By diagnosing intermittent fault, BIT with the method is better than that of two-state method in reducing false alarm rate as well as increasing fault detection rate.

The influences of several factors such as harmonics, intermittent arc grounding, ct, load and fault resistance have been thoroughly analyzed, therefore, it is fundamental work for its application.

It is immune from the unbalanced status of network and the values of earthed resistance. To the complicated intermittent arc-earth fault, the proposed method also works well.