Patent ID: 6262872
Filing Date: 2001-07-17
Classification: H02H

Abstract:
A method of protection in an electronic trip unit, the method comprising the steps of:(a) selecting a limit value;(b) resetting a sample count;(c) resetting a peak count;(d) incrementing the sample count;(e) sensing an electrical signal to provide a sensed signal indicative of an electrical characteristic of the electrical signal;(f) comparing said sensed signal to a threshold;(g) incrementing the peak count when said sensed signal exceeds said threshold;(h) if said sensed signal does not exceed said threshold, comparing the sample count to a maximum number of samples;(i) if the sample count is less than the maximum number of samples. returning to step (d);(j) if the sample count is not less than the maximum number of samples, returning to step (b);(k) generating a trip signal when said peak count reaches said limit value;(l) if the peak count is less than the limit value, comparing the sample count to the maximum number of samples and returning to step (i).