Abstract: As the core component of the ventilation and air conditioning system of the power house, the key to realize the temperature control of the power house is to ensure its normal operation. It is found that during the operation of the chiller, the water in the refrigerant system of the supercompressor often occurs, and the insulation of the motor to the ground is insufficient. Based on this, this paper mainly analyzes the causes of the above two faults and puts forward the corresponding improvement measures, in order to provide experience for the later effective solution of such problems.