零线断线是常见的电气事故,它给人们造成的损失有时是严重的。随着四化建设的发展,我国城乡人民生活水平逐渐提高,家用电器如洗衣机、电视机、收音机、电风扇、电冰箱及小型空调设备等使用的越来越多,对零线断线这个问题引起重视是有现实意义的。单相用电设备比较多的场所,各相负载只能做到大致平衡,不可能完全平衡。即使设计或使用中尽量做到三相负载均匀分配,也不可 Zero line breakage is a common electrical accident and the losses it causes to people are sometimes severe. With the development of Sihua construction, the living standards of urban and rural people in our country have gradually improved. Household appliances such as washing machines, televisions, radios, electric fans, refrigerators, and small air-conditioning equipment are used more and more. It is of practical significance to pay attention. In places where there are many single-phase electrical devices, the load of each phase can only be roughly balanced and it cannot be completely balanced. Even if the three-phase load is evenly distributed during design or use, it must not be