Switching device including spark gap for switching electrical power, method for protection of an electric object and its use

摘要

This invention is related to a device and a method in an electric power plant for protection of an object (1) against over-currents from a network (3) or another equipment included in the high voltage plant, the device comprising a switching device (4) in a line (2) between the object and the network/equipment. The line (2) between the object and the network/equipment is connected to an arrangement (5) reducing over-currents towards the object (1), said arrangement (5) being actuatable for over-current reduction with the assistance of an over-current condition detecting arrangement (11-13) within a time period substantially less than the break-time of the switching device (4). The over-current reducing arrangement (5) comprises a switch means (10) with an electrode gap, which may be imparted electrical conductivity for over-current diversion.