PART XXXIII USE OF ELECTRICITY IN MINES — Grounding
698
(1) The metallic covering of a cable shall not be used as the sole grounding conductor.
698(2)
Electrical motors, component parts, or chambers associated with assembly of machines or equipment shall be grounded with copper conductors to the power supply ground system and the conductance of this ground conductor shall be more than 50% of the conductance of the largest power conductor and have a minimum size of No. 10 AWG.
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