TRANE 4TTX3 (01) PDF Document

When working with the TRANE 4TTX3, you must be aware of the following safety precautions regarding its R-410A refrigerant:

• The unit contains R-410A refrigerant, which operates at 50% to 70% higher pressures than R-22. Its operating pressure exceeds the limit of R-22.

• Proper R-410A approved service equipment is required. Failure to use proper service tools may result in equipment damage or personal injury.

• Refrigerant cylinders for R-410A are painted a “Rose” color to indicate the type of refrigerant and may contain a “dip” tube for charging liquid refrigerant.

• 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.

• Never break a vacuum with air and always change the driers when opening the system for component replacement.

• For service, use only R-410A refrigerant and approved POE compressor oil.

• In scroll compressor applications, the dome temperatures may be hot. Do not touch the top of the compressor, as this may cause minor to severe burning.

1. After uncrating, check for transportation damage. Report any damage promptly to the carrier.

2. To determine the electrical power requirements, refer to the nameplate of the unit. The available electrical power must match what is listed.

3. When removing the unit from the pallet, notice the tabs on the basepan. Remove these tabs by cutting with a sharp tool.

4. The unit should be set on a level support pad at least as large as the unit base pan, such as a concrete slab.

5. The support pad must NOT be in direct contact with any structure.

6. Position the unit a minimum of 12 inches from any wall or surrounding shrubbery to ensure adequate airflow. Clearance must also be provided in front of the control box (access panels) and any other side requiring service access to meet National Electrical Code.

7. The unit’s location must be far enough away from any structure to prevent excess roof run-off water from pouring directly on it. Do not locate units close to bedrooms.

8. The top discharge area must be unrestricted for at least five (5) feet above the unit.

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

• The maximum length of refrigerant lines from the outdoor to the indoor unit should NOT exceed sixty (60) feet.

• If the outdoor unit is mounted above the air handler, the maximum lift should not exceed sixty (60) feet (suction line).

• If the air handler is mounted above the condensing unit, the maximum lift should not exceed sixty (60) feet (liquid line).

If the indoor unit’s refrigerant flow control is an Accutron™ orifice and check valve assembly, an orifice size change may be necessary. The outdoor model determines the required orifice size. Check the listed orifice size on the nameplate of the selected outdoor model. If the indoor unit is factory shipped with a different orifice size, it must be changed to obtain the system’s rated performance.

The outdoor unit is shipped with the proper size orifice and a stick-on orifice size label in an envelope attached to the unit. The nameplate will specify the correct orifice size. You should also attach the R-410A CAUTION Label (located in the documentation package) to the access panel of the indoor section.

1. Determine the most practical way to run the lines, considering bend types and space limitations. Note that large diameter tubing is very difficult to rebend once shaped.

2. Determine the best starting point for routing the refrigerant tubing, either inside or outside the structure.

3. Provide a pull-thru hole of sufficient size to allow for both liquid and gas lines.

4. Be sure the tubing is of sufficient length.

5. Uncoil the tubing carefully; do not kink or dent it.

6. Route the tubing, making all required bends, and properly secure it before making connections.

7. To prevent noise from vibration transmission, take the following precautions:

a. When fastening refrigerant lines to floor joists or other framing, use isolation-type hangers.

b. Also use isolation hangers when refrigerant lines are run in stud spaces or enclosed ceilings.

c. Insulate and isolate refrigerant lines where they run through a wall or sill.

d. Isolate the lines from all ductwork.

Important: If using existing refrigerant lines, make certain that all joints are brazed, not soldered. The gas line must always be insulated.

1. Remove the lower access cover to access the service valves.

2. Before brazing, remove plugs from external copper stub tubes. Clean the internal and external surfaces of the stub tubes.

3. Cut and fit the tubing, minimizing the use of sharp 90° bends.

4. Insulate the entire gas line and its fittings.

5. Do NOT allow the uninsulated liquid line to come in direct contact with the bare gas line.

6. Take precautions to avoid heat damage to the pressure tap valve core. It is recommended that the pressure tap port valve core be removed and a wet rag be wrapped around the valve body. Use care to ensure no moisture enters the port while the wet rag is in use.

7. Use a Dry Nitrogen Purge and a Brazing Alloy without flux. Flow dry nitrogen into either valve pressure tap port, through the tubing, and out the other port while brazing.

8. Braze using accepted good brazing techniques. Avoid heat damage to the basepan by keeping the flame directly off of it.

Leak Check

1. After brazing, check all field-brazed connections for leaks.

2. Pressurize the indoor unit and field refrigerant lines with dry nitrogen to 350-400 psi through the service valve ports.

3. Use soap bubbles or other leak-checking methods to verify that all joints are leak-free. If leaks are found, release the pressure and repair the joints.

4. IMPORTANT: Replace the pressure tap port valve core before attaching hoses for evacuation.

System Evacuation

NOTE: Since the outdoor unit has a refrigerant charge, the gas and liquid line valves must remain closed during this process.

1. Evacuate the refrigerant lines and indoor coil before opening the gas and liquid line valves.

2. Attach appropriate hoses from a manifold gauge to the gas and liquid line pressure taps.

3. Attach the center hose of the manifold gauges to a vacuum pump.

4. Evacuate until the micron gauge reads no higher than 350 microns.

5. Close the valve to the vacuum pump and observe the micron gauge. If the pressure rises above 500 microns in one (1) minute, the evacuation is incomplete or the system has a leak.

6. If the vacuum gauge does not rise above 500 microns in one (1) minute, the evacuation is complete.

7. With the vacuum pump and micron gauge blanked off, open the valve on the R-410A cylinder and charge the refrigerant lines and indoor coil with vapor to the tank pressure of the R-410A supply.

1. Close the valve on the R-410A supply cylinder. Close the valves on the manifold gauge set and remove the refrigerant charging hoses from the liquid and gas pressure tap ports.

2. Liquid Line Valve: A 3/16″ Allen wrench is required. Remove the shut-off valve cap. Fully insert the hex wrench into the stem and turn it counterclockwise until the stem just touches the rolled edge (approximately five turns). WARNING: Extreme caution should be exercised. Turn the valve stem counterclockwise only until it contacts the rolled edge. No torque is required.

3. Replace the liquid service pressure tap port cap and valve stem cap. These caps MUST BE REPLACED to prevent leaks. Finger tighten, then tighten an additional 1/6 turn.

4. Gas Line Valve: A 1/4″ Open End or Adjustable wrench is required. Remove the shut-off valve cap. Turn the valve stem 1/4 turn counterclockwise to the full open position.

5. Replace the gas valve stem cap to prevent leaks. Finger tighten the valve stem cap and pressure tap cap, then tighten an additional 1/6 turn.

NOTE: If refrigerant lines are longer than 15 feet or a different size than recommended, the system refrigerant charge must be adjusted. Refer to the unit Service Facts.

WARNING: When installing or servicing, always exercise basic safety precautions to avoid electric shock.

1. Power wiring and grounding must comply with local codes.

2. The power supply must agree with the equipment nameplate.

3. Install a separate disconnect switch at the outdoor unit.

4. Ground the outdoor unit per local code requirements.

5. Provide flexible electrical conduit where vibration transmission may create a noise problem.

6. Use of color-coded low voltage wire is recommended to simplify connections between the outdoor unit, thermostat, and indoor unit.

7. Mount the indoor thermostat according to its instructions and wire per the appropriate hook-up diagram.

Table 1 – NEC Class II Control Wiring (24 VOLTS)

After all electrical wiring is complete:

1. Set the thermostat system switch to the OFF position so the compressor will not run.

2. Apply power by closing the system main disconnect switch. This will activate the compressor sump heat (if equipped).

3. Do not change the Thermostat System Switch from OFF until power has been applied for one (1) hour.

Following this procedure will prevent a potential compressor overload trip at the initial start-up.

1. Be sure the power supply agrees with the equipment nameplate.

2. Power wiring and grounding of the equipment must comply with local codes.

3. Low voltage wiring should be No. 18 AWG minimum conductor.

4. If using outdoor thermostats, ODT-B must be set lower than ODT-A.

5. If outdoor thermostats (ODT) are not used, connect W1 to W2 and W3.

It is recommended that the entire system be checked against the following list:

1. Refrigerant Line, Leak checked

2. Suction Lines and Fittings properly insulated

3. All Refrigerant Lines have been secured and isolated properly

4. Passages through masonry have been sealed. If mortar is used, prevent it from coming into direct contact with copper tubing.

5. Verify tightness of all electrical connects

6. Observe outdoor fan during on cycle for clearance and smooth operation

7. Indoor coil drain line drains freely. Pour water into drain pan to check.

8. Supply registers and return grilles are open and unobstructed

9. Return air filter is installed

10. Thermostat thermometer is accurate. Check against a reliable thermometer and adjust per instructions with the thermostat.

11. The correct speed tap is being used for the indoor blower motor

12. Operate the complete system in each mode to insure safe operation.

The following table shows the expected component operation based on the indoor thermostat switch settings with the main power disconnects closed (ON).

Checkout Procedure with Main Power Disconnects Closed (ON)

Notes:

① Also set thermostat dial to call for cooling or heating as necessary.

② Check only necessary if heating unit is used for indoor section and wiring has been disturbed during installation of cooling equipment.

Troubleshooting Chart – What to Check (P – Primary Causes, S – Secondary Causes)

The following table provides the outline dimensions for the TRANE 4TTX3; 4TTX4 models. All dimensions are in MM (Inches).

Legend for Dimensions:

D: Gas Line 1/4 Turn Ball Service Valve, I.D. Female Brazed Connection with 1/4″ SAE Flare Pressure Tap Fitting.

E: Liquid Line Service Valve, I.D. Female Braze Connection with 1/4″ SAE Flare Pressure Tap Fittings.