Section 64(2)(ii) in The Indian Electricity Rules, 1956
(ii)[ The following minimum safety working clearances shall be maintained for the bare conductors or live parts of any apparatus in outdoor sub-stations, excluding overhead lines of HV and EHV installations. [Substituted by G.S.R. 112, dated 22.3.2000 (w.e.f. 15.4.2000). ]