Abstract A factory of ceiling lighting 220v power supply is direct access from one of the three-phase circuit and neutral lines, without going through the transformer. This kind of power supply is simple and effective, not only to meet the 220V power supply, but also to reduce the transformers, and saves power supply expenses. However, this power supply failure will not only cause large-area power outages, sometimes cause the damage of large areas of equipment, in view of the special power supply and the failure will cause serious consequences, this paper analyses the principle of the power supply, discusses the failure can cause significant consequences and solutions.
2013, Vol. 14 
