30 CFR § 75.504
Permissibility of new, replacement, used, reconditioned, additional, and rebuilt electric face equipment.
On and after March 30, 1971, all new, replacement, used, reconditioned, and
additional electric face equipment used in any mine referred to in
shall be permissible and shall be maintained in
a permissible condition, and in the event of any major overhaul of any item
of electric face equipment in use on or after March 30, 1971, such equipment
shall be put in, and thereafter maintained in, a permissible condition,
unless in the opinion of the Secretary, such equipment or necessary
replacement parts are not available.
[38 FR 4975, Feb. 23, 1973]