Method for operating a power switch

摘要

By suitable control of the switching operation, the intention is, while avoiding voltage-limiting components, to avoid overvoltages which can be produced especially by vacuum switching devices in particular three-phase circuits. A tripping-control device (4) first causes switching off of a pole (phase R) of the switching device (2) at a time which excludes the creation of multiple restarts. Depending on the configuration of the mains, either the remaining poles (phases S, T) are opened together approximately 1.5 half-cycles later, or the remaining poles (phases S, T) are each opened at a separation of approximately 2/3 of a half-cycle one after the other. Switches of three-phase motor circuits having vacuum switches or pressurised-gas switches. <IMAGE>