Patent ID: 8089737

Claim:
An arc fault circuit interrupter comprising: separable contacts; an operating mechanism structured to open and close said separable contacts; an arc fault detector structured to detect an arc fault condition operatively associated with said separable contacts, said arc fault detector comprising: a tuned current sensor structured to sense broadband noise of a current flowing through said separable contacts, a compression circuit including an input of said sensed broadband noise from said tuned current sensor and an output, said compression circuit being structured to compress the dynamic range of said sensed broadband noise, a minimum detector including an input of the output of said compression circuit and an output of the minimum value of said input of said minimum detector, and processor including a number of inputs and an output, one of said number of inputs being the output of the minimum value of said minimum detector; and a trip mechanism cooperating with the output of said processor and said operating mechanism to trip open said separable contacts responsive to said detected arc fault condition, wherein said processor is structured to determine a minimum value from the output of said minimum detector for each of a plurality of line half-cycles, a maximum value from the output of said minimum detector for each of said line half-cycles, and a dynamic range value from the difference between said maximum value and said determined minimum value.