Electric Wiring, 3rd Edition

10 Safe and efficient earthing

The necessity for earthing non-current-carrying metalwork of wiring systems

and exposed metalwork of electrical apparatus derives from the fact that the

neutral point of most low voltage distribution systems is earthed, so that a

voltage exists between earth and the other pole or poles (Fig. 1.4).

IEE Regulation 130-09-01 requires that, where metalwork of equipment

(other than current-carrying conductors) may become live due to a fault and

this condition would cause danger, the following precautions must be taken:

1 the metalwork should be earthed in such a manner as will cause

discharge of electrical energy withou ...