Patent ID: 8854066
Filing Date: 2014-10-07
Classification: G01R,H02H

Abstract:
1. A method of detecting a glowing contact in a power circuit, said method comprising: applying at least two different resistance values across said power circuit and responsively sensing at least two voltages across said power circuit, each of said at least two voltages corresponding to one of said at least two different resistance values; determining if a number of changes in said sensed at least two voltages with respect to a number of changes in said at least two different resistance values is linear within a predetermined range or if a change in two of said sensed at least two voltages does not increase with a decrease in two of said at least two different resistance values and, otherwise, responsively generating at least one of a trip signal and an alarm signal corresponding to detecting the glowing contact in said power circuit; and employing as said at least two different resistance values three different resistance values corresponding to about one unit of current, about two units of current and about four units of current flowing in said power circuit.