit
to the flat surface except where required by local codes.
The unit should be level to within 1/4 inch. This is necessary for
the unit drain to function properly.
GROUND MOUNT
The unit may also be installed directly on the ground if local codes
permit. Place unit on level ground prepared with gravel for
condensate discharge.
Step 3—Provide Clearances
The required minimum service clearances and clearances to
combustibles are shown in Fig. 2-4. Adequate ventilation and
outdoor coil air must be provided.
The outdoor fan pulls air through the outdoor coil and discharges
it through the fan on the top cover. Be sure that the fan discharge
does not recirculate to the outdoor coil. Do not locate the unit in
either a corner or under an overhead obstruction. The minimum
clearance under a partial overhang (such as a normal house
overhang) is 48 in. above the unit top. The maximum horizontal
extension of a partial overhang must not exceed 48 inches.
Do not place the unit where water, ice, or snow from an overhang
or roof will damage or flood the unit. The unit may be installed on
wood flooring or on Class A, B, or C roof covering materials.
Do not restrict outdoor coil airflow. An air restriction at either
the outdoor-air inlet or the fan discharge can be harmful to
compressor life.
Step 4—Place Unit
Unit can be moved with the rigging holds provided in the unit base.
Refer to Table 1 for operating weights. Use extreme caution to
prevent damage when moving the unit. Unit must remain in an
upright position during all moving operations. The unit must be
level with in 1/4” for proper condensate drainage; the ground-level
pad must be level before setting the unit in place. When a
field-fabricated support is used, be sure that the support is level
and that it properly supports the unit.
Step 5—Select and Install Ductwork
The design and installation of the duct system must be in
accordance with:
• the standards of the NFPA (National Fire Protection Association) for installation of nonresidence-type air conditioning and
ventilating systems
• NFPA90A or residence-type, NFPA90B; and/or local codes
and residence-type, NFPA 90B
• and/or local codes and ordinances
Select and size ductwork, supply-air registers and return-air grilles
according to ASHRAE (American Society of Heating, Refrigeration, and Air Conditioning Engineers) recommendations.
Use the duct flanges provided on the supply- and return-air
openings on the side of the unit. See Fig. 2-4 for connection sizes
and locations. The 14-in. round duct collars (size 024-048 units)
are shipped inside the unit attached to the indoor blower. They are
field-installed and must be removed from the indoor cavity prior to
start-up, even if they are not used for installation.
2
REQUIRED CLEARANCE TO COMBUSTIBLE MATL.
TOP OF UNIT.........................................................................................0
DUCT SIDE OF UNIT.............................................................................0
SIDE OPPOSITE DUCTS ......................................................................0
BOTTOM OF UNIT.................................................................................0
NEC. REQUIRED CLEARANCES.
BETWEEN UNITS, POWER ENTRY SIDE....................................42.00 [1066.8]
UNIT AND UNGROUNDED SURFACES, POWER ENTRY SIDE.36.00 [914.0]
UNIT AND BLOCK OR CONCRETE WALLS AND OTHER
GROUNDED SURFACES, POWER ENTRY SIDE.........................42.00 [1066.8]
REQUIRED CLEARANCE FOR OPERATION AND SERVICING
CONDENSER . COIL ACCESS SIDE..............................................30.00 [762.0]
POWER ENTRY SIDE....................................................................30.00 [762.0]
(EXCEPT FOR NEC REQUIREMENTS)
UNIT TOP.......................................................................................48.00 [1219.2]
SIDE OPPOSITE DUCTS ..............................................................30.00 [762.0]
LEGEND
NEC – National Electrical Code
NOTES:
1. Clearances must be maintained to prevent recirculation of air from outdoorfan discharge, with the exception of the condenser coil (36.00 in [914.0 mm]. A
removable fence or barricade requires no clearance.
2. Dimensions are in inches. Dimensions in [ ] are in millimeters.
INCHES [mm]
INCHES [mm]
INCHES [mm]
C00156
UNIT ELECTRICAL CHARACTERISTICS
UNIT WEIGHT CENTER OF GRAVITY IN. (MM)
lb kg X Y Z
50ZH024 208/230-1-60 232 106 14.0 (356) 19.0 (483) 12.0 (305)
50ZH030
208/230-1-60,
208/230–3–60
254 116 14.0 (356) 19.0 (483) 12.0 (305)
Fig. 2—Unit Base Dimensions, 50ZH024-030
3
REQUIRED CLEARANCE TO COMBUSTIBLE MATL.
TOP OF UNIT.........................................................................................0
DUCT SIDE OF UNIT.............................................................................0
SIDE OPPOSITE DUCTS ......................................................................0
BOTTOM OF UNIT.................................................................................0
NEC. REQUIRED CLEARANCES.
BETWEEN UNITS, POWER ENTRY SIDE....................................42.00 [1066.8]
UNIT AND UNGROUNDED SURFACES, POWER ENTRY SIDE.36.00 [914.0]
UNIT AND BLOCK OR CONCRETE WALLS AND OTHER
GROUNDED SURFACES, POWER ENTRY SIDE.........................42.00 [1066.8]
REQUIRED CLEARANCE FOR OPERATION AND SERVICING
CONDENSER . COIL ACCESS SIDE.............................................. 30.00 [762.0]
POWER ENTRY SIDE....................................................................30.00 [762.0]
(EXCEPT FOR NEC REQUIREMENTS)
UNIT TOP.......................................................................................48.00 [1219.2]
SIDE OPPOSITE DUCTS ..............................................................30.00 [762.0]
LEGEND
NEC – National Electrical Code
NOTES:
1. Clearances must be maintained to prevent recirculation of air from outdoorfan discharge, with the exception of the condenser coil (36.00 in [914.0 mm]. A
removable fence or barricade requires no clearance.
2. Dimensions are in inches. Dimensions in [ ] are in millimeters.
INCHES [mm]
INCHES [mm]
INCHES [mm]
UNIT ELECTRICAL CHARACTERISTICS
50ZH036
50ZH042
50ZH048
208/230-1-60, 208/230-3-60,
460–3–60
208/230-1-60, 208/230-3-60,
460–3–60
208/230-1-60, 208/230-3-60,
460–3–60
Fig. 3—Unit Base Dimensions, 50ZH036–048
C00003
UNIT WEIGHT CENTER OF GRAVITY IN. (MM)
lb kg X Y Z
277 126 14.0 (356) 19.0 (483) 15.0 (381)
295 134 14.0 (356) 19.0 (483) 15.0 (381)
328 149 14.0 (356) 19.0 (483) 15.0 (381)
4
REQUIRED CLEARANCE TO COMBUSTIBLE MATL.
TOP OF UNIT.........................................................................................0
DUCT SIDE OF UNIT.............................................................................0
SIDE OPPOSITE DUCTS ......................................................................0
BOTTOM OF UNIT.................................................................................0
NEC. REQUIRED CLEARANCES.
BETWEEN UNITS, POWER ENTRY SIDE....................................42.00 [1066.8]
UNIT AND UNGROUNDED SURFACES, POWER ENTRY SIDE.36.00 [914.0]
UNIT AND BLOCK OR CONCRETE WALLS AND OTHER
GROUNDED SURFACES, POWER ENTRY SIDE.........................42.00 [1066.8]
REQUIRED CLEARANCE FOR OPERATION AND SERVICING
CONDENSER . COIL ACCESS SIDE..............................................30.00 [762.0]
POWER ENTRY SIDE....................................................................30.00 [762.0]
(EXCEPT FOR NEC REQUIREMENTS)
UNIT TOP.......................................................................................48.00 [1219.2]
SIDE OPPOSITE DUCTS ..............................................................30.00 [762.0]
LEGEND
NEC – National Electrical Code
NOTES:
1. Clearances must be maintained to prevent recirculation of air from outdoorfan discharge, with the exception of the condenser coil (36.00 in [914.0 mm]. A
removable fence or barricade requires no clearance.
2. Dimensions are in inches. Dimensions in [ ] are in millimeters.
INCHES [mm]
INCHES [mm]
INCHES [mm]
C00158
UNIT ELECTRICAL CHARACTERISTICS
UNIT WEIGHT CENTER OF GRAVITY IN. (MM)
lb kg X Y Z
50ZH060 208/230-1-60, 208/230-3-60, 460-3-60 368 167 14.0 (356) 20.0 (508) 16.0 (406)
Fig. 4—Unit Base Dimensions, 50ZH060
5
INSTALL FLANGES FOR DUCTWORK CONNECTIONS
(50ZH060 ONLY)
The 50ZH060 units are shipped with flanges which must be
field-installed on the unit.
To install unit flanges:
1. Five pieces of flange are shipped on the return-air opening of
the unit. Remove the flanges from the shipping position (See
Fig. 5). Screws are field-supplied.
2. One piece of flange is used as it is shipped (straight). Bend the
other 4 pieces at right angles.
3. Install the straight flange on the right side of the return-air
opening in holes provided. (See Fig. 6). Flanges should stick
out from unit to allow for connection of ductwork.
4. Install 2 hand-formed flanges onto return air opening in holes
provided to form a rectangle around the return air opening.
5. Install remaining 2 hand-formed flanges around discharge air
opening in holes provided.
6. Ductwork can now be attached to flanges.
When designing and installing ductwork, consider the following:
When connecting ductwork to units, do not drill deeper than
3/4 inch in shaded area shown in Fig. 7 or coil may be
damaged.
FIVE PIECES OF DUCT
FLANGE ATTACHED
HERE FOR SHIPMENT
C00005
Fig. 5—Shipping Location of Duct Flanges
(Size 060 Only)
• All units should have field-supplied filters installed in the
return-air side of the unit. Recommended sizes for filters are
shown in Table 1.
• Avoid abrupt duct size increases and reductions. Abrupt change
in duct size adversely affects air performance.
IMPORTANT: Use flexible connectors between ductwork and
unit to prevent transmission of vibration. Use suitable gaskets to
ensure weathertight and airtight seal. When electric heat is
installed, use fire proof canvas (or similar heat resistant material)
connector between ductwork and unit discharge connection. If
flexible duct is used, insert a sheet metal sleeve inside duct. Heat
resistant duct connector (or sheet metal sleeve) must ectend 24–in.
from the unit discharge connection flange into the ductwork.
• Size ductwork for cooling air quantity (cfm). The minimum air
quantity for proper electric heater operation is listed in Table 2.
Heater limit switches may trip at air quantities below those
recommended.
• Insulate and weatherproof all external ductwork. Insulate and
cover with a vapor barrier all ductwork passing through
conditioned spaces. Follow latest Sheet Metal and Air Conditioning Contractors National Association (SMACNA) and Air
Conditioning Contractors Association (ACCA) minimum installation standards for residential heating and air conditioning
systems.
• Secure all ducts to building structure. Flash, weatherproof, and
vibration-isolate duct openings in wall or roof according to
good construction practices.
Figure 8 shows a typical duct system with 50ZH unit installed.
HAND
FORM
HAND FORM
STRAIGHT PIECE
C00006
Fig. 6—Flanges Installed on 50ZH060 Units
CONVERTING HORIZONTAL DISCHARGE UNITS TO
DOWNFLOW (VERTICAL) DISCHARGE
Before performing service or maintenance operations on
system, turn off main power to unit and install lockout tag.
Turn off accessory heater power switch if applicable. Electrical shock can cause serious injury or death.
Units are dedicated side supply products. They are not convertible
to vertical air supply. A field-supplied plenum must be used to
convert to vertical air discharge.
Step 6—Provide for Condensate Disposal
NOTE: Be sure that condensate-water disposal methods comply
with local codes, restrictions, and practices.
6
Unit removes condensate through a 1 3/64-in. ID hole (using
19.17″ 3.92″
3/4-in. OD piping or tubing) which is located at the end of the unit.
See Fig. 2-4 for location of condensate connection.
Fig. 7—Area Not to Be Drilled More Than 3/4-in.
Condensate water can be drained directly onto the roof in rooftop
installations (where permitted) or onto a gravel apron in groundlevel installations. Install a field-supplied condensate trap at end of
condensate connection to ensure proper drainage. Make sure that
the outlet of the trap is at least 1 in. lower than the drain-pan
condensate connection to prevent the pan from overflowing. Prime
the trap with water. When using a gravel apron, make sure it slopes
away from the unit.
If the installation requires draining the condensate water away
from the unit, install a 2-in. trap using a 3/4-in. OD tubing or pipe.
(See Fig. 9 and 10.) Make sure that the outlet of the trap is at least
1 in. lower than the unit drain-pan condensate connection to
prevent the pan from overflowing. Prime the trap with water.
Connect a drain tube using a minimum of 3/4-in. PVC, 3/4-in.
CPVC, or 3/4-in. copper pipe (all field supplied). Do not undersize
the tube. Pitch the drain tube downward at a slope of at least 1 in.
for every 10 ft of horizontal run. Be sure to check the drain tube
for leaks. Prime trap at the beginning of the cooling season
start-up. Allowable glues for condensate trap connection are:
Standard ABS, CPVC, or PVC cement.
Step 7—Install Electrical Connections
The unit cabinet must have an uninterrupted, unbroken
electrical ground to minimize the possibility of personal
injury if an electrical fault should occur. This ground may
consist of an electrical wire connected to the unit ground in
the control compartment, or conduit approved for electrical
ground when installed in accordance with NEC (National
Electrical Code), ANSI (American National Standards
Institute)/NFPA (latest edition) (in Canada, Canadian Electrical Code CSA C22.1) and local electrical codes. Failure to
adhere to this warning could result in serious injury or death.
C00007
Failure to follow these precautions could result in damage to
the unit being installed:
1. Make all electrical connections in accordance with NEC
ANSI/NFPA (latest edition) and local electrical codes
governing such wiring. In Canada, all electrical connections must be in accordance with CSA standard C22.1
Canadian Electrical Code Part 1 and applicable local
codes. Refer to unit wiring diagram.
2. Use only copper conductor for connections between
field-supplied electrical disconnect switch and unit. DO
NOT USE ALUMINUM WIRE.
3. Be sure that high-voltage power to unit is within operating
voltage range indicated on unit rating plate.
4. Insulate low-voltage wires for highest voltage contained
within conduit when low-voltage control wires are run in
same conduit as high-voltage wires.
5. Do not damage internal components when drilling through
any panel to mount electrical hardware, conduit, etc. On
3-phase units, ensure phases are balanced within 2 percent.
Consult local power company for correction of improper
voltage and/or phase imbalance.
HIGH-VOLTAGE CONNECTIONS
INDOOR
THERMOSTAT
RETURN
AIR
TOP COVER
Power Wiring
Control Wiring
Condenser Airflow
Evaporator Airflow
POWER AND
LOW-VOLTAGE
ENTRY
COMPOSITE
RUST-PROOF
BASEPAN
CONDENSATE
DRAIN
CONNECTION
*Separate disconnect per NEC
(National Electrical Code) required
for electric heater when singlepoint conection is not used.
FROM
POWER
SOURCE
DISCONNECT
PER NEC*
(UNIT AND
ELECTRIC
HEATER)
C00008
C00008
Table 2—Minimum Airflow for Safe Electric Heater
Operation (CFM)
SIZE
024 030 036 042 048 060
600 750 900 1050 1200 1500
Fig. 8—Typical installation
1” (25mm) MIN.
TRAP
OUTLET
2” (50mm) MIN.
Fig. 9—Condensate Trap (Using Tubing)
The unit must have a separate electrical service with a fieldsupplied, waterproof disconnect switch mounted at, or within sight
from the unit. Refer to the unit rating plate for maximum
fuse/circuit breaker size and minimum circuit amps (ampacity) for
wire sizing. See Table 3 for electrical data.
7
C99013
Table 1 — Physical Data
UNIT 50ZH 024 030 036 042 048 060
OPERATING WEIGHT (lbs) 232 254 277 295 328 368
COMPRESSOR TYPE Scroll
1/4
20
4.0
3
1/2
14
14
R-22
2...17
Propeller
3...15
Direct Drive
10x9
800-1050
9.3
2600
1100
1/4
20
4.0
1400
3
Med
1/2
2...17
11.1
2600
1100
1/4
20
4...15
4.4
10x9
1600
1000-1100
2
Low
3/4
2...17
12.7
3200
1100
1/2
20
4...15
4.9
10x10
2000
950-1100
3
Low
1
Square
13.9 x 13.9
13.9 x 27.8
REFRIGERANTCharge(lb)
REFRIGERANT METERING DEVICE Acutrol™ System
OUTDOOR COIL
Rows...Fins/in.
Face Area (sq ft)
OUTDOOR-FAN MOTOR CFM
FIELD-SUPPLIED RETURN-AIR FILTER†
* 460-v motors are 2-speed or 3-speed.
†Required filter sizes shown are based on the ARI (Air Conditioning and Refrigeration Institute) rated airflow at a velocity of 300 ft/min for throwaway type or 450 ft/min
for high capacity type. Recommended filters are 1-in. thick.
Nominal Rpm
Motor Hp
Diameter (in.)
INDOOR COIL Copper Tubes, Aluminum Plate Fins
Rows...Fins/in.
Face Area (sq ft)
INDOOR FAN MOTOR
Blower Motor Size (in.)
Nominal Cfm
Rpm Range
Number of Speeds
Factory Speed Setting
Motor Hp
CONNECTING DUCT SIZES
Supply Air (in.)
Return Air (in.)
Throwaway (in.)
3.7 5.85.96.69.19.7
Copper Tubes, Aluminum Plate Fins
1...17
7.9
1800
825
1/8
20
2...15
3.1
10x8
800
550-1000
3
Low
1/4
24x24 24x24 24x24 24x24 24x30 24x30
2...17
6.7
2000
1100
1/4
20
3...15
3.1
10x8
1000
550-1000
3
Med
1/4
1...17
11.1
2600
1100
3...15
10x9
1200
800-1050
Low
Round
TRAP
OUTLET
1" min.
2" min.
C00009
Fig. 10–PVC Condensate Trap
The field-supplied disconnect may be mounted on the unit over the
high-voltage inlet hole. See Fig. 2-4.
Operation of unit on improper line voltage constitutes abuse
and may cause unit damage that could affect warranty.
ROUTING POWER LEADS INTO UNIT
Use only copper wire between disconnect and unit. The high-
voltage leads should be in a conduit until they enter the unit;
conduit termination at the unit must be watertight. Run the
high-voltage leads through the hole on the control box side of the
unit (see Fig. 11 for location). When the leads are inside the unit,
run leads to the control box (Fig. 12). For single-phase units,
connect leads to the black and yellow wires; for 3-phase units,
connect the leads to the black, yellow, and blue wires (see Fig. 13).
CONNECTING GROUND LEAD TO UNIT GROUND
Refer to Fig. 12 and 13. Connect the ground lead to the chassis
using the unit ground lug in the control box.
ROUTING CONTROL POWER WIRES
Form a drip-loop with the thermostat leads before routing them
into the unit. Route the thermostat leads through grommeted hole
provided in unit into unit control box (See Fig. 11). Connect
thermostat leads and unit power leads as shown in Fig. 13 & 14.
Route thermostat wires through grommet providing a drip-loop at
the panel. Connect low-voltage leads to the thermostat as shown in
Fig. 14.
The unit transformer supplies 24-v power for complete system
including accessory electrical heater. Transformer is factory wired
for 230-v operation. If supply voltage is 208 v, rewire transformer
primary as described in the Special Procedures for 208-v Operation section below.
ACCESSORY ELECTRIC HEAT WIRING
Refer to accessory electric heat installation instructions for infor-
mation on installing accessory electric heat. Accessory electric
heat wiring is shown in Fig. 15A & 15B.
SPECIAL PROCEDURES FOR 208-V OPERATION
Make sure that the power supply to the unit is switched OFF
and install lockout tag before making any wiring changes.
Electrical shock can cause serious injury or death.
1. Remove wirenut from connection of ORG wire to BLK wire.
Disconnect the ORG transformer-primary lead from the BLK
wire. Save wirenut. See unit wiring label.
2. Remove the wirenut from the terminal on the end of the RED
transformer-primary lead.
3. Save the wirenut.
8
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