Electrical endurance test at nominal current of vacuum interrupters

Vacuum Interrupters used for short circuit interruption have demonstrated excellent short circuit interruption behavior throughout many tests performed according to severe standards. With this components, nominal current endurance is commonly assumed to be easy, and thousands of operations are claimed to be feasible even though no standards are available for this type of endurance. Scn Electric, we developed a new nominal current test bench able to perform thousands of operations at current up to 4000 A that we will describe in this paper. We will also present the nominal current test result of some of our internal vacuum interrupter range and analyze the ageing mechanism specific to this current level.