| 摘要 |
In the case of a contact system for gas-blast power circuit breakers having two stationary contact elements (1, 2) which are arranged on one axis, said stationary contact elements (1, 2) are connected in the switched-on position by means of a moving bridging switching element (3). The bridging switching element (3) consists of a multiplicity of spring-loaded contact fingers (4) which are arranged in an annular shape and continuously rest against a contact element (2) (guide contact element). The bridging switching element (3) furthermore consists of a sleeve (6) which surrounds these contact fingers and is electrically conductively connected, on its side (3a) facing the other contact element (1) (interrupter contact element) to an arcing ring (7) which is mounted in front of the contact fingers (4). In order to increase the life of the contact fingers (4) in that the contact fingers (4) are removed from the effects of the arc in the region of the interruption path (T), the invention consists of the contact fingers (4) being electrically insulated from the sleeve (6) and being capable of being moved (in the course of the switching-on movement) into an insulating region (14) of the guide contact elements (2) before the bridging switching element has separated from the interruption contact element (1), in that, under load, an arc is struck with a burning voltage which exceeds the ignition voltage between the interrupter contact element (1) and the arcing ring (7). <IMAGE>
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