Study of Arc Mobility and Reignition in a Static Gap Discharge with Magnetic Field

Arc mobility on contact surface is an important factor in contact erosion and circuit interruption. The two stages of arc mobility are the initial immobile arc followed by the running arc. Past work in the literature showed that immobile arc time is dependent of contact material, current and contact separation speed until a minimum separation speed is reached. When the arc is in the running stage, then contact material strongly affects arc velocity. In this paper, we re-examine the contact material effect with analysis of the arc spot eroded surface morphology to compare material modifications that can affect the arc mobility and reignition. A static gap discharge with various external magnetic field strength is used to affect the arc mobility. Several groups of contact materials are examined including Ag or Cu, Ag, and in composites with C, W, WC, CdO, SnO2.