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 line of the three-phase line is zero, but for a single phase, the current is not zero. When the three-phase load is asymmetrical, the current vector sum of the neutral line is not zero, and the voltage to ground will be generated.
The three-phase five-wire system standard wire colors are: A wire is yellow, B wire is green, C wire is red, N wire is light blue, and PE wire is yellow-green.
The three-phase five-wire system is divided into TT grounding mode and TN grounding mode, of which TN is divided into three modes: TN-S, TN-C, and TN-C-S.

The voltage between the phase lines of the civil power supply line (that is, the line voltage) is 380V, and the voltage (that is, the phase voltage) between the phase line and the ground line or the neutral line (that is, the phase voltage) is 220V. The household line generally adopts the single-phase two-wire system, that is, any one of the three phase lines and the neutral line (as the zero line). In case of high-power electrical appliances, you need to set up a ground wire yourself.
The three-phase five-wire system standard wire colors are: A wire is yellow, B wire is green, C wire is red, N wire is light blue, and PE wire is yellow-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 line of the three-phase line is zero, but for a single phase, the current is not zero. When the three-phase load is asymmetrical, the current vector sum of the neutral line is not zero, and the voltage to ground will be generated.