关键词: 零序电流互感器, 误动作, 拒动作

Abstract: Due to the mismatch of power supply system，improper selection of electrical equipment matching with leakage protector and the reasons of the protected electrical equipment itself，the leakage protector will cause misoperation or refusal of action.In this paper，the common faults of leakage protection devices in engineering practice are described in detail，the causes of the faults are analyzed and the safe and effective solutions are given.

Key words: zero phase current transformer, malfunction, refusal action