Relay box is an operational device to tripping and closing of breaker instructed by protection, breaker controlling unit, monitor unit, and auxiliary device of breaker.

操作箱的作用是用来完成保护、断控单元、测控单元、断路器辅助装置对断路器跳合闸操作的装置。

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The operational features and the fault modes of contactor relay were analyzed.

分析了接触器式继电器的工作特点和失效模式。

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On February 28th and March 1st, American missiles blew up radio relay stations near Mosul in the north that transmit operational data for Iraq's main oil pipeline.

ECONOMIST: Why the bombs are falling on Iraq