PART XXXIII USE OF ELECTRICITY IN MINES — Underground electrical protection
697
(1) Where electrical energy is taken underground, provisions shall be made so that the current can be cut off on the surface.
697(2)
Conductors, cables, or portable power cables supplying power to fixed equipment at voltages-to-ground in excess of 150 volts shall be protected by armour or conduit and shall be suitably designed for the conditions under which they will be operated.
697(3)
Electrical supply lines installed in boreholes shall be armoured.
697(4)
Unless they are effectively guarded at places where they may be inadvertently touched by persons or objects, trolley wires underground shall be
697(a)
at least 2.4 metres vertically above the top surface of the trolley track rails when operating at 300 volts or less;
697(b)
at least 2.7 metres vertically above the top surface of the trolley track rails when operating in excess of 300 volts and less than 750 volts; and
697(c)
at least 4 metres vertically above the top surface of the trolley track rails when operating in excess of 750 volts.
697(5)
Trolley wires shall be supported by insulated hangers, solidly attached to the roof or ceiling, and may not zigzag.
697(6)
The tracks in a trolley transport system that are used for current return shall be electrically bonded by linkages at the switches, the frogs and other openings to provide electrical continuity for the rails, and cross bonding shall be installed between the 2 rails at more than 60 metre intervals.
697(7)
The ends of trolley line conductors or feeders shall be dead-ended by strain insulators.
Not legal advice. Verify the cited article against the signed agreement.