What is earthing or grounding in household electrical circuit ?

When we bring a charged body in contact with the earth, all the excess charge on the bodydisappears by causing a momentary current to pass to the ground through the connectingconductor (such as our body). This process of sharing the charges with the earth is calledgrounding or earthing.

A thick metal plate is buried deep into the earth and thick wires are drawn from this plate;these are used in buildings for the purpose of earthing near the mains supply.

The electric wiring in our houses has three wires : live, neutral and earth.

The first two carry electric current from the power station and the third is earthed byconnecting it to the buried metal plate.

Metallic bodies of the electric appliances such as electric iron, refrigerator, TV are connected tothe earth wire. When any fault occurs or live wire touches the metallic body, the charge flows tothe earth without damaging the appliance and without causing any injury to the humans.

Earthing provides a safety measure for human body, electrical circuits and appliances.