Electrical switching device for high switching voltages

Claim 1

In an electrical switching device for switching high voltages in a network having a defined rated voltage, the device including a series connection of at least first and second current interrupters having control elements across which a load voltage is distributed, each interrupter operating according to different quenching principles and exhibiting different dielectric behavior immediately after a zero passage of load current to be interrupted, the first interrupter exhibiting a steep rate of rise in its dielectric strength with a maximum dielectric strength value which is a fraction of the defined rated voltage, and the second interrupter having a relatively flat rate of rise in dielectric strength compared to the first interrupter with a maximum dielectric strength value which lies above the maximum dielectric strength value of the first interrupter; the improvement wherein: said first interrupter comprises a first switch which has an operating voltage that is low relative to a mains voltage of the network and which includes means for interrupting, at relatively low switching voltages without participation of said second interrupter, currents having inductive components; and said second interrupter comprises a second switch having switching contacts and delay means for opening said switching contacts with a time delay of several milliseconds after said first interrupter is opened, for interrupting load currents that are small relative to currents interrupted by said first interrupter; wherein said series connection of said interrupters interrupts capacitive currents also under grounding conditions with comparatively large recovery voltages and without restriking, with a distribution of voltage across said interrupters when both are open being controlled solely by their own and ground capacitances.