Protective-earth conductor contact monitor for a plug-in, mobile protection device

摘要

The invention relates to a protective-earth conductor contact monitor for a plug-in, mobile protection device whose function is based on the principle of a residual current device (fault current circuit breaker) or differential current circuit breaker. The object is now to expand this protection device such that all the poles of a defective load apparatus are disconnected in the event of a fault current, even if the protective-earth conductor contact fails. The solution is regarded as being a monitoring circuit (10 or 20) which is connected in parallel with the protective-earth conductor contact (9). This monitoring circuit acts directly or indirectly on the tripping device (5) of the protection device. This ensures that disconnection results in the case of a fault current when there is a contact defect in the protective-earth conductor contact (9). <IMAGE>