Carrier HVAC Unit 30GT080

Turn off all power to unit before servicing

Use field disconnect instead of ON-OFF switch on control panel

Is there sufficient pressure in the system for a leak test?

Conduct leak test using standard refrigeration practices

Leak Repair and System Evacuation

Repair the leak using good refrigeration practices

Evacuate and dehydrate the system after leaks are repaired

Select the cleaning method used

Corrosive Environment Considerations

Is the unit installed in a corrosive environment?

Ensure coil cleaning is part of the planned maintenance schedule

Clean all accumulations of dirt off the coil

Avoid using high-pressure water or air to prevent fin damage

Open and tag all electrical disconnects before any work begins.

Ensure the refrigerant is in the condenser by opening circuit breakers and closing discharge valves for lag compressors.

Ensure the discharge valve of an operating compressor is not closed.

Close the liquid line service valve for one circuit.

Allow the lead compressor to pump down the circuit until it reaches approximately 10 to 15 psig (68.8 to 103.2 kPa).

Shut down the lead compressor by opening the compressor circuit breaker and quickly close the discharge service valve for that compressor.

Repeat the procedure for the other circuit.

Brush gaskets with a light film of compressor oil

Ensure gaskets are not soaked to prevent deterioration

Use new gaskets within 30 minutes to prevent deterioration

Reassemble cooler nozzle end or plain end cover with gaskets

Torque 5/8-in. Diameter Perimeter Bolts to 150 to 170 ft-lb (201 to 228 N-m)

Record the current oil level in the sight glass

Is the oil level within the acceptable range (1/8 to 3/8 of sight glass)?

Use only Carrier-approved compressor oil for refilling

Ensure oil has not been exposed to atmosphere before use