30 CFR 77.704 : 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) — Coal Mine Safety And Health (§ 70.1 To § 90.301) — Mandatory Safety Standards, Surface Coal Mines And Surface Work Areas Of Underground Coal Mines (§ 77.1 To Subpart U) — Grounding (§ 77.700 To § 77.705) — Work on high-voltage lines; deenergizing and grounding.

High-voltage lines shall be deenergized and grounded before work is performed on them, except that repairs may be permitted on energized high-voltage lines if (a) such repairs are made by a qualified person in accordance with procedures and safeguards set forth in §§ 77.704-1 through 77.704-11 of this Subpart H as applicable, and (b) the operator has tested and properly maintained the protective devices necessary in making such repairs.