Section 51(1)(b) in The Indian Electricity Rules, 1956
(b)[ All metal works, enclosing, supporting or associated with the installation, other than that designed to serve as a conductor shall be connected with an earthing system as per standards laid down in the Indian Standards in this regard and also in accordance with rule 61 (4).] [ Substituted by G.S.R. 358, dated 30.4.1987 (w.e.f. 9.5.1987).]