30 CFR § 18.35 Portable (trailing) cables and cords.
(a) Portable cables and cords used to conduct electrical energy to
face equipment shall conform to the following:
(1) Have each conductor of a current-carrying capacity
consistent with the Insulated Power Cable Engineers Association (IPCEA)
standards. (See Tables 1 and 2 in Appendix I.)
(2) Have current-carrying conductors not smaller than No.
14 (AWG). Cords with sizes 14 to 10 (AWG) conductors shall be constructed
with heavy jackets, the diameters of which are given in Table 6 in Appendix I.
(3) Be accepted as flame resistant under this part or approved under
subpart K of part 7 of this chapter.
(4) Have short-circuit protection at the outby
(circuit-connecting) end of ungrounded conductors. (See Table 8 in Appendix I.) The fuse
rating or trip setting shall be included in the assembler's
(5) Ordinarily the length of a portable (trailing) cable
shall not exceed 500 feet. Where the method of mining requires the length of
a portable (trailing) cable to be more than 500 feet, such length of cable
shall be permitted only under the following prescribed conditions:
(a)(5)(i) The lengths of portable (trailing) cables shall not
exceed those specified in Table 9,
Appendix I, titled "Specifications for Portable
Cables Longer Than 500 Feet."
(a)(5)(ii) Short-circuit protection shall be provided by a
protective device with an instantaneous trip setting as near as practicable
to the maximum starting-current-inrush value, but the setting shall not
exceed the trip value specified in MSHA approval for the equipment for which
the portable (trailing) cable furnishes electric power.
(6) Have nominal outside dimensions consistent with IPCEA
standards. (See Tables 4, 5, 6, and 7 in Appendix I.)
(7) Have conductors of No. 4 (AWG) minimum for
direct-current mobile haulage units or No. 6 (AWG) minimum for
alternating-current mobile haulage units.
(8) Have not more than five well-made temporary splices in
a single length of portable cable.
(b) Sectionalized portable cables will be acceptable provided the
connectors used inby the last open crosscut in a gassy mine meet the
requirements of §18.41.
(c) A portable cable having conductors smaller than No. 6 (AWG), when
used with a trolley tap and a rail clamp, shall have well insulated single
conductors not smaller than No. 6 (AWG) spliced to the outby end of each
conductor. All splices shall be made in a workmanlike manner to insure good
electrical conductivity, insulation, and mechanical strength.
(d) Suitable provisions shall be made to facilitate disconnection of
portable cable quickly and conveniently for replacement.
U.S. Department of Labor | Mine Safety and Health Administration (MSHA) | 1100 Wilson Boulevard, 21st Floor | Arlington, VA 22209-3939 www.msha.gov | Telephone: (202) 693-9400 | Fax-on-demand: (202) 693-9401