Protection device , circuit breaker and bayonet system

The utility model provides a protection device, circuit breaker and bayonet system belongs to electrical apparatus technical field. Protection device includes body, mounting and swing arm piece, and the body is installed in the circuit breaker, and mounting and this body coupling, swing arm piece be including the service portion, rotation portion and the butt portion that connect gradually, rotatable connection in the body of rotation portion, and butt position in one side of body, butt portion is used for stretching into in the circuit breaker and acts on the circuit breaker hasp, and the service portion lies in the opposite side of body and is used for the contact or keeps away from bayonet base. When the circuit breaker inserted or extract bayonet base, the service portion drove the swing of butt portion, made butt portion act on the circuit breaker hasp, and then made butt portion trigger circuit breaker removing fastener, ensured no matter install still to dismantle, the circuit breaker is all at off -st