AbstractThis paper presents a new proposal for detection of arcing faults and evaluates the detection rate and the security level of the proposed method. This method is based on analysis of three‐phase unbalanced current, easily accessible feeder 3I0, using decomposition of the signal by means of wavelet transform techniques. Combining both temporal and frequency localizing properties, criteria are set in order to detect electric arc existence related to high impedance faults. The method has been tested with signals from staged fault records, normal condition records and substation event records. The test results show that the proposal is a satisfactory fault detection method and the relevant results are presented. Copyright © 2004 John Wiley & Sons, Ltd.