METHOD AND APPARATUS FOR PROTECTING ELECTRICAL SYSTEMS

摘要

Apparatus for providing an electrical system with protection against electrical shock in the event of a ground fault is disclosed which electrical system supplies power from a central mains inlet (MI) to at least one local electrical device (LD1, 2, 3) and which central mains inlet includes a central ground fault detector (I) and interrupter actuatable upon detection of a first predetermined level of current imbalance TH1 to interrupt the central mains inlet (CMJ) which comprises a local ground fault detector (LSS) in said at least one local electrical device supplied from the central mains inlet and actuatable upon detecting, in its respective device, a current imbalance of a second predetermined level (TH2) which is lower than said first predetermined level; and control means effective upon actuation of said local ground fault detector, to actuate the central ground fault detector (CI) and to cause it to interrupt said central mains inlet (CMJ).