## Definition/Concept

The normally zero potential carrying wire that helps to return back the electricity from the load to the power supply or complete any single phase electrical circuit is known as Neutral. Yes, in normal conditions there is no potential or voltage in the neutral wire with respect ground. When you measure the voltage between a hot wire and ground wire you will get a potential difference but if you measure the voltage between neutral and ground then you will not get any voltage identically.

Without neutral wire a single phase circuit is useless. We know that to drive a load we need a minimum of two wires. The phase or hot wire brings electricity from the power source to load while the neutral wire is used as a returned path. That means if the current flow from the power source to the load through the hot wire then the current will be returned from the load to the power source through the neutral wire.

## Neutral Wire Function

The main function of a neutral wire is to provide a return path to complete an electrical circuit. Remember that in a pure double phase or three phase system there is no neutral wire. There one phase starts the circuit while another phase or hot wire closed the circuit. Also, remember that in normal conditions there is no voltage between the neutral and ground wire but if there is any fault in the circuit you may get voltage between neutral and earth. And this causes flow leakage current.

## Neutral Wire Color

The color of the neutral wire varies according to country standards.

In IEC(European Countries)

Neutral Wire Color - Blue

United Kingdom(UK),

Neutral Wire Color - Blue

United States(USA),

Neutral Wire Color - White(common) and Gray(alternative)

In India,

Neutral Wire Color - Black

## Neutral Wire Use

As I told you before neutral wire is used to complete a single-phase electrical circuit. So neutral wire is used in single-phase circuits and three phase-four wire circuits. In three phase system, a neutral wire helps to get the lower phase voltage between a phase and neutral. Otherwise, we will get only the line voltages between any two phases.

## How to Identify Neutral Wire

1. The easiest method is color coding. Find out the neutral wire according to your country's color code for the neutral wire.

2. Take a tester and touch wires one by one. In the case of the hot wire, the tester will glow but in the case of the neutral wire, the tester will not glow.

3. Measure the voltage between two wires with respect to the ground one by one. In the case of phase or hot wire, you will get the voltage near the system voltage. But in the case of a neutral wire, you will get zero voltage or a very low voltage.

## Neutral Wire Size

Although the neutral wire is used to make a returned path or complete the electrical circuit, but it conducts the same current as the phase wire conducts for a particular load. So the size of the neutral wire must be the same as the hot wire.