Abstract:

In order to solve the problem that the moving and static contacts vibrate due to high-strength impact load or alternating load during the closing process of double breakpoint moulded case circuit breaker,a contact mechanism of circuit breaker is proposed.The test results show that the new circuit breaker contact mechanism increases the limit short-circuit breaking capacity from 100 kA to 150 kA,greatly reduces the arcing time and on-off time,and effectively improves the contact bounce problem.

Key words: contact mechanism, contact vibration, limit short-circuit breaking capacity, arcing time, on-off time