Trane 4TWX7 Series User Manual

18-BC109D1-1A-EN
ALL phases of this installation must comply with NATIONAL, STATE AND LOCAL CODES
IMPORTANT — This Document is customer property and is to remain with this unit. Please return to service informa-
tion pack upon completion of work.
Heat Pumps
These instructions do not cover all variations in systems or provide for every possible contingency to be met in connection with
the installation. Should further information be desired or should particular problems arise which are not covered sufficiently for the
purchaser’s purposes, the matter should be referred to your installing dealer or local distributor.
Note: The manufacturer recommends installing only approved matched indoor and outdoor systems. All of the manufacture’s split
systems are AHRI rated only with TXV/EEV indoor systems. Some of the benefits of installing approved matched indoor and out-
door split systems are maximum efficiency, optimum performance and the best overall system reliability.
4TWX7
Installer’s Guide
Table of Contents
Section 1. Safety ..................................................................................... 2
Section 2. Unit Location Considerations ............................................. 3
Section 3. Unit Preparation.................................................................... 5
Section 4. Setting the Unit ..................................................................... 5
Section 5. Refrigerant Line Considerations ......................................... 6
Section 6. Refrigerant Line Routing ..................................................... 8
Section 7. Refrigerant Line Brazing ...................................................... 9
Section 8. Refrigerant Line Leak Check ............................................. 11
Section 9. Evacuation .......................................................................... 12
Section 10. Service Valves .................................................................. 12
Section 11. Electrical - Low Voltage ................................................... 13
Section 12. Electrical - High Voltage .................................................. 15
Section 13. Start Up.............................................................................. 16
Section 14. System Charge Adjustment............................................. 17
Section 15. Checkout Procedures and Troubleshooting .................. 23

Trane 4TWX7 Series Specifications

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

Summary

Section 1. Safety

Section 2. Unit Location Considerations

2.1 Unit Dimensions and Weight

Details unit dimensions (H x D x W) and estimated weights for various models.

2.2 Refrigerant Piping Limits

Specifies maximum total and vertical lengths for refrigerant lines.

2.3 Suggested Locations for Best Reliability

Recommends placement for optimal airflow, noise avoidance, and protection from elements.

2.4 Cold Climate Considerations

Provides precautions for installing units in areas with snow and freezing temperatures.

2.5 Coastal Considerations

Addresses requirements for installations near salt water environments.

Section 3. Unit Preparation

3.1 Prepare The Unit For Installation

Steps for checking unit for damage and removing it from the pallet.

Section 4. Setting the Unit

4.1 Pad Installation

Guidelines for installing the unit on a support pad, including level and clearance.

Section 5. Refrigerant Line Considerations

5.1 Refrigerant Line and Service Valve Connection Sizes

Details line sizes and service valve connection sizes for different models.

5.2 Factory Charge

Information on factory charge for outdoor condensing units and system verification.

5.3 Required Refrigerant Line Length

Instructions to determine required line length and lift for system configuration.

5.4 Refrigerant Line Insulation

Emphasizes insulating the vapor line and preventing metal-to-metal contact.

5.5 Reuse Existing Refrigerant Lines

Precautions for using existing refrigerant lines, including brazing and cleanliness.

Section 6. Refrigerant Line Routing

6.1 Precautions

Guidelines for routing refrigerant lines to prevent noise and ensure proper isolation.

Section 7. Refrigerant Line Brazing

7.1 Braze The Refrigerant Lines

Detailed steps for preparing and brazing refrigerant lines to service valves.

Section 8. Refrigerant Line Leak Check

8.1 Check For Leaks

Procedure for pressurizing lines with nitrogen and checking for leaks using soapy solution.

Section 9. Evacuation

9.1 Evacuate the Refrigerant Lines and Indoor Coil

Instructions for evacuating the system to a specific micron level.

Section 10. Service Valves

10.1 Open the Gas Service Valve

Steps to open the gas service valve after leak check and evacuation.

10.1 Open the Liquid Service Valve

Procedure for carefully opening the liquid line service valve without over-torquing.

Section 11. Electrical - Low Voltage

11.1 Low Voltage Maximum Wire Length

Table specifying maximum wire lengths for low voltage wiring based on gauge.

11.2 Low Voltage Hook-up Diagrams

Wiring diagrams for connecting thermostat, air handler, and outdoor unit.

11.3 Defrost Control

Details on defrost control settings, termination temperatures, and checkout procedures.

Section 12. Electrical - High Voltage

12.1 High Voltage Power Supply

Guidance on high voltage power supply requirements and compliance with codes.

12.2 High Voltage Disconnect Switch

Recommendation for installing a separate disconnect switch at the outdoor unit.

12.3 High Voltage Ground

Requirement to ground the outdoor unit according to national, state, and local codes.

Section 13. Start Up

13.1 System Start Up

Step-by-step procedure for starting the installed HVAC system.

Section 14. System Charge Adjustment

14.1 Temperature Measurements

Instructions for measuring outdoor and indoor temperatures for system charging.

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

Method for adjusting refrigerant charge using subcooling for temperatures above 55°F.

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

Method for charging in heating mode below 55°F outdoor temperature using weigh-in.

Section 15. Checkout Procedures and Troubleshooting

15.1 Operational And Checkout Procedures

Final inspection and operational checks to ensure system performance and safety.

15.2 Troubleshooting

Guide to identifying and resolving system faults based on symptoms and causes.