Measuring the opening arc duration between the punched and/or nonpunched contacts

Abstract

AbstractSince 1984, various kinds of experimental data on the punched contacts were gathered to confirm their efficacy. In this paper, the duration data of the opening arc which causes the damage of relay contacts are collected and investigated in every production lot of specimens.The production lot number in all specimens is seven. The specimen contacts are four kinds of external forms and mounted on three kinds of relays which differ in the driving mechanism for movable contact.AgCd012 wt% contacts are mounted on three kinds of relays. Also, AgCd012 wt%, Ag and AgSnO29.3 wt% contact pairs are mounted on one kind of relay.In the 1985 and 1986 production lot, a few specimens showed a wide scatter of data under the same experimental conditions. Even though specimens were made by three companies and differed from production lots in the same company, all specimens show that the opening arc duration between the punched contacts becomes long together with the increase of switching operations. Also, the opening arc duration is nearly equal to that of the nonpunched contacts in experiments over a five‐year period.