In a 3 pin plug, the earth pin seems bigger than the live and neutral pins. Have you ever wondered about this size difference? This article would definitely give you an understanding of this size significance.
Purpose of Earth Pin
Every electrical installation requires proper earthing for a safer operation. The exposed metallic parts of an electrical installation are connected to earth potential via earthing. In the event of any current contact with the metallic surface of the installation, the resultant high current will flow to the ground via earth pin of that installation. Thus preventing us from electrical shocks from the exposed metallic surfaces of the installations.
Significance of Bigger Earth Pins
As mentioned before, earth pins are longer and thicker than the live and neutral pins. The lengthier version of the earth pin makes its presence prior to other pins while a 3pin plug is plugged to a socket. Also, when it is unplugged from the socket, earth pin is the last one to get ejected out of the live system. This process makes sure that proper earthing is established before the electricity is supplied to a system. Also, it makes sure that earthing is maintained till the unplugging happens.
We know that thickness of a material is proportional to its area. As per the law of resistance, the thickness of a conductor is inversely proportional to its resistance. Hence the fault current flows to the earth through the earth pin in the event of a fault.
