What is the function of an earth wire? Why is it necessary to earth metallic appliances?

AcademicPhysicsNCERTClass 10

An earth wire is a safety wire, generally coated with green insulation, connects the metal parts of appliances to the earth. Its function is to conduct the excess current to the earth, reducing the risk of accidents such as fatal electric shock.

It is necessary to earth the metallic bodies of electric appliances because when the live wire of a faulty appliance comes in direct contact with its metallic case, then due to being connected with the earth wire the large current passes directly to the earth without passing through the user\'s body. Thus, we do not get an electric shock.


To avoid the risk of the electric shock, the metal body of an electrical appliance is \'earthed\' or \'grounded\'. Earthing means connecting the metal case (or metal body) of an electrical appliance to the earth (at zero potential) through a metal wire called \'Earth Wire\'.

The electric wiring in houses, shops, or factories has three wires: liveneutral and earth. The first two carry electric current from the power station and the third is earthed by connecting it to the earth through a metal wire called \'Earth Wire\'.

Metallic bodies of electric appliances such as refrigerator, electric irons, televisions are connected to the earth wire so that when any fault occurs or the live wire touches the metallic body the charge flows to the earth without damaging the appliance and without causing any injury to the humans.

Updated on 10-Oct-2022 13:21:52