Trane 4TWR7 - User Manual

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Summary

Section 2: Unit Location Considerations

2.1 Unit Dimensions and Weight

Details unit dimensions and weight, with mounting and isolation recommendations.

2.2 Refrigerant Piping Limits

Specifies maximum total length and vertical change for refrigerant lines.

2.3 Suggested Locations for Best Reliability

Provides guidance on unit placement for optimal performance and avoiding issues.

2.4 Cold Climate Considerations

Offers precautions for installations in areas with snow and freezing temperatures.

2.5 Coastal Considerations

Addresses requirements for installations near saltwater environments.

Section 3: Unit Preparation

3.1 Prepare The Unit For Installation

Outlines steps for checking unit for damage and removing it from the pallet.

Section 4: Setting the Unit

4.1 Pad Installation

Details requirements for installing the unit on a support pad, including size and levelness.

Section 5: Refrigerant Line Considerations

5.1 Refrigerant Line and Service Valve Connection Sizes

Provides a table detailing line sizes and service valve connection sizes for different models.

5.2 Factory Charge

Explains the factory charge details and the importance of verifying system charge.

5.3 Required Refrigerant Line Length

Instructs on determining required line length and lift for system charge calculations.

5.4 Refrigerant Line Insulation

Emphasizes the necessity of insulating the vapor line and avoiding metal-to-metal contact.

5.5 Reuse Existing Refrigerant Lines

Provides precautions for reusing existing refrigerant lines in retrofit applications.

Section 6: Refrigerant Line Routing

6.1 Precautions

Details precautions to prevent noise transmission from refrigerant lines within the building structure.

Section 7: Refrigerant Line Brazing

7.1 Braze The Refrigerant Lines

Step-by-step guide for preparing and brazing refrigerant lines to service valves.

Section 8: Refrigerant Line Leak Check

8.1 Check For Leaks

Describes the process of pressurizing lines with nitrogen and checking for leaks using a soapy solution.

Section 9: Evacuation

9.1 Evacuate the Refrigerant Lines and Indoor Coil

Details the procedure for evacuating refrigerant lines and the indoor coil using a micron gauge.

Section 10: Service Valves

10.1 Open the Gas Service Valve

Explains how to properly open the gas service valve after leak check and evacuation.

10.2 Open the Liquid Service Valve

Provides critical safety warnings and instructions for opening the liquid service valve.

Section 11: Electrical - Low Voltage

11.1 Low Voltage Maximum Wire Length

Defines the maximum allowable lengths for low voltage wiring based on wire size.

11.2 Low Voltage Hook-up Diagrams (cont.)

Illustrates low voltage wiring connections for different thermostat and air handler models.

11.3 Defrost Control

Explains defrost control settings, termination temperatures, and checkout procedures.

Section 12: Electrical - High Voltage

12.1 High Voltage Power Supply

Covers high voltage power supply requirements and compliance with codes and nameplate data.

12.2 High Voltage Disconnect Switch

Recommends installing a separate disconnect switch and using flexible conduit for connections.

12.3 High Voltage Ground

Specifies grounding requirements for the outdoor unit according to national, state, and local codes.

Section 13: Start Up

13.1 System Start Up

Guides through the initial steps for starting up the system, including thermostat settings and power application.

Section 14: System Charge Adjustment

14.1 Temperature Measurements

Details how to measure outdoor and indoor temperatures for system charging.

14.2 Subcooling Charging in Cooling (Above 55º F Outdoor Temp.)

Provides charts and instructions for charging the system using subcooling above 55°F ambient.

14.3 Subcooling Charging Below 55º F Outdoor Temp. (In Heating Only)

Explains the weigh-in method for charging when outdoor temps are below 55°F.

Section 15: Checkout Procedures and Troubleshooting

15.1 Operational And Checkout Procedures

Outlines essential operational checks and final inspections for proper system performance.

15.2 Troubleshooting

Lists system faults and potential causes across refrigerant circuit, electrical, and defrost categories.

This document is an Installer's Guide for Trane Condensing Units, specifically the 4TWR7 series. It provides comprehensive instructions for the installation, start-up, and servicing of these outdoor air conditioning units.

Function Description:

The Trane 4TWR7 series condensing units are outdoor components of a central air conditioning system. They are designed to work in conjunction with an indoor evaporative coil and refrigerant lines to provide heating, ventilating, and air-conditioning (HVAC) for residential and commercial applications. These units utilize R-410A refrigerant, which operates at higher pressures than R-22.

Important Technical Specifications:

Refrigerant Type: R-410A. It is crucial to use only R-410A approved service equipment and POE compressor oil. Refrigerant cylinders are "Rose" colored.
Operating Pressures: R-410A systems operate at 50-70% higher pressures than R-22.
POE Oil: The system uses POE oil, which readily absorbs moisture. Systems should remain sealed whenever possible. If a system has been open to the atmosphere for more than 4 hours, the compressor oil must be replaced. Driers should always be changed when opening the system for component replacement.
Unit Dimensions and Weight (Estimated):
- 4TWR7024A: 41" H x 34" D x 37" W, 236 lbs
- 4TWR7036B: 41" H x 34" D x 37" W, 210 lbs
- 4TWR7048A: 45" H x 34" D x 37" W, 292 lbs
- 4TWR7060A: 45" H x 34" D x 37" W, 293 lbs
Refrigerant Piping Limits:
- Maximum TOTAL line length (outdoor to indoor unit): 150 feet (including lift).
- Maximum vertical change (lift): 50 feet.
- Specific line sizes and service valve connection sizes are provided in Table 5.1, with alternate line sizes also listed, affecting maximum line length and lift for certain tonnages.
Low Voltage Wiring:
- 18 AWG: Max. 150 Ft.
- 16 AWG: Max. 225 Ft.
- 14 AWG: Max. 300 Ft.
Defrost Termination Temperatures:
- As Shipped (Jumper 2 intact):
  - 22°F Outdoor Temp: 47°F Termination Temp
  - 10°F-22°F Outdoor Temp: ODT + 25°F Termination Temp
  - 6°F-10°F Outdoor Temp: 35°F Termination Temp
- Cut Jumper 2:
  - 30°F Outdoor Temp: 47°F Termination Temp
  - 6°F-30°F Outdoor Temp: 70°F Termination Temp
- All < 6°F Outdoor Temp: 12 min. or 35°F every 3 hrs.
Factory Charge: Units are factory charged with the system charge required for the outdoor condensing unit, ten (10) feet of tested connecting line, and the smallest rated indoor evaporative coil match.

Usage Features:

Installation Location:
- Top discharge area must be unrestricted for at least five feet above the unit.
- Three feet clearance is required in front of the control box (access panels) and any other side requiring service.
- Minimum 12 inches clearance from any wall or surrounding shrubbery for adequate airflow.
- Avoid locations near bedrooms or windows where noise or defrost vapor could be an issue.
- For roof mounting, ensure the roof can support the unit's weight, and consider isolation to alleviate sound/vibration transmission.
- In cold climates, units should be elevated 3-12 inches above the pad/rooftop to allow for drainage of melted snow/ice and prevent obstruction of drain holes. Snow drift barriers may be necessary.
- For installations within one mile of salt water, the BAYSEAC001 (Seacoast Kit) is required for models without factory-supplied Seacoast Salt Shields.
Pad Installation: The support pad (e.g., concrete slab) should be at least 1 inch larger than the unit on all sides, separate from any structure, level, and high enough for drainage.
Refrigerant Line Routing:
- Comply with National, State, and Local Codes for isolating line sets.
- Use isolation-type hangers when fastening lines to joists/framing.
- Insulate and isolate lines running through walls or sills.
- Isolate lines from all ductwork.
- Minimize 90-degree turns.
- Secure vapor lines from joists using isolators every 8 ft. Secure liquid lines directly to vapor lines using tape, wire, or other methods every 8 ft.
Refrigerant Line Insulation: The vapor line must always be insulated. The liquid line and vapor line should not come into direct (metal-to-metal) contact.
Reusing Existing Lines: If using existing refrigerant lines, ensure all joints are brazed (not soldered), lines are the correct size, and free of leaks, acid, and oil.
Brazing:
- Debur and clean pipe ends.
- Remove pressure tap caps and valve cores from service valves before brazing.
- Purge lines and indoor coil with dry nitrogen.
- Wrap a wet rag around the valve body to prevent heat damage during brazing.
- Check the liquid line filter drier's directional flow arrow for correct refrigeration flow.
- Continue dry nitrogen purge until brazing is complete.
- Avoid direct flame on the basepan.
Leak Check: Pressurize lines and evaporator coil to 150 PSIG with dry nitrogen and check for leaks with soapy solution.
Evacuation: Evacuate until the micron gauge reads no higher than 350 microns. Evacuation is complete if the micron gauge does not rise above 500 microns in one minute.
Service Valve Operation:
- Gas Service Valve: Remove cap, turn valve stem 1/4 turn counterclockwise to fully open, replace cap (finger tight plus 1/6 turn).
- Liquid Service Valve: Remove cap, fully insert 3/16" hex wrench, back out counterclockwise until valve stem just touches the rolled edge (approx. 5 turns), replace cap (finger tight plus 1/6 turn). Extreme caution is advised to prevent abrupt release of system charge.
Electrical Connections:
- High Voltage: Power supply must match nameplate. Comply with codes. Install a separate disconnect switch. Use flexible electrical conduit to prevent vibration transmission.
- Low Voltage: Wiring diagrams are provided for TEM 6/8 and TAM 7/9 air handlers.
Start-Up Procedure:
- Ensure all installation steps are complete.
- Set system thermostat to OFF.
- Turn on disconnects to apply power.
- Wait one hour before starting if a compressor crankcase heater accessory is used and outdoor ambient is below 70°F.
- Set system thermostat to ON.
System Charge Adjustment:
- Subcooling Charging (Above 55°F Outdoor Temp.): This is the recommended method. Use provided charts to determine final subcooling value based on total line length and lift. Stabilize the system for at least 20 minutes before making measurements. Add or recover refrigerant to achieve the proper liquid gage pressure based on the R-410A Refrigerant Charging Chart.
- Weigh-In Method (Below 55°F Outdoor Temp. or Initial Installation): This is the recommended method for heating mode below 55°F. Calculate additional charge needed based on line length (0.6 oz/ft for interconnecting tubing beyond 10 ft). Stabilize the system for 20 minutes. Check liquid line temperature and liquid gage pressure to obtain a minimum of 10° subcooling.
Defrost Control: Defrost termination temperature is selectable (47°F as shipped, or 70°F by cutting Jumper J2 for ambient below 30°F). Test pins are available for speeding up defrost board timings (TST) or initiating a forced defrost (FRC_DFT).

Maintenance Features:

General Safety: Only qualified personnel should install and service the equipment. Observe all precautions.
System Sealing: Keep the system sealed to limit moisture absorption by POE oil.
Drier Replacement: Always change driers when opening the system for component replacement.
Leak Checks: Regular leak checks are part of the installation and troubleshooting process.
Operational Checkout: After installation, perform a checkout procedure including:
- Leak checking refrigerant lines.
- Insulating suction lines and fittings.
- Securing and isolating refrigerant lines.
- Sealing masonry passages.
- Verifying electrical connections.
- Observing outdoor fan operation.
- Ensuring indoor coil drain line drains freely.
- Confirming supply registers and return grilles are open.
- Installing a return air filter.
- Setting correct airflow.
- Operating the system in each mode.
Troubleshooting: A detailed "SYSTEM FAULTS" chart is provided to assist in diagnosing refrigerant circuit and electrical issues, categorizing causes as primary (P) or secondary (S).
Record Keeping: Record system information (outdoor model number, measured ambient temperatures, liquid line temp, liquid gage pressure, suction line temp, suction gage pressure) after charging for future reference.