TRANE 4TWA4036A3000A Split System Heat Pump Instruction Manual

Installation and Operation Manual
Split System Heat Pump
3-Phase, 230V
3-Phase, 460V 2008-230V MODELL
4TWA4036A3000A
4TWA4042A3000A
4TWA4048A3000A
4TWA4060A3000A
4660V MODEL
4TWA4036A4000A
4TWA4042A4000A
4TWA4048A4000A
4TWA4060A4000A

4TWA4036A3000A Split System Heat Pump

Note : “Graphics in this document are for representation only. Actual model may differ in appearance.”

SAFETY WARNING
Only qualified personnel should install and service the equipment. The installation, starting up, and servicing of heating, ventilating, and air- conditioning equipment can be hazardous and requires specific knowledge and training. Improperly installed, adjusted or altered equipment by an unqualified person could result in death or serious injury. When working on the equipment, observe all precautions in the literature and on the tags, stickers, and labels that are attached to the equipment.

May 2023
18-BC97D1-1E-EN

SAFETY SECTION
Important— This document contains service information. This is customer property and is to remain with this unit. Please return to service information pack upon completion of work.

WARNING
HAZARDOUS VOLTAGE!
Failure to follow this Warning could result in property damage, severe personal injury, or death.
Disconnect all electric power, including remote disconnects before servicing. Follow proper lockout/tagout procedures to ensure the power cannot be inadvertently energized.

WARNING
REFRIGERANT OIL!
Failure to follow this Warning could result in property damage, severe personal injury, or death.

These units use R-410A refrigerant which operates at 50–70% higher pressures than R-22. Use only R- 410A approved service equipment. Refrigerant cylinders are painted a “Rose” color to indicate the type of refrigerant and may contain a “dip” tube to allow for charging of liquid refrigerant into the system. All R-410A systems use a POE oil that readily absorbs moisture from the atmosphere. To limit this “hydroscopic” action, the system 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. Never break a vacuum with air and always change the driers when opening the system for component replacement. For specific handling concerns with R-410A and POE oil, reference Retrofit Bulletin TRN-APG02–EN.

CAUTION

HOT SURFACE!
May cause minor to severe burning. Failure to follow this Caution could result in property damage or personal injury.
Do not touch top of compressor.

CAUTION
CONTAINS REFRIGERANT!
Failure to follow proper procedures can result in personal illness or injury or severe equipment damage.
System contains oil and refrigerant under high pressure. Recover refrigerant to relieve pressure before opening system.

CAUTION
GROUNDING REQUIRED!
Failure to inspect or use proper service tools may result in equipment damage or personal injury. Reconnect all grounding devices. All parts of this product that are capable of conducting electrical current are grounded. If grounding wires, screws, straps, clips, nuts, or washers used to complete a path to ground are removed for service, they must be returned to their original position and properly fastened.

WARNING
SERVICE VALVES!
Failure to follow this warning will result in abrupt release of system charge and may result in personal injury and/or property damage. Extreme caution should be exercised when opening the Suction and Liquid Line Service Valve.
Turn valve stem counterclockwise only until the stem contacts the rolled edge. No torque is required.

WARNING
BRAZING REQUIRED – IF USING MECHANICAL CONNECTIONS, ENSURE LEAK TEST IS NEGATIVE!
Failure to inspect lines or use proper service tools may result in equipment damage or personal injury.
If using existing refrigerant lines make certain that all joints are brazed, not soldered.

WARNING
Warning!
This product can expose you to chemicals including lead which are known to the State of California to cause cancer and birth defects or other reproductive harm.
For more information go to www.P65Warnings.ca.gov

Important: Ifusing other than copper pipe, follow manufacturer’s installation instructions. Joints mustbe brazed or otherUL/IMC/ URMCapproved joint that meets pressure requirements.

Unit Location Considerations

Table 1. Unit Dimensions and Weight

• Weight values are estimated (uncrated).

  • When mounting the outdoor unit on a roof, be sure the roof will support the unit’s weight.
  • Properly selected isolation is recommended to alleviate sound or vibration transmission to the building structure.

Table 2. Refrigerant Line and Service Valve Connection Sizes

1. The maximum TOTAL length of refrigerant lines from outdoor to indoor unit should NOTexceed 150 feet (including lift).
2. The maximum vertical change should not exceed 50 feet.
3. Service valve connection diameters are shown in the Refrigerant line and Service Valve connection size table on page 7.

Note: For other line lengths, Refer to Refrigerant Piping Application Guide, SS-APG006F-EN, or Refrigerant Piping Software Program.

Table 3. Suggested Locations for Best Reliability

• Ensure the top discharge area is unrestricted for at least 5 feet above the unit.
• Provide at least 3 feet clearance in front of the control box (access panels) and any other side requiring service.
• Do not locate close to bedrooms as operational sounds may be objectionable.
• Avoid locations near windows and similar areas where condensation and freezing defrost vapor can annoy a customer.
• Position the outdoor unit a minimum of 12” from any wall or surrounding shrubbery to ensure adequate airflow.
• Outdoor unit location must be far enough away from any structure to prevent excess roof runoff water or icicles from falling directly on the unit.
• Position the outdoor unit a minimum of 12” from any wall or surrounding shrubbery to ensure adequate airflow.
• Outdoor unit location must be far enough away from any structure to prevent excess roof runoff water or icicles from falling directly on the unit.

Table 4. Cold Climate Considerations (Heat Pump Only)
Note: It is recommended that these precautions be taken for units being installed in areas where snow accumulation and prolonged below-freezing temperatures occur.

• Units should be elevated 3–12 inches above the pad or rooftop, depending on local weather. This additional height will allow drainage of snow and ice melted during defrost cycle prior to its refreezing. Ensure that drain holes in unit base pan are not obstructed, preventing drainage of defrost water.
• If possible, avoid locations that are likely to accumulate snow drifts. If not possible, a snow drift barrier should be installed around the unit to prevent a build-up of snow on the sides of the unit.

Table 5. Coastal Considerations
If installed within one mile of salt water, including seacoasts and inland waterways, models without factory supplied Seacoast Salt Shields require the addition of BAYSEAC001 (Seacoast Kit) at installation time.

Unit Preparation

1. Check for damage and report promptly to the carrier any damage found to the unit.
2. To remove the unit from the pallet, remove tabs by cutting with a sharp tool.

Setting Up the Unit
Table 6. Pad Installation
When installing the unit on a support pad, such as a concrete slab, consider the following:

• The pad should be at least 1” larger than the unit on all sides.
• The pad must be separate from any structure.
• The pad must be level.
• The pad should be high enough above grade to allow for drainage.
• The pad location must comply with National, State, and Local codes.

Refrigerant Line Considerations
Table 7. Refrigerant Line and Service Valve Connection Sizes

| Line Sizes| Service Valve Connection Sizes
---|---|---
Model| Vapor Line| Liquid Line| Vapor Line Connection| Liquid Line Connection
4TWA4036A3| 7/8| 3/8| 7/8| 3/8
4TWA4042A3| 7/8| 3/8| 7/8| 3/8
4TWA4048A3| 7/8| 3/8| 7/8| 3/8
4TWA4060A3| 1–1/8| 3/8| 7/8| 3/8
4TWA4036A4| 7/8| 3/8| 7/8| 3/8
4TWA4042A4| 7/8| 3/8| 7/8| 3/8
4TWA4048A4| 7/8| 3/8| 7/8| 3/8
4TWA4060A4| 1–1/8| 3/8| 7/8| 3/8

Table 8. Factory Charge
The outdoor condensing 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. Always verify proper system charge via subcooling (TXV/EEV) or superheat (fixed orifice) per the unit nameplate.

Table 9. Required Refrigerant Line Length
Determine required line length and lift. You will need this to determine the subcooling charging corrections later in the installation process.
Total Line Length = __Ft.
Total Vertical Change (lift) = ____Ft.

Table 10. Refrigerant Line Insulation

Important: The Vapor Line must always be insulated. DO NOTallow the Liquid Line and Vapor Line to come in direct (metal to metal) contact.
Note: The gas line must always be insulated. Insulating the liquid line through attic spaces may benefit system performance by minimizing heat gain in the liquid line.

Table 11. Reuse Existing Refrigerant Lines

CAUTION

REFRIGERANT!
Failure to inspect or use proper service tools may result in equipment damage or personal injury.
If using existing refrigerant lines make certain that all joints are brazed, not soldered.

For retrofit applications, where the existing indoor evaporator coil and/or refrigerant lines will be used, the following precautions should be taken.

• Ensure that the indoor evaporator coil and refrigerant lines are the correct size.
• Ensure that the refrigerant lines are free of leaks, acid, and oil.

Important: For more information, see publication number SS-APG006F-EN.

Table 12. Refrigerant Line Routing Precautions

Important: Comply with National, State, and Local Codes when isolating line sets from joists, rafters, walls, or other structural elements.
Important: Take precautions to prevent noise within the building structure due to vibration transmission from the refrigerant lines.
For Example:

• When the refrigerant lines must be fastened to floor joists or other framing in a structure, use isolation type hangers.
• Isolation hangers should also be used when refrigerant lines are run in stud spaces or enclosed ceilings.
• Where the refrigerant lines run through a wall or sill, they should be insulated and isolated.
• Isolate the lines from all duct work.
• Minimize the number of 90° turns.

Table 13. Isolation From Joist/Rafter

Secure Vapor Line from joists using isolators every 8 ft. Secure Liquid Line directly to insulated Vapor Line using tape, wire, or other appropriate method every 8 ft.

Table 14. Isolation In Wall Spaces

Secure Vapor Line from joists using isolators every 8 ft. Secure Liquid Line directly to insulated Vapor Line using tape, wire, or other appropriate method every 8 ft.

Table 15. Isolation Through Wall

Refrigerant Line Brazing

Table 16. Braze the Refrigerant Lines

1. Remove caps or plugs. Use a deburring tool to debur the pipe ends. Clean both internal and external surfaces of the tubing using an emery cloth.

2. Remove the pressure tap cap and valve core from each service valves.

3. Purge the refrigerant lines and indoor coil with dry nitrogen.

4. Wrap a wet rag around the valve body to avoid heat damage and continue the dry nitrogen purge.

5. Braze the refrigerant lines to the service valves.
   a. For Units shipped with a field-installed external drier, check liquid line filter drier’s directional flow arrow to confirm correct direction of refrigeration flow (away from outdoor unit and toward evaporator coil) as illustrated. Braze the filter drier to the Liquid Line.

6. Continue the dry nitrogen purge. Do not remove the wet rag until all brazing is completed.
   Important: Remove the wet rag before stopping the dry nitrogen purge.
   Note: Precautions should be taken to avoid heat damage to base pan during brazing. It is recommended to keep the flame directly off of the base pan.

7. Replace the pressure tap valve cores after the service valves have cooled.

Refrigerant Line Leak Check

Table 17. Check for Leaks

1. Pressurize the refrigerant lines and evaporator coil to 150 PSIG using dry nitrogen.
2. Check for leaks by using a soapy solution at each brazed location.

Note: Remove nitrogen pressure and repair any leaks before continuing.

Refrigerant Line and Indoor Coil Evacuation

Important: Do notopen the service valves until the refrigerant lines and indoor coil leakcheckand evacuation are complete.

1. Evacuate until the micron gauge reads no higher than 350 microns, then close off the valve to the vacuum pump.
2. Observe the micron gauge. Evacuation is complete if the micron gauge does not rise above 500 microns in one (1) minute.
3. When evacuation is complete, blank off the vacuum pump and micron gauge, and close the valves on the manifold gauge set.

Service Valves

Table 18. Open the Gas Service Valve

Important: Leak check and evacuation must be completed before opening the service valves.
Note: Do not vent refrigerant gases into the atmosphere.

1. Remove valve stem cap.

2. Using a wrench, turn valve stem 1/4 turn counterclockwise to the fully open position.

3. Replace the valve stem cap to prevent leaks. Tighten finger tight plus an additional 1/4 turn. Table 19. Open the Liquid Service Valve
   WARNING
   SERVICE VALVES!
   Failure to follow this warning will result in abrupt release of system charge and may result in personal injury and/or property damage.
   Extreme caution should be exercised when opening the Suction and Liquid Line Service Valve. Turn valve stem counterclockwise only until the stem contacts the rolled edge. No torque is required.
   Important: Leak check and evacuation must be completed before opening the service valves.

4. Remove service valve cap.

5. Fully insert 3/16” hex wrench into the stem and back out counterclockwise until valve stem just touches the rolled edge (approximately five (5) turns).

6. Replace the valve cap to prevent leaks. Tighten finger tight plus an additional 1/4 turn.

Electrical – Low Voltage

Table 20. Low Voltage Maximum Wire Length

The table defines the maximum total length of low voltage wiring from the outdoor unit, to the indoor unit, and to the thermostat.| 24 VOLTS
---|---
WIRE SIZE| MAX. WIRE LENGTH
18 AWG| 150 Ft
16 AWG| 225 Ft.
14 AWG| 300 Ft.

Note: The use ofcolor coded low voltage wire is recommended to simplify connections between the outdoor unit, the control, and the indoor unit.

Table 21. Low Voltage Hook-up Diagrams

• Units with pigtails require wirenuts for connections.

• In AC systems for multiple stages of electric heat, jumper W1 and W2 together if comfort control has only one stage of heat.

• Y2 for TEM6

Table 22. Defrost Control
Defrost controls have a selectable termination temperature. As shipped, defrost will terminate at 47°F. for higher termination temperature, cut Jumper J2 to achieve 70°F. Refer to the “Defrost Control,” p. 18 for more information.

Electrical – High Voltage

Table 23. High Voltage Power Supply
WARNING
LIVE ELECTRICAL COMPONENTS!
Failure to follow this Warning could result in property damage, severe personal injury, or death.
Follow all electrical safety precautions when exposed to live electrical components. It may be necessary to work with live electrical components during installation, testing, servicing, and troubleshooting of this product.
The high voltage power supply must agree with the equipment nameplate.
Power wiring must comply with national, state, and local codes.
Follow instructions on unit wiring diagram located on the inside of the control box cover and in this document included with the unit. 

Table 24. High Voltage Disconnect Switch

WARNING
HIGH LEAKAGE CURRENT!
Failure to follow this Warning could result in property damage, severe personal injury, or death.
Earth connection essential before connecting electrical supply.

Install a separate disconnect switch at the outdoor unit.
For high voltage connections, flexible electrical conduit is recommended whenever vibration transmission may create a noise problem with in the structure.

Table 25. High Voltage Disconnect Switch
Ground the outdoor unit per national, state, and local code requirements.

System Start Up

1. Set the system thermostat to OFF.
2. Turn on electrical power disconnect(s) to apply power to the indoor and outdoor units.
3. Wait one (1) hour before starting the unit if compressor crankcase heater accessory is used and the Outdoor Ambient is below 70°F.
4. Set the system thermostat to ON.

System Charge Adjustment
Table 26. Temperature Measurements
Check the outdoor temperatures.
Subcooling using “Charging Mode-Cooling” is the only recommended method of charging between 55 ° F and 120° F ambient outdoor temperature.
For best results the indoor temperature should be kept between 70° F to 80° F.

Table 27. Subcooling Charging Corrections

Determine the final subcooling value using total Line Length and Lift measured in “Required Refrigerant Line Length” and the “Subcooling Charging Corrections Charts.”| Subcooling Charging Correction Worksheet
Total Line Length (ft) __
Total Vertical Charge (lift) _____
(Values from — Required Refrigerant Line Length)
Design Subcooling Value ____
(from nameplate)
Final Subcooling Value ____
---|---

Note: The only mode approved for setting or validating system charge is using Charging Mode-Cooling. Charging Mode-Cooling is a variable speed test mode found in the 850/950/1050 and UX360 comfort control Technician Menu’s. Test modes can also be accessed using the Diagnostic Mobile App on Link systems. Outdoor Temperature must be between 55°Fand 120°Fwith Indoor Temperature kept between 70°Fand 80°F.
Important: VARIABLE SPEED OUTDOOR UNITS REQUIRE THEINDOOR UNITBECONFIGURED FOR 400 CFM/TON IN clii MODE.

Subcooling Charging in Cooling between 55° F and 120° OD Ambient
Trane has always recommended installing Trane approved matched indoor and outdoor systems.
The benefits of installing approved indoor and outdoor split systems are maximum efficiency, optimum performance and the best overall reliability.
The following charging methods are therefore prescribed for matched systems with indoor TXVs / EEVs.
(Systems can be rated with TXV, EEV or Piston. Ensure charging method is correct).

1. Subcooling (in the cooling mode) is the only recommended method of charging above 55° ambient temperatures.
2. For best results – the indoor temperature should be kept between 70° to 80° F. Add system heat if needed.
3. At startup, or whenever charge is removed or added, the system must be operated for a minimum of (20) minutes to stabilize before accurate measurements can be made.
4. Measure Liquid Line Temperature and Refrigerant Pressure at service valves.
5. Determine total refrigerant line length, and height (lift) if indoor section is above the condenser.
6. Determine the Design Subcooling Charging Temperature from the unit nameplate.
7. Locate this value in the appropriate column of the Subcooling Charging Table. Locate your liquid line temperature in the left column of the table, and the intersecting liquid line pressure under yournameplate subcool value column. Add refrigerant to raise the pressure to match the table, or remove refrigerant to lower the pressure. Again, wait (20) minutes for the system conditions to stabilize before adjusting charge again.
8. When system is correctly charged, you can refer to System Pressure Curves to verify typical performance.

Subcool Charging Correction Charts

Charging the Unit
Table 28. Proper Gage Pressure

Using the Standard R-410A Subcool Charging Chart, adjust refrigerant level to attain proper gage pressure.
Add refrigerant if the Liquid Gage Pressure is lower than the chart value.

1. Connect gauges to refrigerant bottle and unit as illustrated.

2. Purge all hoses.

3. Open bottle.

4. Stop adding refrigerant when liquid line temperature and Liquid Gage Pressure match the charging chart.
   Note: Recover refrigerant ifthe Liquid Gage Pressure is higher than the chart value.
   Table 29. Stabilize the system

5. Wait 20 minutes for the system condition to stabilize between adjustments.
   Note: When the Liquid Line Temperature and Gage Pressure approximately match the chart, the system is properly charged.

6. Remove gauges.

7. Replace service port caps to prevent leaks. Tighten finger tight plus an additional 1/6 turn.
   Table 30. Verify Performance

8. Refer to “Pressure Curves,” p. 28 to verify typical performance.
   PRESSURE CURVE SAMPLE Table 31. System Information

9. Record system pressures and temperatures after charging is complete.
   Outdoor model number = __
   Measured Outdoor Ambient = _°F
   Measured Indoor Ambient = ___°F
   Measured Liquid Line Temp = __°F
   Measured Suction Line Temp = _°F
   Indoor Wet Bulb = ___°F
   Liquid Gage Pressure = _ PSIG
   Suction Gage Pressure = ___ PSIG

Refrigerant Charging Chart and Checkout Procedures

Table 32. R-410A Refrigerant Charging Chart

LIQUID GAGE PRESSURE (PSI)
55| 179| 182| 185| 188| 191| 195| 198
60| 195| 198| 201| 204| 208| 211| 215
65| 211| 215| 218| 222| 225| 229| 232
70| 229| 232| 236| 240| 243| 247| 251
75| 247| 251| 255| 259| 263| 267| 271
80| 267| 271| 275| 279| 283| 287| 291
85| 287| 291| 296| 300| 304| 309| 313
90| 309| 313| 318| 322| 327| 331| 336
95| 331| 336| 341| 346| 351| 355| 360
100| 355| 360| 365| 370| 376| 381| 386
105| 381| 386| 391| 396| 402| 407| 413
110| 407| 413| 418| 424| 429| 435| 441
115| 435| 441| 446| 452| 458| 464| 470
120| 464| 470| 476| 482| 488| 495| 501
125| 495| 501| 507| 514| 520| 527| 533

Table 33. Checkout Procedures
The final phase of the installation is the system Checkout Procedures. The following list represents the most common items covered in a Checkout Procedure. Confirm all requirements in this document have been met.

• All wiring connections are tight and properly secured.
• Voltage and running current are within limits.
• All refrigerant lines (internal and external to equipment) are isolated, secure, and not in direct contact with each other or structure.
• All braze connections have been checked for leaks. A vacuum of 350 microns provides confirmation that the refrigeration system is leak free and dry.
• Final unit inspection to confirm factory tubing has not shifted during shipment. Adjust tubing if necessary so tubes do not rub against each other or any component when unit runs.
• Ductwork is sealed and insulated.
• All drain lines are clear with joints properly sealed. Pour water into drain pan to confirm proper drainage. Provide enough water to ensure drain trap is primed.
• Supply registers and return grilles are open, unobstructed, and air filter is installed.
• Indoor blower and outdoor fan are operating smoothly and without obstruction.
• Indoor blower motor set on correct speed setting to deliver required CFM. “Blower and fan set screws are tight.”
• Cover panels are in place and properly tightened.
• For gas heating systems, manifold pressure has been checked and all gas line connections are tight and leak free.
• For gas heating systems, flue gas is properly vented.
• System functions safely and properly in all modes.
• Owner has been instructed on use of system and given manual.

Defrost Control

Defrost Control
The demand defrost control measures heat pump outdoor ambient temperature with a sensor located outside the outdoor coil. A second sensor located on the outdoor coil is used to measure the coil temperature. The difference between the ambient and the colder coil temperature is the difference or delta-T measurement. This delta-T measurement is representative of the operating state and relative capacity of the heat pump system. Measuring the change in delta-T determines the need for defrost. The coil sensor also serves to sense outdoor coil temperature for termination of the defrost cycle.

Fault Detection
A fault condition is indicated by the flashing Fault LED light on the defrost control board located inside the heat pump control box.
In normal operation, the status LED will flash once each second when idle or twice each second with a call for heating or cooling.

PIN Identification

1. TEST_COMMON (Shorting any of the other pins to this pin causes the function of the other pin to be executed. Leaving this pin open results in the normal mode of operation).
2. FRC_DFT = Forced Defrost (Short TEST_COMMON to this pin speeds up all defrost. Remove the short after defrost initiates.

Defrost Control Checkout
Normal operation requires:
a. Status LED on board flashing 1 time/second in standby or 2 times/second with a call for heating or cooling.
b. 24V AC between R & B
c. 24V AC between Y, Y0 & B with unit operating
d. Defrost initiation when FRC_DFT pin is shorted to TEST_COMMON pin.

Test Sensors
Measure the temperature the subject sensor is exposed to. If the sensor is mounted on a tube, place the lead on an Annie A-8 (or equiv.) temperature tester on the same tube near the sensor and insulate the bulb.
Unplug the sensor and measure the resistance with a good quality ohmmeter (Simpson 260 or equiv.). Read the value as quickly as possible to prevent the meter current from changing the resistance reading.
Using the chart, locate (as close as possible) the actual sensor temperature. The measured resistance should be relatively close to the resistance value shown in the chart.

Table 34. Defrost Control Thermistor Table

TEMP °F| TEMP °C| THERMISTOR RESISTANCE (OHMS)| Volts DC
---|---|---|---
-15.00| -26.11| 135976| 2.50
-10.00| -23.33| 115112| 2.40
-5.00| -20.56| 97745| 2.29
0.00| -17.78| 83247| 2.17
5.00| -15.00| 71108| 2.05
10.00| -12.22| 60916| 1.93
15.00| -9.44| 52333| 1.81
20.00| -6.67| 45076| 1.69
25.00| -3.89| 38927| 1.56
30.00| -1.11| 33703| 1.45
35.00| 1.67| 29253| 1.33
40.00| 4.44| 25452| 1.22
45.00| 7.22| 22198| 1.12
50.00| 10.00| 19405| 1.02
55.00| 12.78| 17002| 0.93
60.00| 15.56| 14930| 0.85
65.00| 18.33| 13138| 0.77
70.00| 21.11| 11586| 0.70
75.00| 23.89| 10238| 0.63
80.00| 26.67| 9065| 0.57
85.00| 29.44| 8043| 0.52
90.00| 32.22| 7150| 0.47
95.00| 35.00| 6368| 0.42
100.00| 37.78| 5682| 0.38
105.00| 40.56| 5079| 0.35
110.00| 43.33| 4548| 0.31
115.00| 46.11| 4079| 0.28
120.00| 48.89| 3665| 0.26
125.00| 51.67| 3298| 0.23
130.00| 54.44| 2972| 0.21
135.00| 57.22| 2683| 0.19

Example:
Sensor temp. = 19°F
Measured Resistance = 46K ohms
This sensor is good since the measured value is relatively close to the chart value.

Table 36. LED FAULT CODES

(a) GROUP suffix for drawing number D
(b) ≤ (EQUAL OR LESS THAN)

Table 36. LED FAULT CODES

after every 60 minutes of runtime. Defrost will terminate on coil temp. See Note 1 & 2.
2 FLASH| Coil Temp Sensor is out of range (open/shorted)| Initiate a 15 minute forced defrost after every 60 minutes of runtime. See Note 1 & 2.
3 FLASH| Low Pressure Switch is open| 3 flash goes away when/if LPCO closes.
4 FLASH| Hard Lock Out (can only be cleared with a low voltage power cycle)| Occurs after 9th trip of LPCO. See Note 6.
5 FLASH| Soft Lock Out| 5 flash goes away after soft lockout period expires. See Note 2.
---|---|---
6 FLASH| Defrost cycles too close together| Heating short cycle fault triggers 6 flash. The system will follow 10 adaptive time heating cycles and then return to demand defrost.
9 FLASH| Low Ambient Soft Lockout. Outdoor temperature dropped below 3°F.
(OFF at -12°F/ON at 3°F)| Outdoor temperature is below -12°F. See Note 5.

1. Initiate Adaptive/Timed Limp Mode so long as Coil Temp Sensor is functional. Monitor actual time in defrost and add or reduce run time until next forced defrost based on achieving a 4 minute (+/-1) defrost period.

2. This defrost control utilizes a safety strategy called “Adaptive Limp Mode”. Adaptive limp mode is defined as a timed heating mode following rapid defrosts (accumulated heating times between defrost totaling less than 15 minutes). Once invoked the DFC will limit defrost periods and maximize heating capacity. While in adaptive limp mode the DFC will monitor heating and defrost periods for no longer than 10 cycles. The DFC will then release the board to demand defrost; however, if the LPCO rips while in  limp mode the system will initiate a soft lockout and exit limp mode.
   If both Coil Temp Sensor and Ambient Temp Sensor have failed, initiate a 5 minute forced defrost every 60 minutes of run time. This in conjunction with the normal low pressure trip, will initiate a soft lockout.
   a. A short heating cycle that enters defrost in 15 minutes or less and/or enters two more defrosts with less than 15 minutes of accumulative run time each will enter an Adaptive Limp Mode (6 Flash).
   b. Coil sensor failure will initiate a Timed Limp Mode. This will be accompanied by a 2 flash. The DFC will initiate defrost after 60 minutes of accumulated heating runtime and terminate after a 5 minute defrost. The limp mode will clear after the sensor fault is cleared.
   c. Ambient sensor failure will initiate an Adaptive Timed Limp Mode. This will be accompanied by a 1 flash. The DFC will initiate defrost after 60 minutes of accumulated heating runtime and force a defrost, which will terminate on coil temp. The limp mode will clear after the sensor fault is cleared.
   d. This could be caused by a condenser fan motor failure, low charge or other reasons.

3. The first 15 minute soft lockout the system will return to normal operation. Should this continue to  operate in this manner there will be a 30 minute soft lockout and so on. At the end of the lockout process, if a hard lock is necessary, a 4 flash will be announced and system operation is interrupted. If the ambient temperature climbs above 40°F for more than 30 minutes this clears this fault count and resumes normal operation.
   a. If or when normal operation is restored after the ambient temperature climbs above 40°F for more than 30 minutes and another LP trip is monitored on the 9th trip this will initiate a hard lockout that will not be cleared by temperature or time.

4. Once ambient drops to -12 or lower wait 5 minutes before soft lockout begins. During soft lockout the Y signal passes through to the X2 output. Resume operation when ambient temperature rises to -3°F or higher and after 5 minute soft lockout period expires. LPCO should reset around 5°F.

5. During a Hard Lockout, the X2 relay opens so that the Y signal does not pass through.

Note: Once the LPCO closes, the 3 flash fault will not continue showing – only 5 flash if in the soft- lockout perio

Troubleshooting

Wiring Diagrams

Figure 1. 3.0 Ton 230V Models

Figure 2. 3.0 Ton 460V Models

Figure 3. 3.5, 4.0 & 5.0 Ton 230V Models

Figure 4. 3.5, 4.0 & 5.0 Ton 460V Models

NOTES:

1. BE SURE POWER SUPPLY AGREES WITH EQUIPMENT NAMEPLATE.
2. POWER WIRING AND GROUNDING OF EQUIPMENT MUST COMPLY WITH LOCAL CODES.
3. LOW VOLTAGE WIRING TO BE NO. 18 AWG MINIMUM CONDUCTOR.
4. ODT-B MUST BE SET LOWER THAN ODT-A, IF ODT-B IS NOT USED, ADD JUMPER BETWEEN W2 AND W3 AT AIR HANDLER, IF USED, ODT-B MUST BE MOUNTED REMOTE OF CONTROL BOX IN AN APPROVED WEATHERPROOF ENCLOSURE
5. IF ODT-A IS NOT USED, ADD JUMPER BETWEEN WI AND W2 AT AIR HANDLER

LEGEND

| FIELD-INSTALLED FACTORY WIRING
---|---
| TERMINAL BLOCK/BOARD
| RELAY CONTACT (N.O)
| RELAY CONTACT (N.C)
| THERMISTOR
| MOTOR WINDING
| MAGNETIC COIL
| GROUND
| JUNCTION
| CAPACITOR
| WIRE NUT OR
| TERMINAL
| FUSE
| TRANSFORMER
| TEMP ACTUATED SWITCH
| INTERNAL OVERLOAD PROTECTION
| PRESSURE ACTUATED SWITCH
| REGISTER OR HEATING ELEMENT
| POL. PLUG FEMALE HOUSING (MALE TERMINALS)
POL. PLUG MALE HOUSING (FEMALE TERMINALS)
| SINGLE INLINE CONNECTION

  WARNING
HAZARDOUS VOLTAGE!
DISCONNECT ALL ELECTRICAL POWER INCLUDING REMOTE DISCONNECTS BEFORE SERVICING.
Failure to disconnect power before servicing can cause severe personal injury or death.

CAUTION
USE COPPER CONDUCTORS ONLY!
UNIT TERMINALS ARE NOT DESIGNED TO ACCEPT OTHER TYPES OF CONDUCTORS.
Failure to do so may cause damage to the equipment.

Pressure Curves

COOLING PERFORMANCE CAN BE CHECKED WHEN THE OUTDOOR TEMP IS ABOVE 65 DEG F.
TO CHECK COOLING PERFORMANCE, SELECT THE PROPER INDOOR CFM, ALLOW PRESSURES TO STABILIZE. MEASURE INDOOR WET BULB TEMPERATURE, OUTDOOR TEMPERATURE, DISCHARGE AND SUCTION PRESSURES. ON THE PLOTS LOCATE OUTDOOR TEMPERATURE (1); LOCATE INDOOR WET BULB (2); FIND INTERSECTION OF OD TEMP. & ID W.B. (3); READ DISCHARGE OR SUCTION PRESSURE IN LEFT COLUMN (4).

EXAMPLE:

1. OUTDOOR TEMP. 82 F.
2. INDOOR WET BULB 67 F.
3. AT INTERSECTION
4. DISCHARGE PRESSURE @ 1300 CFM IS 317 PSIG.
5. SUCTION PRESSURE @ 1300 CFM IS 144 PSIG.

ACTUAL:
DISCHARGE PRESSURE SHOULD BE +/- 10 PSI OF CHART
SUCTION PRESSURE SHOULD BE +/- 3 PSIG OF CHART

PRESSURE CURVES FOR 4TWA4036A

PRESSURE CURVES FOR 4TWA4042A

PRESSURE CURVES FOR 4TWA4048A

PRESSURE CURVES FOR 4TWA4060A

Refrigerant Circuits (only for reference)

Heating Refrigeration Cycle![TRANE 4TWA4036A3000A Split System Heat Pump

• Heating Refrigeration Cycle](https://manuals.plus/wp-content/uploads/2024/02 /TRANE-4TWA4036A3000A-Split-System-Heat-Pump-Heating-Refrigeration-Cycle.jpg)

Cooling Refrigeration Cycle![TRANE 4TWA4036A3000A Split System Heat Pump

• Cooling Refrigeration Cycle](https://manuals.plus/wp-content/uploads/2024/02 /TRANE-4TWA4036A3000A-Split-System-Heat-Pump-Cooling-Refrigeration-Cycle.jpg)

Printed from D158862

Trane – by Trane Technologies (NYSE: TT), a global innovator – creates comfortable, energy efficient indoor environments for commercial and residential applications. For more information, please visit trane.com or tranetechnologies.com.

www.ahridirectory.org

Unitary Small HP
AHRI Standard 210/240
Certification applies only when the complete system is listed with AHRI.

The AHRI Certified mark indicates Trane U.S. Inc. participation in the AHRI Certification program. For verification of individual certified products, go to ahridirectory.
org.
Trane has a policy of continuous data improvement and it reserves the right to change design and specifications without notice. We are committed to using environmentally conscious print practices.

18-BC97D1-1E-EN 02 May 2023
Supersedes 18-BC97D1-1D-EN (May 2020)
©2023 Trane

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