Methods, systems, and apparatus and for detecting parallel electrical arc faults

Abstract

In one aspect, a method for detecting arc faults with a dynamically-changeable slope threshold is disclosed. The method may include monitoring a current waveform to determine a peak amplitude of a half cycle and a slope at a zero crossing of a half cycle. An arc fault counter may be incremented if the maximum amplitude of the half cycle and the slope at a zero crossing are greater than a preset magnitude threshold level and the dynamically-changeable slope threshold, respectively. In another aspect, a decay of the amplitude of a predetermined number of half cycles of the current waveform is measured and an arc counter is not incremented, even if the conditions would otherwise indicate an arc counter increment, when the decay is above a decay threshold for greater than a predetermined number of half cycles. An arc fault detection apparatus adapted to carry out the methods, and systems including the arc fault detection apparatus are disclosed, as are various other aspects.