Compressor Replacement
Before replacing a hermetic compressor, be sure to check other possible causes of system malfunction (see Troubleshooting Compressors). Do not replace the compressor unless you are absolutely certain it is the source of the trouble.
Many manufacturers will provide instructions for replacing the compressor along with their installation, servicing, and operating literature. Carefully read these instructions before attempting to disconnect the compressor.
Disconnect the power supply, remove the fuses, and check the liquid refrigerant for oil discoloration or an acrid odor. These are indications that a compressor burnout has contaminated the system. If the system is not properly cleaned up, the replacement compressor will also burn out.
The system can be checked for contamination by discharging a small amount of refrigerant and oil through the high-side port onto a clean white cloth and checking it for discoloration and odor. Perform the same test on the low-side gauge port. If the system shows signs of contamination, discharge the remainder of the refrigerant through the liquid line gauge port (on a factory-charged sys- tem) or the high-side gauge port (on a field-charged system). Inspect the refrigerant lines to determine the exact extent of contamination.
Examine the refrigerant lines connected to the evaporator for contamination. A rapid compressor burnout will usually leave the evaporator coil unaffected. If the burnout has been particularly slow and the refrigerant and oil have been circulated through the system, the evaporator will also be contaminated. A contaminated evaporator can be cleaned by flushing it with a refrigerant.