The big dipper compressor fan is turned on and off.

Circuit system failure, lack of refrigerant.

1. Circuit system failure: short circuit or open circuit directly loses the path of power transmission, and the electromagnetic clutch cannot normally control the working state of the compressor.

2. Insufficient refrigerant: the refrigerant and the refrigerating oil are mutually soluble and circulated back to the compressor through the system. Freon in refrigerant is consumed, which will lead to insufficient oil return of refrigeration oil, reduce the lubrication effect of compressor and lead to stagnation and damage.