In the three-phase four wire system, N represents the neutral wire, also known as the neutral wire. This line configuration is widely used in low-voltage distribution networks, which includes three lines representing phases A, B, and C, as well as a neutral line N. The function of neutral wire (N-wire):
1. Current circuit: In a three-phase four wire system, theoretically there is no current in the neutral line (N line) when the three-phase loads are balanced. However, in practical applications, due to incomplete load balancing, unbalanced currents may flow through the neutral line. In the single-phase transmission line entering the user, a neutral line (N line) is necessary to form the current loop in the single-phase line.
2. Voltage Conversion: In a 380V low-voltage distribution network, a neutral line (N-line) is installed to obtain a 220V phase voltage from the 380V line voltage. In this way, users can obtain the required 220V voltage by the voltage difference between the phase line and the neutral line.
3. Zero sequence current detection: In some cases, the neutral wire (N-wire) can also be used for zero sequence current detection to monitor the balance of three-phase power supply. Wire color identification:
In a three-phase four wire system, specific wire colors are usually used to identify and maintain different lines for ease of identification. Generally speaking, phase A is yellow, phase B is green, phase C is red, and the neutral line (N line) is light purple. This color identification helps electricians quickly and accurately identify circuits during installation, maintenance, and repair.
In the three-phase four wire system, N represents the neutral wire (neutral wire), which plays a crucial role in the system, including forming current circuits, implementing voltage conversion, and performing zero sequence current detection.