Pennsylvania Statutes Title 52 P.S. Mines and Mining § 690-326. Trolley installation

(a) Trolley wires and feeder lines.--All trolley wires and feeder lines installed on underground haulage roads shall be placed as far to one side of the passageway as is practicable, but not less than six inches outside of line of rail, and securely supported upon hangers which shall not be more than 24 feet apart and efficiently insulated.

(b) Prohibition.--In all mines, trolley and feeder wires shall not extend beyond the last open crosscut and shall be kept at least 150 feet from open pillar workings.

(c) Switches or circuit breakers.--All branch trolley lines shall be fitted with either a trolley switch, circuit breaker or section insulator and line switch or some other device that will allow the current to be shut off from the branch headings. Switches or circuit breakers shall be provided on haulage roads to de-energize all trolley and feeder lines at intervals not to exceed 2,000 feet.