TRANE 4TWA7 Heat Pumps Air Conditioner Instruction Manual

TRANE 4TWA7 Heat Pumps Air Conditioner

Product Information

• Product Name: Heat Pumps
• Model: 4TWA7
• Manufacturer: Unknown

Product Usage Instructions

1. All phases of the installation must comply with national, state, and local codes.
2. Ensure that individuals performing the installation possess adequate backgrounds of electrical and mechanical experience to avoid personal injury and/or property damage.
3. Repairing the central air conditioning product should only be carried out by qualified professionals to prevent personal injury and/or property damage.
4. The product contains R-410A refrigerant, which operates at higher pressures than R-22. Proper service equipment is required to handle R-410A refrigerant to avoid equipment damage or personal injury.
5. Only use R-410A refrigerant and approved POE compressor oil for service purposes.
6. Exercise extreme caution when opening the Liquid Line Service Valve. Turn counterclockwise until the valve stem just touches the rolled edge without applying torque. Failure to follow this warning may result in an abrupt release of system charge, leading to personal injury and/or property damage.
7. Disconnect power and discharge capacitors before servicing to avoid hazardous voltage exposure.
8. When working with live electrical components during installation, testing, servicing, and troubleshooting, follow all electrical safety precautions to prevent death or serious injury.
9. If using existing refrigerant lines, ensure that all joints are brazed, not soldered.
10. Avoid touching the top of the scroll compressor as it may cause minor to severe burning.
11. Avoid touching hot surfaces as they may cause minor to severe burning. Do not touch the top of the compressor.
12. Follow proper procedures when handling refrigerant to prevent personal illness or injury and severe equipment damage. Before opening the system, recover refrigerant to relieve pressure.
13. Grounding is required. Inspect and reconnect all grounding devices to avoid equipment damage or personal injury. Ensure that all parts capable of conducting electrical current are properly grounded.

Unit Location Considerations

When mounting the outdoor unit on a roof, ensure that the roof can support the weight of the unit. It is recommended to use proper isolation techniques to minimize sound or vibration transmission to the building structure.

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 information pack upon completion of work.

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 outdoor split systems are maximum efficiency, optimum performance and the best overall system reliability.

Safety

WARNING

• This information is intended for use by individuals possessing adequate backgrounds of electrical and mechanical experience. Any attempt to repair a central air conditioning product may result in personal injury and/or property damage. The manufacture or seller cannot be responsible for the interpretation of this information, nor can it assume any liability in connection with its use.
• These units use R-410A refrigerant which operates at 50 to 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 “hygroscopic” 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 Bulletins SS-APG006-EN and APP-APG011-EN or APP-APG012-EN.

WARNING: UNIT CONTAINS R-410A REFRIGERANT!

• R-410A operating pressures exceed the limit of R-22. Proper service equipment is required. Failure to use proper service tools may result in equipment damage or personal injury.
  • SERVICE
  • USE ONLY R-410A REFRIGERANT AND APPROVED POE COMPRESSOR OIL.

WARNING

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

WARNING: HAZARDOUS VOLTAGE!

• Disconnect power and discharge capacitors before servicing.

WARNING: LIVE ELECTRICAL COMPONENTS!

During installation, testing, servicing, and troubleshooting of this product, it may be necessary to work with live electrical components. Failure to follow all electrical safety precautions when exposed to live electrical components could result in death or serious injury.

CAUTION

• If using existing refrigerant lines make certain that all joints are brazed, not soldered.
• Scroll compressor dome temperatures may be hot. Do not touch the top of compressor; it may cause minor to severe burning.

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.

Unit Location Considerations

Unit Dimensions and Weight

Unit Dimensions and Weight

Models| H x D x W (in)| Weight* (lb)
4TWA7036A3/4| 45 x 34 x 37| 245
4TWA7048A3/4| 45 x 34 x 37| 265
4TWA7060A3/4| 45 x 34 x 37| 265

• Weight values are estimated.

  • 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.

Refrigerant Piping Limits

1. The maximum TOTAL length of refrigerant lines from outdoor to indoor unit should NOT exceed 150 feet* (including lift).
2. The maximum vertical change should not exceed 50 feet*.
3. Standard and alternate line sizes and service valve connection sizes are shown in Table 5.1.
   • See Table 5.1 for exceptions for certain tonnages.

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

Suggested Locations for Best Reliability

• Ensure the top discharge area is unrestricted for at least five (5) feet above the unit.
• Three (3) feet clearance must be provided in front of the control box (access panels) and any other side requiring service.
• It is not recommended to install in a location where noise may distract the building occupants. Some examples of these types of locations are sleeping quarters and by windows of a living area. Please discuss location with the building owner prior to installation.
• Avoid locations such as near windows 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 anystructure to prevent excess roof runoff water or icicles from falling directly on the unit.

Cold Climate Considerations

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 draining 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.

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

Prepare The Unit For Installation

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

Setting the Unit

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.

For other applications refer to application guide.

Refrigerant Line Considerations

Refrigerant Line and Service Valve Connection Sizes

RATED LINE SIZES

| Line Sizes| Service Valve Connection Sizes| Max Line & Lift Lengths
---|---|---|---
Vapor Line| Liquid Line| Vapor Line Connection| Liquid Line Connection| TOTAL Max

Line Length (ft.)

| Max Lift (ft.)
4TWA7036A3/4| 3/4| 3/8| 3/4| 3/8| 80| 25
4TWA7048A3/4| 7/8| 3/8| 7/8| 3/8| 150| 50
4TWA7060A3/4| 1-1/8| 3/8| 7/8| 3/8| 80| 25

4TWA7036A3/4

| 5/8| 3/8| 3/4| 3/8| 150| 50
---|---|---|---|---|---|---
7/8| 3/8| 3/4| 3/8| 80| 25
4TWA7048A3/4| 3/4| 3/8| 7/8| 3/8| 150| 50

4TWA7060A3/4

| 3/4| 3/8| 7/8| 3/8| 150| 50
7/8| 3/8| 7/8| 3/8| 150| 50

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

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.

Required Refrigerant Line Length

Determine required line length and lift. You will need this later in STEP 2 of Section 14.

• Total Line Length = __ Ft.
• Total Vertical Change (lift) = __ Ft.

Refrigerant Line Insulation

Important: The Vapor Line must always be insulated. DO NOT allow the Liquid Line and Vapor Line to come in direct (metal to metal) contact.

Reuse Existing Refrigerant Lines

CAUTION: 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.

Refrigerant Line Routing

Precautions

Important

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

For Example

• When the refrigerant lines have to 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 ductwork.
• Minimize the number of 90º turns.

Refrigerant Line Brazing

Braze The Refrigerant Lines

• STEP 1: Remove caps or plugs. Use a deburing tool to debur the pipe ends. Clean both internal and external surfaces of the tubing using an emery cloth.
• STEP 2:  Remove the pressure tap cap and valve cores from both service valves.
• STEP 3:  Purge the refrigerant lines and indoor coil with dry nitrogen.
• STEP 4:  Wrap a wet rag around the valve body to avoid heat damage and continue the dry nitrogen purge.
  • Braze the refrigerant lines to the service valves.
  • 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.
  • 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: Install drier in Liquid Line.
  • NOTE: Precautions should be taken to avoid heat damage to basepan during brazing. It is recommended to keep the flame directly off of the basepan.
• STEP 5:  Replace the pressure tap valve cores after the service valves have cooled.

Refrigerant Line Leak Check

Check For Leaks

• STEP 1:  Pressurize the refrigerant lines and evaporator coil to 150 PSIG using dry nitrogen.
• STEP 2:  Check for leaks by using a soapy solution or bubbles at each brazed location. Remove nitrogren pressure and repair any leaks before continuing.

Evacuation

Evacuate the Refrigerant Lines and Indoor Coil

Important: Do not open the service valves until the refrigerant lines and indoor coil leak check and evacuation are complete.

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

Service Valves

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.

• STEP 1:  Remove valve stem cap.
• STEP 2: Using an adjustable wrench, turn valve stem 1/4 turn counterclockwise to the fully open position.
• STEP 3:  Replace the valve stem cap to prevent leaks. Tighten finger tight plus an additional 1/6 turn.

Open the Liquid Service Valve

WARNING

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

Important: Leak check and evacuation must be completed before opening the service valves.

• STEP 1:  Remove service valve cap.
• STEP 2:  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.)
• STEP 3:  Replace the valve cap to prevent leaks. Tighten finger tight plus an additional 1/6 turn.

Electrical – Low Voltage

Low Voltage Maximum Wire Length

Table 11.1 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.

Low Voltage Hook-up Diagrams

• Units with pigtails require wirenuts for connections.
• In systems with multiple stages of electric heat, jumper W1 and W2 together if comfort control has only one stage of heat.
  • ** TEM6 only – When using a BK enabled comfort control, cut BK jumper and bypass Y1 and Y2 at the air handler. Connect BK from comfort control to BK of the air handler
• TAM7 only – When using a BK enabled comfort control, cut BK jumper on the AFC and connect BK from comfort control to BK of the air handler. TAM7 DIP switches must be configured for “HP: 2-Stage/1 Compressor”.

Note: Refer to Indoor Unit Literature for proper configuration.

Defrost Control

Defrost controls have a selectable termination temperature. As shipped, defrost will terminate at 47°F. For a higher termination temperature, cut Jumper J2 to achieve 70°F. Refer to the Defrost Control section in this document for more information.

Pin Identification on J5 (See Illustration)

1. TEST_COMMON (Shorting to FRC_DFT causes the control to initiate Forced Defrost. Leaving this pin open results in the normal mode of operation.)
2. FRC_DFT = Forced Defrost (Short TEST_COMMON to this pin for two (2) seconds to initiate a forced defrost. Remove the short after defrost initiates.)

Defrost Control Checkout

Normal operation requires:

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

If a defrost control problem is suspected, refer to the service information in control box.

Electrical – High Voltage

High Voltage Power Supply

WARNING: LIVE ELECTRICAL COMPONENTS!

During installation, testing, servicing, and troubleshooting of this product, it may be necessary to work with live electrical components. Failure to follow all electrical safety precautions when exposed to live electrical components could result in death or serious injury.

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.

High Voltage Disconnect Switch

• 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 within the structure.

High Voltage Ground

• Ground the outdoor unit per national, state, and local code requirements.

Start Up

System Start Up

• STEP 1:  Ensure Sections 7 through 12 have been completed.
• STEP 2:  Set System Thermostat to OFF.
• STEP 3:  Turn on disconnect(s) to apply power to the indoor and outdoor units.
• STEP 4:  Wait one (1) hour before starting the unit if compressor crankcase heater accessory is used and the Outdoor Ambient is below 70ºF.
• STEP 5 :  Set system thermostat to ON.

System Charge Adjustment

Temperature Measurements

STEP 1:  Check the outdoor temperatures.

• Subcooling (in cooling mode) is the only recommended method of charging above 55º F ambient outdoor temperature. See Section 14.2.
• For outdoor temperatures below 55º F, see Section 14.3.

Note: It is important to return in the spring or summer to accurately charge the system in the cooling mode when outdoor ambient temperature is above 55º F.

For best results the indoor temperature should be kept between 70º F to 80º F.

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

1. STEP 1:  Use the refrigerant line total length and lift measurements from Section 5.3.

• Total Line Length = __ Ft.
• Vertical Change (Lift) = __ Ft.

1. STEP 2:  Determine the final subcooling value using total Line Length and Lift measured in STEP 1 and the charts below.

• Design Subcooling Value = __º F
  • (from nameplate)
• Subcooling Correction = __º F
• Final Subcooling Value = __º F

1. STEP 3: Stabilize the system by operating for a minimum of 20 minutes.
   • 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.
2. STEP 4:  Measure the liquid line temperature and pressure at the outdoor unit’s service valve.
   • Measured Liquid Line Temp = __ º F
   • Liquid Gage Pressure = __ PSIG
   • Final Subcooling Value = __ º F
3. STEP 5:  Use the final subcooling value, refrigerant temperature and pressure from STEP 4, to determine the proper liquid gage pressure using Table 14.2.
   • Example: Assume a 12º F Final Subcooling value and liquid temp of 90º F.
   1. Locate 12º F Final Subcooling in Table 14.2.
   2. Locate the Liquid Temperarature (90º F) in the left column.
   3. The Liquid Gage Pressure should be approximately 327 PSIG. (This is the shown as the intersection of the Final Subcooling column and the Liquid Temperature row.)

R-410A REFRIGERANT CHARGING CHART

LIQUID TEMP ( ° F)| FINAL SUBCOOLING ( ° F)
8| 9| 10| 11| 12| 13| 14
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

From Dwg. D154557P01 Rev. 3

STEP 6:  Adjust refrigerant level to attain proper gage pressure.

Add refrigerant if the Liquid Gage Pressure is lower than the chart value.

1. Connect gages 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 matches the charging chart Final Subcooling value.

Recover refrigerant if the Liquid Gage Pressure is higher than the chart value.

STEP 7: Stabilize the system

1. 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.
2. Remove gages.
3. Replace service port caps to prevent leaks. Tighten finger tight plus an additional 1/6 turn.

STEP 8: Verify typical performance.

• Refer to System Pressure Curves in this document to verify typical performance.

STEP 9:  Record System Information for reference.

Record system pressures and temperatures after charging is complete.

• Outdoor model number = _____
• Measured Outdoor Ambient = __ º F
• Measured Indoor Ambient = __ º F
• Measured Liquid Line Temp = __ º F.
• Measured Suction Line Temp = __ º F
• Liquid Gage Pressure = __ PSIG
• Suction Gage Pressure = __ PSIG

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

The Subcooling Charging method in cooling is not recommended below 55º F outdoor temperature. The only recommended method of charging at outdoor temperatures below 55º F is weighing in the charge in heating mode and referencing the refrigerant pressure curves for typical performance.

STEP 1:  Determine additional charge.

Note: The nameplate charge value represents the amount of refrigerant shipped in the outdoor unit and is compatible with 10 feet of AHRI rated refrigerant lines and the smallest AHRI rated coil.

Using the method below, find the charge associated with the additional length of tubing above 10 ft. and record it below.

Weigh-In Method can be used for the initial installation, or anytime a system charge is being replaced. Weigh-In Method can also be used when power is not available to the equipment site or operating conditions (indoor/outdoor temperatures) are not in range to verify with the subcooling charging method.

Calculating Charge Using the Weigh-In Method

1. Measure in feet the distance between the outdoor unit and the indoor unit. (Include the entire length of the line from the service valve to the IDU.) Subtract 10 ft from this entire length and record on line 1.
2. Enter the charge multiplier (0.6 oz/ft). Each linear foot of interconnecting tubing requires the addition of 0.6 oz of refrigerant.
3. Multiply the total length of refrigerant tubing (Line 1) times the value on Step 2. Record the result on Line 3 of the Worksheet.
4. This is the amount of refrigerant to weigh-in prior to opening the service valves.

• Total Line length (ft) –10 ft ___
• Charge multiplier x 0.6 oz__
• Step 1 x Step 2 = __
• Refrigerant (oz) = __

STEP 2:  Stabilize the system by operating for a minimum of 20 minutes.

• 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.

STEP 3:  Check the liquid line temperature and liquid gage pressure to obtain a minimum of 10º subcooling in heating mode.

• Measured Liquid Line Temp = __ º F
• Liquid Gage Pressure = __ PSIG

STEP 4:  Add charge if a minimum of 10º subcooling is not obtained with the namplate charge plus additional charge previously added.

STEP 5:  Return to site for adjustment.

Important: Return in the spring or summer to accurately charge the system in the cooling mode with outdoor ambient above 55º F.

Checkout Procedures

Operational and Checkout Procedures

Final phases of this installation are the unit Operational and Checkout Procedures. To obtain proper performance, all units must be operated and charge adjustments made.

Important: Perform a final unit inspection to be sure that factory tubing has not shifted during shipment. Adjust tubing if necessary so tubes do not rub against each other when the unit runs. Also be sure that wiring connections are tight and properly secured.

CHECKOUT PROCEDURE

After installation has been completed, it is recommended that the entire system be checked against the following list:

1. Leak check refrigerant lines. ………………………………….. [ ]
2. Properly insulate suction lines and fittings………………… [ ]
3. Properly secure and isolate all refrigerant lines…………. [ ]
4. Seal passages through masonry.
   • If mortar is used, prevent mortar from coming into direct contact with copper tubing………………………. [ ]
5. Verify that all electrical connections are tight…………….. [ ]
6. Observe outdoor fan during on cycle for clearance and smooth operation……………………………………………. [ ]
7. Be sure that indoor coil drain line drains freely. Pour water into drain pan……………………………………………………….. [ ]
8. Be sure that supply registers and return grilles are .open and unobstructed………………………………………………….. [ ]
9. Be sure that a return air filter is installed………………….. [ ]
10. Be sure that the correct airflow setting is used.
    • (Indoor blower motor)……………………………………………. [ ]
11. Operate complete system in each mode to ensure safe operation……………………………………………. [ ]

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. By measuring the change in delta-T, we can determine the need for defrost. The coil sensor also serves to sense outdoor coil temperature for termination of the defrost cycle.

Termination Temperature

• Defrost controls have a selectable termination temperature. As shipped, defrost will terminate at 47°F.
• For a higher termination temperature, cut Jumper J2 to achieve 70°F when at or below 30°F ambient.

Fault Identification

• A fault condition is indicated by the flashing light on the defrost control inside the heat pump control box.
• In normal operation, the defrost control light will flash once each second. If the light is flashing more than once per second or not at all, refer to the Defrost Checkout sheet found with the service information in the control box.

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. TST = Test (Shorting TEST_COMMON to this pin speeds up all defrost board timings.)
3. FRC_DFT = Forced Defrost (Short TEST_COMMON to this pin for two [2] seconds to initiate a forced defrost. Remove the short after defrost initiates.)

Defrost Control Checkout

Normal operation requires:

• LED on board flashing 1 time/second.
• 24V AC between R & B.
• 24V AC between Y & B with unit operating.
• Defrost initiation when FRC_DFT pin is shorted to TEST_COMMON pin.

If a defrost control problem is suspected, refer to the service information in control box.

DEFROST TERMINATION TEMPERATURE

Defrost Termination Temperatures

| Outdoor Temp.| Termination Temperature

As Shipped

| >22°F| 47°F
10°F–22°F| ODT + 25°F
6°F–10°F| 35°F
Cut Jumper 2| >30°F| 47°F
6°F–30°F| 70°F

All

| < 6°F| 12 min. or 35°F every 3 hrs.
£ 0°F| Outdoor unit will be turned OFF
³ 5°F| Resume outdoor unit operation

• Defrost controls have a selectable termination temperature.
• Cutting jumper J2 (shown below) will achieve a termination temperature of 70° when the ambient temperature is below 30° (see table at left).

EEV CONTROL BOARD TEST POINTS

Note: Close Valve and Open Valve Tests are active in any mode of operation

Test Pins: OPEN, CLOSE, TEST (See EEV Board drawing for locations)

Close Valve Test:  Touch CLOSE pin to TEST pin.

EEV drives closed (5 seconds max) and stays closed for 1.5 minutes (90 seconds).

1. Status LED will be flashing.
2. Gauges should indicate suction pressure dropping.
   • Valve is working.
   • LPCO may trip.

Note: The Close Valve Test will exit after 1.5 minutes (90 seconds) and will not reinitiate (requires a break and make to initialize). To clear faults stored in memory, apply a jumper between Close and Test pins for 10 seconds.

Open Valve Test:  Touch OPEN pin to TEST pin.

EEV drives open (5 sec max) and stays open for 30 seconds.

1. Status LED will be flashing.
2. Temperature probe should indicate superheat falling.
   • Valve is working.

Note: If jumper is left on pins, the OPEN VALVE TEST will be cleared after 30 seconds and will not reinitiate (requires a break and make to reinitialize).

Exit Test Mode:  The Open Valve Test or Closed Valve Test can be cancelled by jumping to the opposite mode Test pin. The system will return to normal super heat control.

Test mode will cancel if:

1. Unit enters Defrost
2. Y1 input is lost

TABLE 1: Suction Line Temperature Sensor – J10

Temp °F

| ****

Temp °C

| THERMISTOR RESISTANCE

(OHMS)

| ****

Volts DC at Plug J10 (pin to pin)

---|---|---|---
0| -17.8| 83247| 3.87
5| -15.0| 71108| 3.73
10| -12.2| 60916| 3.57
15| -9.4| 52333| 3.41
20| -6.7| 45076| 3.25
25| -3.9| 38927| 3.08
30| -1.1| 33703| 2.91
35| 1.7| 29253| 2.73
40| 4.4| 25452| 2.56
45| 7.2| 22198| 2.39
50| 10.0| 19405| 2.22
55| 12.8| 17002| 2.06
60| 15.6| 14930| 1.90
65| 18.3| 13138| 1.75
70| 21.1| 11586| 1.61
75| 23.9| 10238| 1.48
80| 26.7| 9065| 1.36
85| 29.4| 8043| 1.24
90| 32.2| 7150| 1.14
95| 35.0| 6368| 1.04
100| 37.8| 5682| 0.95
105| 40.6| 5079| 0.86
110| 43.3| 4548| 0.79
115| 46.1| 4079| 0.72
120| 48.9| 3665| 0.66
125| 51.7| 3298| 0.60
130| 54.4| 2972| 0.54
135| 57.2| 2683| 0.50
136| 57.8| 2629| 0.49
137| 58.3| 2576| 0.48
138| 58.9| 2525| 0.47
139| 59.4| 2474| 0.46
140| 60.0| 2425| 0.45
141| 60.6| 2377| 0.45
142| 61.1| 2330| 0.44
143| 61.7| 2284| 0.43
144| 62.2| 2239| 0.42
145| 62.8| 2195| 0.41
146| 63.3| 2153| 0.41
147| 63.9| 2111| 0.40
148| 64.4| 2070| 0.39
149| 65.0| 2030| 0.39
150| 65.6| 1990| 0.38

TABLE 2: Suction Line

Pressure Transducer – J7

Voltage to pressure reference Chart

Pressure (PSIG)| Volts DC at plug J7

(to test point common)

---|---
34| 0.8
41| 0.9
51| 1.0
60| 1.1
70| 1.2
80| 1.3
89| 1.4
99| 1.5
108| 1.6
118| 1.7
130| 1.8
140| 1.9
147| 2.0
159| 2.1
169| 2.2
178| 2.3
188| 2.4
198| 2.5

ELECTRONIC EXPANSION VALVE (EEV) CONTROL BOARD

Status LED (Green)

• On – Control has power
• Flashing Fast – Control is driving valve (5 seconds max drive time)
• Flashing Pattern – See Table 6.

TABLE 3: Control Input and Status LED – J6

Heat

| Standby| | ON Continuous| B to R
---|---|---|---|---
1st Stage| ON| OFF| ON| OFF| B to R & Y1
2nd Stage| ON| OFF| ON| OFF| ON| | ON| OFF| B to R, Y1 & Y2
| |

Cool

| Standby| | OFF| ON| OFF| ON| B to R & O
1st Stage| ON| OFF| | B to R, Y1 & O
2nd Stage| ON| OFF| ON| OFF| B to R, Y1, Y2 & O
| |
1 sec| 2 sec| 3 sec| 4 sec

Fault LED (Red)

LED

Color

| EEV

Fault LED

| Description
---|---|---
__

__

__

__

__

__

__

Red

| OFF| Standby
1 Flash| Coil has an open circuit or intermittent short (Replace Coil)
2 Flash| Control has detected an internal failure (Replace EEV control board)
3 Flash| Suction Pressure Transducer input is out of range (Replace transducer) (1)
4 Flash| Suction Temperature Sensor input is out of range (Replace sensor) (1)
5 Flash| Coil has short circuit (Replace Coil) (2)
The following may require additional diagnostics
6 Flash| Valve is not responding to a position change command (Possible stuck valve)
7 Flash| Valve is responding but system is not performing properly (Low charge or restriction)
8 Flash| Compressor is not pumping (3)
9 Flash| Low superheat in Cooling Mode (Indoor TXV stuck open or ID Fan failure)
10 Flash| Not used at this time
EEV Fault Codes
__

__

Notes:

| EEV not used on all models

(1) Valve will close and LPCO will trip

(2) Power supply will shut down to protect board

(3) Monitor superheat and pressure: <3′ SH for 5 minutes with valve @ minimum position, Monitor off-cycle pressure and compare to next on-cycle for pressure drop within 60 seconds

Fault Storing/Clearing

• Faults 6-9 will be stored in non-volatile memory. See Close Valve Test for fault clearing procedure.
• Faults 1-5 will clear with a power cycle.

Troubleshooting

TROUBLESHOOTING THE EEV

kinkedThe Electronic Expansion Valve (EEV) installed in this heat pump is designed to controlsuperheat entering the compressor when the system is running in mechanical heating mode.During cooling mode, refrigerant flow reverses through the outdoor EEV and superheat is controlled by the expansion device in the indoor unit. Therefore, any operational problems observed in cooling mode are not caused by the outdoor EEV.The following flow chart was designed to assist in troubleshooting the EEV.

Note: The EV closes with every OFF cycle in the heating mode of operation. During Defrost and in the cooling mode of operation, the EEV will drive to full open. An audible sound can be heard when valve is changing positions.

Wiring Diagrams

Wiring Diagram 230V – 036A, 048A & 060A

Wiring Diagram 460V – 036A, 048A & 060A

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
5. IF ODT-B IS NOT USED, CONNECT A JUMPER WIRE FROM W3 TO W2. IF ODT-A IS NOT USED, CONNECT A JUMPER WIRE FROM W2 TO WI.
6. WITH YI ENERGIZED, INDOOR FAN IS IST STAGE AIRFLOW.
7. WITH YI & Y2 ENERGIZED, INDOOR FAN IS 2ND STAGE AIRFLOW.
8. SEE AIR HANDLER INSTALLER GUIDE FOR DIP SWITCH CONFIGURATIONS.

LEGEND

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 @ 900 CFM IS 299 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 4TWA7036A3 & 4TWA7036A4

PRESSURE CURVES FOR 4TWA7048A3 & 4TWA7048A4

PRESSURE CURVES FOR TWA7048A3 & 4TWA7048A4

Refrigerant Circuit

Refrigerant Circuit (only for reference)

Heating Refrigeration Cycle

Cooling Refrigeration Cycle

NOTE: 4TWA7036A unit does not have suction accumulator in its refrigeration circuit.

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

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.

© 2023 Trane

References

• DWG.no - DWG Cad Software | DWG View | DWG til PDF | Norsk nettside som går gjennom nyheter og muligheter innen 2D og 3D design
• Trane Heating & Air Conditioning

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