黑山县八道壕公社农具厂为防止因三相闸刀开关熔丝烧断一相而产生“掉相”造成电机烧毁的事故,他们应用下列装置能在发生短路故障时自动切断短路电流。构造:在三相闸刀开关的每相熔断丝接头两端引出一对线接一段电炉电阻丝,长3～圈,将三组阻丝放在一条直线上,再从中间穿一条塑料丝 In order to prevent the motor from burning out due to the “phase loss” caused by the blown-out phase of the three-phase switch fuse, they applied the following devices to automatically cut off the short-circuit current in the event of a short-circuit fault. Construction: Three-phase switch fuse at each end of the fuse leads to a pair of wires connected to a section of the furnace resistance wire, long 3 ~ circle, the three groups of resistance wire on a straight line, and then wear a plastic wire from the middle