Optical Observation of Arc Discharges between Electrical Contacts Breaking at Low Speed in DC42 V Resistive Circuit

Abstract

Breaking arcs occurring between silver electrical contacts are observed in DC42 V resistive circuit using a high-speed camera. The motion and current densities of the cathode and anode spot regions are investigated for different interrupt currents (1=7 A, 10 A and 14 A). Results indicate that the arc length at which the motion of arc spots becomes stable depends on the interrupt current, and the current densities of the cathode spot region are almost constant immediately before arc extinction for each interrupt current.