Flooded Starts on HVACR Compressors

Refrigerant Migration can cause many issues and will lead to a failure if not corrected. When the system is off and the compressor is colder than the evaporator, because of a pressure differential the refrigerant is forced as a vapor to the colder area (the compressor), and the refrigerant will travel as a vapor from that evaporator or accumulator into the compressor. When the compressor starts up and it is full of liquid refrigerant, it will explode inside the compressor and wash away the oil from a lot of the components and this will lead to compressor issues.

Things that can help prevent refrigerant migration into the compressor:
Adding a crankcase heater
Set up the system to pump down
Add a bump start application
Refrigerant charge to oil ratio - Check manufactures manuals
Relocate compressor if possible