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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 residen-
tial 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 field-
supplied 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 pa-
pers. 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 Associa-
tion) 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, Refrigera-
tion, 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

Summary of Contents for 50ZHA024-060

Page 1: ...AN 14 DEFROST 14 ELECTRIC RESISTANCE HEATING 14 MAINTENANCE 15 Air Filter 15 Unit Top Removal Outdoor Coil Side 15 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 CHECKLIS...

Page 2: ...n 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 nece...

Page 3: ...Fig 2 Unit Base Dimensions 50ZHA024 060 A05201 3 ...

Page 4: ...in 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 U...

Page 5: ...er company for correction of improper voltage HIGH VOLTAGE CONNECTIONS The unit must have a separate electrical service with a field supplied 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 ...

Page 6: ...hen 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 electri cal 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 ...

Page 7: ...d Line Temperature REQUIRED LIQUID LINE TEMPERATURE FOR A SPECIFIC SUBCOOLING R 22 Pressure psig Required Subcooling F Pressure kPa Required Subcooling C 5 10 15 20 3 6 8 11 134 71 66 61 56 924 24 22 19 16 141 74 69 64 59 972 26 23 21 18 156 80 75 70 65 1075 30 27 24 21 163 83 78 73 68 1124 31 28 26 23 170 86 81 76 71 1172 33 30 27 24 177 89 84 79 74 1220 34 31 29 26 184 91 86 81 76 1268 36 33 30 ...

Page 8: ...ressor outdoor fan and indoor blower motors start and that reversing valve shifts Observe that cooling cycle shuts down when control setting is satisfied Reversing valve RV remains energized 3 Place system switch in HEAT position Observe that compres sor indoor fan and outdoor fan energize Reversing Valve is deenergized in heat pump heating mode Set control above room temperature Observe that heat...

Page 9: ...ubcooling 8 Add charge if the measured temperature is higher than the liquid line temperature value in the table 9 Add charge using the service connection on the suction line of the compressor HEATING MODE CHARGE Do not attempt to adjust charge by cooling methods while in heat pump heating mode Recover refrigerant and weigh in according to unit data plate refrigerant data Step 4 Indoor Airflow and...

Page 10: ...Fig 11A Typical Unit Electrical Diagram Sizes 024 042 A05199 10 ...

Page 11: ...A05200 Fig 11B Typical Unit Electrical Diagram Sizes 048 060 11 ...

Page 12: ...7 54 3 57 8 76 9 83 8 99 4 109 9 122 0 135 9 63 2 69 2 40 40 60 70 80 90 100 110 110 150 70 80 048 208 230 1 60 187 253 24 7 116 0 1 5 7 7 3 8 5 0 7 5 10 0 11 3 15 0 15 0 20 0 5 4 7 2 18 1 20 8 36 1 41 7 54 2 62 5 72 2 83 3 26 0 30 0 40 0 40 0 62 6 66 1 85 1 92 1 107 7 118 1 130 3 144 2 72 5 77 5 50 50 80 80 100 100 110 125 125 125 90 90 060 208 230 1 60 187 253 28 0 118 0 3 0 7 7 3 8 5 0 7 5 10 0...

Page 13: ...gized NOTE Some units are equipped with a time delay relay On these units the indoor fan remains on for 30 seconds after G or Y is deenergized Table 7 Dry Coil Air Delivery Horizontal Discharge Deduct 10 percent for 208 Volt Operation 50ZHA SPEED TAP WATTS C F M EXTERNAL STATIC PRESSURE 0 1 0 2 03 0 4 0 5 0 6 0 7 0 8 0 9 1 0 024 1 Watts 99 100 118 130 142 C F M 848 793 757 698 632 2 Watts 222 233 ...

Page 14: ... compressor and switching the indoor fan into high stage The auxiliary or backup heat is controlled by a third stage W2 If the demand is not met W3 is energized in case of staged heating When heating demand is satisfied W3 W2 and Y2 sequentially de energize switching the compressor and the indoor fan into low stage heating When the low stage heating demand is met Y1 de energizes shutting the compr...

Page 15: ...tdoor Coil Side NOTE When performing maintenance or service procedures that require removal of the unit top be sure to perform all of the routine maintenance procedures that require top removal including coil inspection and cleaning and condensate drain pan inspection and cleaning ELECTRICAL SHOCK HAZARD Failure to follow this warning could result in personal injury or death Disconnect and tag ele...

Page 16: ...r similar probe device Ensure that the auxiliary drain port above the drain tube is also clear Step 5 Outdoor Fan UNIT OPERATIONAL HAZARD Failure to follow this caution may result in damage to unit components Keep the Outdoor fan free from all obstructions to ensure proper cooling operation Never place articles on top of the unit 1 Shut off unit power supply and install lockout tag 2 Remove outdoo...

Page 17: ...is clean When necessary refer to Indoor Airflow and Airflow Adjustments section to check the system airflow Step 9 Metering Devices Refrigerant cooling metering device is an Accurator 024 042 or TXV 048 and 060 located upstream of the indoor coil distributor assembly Refrigerant heating mode metering device is an Accu rater located upstrem of the outdoor coil distributor assembly Step 10 Lubricati...

Page 18: ...erant then flows through the 4 way valve accumulator and back to the compressor Fig 15 Typical Heat Pump Operation Cooling Mode C95044 STRAINER ACCUMULATOR COMPRESSOR STRAINER LCS OUTDOOR COIL INDOOR COIL A B D C Check Valves A Closed B Open C Closed D Open LEGEND LCS Loss of Charge Switch Acutrol Metering Device Check Valve Arrow indicates direction of flow COOLING CYCLE 1 Hot gas from compressor...

Page 19: ...tes continuously Dirty air filter Replace filter Unit undersized for load Decrease load or increase unit size Thermostat set too low Reset thermostat Low refrigerant charge Locate leak repair and recharge Leaking valves in compressor Replace compressor Frosted outdoor coil with incorrect defrost operation heating Check defrost time settings Reset as necessary Check defrost temperature switch Repla...

Page 20: ...r Temperature __________ DB ____________WB Return Air Temperature __________ DB __________ WB Cooling Supply Air __________DB___________WB PRESSURES Cooling Mode Refrigerant Suction __________ psig Suction Line Temp ___________ Refrigerant Discharge __________ psig Discharge Temp __________ TEMPERATURE Heating Mode Outdoor Air Temperature __________ DB ____________WB Return Air Temperature _______...

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