CFR › Title 30 › Part 57 › §57.1208330 CFR §57.12083Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗Copy linkPower cables in shafts and boreholes shall be fastened securely in such a manner as to prevent undue strain on the sheath, insulation, or conductors.