Measurement and Design Review of Contact Force by Garter Spring in Connection between Circuit Breaker and Bus Bar

차단기와 모선과의 연결시 가터스프링에 의한 접촉력의 측정 및 설계 고찰

A garter spring, which is a long. special, close-coiled extension spring with its ends joined to form a ring, is used in connection between vacuum circuit breaker and bus bar in switchgear. To carry short-time current and resist welding at the contact surface in the connection, the garter spring must transmits an uniform contact force to the contact surface through the contact chips arranged in the circumference of bus bar. In this paper, the system for measurement of the contact force by the garter spring is developed. Using the developed measurement system, the design of the connection structure including the garter spring is reviewed to obtain the uniform contact forces in all of contact chips.