Earthing Systems – An Overview

The topic of earthing is very important not only in the context of installations where electricity is used but often even where electricity is not in use. At all installations using electricity it is necessary to provide appropriate earthing for all equipment and metallic structures that do not carry current. Proper earthing assures physical safety of the persons who are present in the area of the installation, ensures proper operation of equipment and also prevents damage to it. Some of the functions performed by earthing are: To trip circuit protection devices by allowing sufficient current to flow under certain fault conditions, to provide a preferred path for theenergy of lightening to be carried to earth, to prevent dangerous voltages to exist in exposed conductive surfaces, to protect sensitive electronic equipment by providing alternative paths to earth, to allow tripping of ELCS’s, to prevent build-up of electrostatic charges where they can be dangerous, to provide an earth path for various types of leakage currents from electronic devices or from electrical equipment and appliances.