Influence of source voltage on gaseous phase arc transition in Ag alloy contacts - Relation between damage in contact surface and voltage

摘要

We have studied maintaining mechanism of the contacts arc discharge. In our experiment, the arc duration ta, metallic phase arc duration tm, and transition ratio from metallic to gaseous phase arc G were experimentally studied in Ag and AgSnO{sub}2 breaking contacts. Experiments were carried out under the variation of source voltage E (24, 30, 36, 42V) closed contact current Io (0.4 - 6A). Furthermore, the surface photograph of contacts before and after the experiment was taken with a digital microscope. As the result, AgSnO{sub}2 transits to the gaseous phase arc by a current value that is smaller than Ag. The source voltage doesn't influence the area of the metallic contact part with the metallic luster.