Disconnecting switches shall be installed underground in all main direct-current power circuits within five hundred feet of the bottom of shafts, boreholes, or at other places where main power circuits enter the mine.
52 P.S. § 70-1125
Disconnecting switches shall be installed underground in all main direct-current power circuits within five hundred feet of the bottom of shafts, boreholes, or at other places where main power circuits enter the mine.
52 P.S. § 70-1125