In order to eliminate phenomenon of transient electromagnetism , ac apparatus such as ac relays , ac contacts and breakers must be disjuncted or closed according to special phase 为了消除暂态电磁现象,要求交流电器(如:交流继电器、交流接触器、断路器等等)按照一定的电压或电流相位分合闸。
ac relay meaning:[Electronics] A relay designed to operate on alternating current without chattering or vibrating. ac relay перевод:реле переменного тока