1910.305(h): Portable Cables Over 600 Volts
Employers using portable cables above 600 volts must use No. 8 or larger flexible conductors, shield cables over 2,000 volts, ground all shields and provide grounding conductors. Connectors must lock firmly, splices must be an approved permanent type, and terminations must carry a high voltage warning and be reachable only by authorized, qualified employees.
Key takeaways
- 1910.305(h) is part of OSHA's general industry standards (29 CFR Part 1910, Subpart S).
- OSHA cited it 12 times in the last 3 years, in 12 inspections, with $24,844 in current penalties.
- Most citations: TX (3), KS (2), PR (2).
- Free 5-minute toolbox talk for your crew below.
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In this article
What this rule covers
29 CFR 1910.305(h) ("Portable cables over 600 volts, nominal") is one requirement inside 1910.305 Wiring methods, components, and equipment for general use, an OSHA general industry standard (Part 1910, Subpart S). It includes 8 sub-paragraphs. The official text below is copied word for word from the Electronic Code of Federal Regulations (eCFR). The numbers, injury cases and training on this page show how OSHA enforces it on real job sites.
Official text
(h) Portable cables over 600 volts, nominal. This paragraph applies to portable cables used at more than 600 volts, nominal. 12 citations
(1) Conductor construction. Multiconductor portable cable for use in supplying power to portable or mobile equipment at over 600 volts, nominal, shall consist of No. 8 or larger conductors employing flexible stranding. However, the minimum size of the insulated ground-check conductor of Type G-GC cables shall be No. 10.
(2) Shielding. Cables operated at over 2,000 volts shall be shielded for the purpose of confining the voltage stresses to the insulation.
(3) Equipment grounding conductors. Grounding conductors shall be provided.
(4) Grounding shields. All shields shall be grounded.
(5) Minimum bending radii. The minimum bending radii for portable cables during installation and handling in service shall be adequate to prevent damage to the cable.
(6) Fittings. Connectors used to connect lengths of cable in a run shall be of a type that lock firmly together. Provisions shall be made to prevent opening or closing these connectors while energized. Strain relief shall be provided at connections and terminations. 7 citations
(7) Splices. Portable cables may not be operated with splices unless the splices are of the permanent molded, vulcanized, or other approved type. 5 citations
(8) Terminations. Termination enclosures shall be suitably marked with a high voltage hazard warning, and terminations shall be accessible only to authorized and qualified employees.
Source: eCFR, text current as of 2026-10-15. Read all of 1910.305.
Export the list: 12 inspections cited 1910.305(h) in the last 3 years, with employer, location, penalty and date.
Purple Belt, $59/moWhere and how often it was cited
| Year | Citations |
|---|---|
| 2024 | 9 |
| 2025 | 1 |
| 2026 | 2 |
Top states: TX (3), KS (2), PR (2), KY (2), AZ (1)
Largest penalties
| Employer | Location | Penalty for this rule |
|---|---|---|
| VIRGINIA TILE CO | WICHITA, KS | $8,296 |
| STAR PIPE USA, LLC | COFFEYVILLE, KS | $5,807 |
| BOWIE BAKERY | EL PASO, TX | $3,333 |
| QANNEX CORP. | EL PASO, TX | $2,500 |
| 67774 - SMITH AND LOGSDON INC | LOUISVILLE, KY | $1,750 |
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OSHA interpretation letters
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Frequently asked questions
What conductor size is required?
No. 8 or larger with flexible stranding, though the ground-check conductor of Type G-GC cables may be No. 10.
When must cables be shielded?
Cables operated at over 2,000 volts must be shielded, and all shields must be grounded.
Can a portable high voltage cable be spliced?
Only if the splice is the permanent molded, vulcanized or other approved type.
About this page
Sources
- 29 CFR 1910.305 (eCFR), text current as of 2026-10-15
- U.S. Department of Labor enforcement data: OSHA inspections, citations and accident records, copied nightly; data as of 2026-11-06
3-year window. Federal OSHA only; state-plan rules are not counted. Plain-language text is a summary, not legal advice; the official text controls. Black Belt Safety is not part of OSHA or the Department of Labor.