Sunday, April 8, 2012

What is Earthing?

Earthing is a connection done through a metal link between the body of any electrical appliance, or neutral point, as the case may be, to the deeper ground soil. The metal link is normally of MS flat, CI flat, GI wire which should be penetrated to the ground earth grid. The purpose of earthing is to ensure a low resistance path between earth and metal body. Any short circuit or fault current that occur in the system will be dissipated to earth. The object of an earthing system is to provide as nearly as possible a surface under and around a station which shall be at a uniform potential and as nearly zero or absolute earth potential as possible. The purpose of this is to ensure that in general all parts of apparatus, other than live parts, shall be at earth potential, as well as to ensure that operators and attendants shall be at earth potential at all times. Also by providing such an earth surface of uniform potential under and surrounding the station, as nearly as possible, there can exist no difference of potential in a short distance big enough to shock or injure an attendant when short-circuits or other abnormal occurrence take place. Earthing associated with current-carrying conductor(neutral) is normally essential to the security of the system and is generally known as system Earthing, while earthing of non-current carrying metal work and conductor is essential to the safety of human life, of animals and of property and is generally known as equipment earthing.

No comments:

Post a Comment

Electrical engineering Community - All Forums