Distribution of Arc Duration and Material Wear Due to Arc for Ag, Cu, and Pd Contacts

An apparatus to measure the arc duration in moving contacts has been developed, which not only measures a breaking arc duration for each contact operation, but also integrates the durations of all arcs occurring during the contact operating period. The apparatus is applied to measure the distribution of arc duration and to find the relationship between material wear and integrated arc duration. Ag, Cu, and Pd are tested as basic contact materials. The results obtained in the experiments show that the arc duration distributions have some characteristics peculiar to the contact materials, and the relationship between the wear and the integrated arc duration is found for each contact material. Ag has an interesting character in both the distribution of arc duration and the wear.