30 CFR 56.12025 : Mineral Resources (§ 1.1 To Parts 1291-1299) — (§ 1.1 To Parts 105-199) — Mine Safety And Health Administration, Department Of Labor (§ 1.1 To Parts 105-199) — Metal And Nonmetal Mine Safety And Health (§ 56.1 To § 58.620) — Safety And Health Standards - Surface Metal And Nonmetal Mines (§ 56.1 To § 56.20014) — Electricity (§ 56.12001 To § 56.12071) — Grounding circuit enclosures.
4 Aug 2016
All metal enclosing or encasing electrical circuits shall be grounded or provided with equivalent protection. This requirement does not apply to battery-operated equipment.