Why should lighting transformers be used in factories and mines?
In some factories and mines (such as power plants), in order to supply power reliability, the power system is grounded in a three-phase, ungrounded, or neutral manner. In this way, the transformer must be connected to a neutral grounding type with a special transformer to supply power to the lighting.
There are two cases. One is the general factories and mines, and the low voltage is three-phase four wire system, and the neutral point is directly grounded. Between the phase line and the zero line is 220V, which can be connected with the illumination load.
But in many cases, such as mines and machinery, the voltage is too high and unsafe. The lighting transformer is then used to reduce the voltage to the so-called "safety voltage""
