The sole importance of grounding substation is for protection of equipment from lightning strikes and surges and to protect the individuals operating in the substation. Grounding substation system is essential for connecting the neutral points of generators and transformers to the ground and also the metal parts which do not carry current such as overhead shielding wires, frames, structures, tanks and many more.
Grounding substation of surge arresters is done via earthing systems. The role of substation earthing system is provision of ground mat beneath the surface of the earth and around substation which have a uniform zero potential as per lower earth resistance and the ground to ensure that; the operating staffs are safe through limitation of the voltage gradient at the ground level in substation. Besides, it provides a discharge path for lightning which comes through surge arresters, rod-gaps and shielding wires. More so, it provides reduced resistance path to earthing switch terminals to enable them discharge trapped charges to earth before repairs and maintenance.