A Study on Capacitive Current Switching Capability by Flashover Characteristics between Contacts of Circuit Breakers

This paper describes the capacitive current interruption capability of circuit breakers from the view point of flashover characteristics between contacts of breakers. Authors obtained flashover characteristics between contacts of breakers with short distance by comparing with new condition and eroded condition after 3 shots of T60 according to new JEC 2300 (1998) and new IEC 62271-100. By comparison of flashover characteristics and electric field calculation obtained by the measurement of new and eroded contacts, deterioration of the dielectric capability is of 10 to 20 %. Authors also conducted flashover tests for the contacts and nozzle after significant number of interruption. The total amount of interruption can be considered as the maximum possible interruption according to CIGRE research. The deterioration of dielectric capability is of 10 to 30 %.