Arc fault circuit interrupter and series arc fault detection method using plural high frequency bands

Abstract

A circuit interrupter includes band pass filters cooperating with a current sensor to output bands having different, non-overlapping ranges of frequencies, peak detectors cooperating with the filters to detect corresponding peak current values, envelope detectors cooperating with the filters to detect corresponding occurrences from the bands being within corresponding predetermined magnitude ranges, a counter counting the occurrences, and a processor providing and disabling series arc detection when sensed current is greater than a first predetermined value. The processor determines tallies responsive to peak current values exceeding corresponding thresholds, determines series arcing from sensed current being less than the first predetermined value for a predetermined time, the tally for a current half-cycle being nonzero, and a count for the current half-cycle being different than the count for an immediately previous half-cycle of like polarity by at least a second predetermined value. A series chaos accumulator is increased responsive to series arcing.