In electrical engineering, ground or earth is the reference point in an electrical circuit from which voltages are measured, a common return path for electric current, or a direct physical connection to the earth.
An earth ground connection of the exposed conductive parts of electrical equipment helps protect from electric shock by keeping the exposed conductive surface of connected devices close to earth potential when a failure of electrical insulation occurs.
In addition to electric power systems, other systems may require grounding for safety or function. Structures may have lightning rods as part of a system to protect them from lightning strikes. Telegraph lines may use the Earth as one conductor of a circuit, saving the cost of installation of a return wire over a long circuit. Radio antennas may require particular grounding for operation, as well as to control static electricity and provide lightning protection.
Application of Earthing
Protect Humans against Lightning and Earth Fault.
Protect premises against lightning and earth fault conditions.
Provide low resistance and safe path for lightning and fault current.