Trane Series R™ Helical Rotary Chiller RTAC170S

Manually open EXV for 15 minutes to allow refrigerant to drain to evaporator by gravity (ensure water is flowing in the evaporator prior to opening the EXV)

Let unit sit with heaters on to drive refrigerant out of oil and warm up compressor bearings. Depending upon ambient conditions, this may take up to 24 hours.Ensure the UCM is powered so the pump may be energized if it detects a freeze condition

Once the oil level has returned to normal, the unit can be put back into operation

Perform all weekly maintenance procedures

This procedure should be followed when adding charge to an undercharged unit. When low charge is indicated by low subcooling in the liquid line, charge should be added until sufficient subcooling is achieved.

1. Attach charging hose to evaporator service valve (3/8” (9mm) flare). Open service valve.

2. Add 10 pounds of refrigerant (R-134a) charge.

3. Close valve, remove charging hose and start unit. Monitor subcooling.

4. If subcooling is still insufficient, return to step #1.

NOTE: Proper subcooling can be determined from run log history, service experience, or by contacting Trane technical service.;

Isolate the refrigerant charge outside of the compressor and close all four valves leading to the compressor?

Disconnect power to the chiller. Remove the electrical junction box cover and disconnect the wires?

WARNING: Hazardous Voltage! Disconnect all electric power, including remote disconnects before servicing. Follow proper lockout/tagout procedures to ensure the power can not be inadvertently energized. Failure to disconnect power before servicing could result in death or serious injury.

Evacuate the compressor through the service fitting provided. If the unit does not have suction service valves, this will include evacuating the low side of the system as well?

Disconnect all four lines attached to the compressor, as well as the junction box. Remove three screws from the bottom of the compressor?

Remove the compressor by sliding it out of the chiller onto a well supported skid or other platform. The compressor is very heavy, so insure that the support is sturdy. A piece of 1x4 lumber placed between the isolators works well to support the compressor feet as it is pulled from the chiller?

Install the new compressor. Reinstall all lines, wires, and screws. Open the service valves, and trim charge as required?

Sign off on the compressor replacement

While unit is running in stable conditions.

Check MP pressure for evaporator, condenser and intermediate oil.

Observe liquid line sight glass on EXV.

If liquid line sight glass has bubbles measure the subcooling entering the EXV. The subcooling should never be less than 4 °F under any circumstances.

A clear sightglass alone does not mean that the system is properly charged. Also check the rest of the system operating conditions.

Inspect the entire system for unusual conditions and inspect the condenser coils for dirt and debris. If the coils are dirty, refer to coil cleaning.

Sign off on the weekly maintenance