ARC FAULT CIRCUIT INTERRUPTER AND METHOD OF PARALLEL ARC FAULT DETECTION
First Claim
1. An arc fault circuit interrupter comprising:
- separable contacts;
a neutral conductor;
an operating mechanism structured to open and close said separable contacts;
a current sensor structured to sense current flowing through said separable contacts and output a sensed current value; and
a processor cooperating with said current sensor to determine and store a plurality of peak values of the sensed current value for a plurality of half-cycles of said current flowing through said separable contacts,wherein said processor is structured to provide arc fault detection and to determine at least one of;
(a) whether a first predetermined plurality of said half-cycles of said current occur in succession and correspond to a non-unity power factor, and to responsively inhibit said arc fault detection for a first predetermined time, and(b) whether a second predetermined plurality of said half-cycles of said current occur in succession and each of said second predetermined plurality of said half-cycles of said current has a smaller peak amplitude than that of an immediately preceding one of said half-cycles of said current of like polarity or of differing polarity, and to responsively inhibit said arc fault detection for a second predetermined time, andwherein said processor is further structured to determine that said arc fault detection is not inhibited for at least one of said first predetermined time and said second predetermined time, and to responsively indicate that at least one of said half-cycles of said current having a peak amplitude greater than or equal to a predetermined amount is a parallel arc.
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Accused Products
Abstract
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.
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Citations
27 Claims
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1. An arc fault circuit interrupter comprising:
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separable contacts; a neutral conductor; an operating mechanism structured to open and close said separable contacts; a current sensor structured to sense current flowing through said separable contacts and output a sensed current value; and a processor cooperating with said current sensor to determine and store a plurality of peak values of the sensed current value for a plurality of half-cycles of said current flowing through said separable contacts, wherein said processor is structured to provide arc fault detection and to determine at least one of; (a) whether a first predetermined plurality of said half-cycles of said current occur in succession and correspond to a non-unity power factor, and to responsively inhibit said arc fault detection for a first predetermined time, and (b) whether a second predetermined plurality of said half-cycles of said current occur in succession and each of said second predetermined plurality of said half-cycles of said current has a smaller peak amplitude than that of an immediately preceding one of said half-cycles of said current of like polarity or of differing polarity, and to responsively inhibit said arc fault detection for a second predetermined time, and wherein said processor is further structured to determine that said arc fault detection is not inhibited for at least one of said first predetermined time and said second predetermined time, and to responsively indicate that at least one of said half-cycles of said current having a peak amplitude greater than or equal to a predetermined amount is a parallel arc. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A method of detecting parallel arc faults in a power circuit, said method comprising:
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(a) sensing a plurality of half-cycles of current flowing in said power circuit; (b) providing arc fault detection of said current flowing in said power circuit; (c) ignoring any of said half-cycles of current having a peak amplitude less than a predetermined amount; (d) determining at least one of; (i) whether a first predetermined plurality of said half-cycles of current occur in succession and have non-unity power factor and responsively inhibiting said arc fault detection for a first predetermined time, and (ii) whether a second predetermined plurality of said half-cycles of current occur in succession and each of said second predetermined plurality of said half-cycles of current has a smaller peak amplitude than that of an immediately preceding one of said half-cycles of current of like polarity or of differing polarity, and responsively inhibiting said arc fault detection for a second predetermined time; and (e) determining whether said (c) ignoring and said (d) determining are not met, and responsively indicating that at least one of said half-cycles of current having a peak amplitude greater than or equal to said predetermined amount is a parallel arc. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27)
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Specification