OUTDOOR SPLIT SYSTEM HEAT PUMP INSTALLATION INSTRUCTIONS

⚠️ WARNING: ELECTRICAL SHOCK, FIRE OR EXPLOSION HAZARD

Failure to follow safety warnings exactly could result in serious injury or property damage. Improper servicing could result in dangerous operation, serious injury, death or property damage.

• Before servicing, disconnect all electrical power to the unit.
• When servicing controls, label all wires prior to disconnecting. Reconnect wires correctly.
• Verify proper operation after servicing.

⚠️ WARNING:

This split system heat pump is shipped charged with R410A refrigerant and ready for installation. If repairs make it necessary for evacuation and charging, it should only be attempted by qualified trained personnel thoroughly familiar with this equipment. Under no circumstances should the owner attempt to install and/or service this equipment. Failure to comply with this warning could result in property damage, personal injury, or death.

⚠️ CAUTION:

This unit uses R-410A refrigerant. DO NOT use any other refrigerant in this unit. Use of another refrigerant will damage the unit.

⚠️ WARNING:

Unless noted otherwise in these instructions, only factory authorized parts or accessory kits may be used with this product. Improper installation, service, adjustment, or maintenance may cause explosion, fire, electrical shock or other hazardous conditions which may result in personal injury or property damage.

• Installation of equipment may require brazing operations. Installer must comply with safety codes and wear appropriate safety equipment (safety glasses, work gloves, fire extinguisher, etc.) when performing brazing operations.
• Follow all precautions in the literature, on tags, and on labels provided with the equipment. Read and thoroughly understand the instructions provided with the equipment prior to performing the installation and operational checkout of the equipment.
• Use caution when handling this appliance or removing components. Personal injury can occur from sharp metal edges present in all sheet metal constructed equipment.

⚠️ WARNING:

The information listed below and the next page must be followed during the installation, service, and operation of this equipment. Failure to follow safety recommendations could result in possible damage to the equipment, serious personal injury or death.

• The installer must comply with all local codes and regulations which govern the installation of this type of equipment. Local codes and regulations take precedence over any recommendations contained in these instructions. Consult local building codes and the National Electrical Code (ANSI CI) for special installation requirements.
• All electrical wiring must be completed in accordance with local, state and national codes and regulations and with the National Electric Code (ANSI/NFPA 70) or in Canada the Canadian Electric Code Part 1 CSA C.22.1.
• This equipment contains liquid and gaseous refrigerant under high pressure. DO NOT USE ANY PORTION OF THE CHARGE FOR PURGING OR LEAK TESTING. Installation or servicing should only be performed by qualified trained personnel thoroughly familiar with this type equipment.
• Fully annealed, refrigerant grade copper tubing should be used when installing the system. Refrigerant suction line tubing should be fully insulated.
• This unit is designed for outdoor installations only and should be positioned as described on page 3.

General Information

Split system heat pumps are designed only for outdoor rooftop or ground level installations. This unit has been tested for capacity and efficiency in accordance with AHRI Standards and will provide many years of safe and dependable comfort, provided it is properly installed and maintained. Abuse, improper use, and/or improper maintenance can shorten the life of the appliance and create unsafe hazards.

To achieve optimum performance and minimize equipment failure, it is recommended that periodic maintenance be performed on this unit. The ability to properly perform maintenance on this equipment requires certain mechanical skills and tools.

Before You Install the Heat Pump

• The cooling load of the area to be conditioned must be calculated and a system of the proper capacity selected. It is recommended that the area to be conditioned be completely insulated and vapor sealed.
• Check the electrical supply and verify the power supply is adequate for unit operation. The system must be wired and provided with circuit protection in accordance with local building codes. If there is any question concerning the power supply, contact the local power company.
• The indoor section (air handler, furnace, etc) should be installed before routing the refrigerant tubing. Refer to the indoor unit's installation instructions for installation details.
• All units are securely packed at the time of shipment and upon arrival should be carefully inspected for damage prior to installing the equipment at the job site. Verify coil fins are straight. If necessary, comb fins to remove flattened or bent fins. Claims for damage (apparent or concealed) should be filed immediately with the carrier.
• Please consult your dealer for maintenance information and availability of maintenance contracts. Please read all instructions before installing the unit.

Locating the Heat Pump

• Survey the job site to determine the best location for mounting the outdoor unit.
• Overhead obstructions, poorly ventilated areas, and areas subject to accumulation of debris should be avoided.
• Sufficient clearance for unobstructed airflow through the outdoor coil must be maintained in order to achieve rated performance. See Figure 1 for minimum clearances to obstructions.
• Consideration should be given to availability of electric power, service access, noise, and shade.

Packaging Removal

To prevent damage to the tubing connections, carefully remove the carton and user's manual from the equipment. Discard the shipping carton.

Ground Level

Ground level installations must be located according to local building codes or ordinances and these requirements:

• Clearances must be in accordance with those shown in Figure 1.
• A suitable mounting pad must be provided and be separate from the building foundation. The pad must be level and strong enough to support the unit's weight. The slab height must be a minimum of 2" (5 cm) above grade and with adequate drainage. See Figure 1.

Rooftop

The method of mounting should be designed so that it does not overload roof structures or transmit noise to the interior of the structure. The roof must be structurally capable of handling the weight of the unit.

• Full perimeter support is required under the unit. Support must be made of weather resistant materials and installed prior to unit installation.
• The support must be built to raise the unit 6" above the roof.

Figure 1. Clearance Requirements Description

This diagram illustrates required clearances around the outdoor unit for proper installation and airflow. It shows dimensions for ground level and rooftop installations. Key clearances include: 6 inches from a building or structure, 24 inches for service access, and 12 or 18 inches between units or between a single unit and a structure (refer to specific notes). A 2-inch high mounting pad is also indicated for ground level installations, ensuring adequate drainage.

⚠️ WARNING: ELECTRICAL SHOCK, FIRE OR EXPLOSION HAZARD

Failure to follow safety warnings exactly could result in serious injury or property damage. Improper servicing could result in dangerous operation, serious injury, death or property damage.

• Before servicing, disconnect all electrical power to the unit.
• When servicing controls, label all wires prior to disconnecting. Reconnect wires correctly.
• Verify proper operation after servicing.

General Electrical Compliance

• All electrical connections must be in compliance with all applicable local codes and ordinances, and with the current revision of the National Electric Code (ANSI/NFPA 70).
• For Canadian installations, the electrical connections and grounding shall comply with the current Canadian Electrical Code (CSA C22.1 and/or local codes).

Pre-Electrical Checklist

• Verify that the voltage, frequency, and phase of the supply source match the specifications on the unit rating plate.
• Verify that the service provided by the utility is sufficient to handle the additional load imposed by this equipment. Refer to the unit wiring label for proper high and low voltage wiring.
• Verify factory wiring is in accordance with the unit's wiring diagram. Inspect for loose connections.

Line Voltage

• A wiring diagram is located on the inside cover of the electrical box of the outdoor unit. The installer should become familiar with the wiring diagram before making any electrical connections to the outdoor unit.
• An electrical disconnect must be located within sight of and readily accessible to the unit. This switch shall be capable of electrically de-energizing the outdoor unit.
• Line voltage to the unit should be supplied from a dedicated branch circuit containing the correct fuse or circuit breaker for the unit. Incoming field wiring and minimum size of electrical conductors and circuit protection must be in compliance with information listed on the outdoor unit data label. Any other wiring methods must be acceptable to authority having jurisdiction.
• The outdoor unit requires both power and control circuit electrical connections. Refer to the wiring diagrams for identification and location of outdoor unit field wiring interfaces. Make all electrical connections in accordance with all applicable codes and ordinances.
• Overcurrent protection must be provided at the branch circuit distribution panel and sized as shown on the unit rating label and according to applicable local codes. See the unit rating plate for minimum circuit ampacity and maximum overcurrent protection limits.
• Provide power supply for the unit in accordance with the unit wiring diagram, and the unit rating plate. Connect the line-voltage leads to the terminals on the contactor inside the control compartment.
• Use only copper wire for the line voltage power supply to this unit in strict accordance with the NEC (ANSI/NFPA 70), applicable local codes, and the instructions provided with the equipment. Use proper code agency listed conduit and a conduit connector for connecting the supply wires to the unit. Use of rain tight conduit is recommended.
• 208/230 Volt units are shipped from the factory wired for 230 volt operation. For 208V operation, remove the lead from the transformer terminal marked 240V and connect it to the terminal marked 208V.
• Optional equipment requiring connection to the power or control circuits must be wired in strict accordance with current provisions of the NEC (ANSI/NFPA 70), applicable local codes, and the instructions provided with the equipment.
• For 2 ton units only: Jumper together Y/Y2 and Y1 on the indoor unit's control board so that the indoor unit operates in second stage when operating in cooling mode.

Grounding

⚠️ WARNING: The unit cabinet must have an uninterrupted or unbroken electrical ground to minimize personal injury if an electrical fault should occur. Do not use gas piping as an electrical ground!

This unit must be electrically grounded in accordance with local codes or, in the absence of local codes, with the National Electrical Code (ANSI/NFPA 70) or the CSA C22.1 Electrical Code. Use the grounding lug provided in the control box for grounding the unit.

Thermostat / Low Voltage Connections

• Thermostat connections should be made in accordance with the instructions supplied with the thermostat and the indoor equipment. A typical installation with a heat pump thermostat and air handler is shown in Figure 2.
• The outdoor unit is designed to operate from a 24 VAC Class II control circuit. The control circuit wiring must comply with the current provisions of the NEC (ANSI/NFPA 70) and with applicable local codes having jurisdiction.
• The low voltage wires must be properly connected to the unit's defrost control board.
• The thermostat should be mounted about 5 feet above the floor on an inside wall. DO NOT install the thermostat on an outside wall or any other location where its operation may be adversely affected by radiant heat from fireplaces, sunlight, or lighting fixtures, and convective heat from warm air registers or electrical appliances. Refer to the thermostat manufacturer's instruction sheet for detailed mounting and installation information.

Outdoor Fan Motor

If the unit utilizes a multi-speed PSC condenser fan motor, this motor will always operate on medium speed except when in second stage cooling. When in second stage cooling, it will operate on high speed. A relay within the control area controls this operation.

If the unit utilizes a multi-speed ECM condenser fan motor, this motor will operate on high speed when in second stage cooling or heating, and will operate on medium speed when in first stage cooling or heating. This application does not require a relay.

Figure 2. Typical 2-Stage Heat Pump w/ Optional Outdoor Thermostat and Variable Speed Air Handler Description

This diagram illustrates a typical wiring configuration for a 2-stage heat pump system, showing connections between the thermostat, the outdoor unit, and the air handler. It details the low-voltage wiring, including connections for the thermostat's R, W2, G, Y1, Y2, and C terminals to the corresponding terminals on the outdoor unit and air handler control boards. It also shows the optional outdoor thermostat connection.

Optional Equipment

Optional equipment requiring connection to the power or control circuits must be wired in strict accordance with current provisions of the NEC (ANSI/NFPA 70), with applicable local codes having jurisdiction, and the installation instructions provided with the equipment. Optional Equipment (low ambient control, hard start kits, etc.) should be installed in strict accordance with the manufacturer's installation instructions. A functional checkout should be performed in accordance with the checkout procedures supplied with the equipment.

Transformer Upgrade Kit

If this 2-stage heat pump is installed in conjunction with a gas furnace and fossil fuel kit, the furnace transformer MUST be upgraded to one with a 60 VA rating or using the transformer upgrade kit (904077). To upgrade the transformer:

• Remove the existing transformer and install the new 60 VA transformer.
• Remove the 3 amp fuse on the furnace control board and install the 5 amp fuse provided.

NOTE: The new transformer may be larger than the existing transformer that is mounted in the furnace. If this happens, mount the 60 VA transformer using one of the mounting holes in the furnace panel. On the other side, either drill a 0.149 hole in the panel and use the existing fastener, or use a self-drilling fastener to secure the other side of the transformer.

Table 1. Heat Pump Operating Temperatures

Pre-Start Check List

• Verify the unit is level and has sufficient clearances for unobstructed airflow.
• Verify the outdoor coil and top of the unit are free from obstructions and debris, and all equipment access/control panels are in place.
• Verify that the line voltage power leads are securely connected and the unit is properly grounded.
• Verify that the low voltage wires are securely connected to the correct leads on the low voltage terminal strip.
• Verify that the power supply branch circuit overcurrent protection is sized properly.
• Verify that the thermostat is wired correctly.

Start-Up Procedures

⚠️ WARNING: This unit is equipped with a crankcase heater. Allow 24 hours prior to continuing the start up procedures to allow for heating of the refrigerant compressor crankcase. Failure to comply may result in damage and could cause premature failure of the system. This warning should be followed at initial start up and any time the power has been removed for 12 hours or longer.

Operating Temperatures

This equipment has been designed to operate within the temperatures specified in Table 1. Running the equipment in heating at higher than 70° F may require the use of a Heat Pump Mild Weather Control Kit or changing over to emergency or auxiliary heating.

Air Circulation - Indoor Blower

1. Set the thermostat system mode on OFF and the fan mode to ON.
2. Verify the blower runs continuously. Check the air delivery at the supply registers and adjust register openings for balanced air distribution. If insufficient air is detected, examine ductwork for leaks or obstructions.
3. Set the thermostat fan mode to AUTO and verify the blower stops running.

System Cooling

1. Set the thermostat's system mode to COOL and the fan mode to AUTO. Gradually lower the thermostat temperature setpoint below room temperature and verify the outdoor unit and indoor blower energize.
2. Verify blower wheel is spinning in direction indicated by arrow. Feel the air being circulated by the indoor blower and verify that it is cooler than ambient temperature. Listen for any unusual noises. If unusual sounds occur, determine the source of the noise and correct as necessary.
3. Verify HI and LO refrigerant pressures.
4. Allow the system to operate for several minutes and then set the temperature selector above room temperature. Verify the fan and compressor cycle off with the thermostat.

NOTE: The blower should also stop unless fan switch is set to the ON position.

System Heating

1. Set the thermostat's system mode to HEAT and the temperature mode to below room temperature.
2. Verify the outdoor unit and indoor fan stop running. After 5 minutes, increase the temperature on the thermostat to its maximum setting.
3. Verify the outdoor unit and indoor blower energize. Feel the air being circulated by the indoor blower and verify that it is warmer than ambient temperature. Listen for any unusual noises. If unusual sounds occur, determine the source of the noise and correct as necessary.

NOTE: Other sources for heating (electric furnace, fossil fuel furnace, air handler with electric heat options, etc.) that interface with the heat pump should be functionally checked to verify system operation and compatibility with the heat pump. Refer to the installation instructions for this equipment and perform a functional checkout in accordance with the manufacturer's instructions.

Short Cycle Protection

1. With the system operating in COOLING mode, record the setpoint temperature setting of the thermostat.
2. Gradually raise the setpoint temperature until the outdoor unit and indoor blower de-energize.
3. Immediately lower the setpoint temperature of the thermostat to its original setting and verify that the indoor blower is energized and that the outdoor unit remains de-energized.
4. After approximately 5 minutes, verify that the outdoor unit energizes and the temperature of the air supplied to the facility is cooler than ambient temperature.

Defrost Control Board Test Pins

• Placing a jumper between the test pins for less than 1 second will bypass the Anti-Short Cycle Timer.
• Placing a jumper between the test pins for more than 1 second will force the unit into a defrost cycle. As soon as the jumper is removed, the defrost cycle will end as determined by the typical criteria.
• Verify the Status Indicator (on the control board) against the codes listed in Table 2 to determine proper diagnostic description.

Table 2. Defrost Control Board Status Indicators

⚠️ WARNING:

To prevent electrical shock, personal injury, or death, disconnect all electrical power to the unit before performing any maintenance or service. The unit may have more than one electrical supply.

Proper maintenance is important to achieve optimum performance from the heat pump. The ability to properly perform maintenance on this equipment requires certain mechanical skills and tools. If you do not possess these skills, contact your dealer for maintenance. Consult your local dealer about the availability of maintenance contracts. Routine maintenance should include the following:

• Inspect the electrical connections for tightness at the beginning of each heating and cooling season. Service as necessary.
• Inspect and clean or replace air filters at the beginning of each heating and cooling season, or more frequently if required.

⚠️ CAUTION:

The unit should never be operated without a filter in the return air system. Replace disposable filters with the same type and size.

• Inspect the outdoor coil at the beginning of each cooling season. Remove any debris. Clean the outdoor coil and louvers as necessary using a mild detergent and water. Rinse thoroughly with water.
• Do not add additional oil to motors unequipped with oil tubes. The compressor is hermetically sealed at the factory and does not require lubrication.

Panel Removal

1. Remove screws securing the panel.
2. Slide the panel up towards the top pan in order to clear the bottom flange from the base pan. See Figure 3.
3. Swing the bottom of the panel out and pull the panel down to remove it from the unit.

Panel Installation

1. Insert the top corners of side panel flanges into the corner post channels as shown in Detail A in Figure 4.
2. Slide the panel up into the top pan. (You may need to push on the center of the panel at the top in order to clear the top pan edge).
3. Swing the panel in and push down until the panel is resting on the top edge of the base pan wall as shown in Detail B.
4. Insert screws into the panel to secure it to the unit.

Figure 3. Panel Removal Description

This diagram illustrates the process of removing an access panel from the unit. It shows the panel being slid upwards to disengage from the base pan flange, then swung outwards and pulled down.

Figure 4. Panel Installation Description

This diagram shows the steps for installing an access panel. It details inserting the top corners into channels, sliding the panel up, swinging it in, and securing it with screws, referencing details A and B for specific alignment points.

⚠️ WARNING:

This split system heat pump is shipped charged with R410A refrigerant and ready for installation. If repairs make it necessary for evacuation and charging, it should only be attempted by qualified trained personnel thoroughly familiar with this equipment. Under no circumstances should the owner attempt to install and/or service this equipment. Failure to comply with this warning could result in property damage, personal injury, or death.

After refrigerant line connections are completed, it is required that you leak check and evacuate the indoor section and all line connections (using proper methods) before finalizing the full system refrigerant charge.

• To achieve rated capacity and efficiency, the compressor must be exposed to refrigerant for at least 24 hours prior to running and then the compressor must be run for a minimum of 12 hours.
• The refrigerant charge can be checked and adjusted through the service ports provided external to the outdoor unit. Use only gage line sets which have a "Schrader" depression device present to actuate the valve. A common suction port for heating mode charging is included and located on the compressor access panel above the outdoor unit service valves.
• A high-pressure switch is factory installed and located internally on the compressor discharge line of the outdoor unit. If the discharge pressure rises above 650 psig, the switch will open and de-energize the outdoor unit. The switch will close again after the discharge pressure decreases to 460 psig. NOTE: When the switch opens and then closes, there will be a 3 minute short cycling delay before the outdoor unit will energize. Under normal conditions the switch is closed.
• A low-pressure switch is factory installed (certain models) and located internally on the suction line of the outdoor unit. The switch is designed to protect the compressor from a loss of charge by interrupting the thermostat inputs to the unit. If the suction pressure falls below 20 psig, the switch will open and de-energize the outdoor unit. The switch will close again when the suction pressure increases above 35 psig. When the switch opens and then closes, there is a 3 minute short cycling delay before the outdoor unit will energize. Under normal conditions the switch is closed.

To properly charge these units:

1. Read all Installation Instructions first.
2. Complete any brazing operations. (e.g. Split system linesets)
3. Leak check and evacuate the whole system using proper methods.
4. Purge the nitrogen holding charge.
5. Evacuate the unit to 350-500 microns.
6. Allow the unit to remain under vacuum for at least 30 min.
7. Weigh-In the proper amount of new (or reclaimed) R-410A refrigerant. Refer to the units Quick Reference Data Sheet to determine the correct amount of charge.

Charging the Unit in AC mode

If the outdoor temperature is 65 degrees F or higher:

After completing the refrigerant line connections, leak checking the system, and evacuating the indoor section and all line connections (using proper methods), perform the following steps:

1. Determine the recommended charge addition (if applicable) for the system being installed. This information is in the unit's QRD (Quick Reference Data sheet).
2. Calculate the amount of additional refrigerant needed for the line set length of the actual installation. This information is on the first page of the unit's QRD (Quick Reference Data sheet).
3. Weigh in the additional charge amounts determined by step 1 and 2 above.
4. Adjust the charge to match the superheat (for fixed orifice systems) or subcooling (for TXV systems). The charging tables are on the inside of the outdoor unit's electrical box cover panel. These tables provide superheat targets for fixed orifice systems and subcooling targets for TXV systems. The system should be charged so that the measured superheat/subcooling are within 1 degree F of the target listed in the table.

For fixed orifice systems:

• If your measured superheat at the suction valve is LESS THAN the recommended superheat value in the table then REMOVE refrigerant.
• If your measured superheat at the suction valve is GREATER THAN the recommended superheat value in the table then ADD refrigerant.

For TXV systems:

• If your measured subcooling at the liquid valve is LESS THAN the recommended subcooling value in the table then ADD refrigerant.
• If your measured subcooling at the liquid valve is GREATER THAN the recommended subcooling value in the table then REMOVE refrigerant.

If the outdoor temperature is between 35 degrees F and 65 degrees F:

After completing the refrigerant line connections, leak checking the system, and evacuating the indoor section and all line connections (using proper methods), perform the following steps:

1. Determine the recommended charge addition (if applicable) for the system being installed. This information is in the unit's QRD (Quick Reference Data sheet).
2. Calculate the amount of additional refrigerant needed for the line set length of the actual installation. This information is on the first page of the unit's QRD (Quick Reference Data sheet).
3. Weigh in the additional charge amounts determined by step 1 and 2 above.
4. Block off the discharge of the outdoor fan. NOTE: One half of the unit should be covered corner to corner as shown in Figure 5.
5. With the unit in cooling mode, adjust the charge to match the superheat (for fixed orifice systems) or subcooling (for TXV systems) by using the low ambient charging tables on the inside of the outdoor unit's electrical box cover panel. These tables provide superheat targets for fixed orifice systems and subcooling targets for TXV systems. The system should be charged so that the measured superheat/subcooling are within 1 degree F of the target listed in the table.

For fixed orifice systems:

• If your measured superheat at the suction valve is LESS THAN the recommended superheat value in the table then REMOVE refrigerant.
• If your measured superheat at the suction valve is GREATER THAN the recommended superheat value in the table then ADD refrigerant.

For TXV systems:

• If your measured subcooling at the liquid valve is LESS THAN the recommended subcooling value in the table then ADD refrigerant.
• If your measured subcooling at the liquid valve is GREATER THAN the recommended subcooling value in the table then REMOVE refrigerant.

If the outdoor temperature is below 35 degrees F:

After completing the refrigerant line connections, leak checking the system, and evacuating the indoor section and all line connections (using proper methods), perform the following steps:

1. Determine the recommended charge addition (if applicable) for the system being installed. This information is in the unit's QRD (Quick Reference Data sheet).
2. Calculate the amount of additional refrigerant needed for the line set length of the actual installation. This information is on the first page of the unit's QRD (Quick Reference Data sheet).
3. Weigh in the additional charge amounts determined by steps 1 and 2 above.
4. Return to the system when the outdoor temperature is 35 degrees F or higher and follow the steps defined in step 4 of the "If the outdoor temperature is between 35 degrees and 65 degrees F" or "If the outdoor temperature is 65 degree F or higher" sections above as applicable.

Figure 5. Blocked Off Outdoor Fan Discharge Description

This diagram shows how to partially block the outdoor fan discharge for operation in low ambient temperatures (below 35°F). It illustrates covering approximately one half of the unit's fan discharge area from corner to corner.

Figure 6. Wiring Diagram for 2 Ton Units Description

This diagram illustrates the wiring for a 2-ton, two-stage split system heat pump with a PSC (Permanent Split Capacitor) fan motor. It details the high-voltage connections for the compressor, outdoor fan motor, and contactor, as well as the low-voltage control wiring to the defrost control board, ambient sensor, and other components. The diagram includes notes on servicing, conductor types, voltage limitations, and grounding.

Figure 7. Wiring Diagram for 3 Ton Units Description

This diagram shows the wiring for a 3-ton, two-stage split system heat pump with a PSC fan motor. It details the high-voltage connections for the compressor, outdoor fan motor, and contactor, as well as the low-voltage control wiring to the defrost control board, ambient sensor, and other components. The diagram includes notes on servicing, conductor types, voltage limitations, and grounding.

Figure 8. Wiring Diagram for 4 Ton Units Description

This diagram illustrates the wiring for a 4-ton, two-stage split system heat pump with an ECM (Electronically Commutated Motor) fan motor. It details the high-voltage connections for the compressor and ECM fan motor, as well as the low-voltage control wiring to the defrost control board, ambient sensor, and other components. The diagram includes notes on servicing, conductor types, voltage limitations, and grounding.

Figure 9. Wiring Diagram for 5 Ton Units Description

This diagram illustrates the wiring for a 5-ton, two-stage split system heat pump with an ECM (Electronically Commutated Motor) fan motor. It details the high-voltage connections for the compressor and ECM fan motor, as well as the low-voltage control wiring to the defrost control board, ambient sensor, and other components. The diagram includes notes on servicing, conductor types, voltage limitations, and grounding.