METHOD FOR PERFORMING A SELF-TEST BY A RESIDUAL CURRENT OPERATED DEVICE, AND RESIDUAL CURRENT OPERATED DEVICE

摘要

A residual current operated device is designed to be able to perform a self-test. The self-test is designed to be performed only in exceptional cases when a heavy current flows through the residual current operated device, because a self-test causes contacts (20, 20') to open, at which contact erosion can occur. Means (40) for measuring the amperage via power supply lines (18, 44; 18', 44') measure the amperage and communicate the result to a control unit (36) comprising a unit (48) in which a decision is made as to whether a self-test will be performed, in order to enable a self-test unit (34) to effect the performance of the self-test. In the decision the amount of time is taken into account that has elapsed since the last self-test, or the time of day. Optionally a self-test is performed also if a heavy current is present after a maximum time interval has elapsed.