High-Speed Spectroscopic Imaging of Contact Surfaces Eroded by Break Arcs

Break arcs are generated between silver electrical contacts in a DC 48V-9.4A resistive circuit. The contact surface is irradiated by a blue LED (Light Emitting Diode). Only the image of contact surface irradiated by the LED is observed by a high-speed camera without the light emitted from the break arc. Simultaneously, only the break arc is also observed by another high-speed camera. Time evolutions of the surface morphology being eroded by the break arcs and the motion of the break arc are observed with these cameras, simultaneously. It is shown that the regions of eroded contact surface are distinguished by the phases of arc duration during the occurrence of the break arcs.