A refrigerator’s compressor can be checked as per the given procedure:
- Connect the nitrogen cylinder to the process tube of the compressor using a double-stage pressure regulator.
- Connect the discharge side of the compressor to a receiver or a condenser coil of appropriate capacity.
- Connect a pressure gauge having a range of 0 to 300 PSIG to the other end of the receiver or condenser coil.
- After connecting, check for leakage at all joints.
- Supply Nitrogen gas at a constant pressure of 20 PSIG in the process tube of the compressor.
- Start the refrigerator/air-conditioner compressor & run it for a few seconds to build up a head pressure of approximately 125 / 150 PSIG. On attaining the specified head pressure, stop the compressor.
- Wait for a minute & check for a drop in head pressure. It should be within the specified limit of 30 / 40 PSIG (refrigerator/air-conditioner).
- If the drop is more than the specified limit, the compressor has a pumping defect, else the compressor is okay.