ARCING FAULT DETECTION SYSTEM

A system to detect arcing faults in an electrical distribution system with a line conductor connected to a utility power transformer . The system monitors the rate of change of electrical current in the line conduct or and produces a signal which represents the rate of ch ange. The system produces a pulse each time the rate-of-change signal exceeds a select ed threshold, filters the rate-of-change signal and/or t he pulses to substantially eliminate a signal or pulse which represents changes in the electrical current outside a selected frequency range, monitors the remaining pulses to detect when the number of pulses that occur within a selected time interval exceeds a predetermined threshol d, and generates an arc-fault-detection signal in response to the occurrence of a n umber of pulses which exceed the threshold within the se lected time interval.