Difference between Earth Wire and Neutral Wire

Differences Digital Electronics Electronics & Electrical

In AC electrical wiring, three types of conductors are used viz. phase wire, neutral wire and earth or ground wire. The phase wire is the live wire of the system which carries electric current from source to load. But, sometimes there is a confusion between neutral and earth wire because both of the conductors are considered to operate with zero voltage or lower voltage than phase wire voltage.

Therefore, this article is created for explaining the differences between neutral and earth wire. But, it may difficult to understand the differences between neutral wire and earth in the beginning, so we have added a brief description of earth and neutral for your reference which makes it easy to understand the differences between them.

What is Neutral Wire?

In an AC (alternating current) electrical circuit, the conductor wire that is used to provide a return path to the electric current is known as neutral or neutral wire. Therefore, a neutral wire is a necessary part of an electric circuit which completes the circuit so that current flow can take place. Thus, a neutral wire carries the return current back to the source of electric supply such as transformer or alternator, etc.

As we known, in practice, two types of AC systems are used viz. single-phase system and three-phase system. In a single-phase system, there are only two wires used which are phase and neutral. Thus, in case of a single phase system, the neutral always carries electric current back to the source of electricity in normal conditions. Whereas, in a three-phase system, when the 3-phase load is balanced, there is no current flow through the neutral wire, but when there is an imbalance in the 3-phase load, a fraction of phase current flows through the neutral wire return to the source of supply.

What is Earth Wire?

In an electrical wiring system, an earth or ground is a conductor wire which is mainly provided to protect the electrical appliances and user of the appliance from the electric shock. Therefore, the earth or ground wire is primarily used for safety concerns against the leakage currents in the electrical systems.

The earth wire is always connected to body of the electrical appliance which does not carry any current under normal conditions. But, in case when there is a fault in the device such as insulation failure or a bare wire inside the device touches its metal body, the earth wire is supposed to carry some current to the ground.

The earth wire is not a mandatory connection from the point of view of the working of the device, it is provided only for safety purposes.

Note − Ideally, in practical AC systems, the neutral is usually connected to the ground or earth wire, hence when voltage is measured between the neutral and earth wire, it found zero.

Difference between Earth Wire and Neutral Wire

All the important differences between earth wire and neutral wire are highlighted in the following table −

Basis of Difference	Neutral Wire	Earth Wire
Definition	The conductor wire provided for carrying the return current back to the supply source in an AC system is known as neutral wire.	In any electrical wiring system, a wire which is provided for safety concerns against leakage currents in the system and is connected to the ground is known as earth wire.
Connection	The neutral wire is connected between neutral terminals of source and load.	The earth wire is connected between body of the electrical appliance and the ground.
Role	The neutral wire provide a return to the electric current in the circuit.	Earth wire provide a path for leakage to flow from device body to the ground.
Current under normal condition	Neutral wire always carry a return current in the normal conditions in the AC circuit.	Earth wire does not carry any electric current under normal condition, it carries current only when there is a fault in the device.
Standard wire color code	The standard color for neutral wire is black.	The color of earth wire is green or green-yellow.
Wire resistance	The conductor wire used for provided neutral has relatively higher resistance than earth wire.	The resistance of the earth wire is lower than that of neutral wire.
Type of circuit	The neutral wire is only exist in AC circuits, and not in DC circuits.	The earth wire exists in both AC and DC circuits, because it provides safety against electric shock to the user of the appliance.
Substitution	When required, a neutral wire can be converted into earth wire, by connecting it to ground.	An earth conductor cannot be converted into neutral wire.

Conclusion

In the above table, we have enlisted all the major differences between neutral wire and earth wire in an electrical wiring system. The most significant difference between them is that the neutral wire is used as a return path for electric current in an AC system, while the earth wire is used as a safety wire in any electric system. However, both the earth wire and the neutral wire have the same voltage equal to zero.