Analysis on Variation in Interruption Performance by Heat-gas Adsorption of Splitter plate in Arc Distinguishing Unit at Molded Case Circuit Breaker

The over-current is inflows to the power system due to various internal and external factors, which cause damage and malfunction of the installed device and lower the stability of the system, resulting in power loss. Therefore, in order to prevent these failures, the circuit breaker with appropriate specifications are installed in the system according to capacity. Among them, the Molded Case Circuit Breaker is the closest to the consumer and the largest quantity is installed in the distribution system. Pre-installation performance of the circuit breaker is verified by the product standards, but no consideration has been made for variations in the use environment. In this paper, a study is conducted on the performance change of MCCB due to repeated inflow of the over-current, and in particular, the effect on the energy consumption section according to the adsorption of hot-gas in the splitter plate is analyzed. As a result, it is experimentally confirmed that the energy consumption time and amount decreased as the hot-gas formed when the circuit breaker is operation by repeated over-current inflow is adsorbed to the splitter plate. Based on these results, it is expected to help develop maintenance, replacement timing and diagnostic methods according to the installation environment and operation frequency.