SKYDDSANORDNING FOER SKYDDNING AV AVEKTRISKA FOER OEVERSPAENNINGAR I STROEMTILLFOERSELNAET

摘要

The protection arrangement contains (in a known manner) voltage-dependent dissipation elements (5 to 8), preferably metal-oxide varistors, a dissipation element being connected to each line (L1, L2, L3, N) of the power supply network. In the case of the present protection arrangement, the dissipation alternating current is intended to be monitored and a signal is intended to be triggered, in order to disconnect the device (1), which is to be protected, from the power supply network in the event of a limit value being exceeded. For this purpose, the protection arrangement has a measurement transformer (11) for detecting the dissipation alternating current (IA) flowing through the dissipation elements (5 to 8) in total. In addition, an evaluation apparatus (16) is provided which supplies a disconnection signal, which is dependent on the measured variable (IA), when the dissipation alternating current flowing through the dissipation elements after a dissipation surge current caused by an overvoltage has not fallen below a specific limit value. In this way, it is possible for the power supply to be disconnected only when the dissipation elements have become damaged as a result of overloading. IMAGE