在电力电路中，必须正确运用各类继电器，才能保障大中型电机的安全运行。1过电流继电器电机过流保护线电器应在电机启动后投入运行，避开电机启动峰值电流，通常与电流互感器配套使用。过流继电器的整定电流值（）I。（电机额定电流）。一般If整定值在l‘5－ZIf。范围内。2热 In the power circuit, we must correctly use various types of relays in order to protect the safe operation of medium-sized motors. 1 over-current relay motor over-current protection Wire electrical equipment should be put into operation after the motor starts, to avoid the peak current motor start, usually with the current transformer supporting the use of. Overcurrent relay setting current value () I. (Motor rated current). The general If setting is at l’5-ZIf. Range. 2 hot