ARC FAULT CIRCUIT INTERRUPTER AND METHOD OF PARALLEL ARC FAULT DETECTION

An arc fault circuit interrupter includes separable contacts, an operating mechanism, a current sensor sensing current flowing through the contacts and outputting a sensed current, and a processor determining and storing peak values of the sensed current for plural half-cycles. The processor provides arc fault detection, determines whether a first predetermined plurality of half-cycles occur in succession and correspond to non-unity power factor, and responsively inhibits the detection for a first predetermined time, and whether a second predetermined plurality of half-cycles occur in succession, each with smaller peak amplitude than that of an immediately preceding half-cycle of like or differing polarity, and responsively inhibits the detection for a second predetermined time. The processor determines that the detection is not inhibited for the first and second predetermined times, and responsively indicates that any of the half-cycles having a peak amplitude greater than a predetermined amount is a parallel arc.