Question

What is the role of neutral wire

Answer 1

The purpose of the neutral wire is to complete the 120volt AC circuit by providing the path back to the electrical panel where the neutral wire is connected and bonded to the earth ground. The neutral is an insulated wire because it is part of the circuit which flows electrical current.

In a symmetrical three-phase four-wire, wye system, the three phase conductors have the same voltage to the system neutral. The voltage between line conductors is √3 times the phase conductor to neutral voltage: The currents returning from the customers' premises to the supply transformer all share the neutral wire.