50ZHA024-060
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Installation, Start-Up and Service Instructions
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
CONVERTING HORIZONTAL DISCHARGE
UNITS TO DOWNFLOW (VERTICAL) DIS-
CHARGE ..................................................................4
Provide for Condensate Disposal .............................................4
Install Electrical Connections...................................................5
HIGH-VOLTAGE CONNECTIONS..................................5
ROUTING POWER LEADS INTO UNIT ........................6
CONNECTING GROUND LEAD TO UNIT GROUND .6
ROUTING CONTROL POWER WIRES ..........................6
ACCESSORY ELECTRIC HEAT WIRING .....................6
PRE-START-UP ............................................................................6
START-UP .....................................................................................7
Check for Refrigerant Leaks ....................................................8
LOCATE AND REPAIR REFRIGERANT LEAKS AND
CHARGE THE UNIT AS FOLLOWS: .............................8
Start-Up Cooling Section and Make Adjustments ..................8
CHECKING COOLING CONTROL OPERATION .........8
Refrigerant Charge....................................................................8
NO CHARGE......................................................................8
LOW CHARGE COOLING ...............................................9
HEATING MODE CHARGE.............................................9
Indoor Airflow and Airflow Adjustments................................9
FOR 208/230-V .................................................................13
Unit Controls...........................................................................13
HIGH-PRESSURE RELIEF VALVE...............................13
LOSS OF CHARGE SWITCH.........................................13
COMPRESSOR OVERLOAD..........................................13
Sequence of Operation............................................................13
FAN OPERATION............................................................13
COOLING..........................................................................14
HEATING..........................................................................14
CONTINUOUS FAN ........................................................14
DEFROST..........................................................................14
ELECTRIC RESISTANCE HEATING............................14
MAINTENANCE.........................................................................15
Air Filter..................................................................................15
Unit Top Removal (Outdoor-Coil Side) ................................15
50ZHA024-060
Packaged Heat Pump Units
A05194
Fig. 1—Unit 50ZHA
Indoor Blower and Motor.......................................................15
Outdoor Coil, Indoor Coil, and Condensate Drain Pan ........16
Outdoor Fan ............................................................................16
Electrical Controls and Wiring...............................................16
Refrigerant Circuit ..................................................................17
Indoor Airflow ........................................................................17
Metering Devices ....................................................................17
Lubrication ..............................................................................17
Liquid Line Strainer................................................................17
High Flow Valves...................................................................17
TROUBLESHOOTING ...............................................................17
START-UP CHECKLIST............................................................17
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.
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
equipment, pay attention to precautions in the literature, tags, and
labels attached to the unit, and other safety precautions that may
apply.
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 Printed in U.S.A. Catalog No. 50ZHA-1SI Pg 1 9-05 Replaces: New
Follow all safety codes. Wear safety glasses and work gloves. Use
quenching cloth for unbrazing operations. Have fire extinguisher
available for all brazing operations.
FIRE, EXPLOSION, ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal injury,
death and/or property damage.
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.
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 may 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
50ZHA heat pump units are fully self-contained and designed for
outdoor installation (See Fig. 1). As shown in Fig. 2, 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 Distributor 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.
HURRICANE HOLD DOWN
Contact you local distributor for specific hurricane hold down
details and PE (Professional Engineer) certification when required.
Step 3—Provide Clearances
The required minimum service clearances and clearances to
combustibles are shown in Fig. 2. 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.
OPERATIONAL HAZARD
Failure to follow this caution may result in unit component
damage.
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 2 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 for connection sizes and
locations. The 14-in. round duct collars are shipped inside the unit
attached to the base pan in the indoor blower compartment. They
2
A05201
Fig. 2—Unit Base Dimensions, 50ZHA024-060
3
Table 1—Unit Specifications
UNIT ELECTRICAL CHARACTERISTICS
50ZHA024 208/230-1-60 293 133 30.13 (765) 14.0 (356) 19.0 (483) 12.0 (305)
50ZHA030 208/230-1-60 324 147 34.13 (867) 14.0 (356) 19.0 (483) 12.0 (305)
50ZHA036 208/230-1-60 377 171 42.13 (1070) 14.0 (356) 19.0 (438) 19.8 (503)
50ZHA042 208/230-1-60 389 177 42.13 (1070) 14.0 (356) 19.0 (483) 21.9 (556)
50ZHA048 208/230-1-60 384 175 42.13 (1070) 14.0 (356) 19.0 (483) 19.8 (503)
50ZHA060 208/230-1-60 433 197 42.13 (1070) 14.0 (356) 19.0 (483) 21.9 (556)
UNIT WEIGHT
lb kg ″A″ XYZ
UNIT HEIGHT
IN. (MM)
CENTER OF GRAVITY IN. (MM)
are field-installed and must be removed from the indoor blower
compartment prior to start-up, even if they are not used for
installation.
When designing and installing ductwork, consider the following:
UNIT DAMAGE HAZARD
Failure to follw this caution may result in damage to unit
components. When connecting ductwork to units, do not drill
deeper than 3/4 inch in shaded area shown in Fig. 3 or coil
may be damaged.
• All units should have field-supplied filters installed in the
return-air side of the unit. Recommended sizes for filters are
shown in Table 2.
• 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 extend 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 3.
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 4 shows a typical duct system with 50ZHA unit installed.
CONVERTING HORIZONTAL DISCHARGE UNITS TO
DOWNFLOW (VERTICAL) DISCHARGE
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal injury
or death.
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.
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.
Unit removes condensate through a 1 3/64-in. ID hole (using
3/4-in. OD piping or tubing) which is located at the end of the unit.
See Fig. 2 for location of condensate connection.
19.17
3.92
Fig. 3—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. 5 and 6.) 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.
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A05195
Table 2—Physical Data
UNIT 50ZHA 024 030 036 042 048 060
OPERATING WEIGHT (lbs) 293 324 377 389 384 433
COMPRESSOR TYPE Scroll Ultra Tech Scroll
15.8
20
4.9
Direct Drive
R-22
Propeller
Round
14
14
2...21
15.8
3200
20
1/4 (1100)
4...17
6.1
1400
11x9
3/4 (1050)
2...21
13.3
3200
20
1/4 (1100)
4...17
4.9
1600
11x10
1 (1050)
2...21
15.8
3300
20
1/2 (1100)
4...17
6.1
1875
11x10
1 (1050)
REFRIGERANT Charge (lb)
REFRIGERANT METERING DEVICE
*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.
Orifice ID (in.)
Orifice OD (in.) .049 .057 .059 .063 .070 .073
CONDENSER COIL
Rows...Fins/in.
Face Area (sq. ft.)
CONDENSER FAN
Nominal Cfm
Diameter (in.)
Motor HP (RPM)
EVAPORATOR COIL
Face Area (sq. ft.)
Evaporator Blower
Nominal Airflow (CFM)
Size (in.)
Motor HP (RPM)
CONNECTING DUCT SIZES
Supply Air (in.)
Return Air (in.)
Return-Air Filters (in.)*
Throwaway
7.5 10.3 10.3 11.9 11.4 13.3
Accurater TXV
.067 .067 .082 .086 — —
Copper Tubes, Aluminum Plate Fins
2...21
11.1
2600
20
1/8 (825)
3...17
4.3
800
10x8
1/2 (1050)
24x24 24x24 24x24 24x30 30x30 30x30
2...21
12.7
2600
20
1/8 (825)
3...17
4.9
1000
10x8
1/2 (1050)
2...21
3200
1/4 (1100)
Copper Tubes, Aluminum Plate Fins
4...17
1200
11x9
3/4 (1050)
Step 7—Install Electrical Connections
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal injury
or death.
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.
UNIT DAMAGE HAZARD
Failure to follow these precautions may 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.
Consult local power company for correction of improper
voltage.
HIGH-VOLTAGE CONNECTIONS
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 6 for electrical data.
The field-supplied disconnect may be mounted on the unit over the
high-voltage inlet hole. (See Fig. 2.)
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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
Fig. 4—Typical installation
1” (25mm) MIN.
TRAP
OUTLET
2” (50mm) MIN.
C99013
Fig. 5—Condensate Trap (Using Tubing)
TRAP
OUTLET
1" min.
2" min.
C00009
Fig. 6—PVC Condensate Trap
Table 3—Minimum Airflow for Safe Electric Heater
Operation (CFM)
SIZE 024 030 036 042 048 060
Cfm 600 750 900 1050 1200 1500
UNIT DAMAGE HAZARD
Failure to follow this caution may result in unit component
damage. 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 highvoltage 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. 7 for location). When the leads are inside the unit,
run leads to the control box (Fig. 8). For single-phase units,
connect leads to the black and yellow wires (see Fig. 9).
CONNECTING GROUND LEAD TO UNIT GROUND
Refer to Fig. 8 and 9. Connect the ground lead to the chassis using
the unit ground 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. 7). Connect
thermostat leads and unit power leads as shown in Fig. 9, 10A &
10B.
Route thermostat wires through grommet providing a drip-loop at
the panel. Connect low-voltage leads to the thermostat as shown in
Fig. 10A & 10B.
The unit transformer supplies 24-v power for complete system
including accessory electrical heater. Transformer is factory wired
for 230-v operation.
ACCESSORY ELECTRIC HEAT WIRING
Refer to accessory electric heat installation instructions for information on installing accessory electric heat. Accessory electric
heat wiring is shown in Fig. 11A, 11B, & 11C.
PRE-START-UP
FIRE, EXPLOSION, ELECTRICAL SHOCK HAZARD
Failure to observe the following warnings could result in
serious injury, death and/or property damage:
1. Follow recognized safety practices and wear protective
goggles when checking or servicing refrigerant system.
2. Do not operate compressor or provide any electric power to
unit unless compressor terminal cover is in place and
secured.
3. Do not remove compressor terminal cover until all electrical sources are disconnected and lockout tag is installed.
4. Relieve all pressure from both high- and low-pressure sides
of the system before touching or disturbing anything inside
terminal box if refrigerant leak is suspected around compressor terminals. Use accepted methods to recover refrigerant.
5. Never attempt to repair soldered connection while refrigerant system is under pressure.
6. Do not use torch to remove any component. System
contains oil and refrigerant under pressure. To remove a
component, wear protective goggles and proceed as follows:
a. Shut off electrical power to unit and install lockout tag.
b. Relieve all refrigerant from system using both high- and
low-pressure ports. Use accepted methods to recover
refrigerant.
c. Cut component connecting tubing with tubing cutter and
remove component from unit.
d. Carefully unsweat remaining tubing stubs when neces-
sary. Oil can ignite when exposed to torch flame.
Use the Start-Up Checklist supplied at the end of this book and
proceed as follows to inspect and prepare the unit for initial
start-up:
1. Remove all access panels.
2. Read and follow instructions on all DANGER, WARNING,
CAUTION, and INFORMATION labels attached to, or
shipped with unit.
Make the following inspections:
a. Inspect for shipping and handling damages such as broken
lines, loose parts, disconnected wires, etc.
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