Experimental Investigation of Improvement in the Dielectric Recovery Characteristics of a Molded Case Circuit Breaker Splitter Plate

Abstract

The dielectric recovery characteristics of a molded case circuit breaker (MCCB) are related to re-ignition after current-zero. This characteristic affects the interruption reliability of an MCCB because the fault current cannot be interrupted if re-ignition occurs despite trip unit operation. Therefore, to prevent electric leakage during re-ignition, an improvement in the dielectric recovery characteristic is required. In this paper, the influence of the dielectric recovery characteristics on the splitter plate after current-zero was investigated, and a structure intended to improve the splitter plate was proposed. Measurement of the dielectric recovery voltage confirmed that the proposed structure offered improvement compared with the existing ones.