Abstract: As a reactive power compensation device, shunt capacitor is widely used in the power network to improve the voltage quality and reduce the line losses. However, due to the large loads in summer results in frequent faults of shunt capacitors, most of them are protection trips caused by three-phase voltage imbalance. This article will provide cases analysis to illustrate several common fault causes, propose maintenance strategies, and make some suggests for the operation, maintenance, and repair of shunt capacitors in operation.