Causes of Compressor Failures and How to Prevent Them
Compressor failures can be caused by many things, some controllable and others not. However, measures can be taken to prevent compressor failure in all of them.
Power problems, such as low voltage, high voltage or a power surge, are out of your control, but you can protect your compressor in case they occur:
- Voltage monitors can be used on single-phase compressors and phase monitors can be used to protect three-phase equipment.
- Surge protectors should also be used to protect the compressor from power spikes and lightning strikes. Some surge protectors even carry a compressor warranty that will cover the compressor in case of damage.
- Be sure to also check all contactor contacts and all electrical connections.
Overheating is a problem you can prevent with proper installation and service techniques:
- Moisture can be avoided by proper evacuation procedures, such as using a good vacuum pump with clean oil and always using a Micron gauge to ensure a deep vacuum.
- Always install a new dryer any time the system has been opened.
- Undercharge and a starving evaporator due to TXV problems can also cause overheating.
- The discharge line temperature for most compressor brands should never exceed 220*F. If the discharge temperature is higher than that you may be overheating the compressor.
- Check charge by superheat for fixed metering device and subcooling for TXVs.
Compressor slugging can also be prevented:
- Keep filters clean and ensure proper airflow by checking belt dampers and ductwork.
- Overcharge and over-feeding evaporator due to TXV problems can also cause slugging so always use proper charging procedures.
- Ensure that the TXV sensing bulb is properly and securely mounted to the suction line on the evaporator outlet.
- Most manufacturers recommend 10 o’clock and 2 o’clock for suction lines smaller than 7/8”, and 8 o’clock and 4 o’clock for suction lines larger than 7/8”.
- Properly insulating the bulb will also help by ensuring that no external heat source effects the TXV operation.
Be sure to always use proper clean-up procedures after a compressor fails to ensure that the new compressor will not suffer the same fate as the old one. If you are retrofitting refrigerants, follow the manufacturer’s retrofit guidelines and never mix refrigerants.