30 CFR § 57.12017 - Work on power circuits.

---
identifier: "/us/cfr/t30/s57.12017"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "30 CFR § 57.12017 - Work on power circuits."
title_number: 30
title_name: "Mineral Resources"
section_number: "57.12017"
section_name: "Work on power circuits."
chapter_name: "MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR"
subchapter_number: "K"
subchapter_name: "METAL AND NONMETAL MINE SAFETY AND HEALTH"
part_number: "57"
part_name: "SAFETY AND HEALTH STANDARDS—UNDERGROUND METAL AND NONMETAL MINES"
positive_law: false
currency: "2026-04-05"
last_updated: "2026-04-05"
format_version: "1.1.0"
generator: "[email protected]"
authority: "30 U.S.C. 811."
regulatory_source: "50 FR 4082, Jan. 29, 1985, unless otherwise noted."
cfr_part: "57"
---


# 57.12017 Work on power circuits.

Power circuits shall be deenergized before work is done on such circuits unless hot-line tools are used. Suitable warning signs shall be posted by the individuals who are to do the work. Switches shall be locked out or other measures taken which shall prevent the power circuits from being energized without the knowledge of the individuals working on them. Such locks, signs, or preventive devices shall be removed only by the person who installed them or by authorized personnel.