| 摘要 |
A RCCB comprises an outgoing supply socket, a circuit breaker mechanism for interrupting the flow of current to the supply socket in response to a fault signal, and means responsive to the absence of a plug (1) in the supply socket for reducing the energy required to close the contacts (8,9) of the breaker mechanism. The reduced energy requirement is achieved either by reducing the contact gap of the breaker mechanism or by reducing the magnitude of a biasing force tending to open the contact gap. As shown, removal of the plug (1) allows the socket shutter (2) to be spring-biased to the left, to move the contact (9) closer to the fixed contact (8) and hence allow the electromagnet (4) to reclose the contacts without manual intervention. Alternatively, a spring is provided between the movable contact (9) and the shutter (2) to provide contact bias to the open position in conjunction with the armature spring. On plug removal, the shutter movement reduces the bias provided by the contact/shutter spring. A further contact can be provided on the shutter (2) for closing with the movable contact (9) in the absence of a plug, for test purposes. <IMAGE> |
