30 CFR § 75.701-4 - Grounding wires; capacity of wires.
---
identifier: "/us/cfr/t30/s75.701-4"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "30 CFR § 75.701-4 - Grounding wires; capacity of wires."
title_number: 30
title_name: "Mineral Resources"
section_number: "75.701-4"
section_name: "Grounding wires; capacity of wires."
chapter_name: "MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR"
subchapter_number: "O"
subchapter_name: "COAL MINE SAFETY AND HEALTH"
part_number: "75"
part_name: "MANDATORY SAFETY STANDARDS—UNDERGROUND COAL MINES"
positive_law: false
currency: "2026-03-24"
last_updated: "2026-03-24"
format_version: "1.1.0"
generator: "[email protected]"
authority: "30 U.S.C. 811, 813(h), 957."
regulatory_source: "35 FR 17890, Nov. 20, 1970, unless otherwise noted."
cfr_part: "75"
---
# 75.701-4 Grounding wires; capacity of wires.
Where grounding wires are used to ground metallic sheaths, armors, conduits, frames, casings, and other metallic enclosures, such grounding wires will be approved if:
(a) The cross-sectional area (size) of the grounding wire is at least one-half the cross-sectional area (size) of the power conductor where the power conductor used is No. 6 A.W.G., or larger.
(b) Where the power conductor used is less than No. 6 A.W.G., the cross-sectional area (size) of the grounding wire is equal to the cross-sectional area (size) of the power conductor.