Patent ID: 7633727

Claim:
An arc fault circuit interrupter for an alternating current power circuit including a plurality of half-cycles, said arc fault circuit interrupter comprising: separable contacts; an operating mechanism structured to open and close said separable contacts; at least one current sensor structured to sense current flowing through said separable contacts; a first band pass filter cooperating with one of said at least one current sensor to output a first pass band having a first range of frequencies of said sensed current; a second band pass filter cooperating with one of said at least one current sensor to output a second pass band having a second range of frequencies of said sensed current, said second range of frequencies not overlapping and being greater than said first range of frequencies; a first peak detector cooperating with said first band pass filter to detect a plurality of first peak current values from said first pass band; a second peak detector cooperating with said second band pass filter to detect a plurality of second peak current values from said second pass band; a first envelope detector cooperating with said first band pass filter to detect a plurality of first occurrences from said first pass band being within a first predetermined range of magnitudes; a second envelope detector cooperating with said second band pass filter to detect a plurality of second occurrences from said second pass band being within a second predetermined range of magnitudes; a counter structured to count said first and second occurrences; and a processor structured to provide series arc detection and cooperating with one of said at least one current sensor to disable said series arc detection when the sensed current is greater than a first predetermined value, said processor further cooperating with said counter to determine a plurality of counts from said counter for said half-cycles, said processor further cooperating with said first and second peak detectors to determine a plurality of tallies responsive to one of said first peak current values exceeding a first threshold for said half-cycles or one of said second peak current values exceeding a second threshold for said half-cycles, said processor being further structured to determine presence of series arcing in said power circuit from: said sensed current being less than said first predetermined value for at least a predetermined time, the tally for a current one of said half-cycles being not zero, and the count of said counter for the current one of said half-cycles being different than the count of said counter for an immediately previous one of said half-cycles of like polarity by at least a second predetermined value, said processor being further structured to increase a series chaos accumulator responsive to said presence of series arcing.