Importance of using three pin plug

Three pin plug is used to supply electrical power with the electical device. It has three pin which are a neutral pin, a live pin and a earth pin. Two pin plug has no earth pin. Interesting thing is that the earth pin is very vital for protecting device from an unusual current flow.

We can see the earth pin is longer and thicker than other two pin. When we connect three pin plug into a pin socket the earth pin is the one to contact first othan than two pins. In contast, when we disconnect three pin plug the earth pin is the last other than two pins. Due to the fault current some electricity will flow to the plug, but the earth pin will passes the current to the ground. So, it gives protection against possible electric shock.