交流继电器 meaning in English

ac relay
alternating current relay
alternating-current relay

Specification for alternating - current relays for railway signalling : track relays double - element , 2 - position , line relays single - element , 2 - position
铁路信号用交流继电器规范.拨轨继电器
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。