Patent ID: 7362553

Claim:
An arc fault circuit interrupter for an electrical circuit including a load, said arc fault circuit interrupter comprising: a line terminal; a load terminal; separable contacts electrically connected between said line terminal and said load terminal; a current sensor adapted to sense current associated with said load and flowing between said line terminal and said load terminal and through said separable contacts, said sensed current including a plurality of line cycles; at least one arc fault detection circuit adapted to provide series arc protection and to generate a trip signal responsive to said sensed current from said current sensor, one of said at least one arc fault detection circuit being adapted to collect a plurality of samples of said sensed current over said line cycles, determine that said load is a dimmer-controlled load, determine a phase angle at which said sensed current begins conduction within one of said line cycles, and determine that said phase angle consistently moves in a forward direction or a reverse direction and responsively inhibit said series arc protection; an operating mechanism adapted to open said separable contacts responsive to said trip signal; and wherein said samples are periodically collected over at least a portion of each of said line cycles; wherein each of said samples for one of said lines cycles is associated with an index number; wherein said one of said at least one arc fault detection circuit identifies one of said samples that corresponds to an onset of current conduction of said sensed current for said dimmer-controlled load for a current one of said line cycles, determines that said identified one of said samples is different from another one of said samples that corresponds to an onset of current conduction of said sensed current for said dimmer-controlled load for another one of said line cycles prior to said current one of said line cycles, and stores the index number of said identified one of said samples in a first-in first-out array having a plurality of elements.