1) Generally, the incoming line of power distribution box adopts five wire system, that is, a, B and C three-way phase line (the general color is yellow, green and red), one way zero line (the color is light blue) and one way ground line (the color is yellow with green. 1) Generally, the incoming line of power distribution box adopts five wire system, that is, a, B and C three-way phase line (the general color is yellow, green and red), one way zero line (the color is light blue) and one way ground line (the color is yellow with green. The three-phase five-wire system includes three phase wires (A, B, C wires), neutral wire (N wire), and ground wire (PE wire) of three-phase electricity. The neutral wire (N wire) is the neutral wire. When the three-phase load is symmetrical, the vector sum of the current flowing into the neutral. The power demanded in electricity systems also determines the cable cross-section and properties as well as the current to be transferred. In case of high power use, to meet the demand of currentAnd in order for the current to be carried at the demanded high powers to be met, the method of parallel. Reliable power delivery is essential in today's world and the three phase five wire system is one of the most efficient ways of providing it. It takes the incoming power and safely distributes it to different circuits throughout your building.