Moulded case circuit breaker

摘要

A moulded case circuit breaker has a toggle-joint mechanism, articulated on a hook and on a moving contact support. The toggle joint includes a swivel pin movably engaged in an aperture of the hook. When tripping takes place, the released hook pushes the toggle-joint, via the swivel pin and aperture, into a broken position to accelerate opening of the contacts. In the closed position, the toggle-joint is practically perpendicular to the hook.