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Details unit dimensions (H x D x W) and estimated weights for various models.
Specifies maximum total and vertical lengths for refrigerant lines.
Recommends placement for optimal airflow, noise avoidance, and protection from elements.
Provides precautions for installing units in areas with snow and freezing temperatures.
Addresses requirements for installations near salt water environments.
Steps for checking unit for damage and removing it from the pallet.
Guidelines for installing the unit on a support pad, including level and clearance.
Details line sizes and service valve connection sizes for different models.
Information on factory charge for outdoor condensing units and system verification.
Instructions to determine required line length and lift for system configuration.
Emphasizes insulating the vapor line and preventing metal-to-metal contact.
Precautions for using existing refrigerant lines, including brazing and cleanliness.
Guidelines for routing refrigerant lines to prevent noise and ensure proper isolation.
Detailed steps for preparing and brazing refrigerant lines to service valves.
Procedure for pressurizing lines with nitrogen and checking for leaks using soapy solution.
Instructions for evacuating the system to a specific micron level.
Steps to open the gas service valve after leak check and evacuation.
Procedure for carefully opening the liquid line service valve without over-torquing.
Table specifying maximum wire lengths for low voltage wiring based on gauge.
Wiring diagrams for connecting thermostat, air handler, and outdoor unit.
Details on defrost control settings, termination temperatures, and checkout procedures.
Guidance on high voltage power supply requirements and compliance with codes.
Recommendation for installing a separate disconnect switch at the outdoor unit.
Requirement to ground the outdoor unit according to national, state, and local codes.
Step-by-step procedure for starting the installed HVAC system.
Instructions for measuring outdoor and indoor temperatures for system charging.
Method for adjusting refrigerant charge using subcooling for temperatures above 55°F.
Method for charging in heating mode below 55°F outdoor temperature using weigh-in.
Final inspection and operational checks to ensure system performance and safety.
Guide to identifying and resolving system faults based on symptoms and causes.
This document serves as an installer's guide for Trane Heat Pumps, specifically the 4TWX7 series, providing essential information for proper installation, operation, and maintenance. It emphasizes compliance with national, state, and local codes throughout all installation phases. The guide is intended for individuals with adequate electrical and mechanical experience, highlighting the importance of safety precautions to prevent personal injury or property damage.
The Trane Heat Pump is an outdoor condensing unit designed to work in conjunction with an indoor evaporative coil to provide heating and cooling for residential and commercial applications. These units utilize R-410A refrigerant, which operates at higher pressures than R-22, necessitating the use of R-410A approved service equipment. The system's primary function is to transfer heat, either from indoors to outdoors for cooling, or from outdoors to indoors for heating, thereby maintaining desired indoor temperatures. The guide outlines procedures for setting up the unit, connecting refrigerant lines, performing electrical hook-ups, and adjusting the system charge to ensure optimal performance and efficiency.
The installation process begins with unit preparation, including checking for shipping damage and carefully removing the unit from its pallet. Proper unit placement is crucial, with considerations for roof support if mounted on a roof, and isolation to prevent sound or vibration transmission to the building structure. The guide provides specific recommendations for unit clearance: at least five feet above the top discharge area, and three feet in front of the control box for service access. It also advises against installing the unit near bedrooms or windows where noise or defrost vapor could be a nuisance, recommending a minimum 12-inch clearance from walls and shrubbery for adequate airflow.
For cold climates, the guide suggests elevating the unit 3-12 inches above the pad or rooftop to allow for proper drainage of snow and ice melted during defrost cycles, preventing refreezing and obstruction of drain holes. Avoiding locations prone to snow drifts or installing a snow drift barrier is also recommended.
Refrigerant line considerations are detailed, including maximum total line lengths (up to 150 feet) and vertical lift limits (up to 50 feet), with exceptions for certain tonnages. The guide stresses the importance of insulating the vapor line and preventing direct metal-to-metal contact between the liquid and vapor lines. For existing refrigerant lines, it's crucial to ensure all joints are brazed, not soldered, and that the lines are free of leaks, acid, and oil.
Refrigerant line routing precautions are outlined to prevent noise and vibration transmission within the building structure. This includes using isolation-type hangers when fastening lines to joists or framing, insulating and isolating lines running through walls or sills, and minimizing 90-degree turns.
Brazing the refrigerant lines involves several steps: deburring and cleaning pipe ends, removing pressure tap caps and valve cores from service valves, purging lines with dry nitrogen, and wrapping wet rags around valve bodies to prevent heat damage during brazing. The guide also specifies checking the directional flow arrow on field-installed filter driers and brazing them into the liquid line.
After brazing, a leak check is performed by pressurizing the lines and evaporator coil to 150 PSIG with dry nitrogen and checking for bubbles at brazed locations. Any leaks must be repaired before proceeding. Evacuation of the refrigerant lines and indoor coil is then performed until a micron gauge reads no higher than 350 microns, and the vacuum holds above 500 microns for one minute.
Opening the service valves is a critical step. The guide provides instructions for both the gas and liquid line service valves, emphasizing extreme caution when opening the liquid line service valve to prevent abrupt release of system charge.
Electrical hook-up instructions cover both low and high voltage. Low voltage wiring length limits are provided based on wire gauge. Low voltage hook-up diagrams are included for various air handler models (TEM 6/8 and TAM 7/9), detailing connections between the thermostat, air handler, and outdoor unit. Defrost control settings and checkout procedures are also described, including termination temperatures and pin identifications for testing. High voltage power supply requirements emphasize compliance with national, state, and local codes, and the installation of a separate disconnect switch at the outdoor unit. Grounding the outdoor unit is also a mandatory step.
System startup procedures include ensuring all previous installation steps are completed, setting the thermostat to OFF, applying power, and waiting one hour if a compressor crankcase heater accessory is used and the outdoor ambient is below 70°F, before setting the thermostat to ON.
System charge adjustment is a key part of the startup. For outdoor temperatures above 55°F, subcooling in cooling mode is the recommended charging method. The guide provides charts to determine the final subcooling value based on total line length and lift. For outdoor temperatures below 55°F, the weigh-in method in heating mode is recommended, with instructions for calculating additional charge based on line length. The system must be operated for a minimum of 20 minutes to stabilize before accurate measurements can be made.
The guide concludes with checkout procedures and troubleshooting. A comprehensive checklist ensures that all aspects of the installation are verified, including leak checks, proper insulation and securing of refrigerant lines, sealing of masonry passages, tight electrical connections, proper indoor coil drain line function, unobstructed supply registers and return grilles, installed return air filter, correct airflow setting, and smooth outdoor fan operation. The system is to be operated in each mode to ensure safe operation.
The troubleshooting section, presented as a "System Faults" table, helps diagnose common issues by categorizing them into Refrigerant Circuit, Electrical, and Defrost problems. For each fault, it lists primary and secondary causes, guiding technicians through a systematic diagnostic process. This includes checking power supply, wiring, compressor components, refrigerant levels, airflow, and control systems. The guide also advises referring to the Service Facts document included with the unit for detailed wiring diagrams and additional information.
The document emphasizes that the manufacturer recommends installing only approved matched indoor and outdoor systems to achieve maximum efficiency, optimum performance, and the best overall system reliability. It also highlights the importance of promptly reporting any damage found upon delivery to the carrier. The use of POE oil in R-410A systems, which readily absorbs moisture, necessitates keeping the system sealed whenever possible and replacing compressor oil and driers if the system has been open to the atmosphere for more than four hours. These maintenance considerations are crucial for the longevity and efficient operation of the heat pump.
General| Model | 4TWX7 Series |
|---|---|
| Type | Heat Pump |
| Refrigerant | R-410A |
| Compressor Type | Variable Speed |
| Voltage | 208/230V |
| SEER Rating | Up to 20 SEER |
| HSPF Rating | Up to 10 HSPF |
| Stages | Variable |
| Unit Weight | Varies by model |
| Dimensions (H x W x D) | Varies by model |
