.- [(1) In the interest of safety, appropriate equipment shall be suitably placed in the mines for automatically disconnecting supply to any part of the system, where a fault, including an [earth fault occurs].[Fault current shall not be more than 750 milli-Amps in 550/1100 volt systems for underground/oil-fields and 50 Amps in 3.3 KV/6.6 KV systems in open-cast mines. The magnitude of the earth fault current shall be limited to these specified values by employing suitably designed, restricted neutral system of power supply.] [ Substituted by G.S.R. 112, dated 22.3.2000 (w.e.f. 15.4.2000).](2)[ The operation of the switchgear and the relays shall be recorded daily at the generating station, sub-station or switch-station in a register kept for the purpose.(3)The effectiveness of the switchgear and the protective system shall always be kept and maintained in working order, shall be checked once every three months and the result thereof shall be recorded in a separate register kept for the purpose.] [Substituted by G.S.R. 1723, dated 21.11.1977 (w.e.f. 31.12.1977). ]
