30 CFR § 75.1002
Installation of electric equipment and conductors; permissibility.
(a) Electric equipment must be permissible and maintained in a
permissible condition when such equipment is located within 150 feet of
pillar workings or longwall faces.
(b) Electric conductors and cables installed in or inby the last
open crosscut or within 150 feet of pillar workings or longwall faces
(1) Shielded high-voltage cables supplying power to permissible
(2) Interconnecting conductors and cables of permissible longwall
(3) Conductors and cables of intrinsically safe circuits; and
(4) Cables and conductors supplying power to low- and medium-
voltage permissible equipment.
[67 FR 11004, March 11, 2002]