Power switch circuit with staggered switches - has device which delays reclosing of switch until current passes through zero

摘要

The power switch circuit has a series of selectively staggered current limiting power switches. Each switch is fitted with a rapid release system and a switch lock. A delay device is connected between the rapid release system and the switch lock to delay the release command to the release system by an amt. equal to the half wave of one phase current or at least until the current next passes through zero. When a short circuit occurs the relevant release system opens irrespective of this delay and closes again at the earliest when the current passes through zero.