Scope of electrical safety

Under 1926.402(a), these rules cover installation safety requirements for electrical equipment and installations used to provide electric power and light at the jobsite, whether temporary or permanent. See the Covered provision in 1926.402(a).

• This includes temporary wiring, cord-and-plug connections, junction boxes, lighting, and other on-site electrical installations used during construction.
• These rules do not apply to permanent installations that were already in place before the construction activity started (they are excluded by the same subsection).

Reference: 1926.402(a).

Under 1926.402(b), installations used for the generation, transmission, and distribution of electric energy (including related communication, metering, control, and transformation installations) are not covered by 1926.402–1926.408. See the Not covered provision in 1926.402(b).

• However, portable and vehicle-mounted generators used to provide power at the jobsite are covered by 1926.402–1926.408 (the exception is noted directly in 1926.402(b)).
• For construction of power distribution and transmission lines, see Subpart V of 29 CFR 1926.

Reference: 1926.402(b).

Under 1926.402(a), if an electrical installation is made in accordance with the National Electrical Code ANSI/NFPA 70-1984 (excluding Formal Interpretations and Tentative Interim Amendments), it will be deemed to comply with 1926.403 through 1926.408, with specific exceptions. See the deeming compliance note in 1926.402(a).

• The NFPA 70-1984 compliance is treated as meeting OSHA requirements for 1926.403–1926.408 except for the provisions at 1926.404(b)(1) and certain parts of 1926.405(a)(2)(ii)—specifically subitems (E), (F), (G), and (J).
• That means following NFPA 70-1984 is a safe compliance path in most situations, but you must still follow those OSHA provisions that are explicitly excepted from the deeming rule.

Reference: 1926.402(a); see also 1926.404(b)(1) and 1926.405(a)(2)(ii).

Under 1926.402(a), the NFPA 70-1984 compliance does not cover the OSHA requirements in 1926.404(b)(1) and the subparts (E), (F), (G), and (J) of 1926.405(a)(2)(ii). See the deeming compliance note in 1926.402(a).

• 1926.404(b)(1) relates to wiring methods, components, and equipment required to be accessible and installed in a manner that minimizes hazards.
• Subsections (E), (F), (G), and (J) of 1926.405(a)(2)(ii) concern specific overcurrent protection arrangements, identification, and grounding-related protective measures that OSHA chose to retain as mandatory regardless of NEC compliance.

Reference: 1926.402(a); see 1926.404(b)(1) and 1926.405(a)(2)(ii).

Under 1926.402(b), portable and vehicle-mounted generators used to provide power at the jobsite are covered by 1926.402–1926.408. See the 1926.402(b) statement.

• Even though the section excludes generation/transmission/distribution systems, it explicitly retains coverage for portable and vehicle-mounted generators used on-site.
• Employers must apply the relevant installation, grounding, overcurrent protection, and guarding requirements in 1926.403–1926.408 to those generators.

Reference: 1926.402(b).

Under 1926.402(a), yes—the installation safety requirements apply to installations that are temporary as well as permanent when they are used on the jobsite. See the Covered provision in 1926.402(a).

• Temporary power setups, temporary lighting, and temporary distribution systems installed for a specific construction activity fall under 1926.403–1926.408.
• You must follow the relevant wiring methods, overcurrent protection, grounding, and guarding requirements in the cited sections for those temporary systems.

Reference: 1926.402(a).

Under 1926.403, OSHA requires that wiring, equipment, and installations be protected against accidental contact, damage, and overcurrent, and that they be installed in a safe and workmanlike manner. See 1926.403.

• Employers must install wiring and equipment to minimize hazards from electric shock and fire (grounding, insulation, and correct wiring methods).
• Disconnecting means and overcurrent protection must be provided where required to protect circuits and equipment.
• Wiring methods and material must be appropriate for the environment and loading conditions.

Reference: 1926.403.

Under 1926.404(b)(1), OSHA requires that switches, circuit breakers, and similar devices be installed so they are readily accessible and installed to minimize electrical hazards. See the requirement in 1926.404(b)(1).

• Equipment must be positioned and enclosed to prevent accidental contact and to allow safe operation and maintenance.
• Accessibility also means clear working space for operation and servicing in accordance with the standard.

Reference: 1926.404(b)(1).

Under 1926.405(a), overcurrent protection is required to protect conductors and equipment from currents that could cause damage or fire, and employers must ensure overcurrent devices are suitable for the circuit and properly installed. See 1926.405(a).

• Employers must select overcurrent devices (fuses, circuit breakers) sized to protect the connected conductors and equipment from overloads and short circuits.
• Overcurrent devices must be installed so they are accessible for operation and maintenance and be properly identified.

Reference: 1926.405(a).

Under 1926.405(a)(2)(ii), OSHA requires that overcurrent devices be identified and marked so that the circuits they protect are readily identifiable and that ratings are visible, as detailed in the subsection. See 1926.405(a)(2)(ii).

• Labels or markings must clearly show the rating and the circuit(s) protected so workers can safely operate and maintain the equipment.
• Certain sub-items in this section (E), (F), (G), and (J) are specifically retained by OSHA as exceptions to the NFPA 70-1984 deeming provision, so these identification and protective measures are mandatory.

Reference: 1926.405(a)(2)(ii).

Under 1926.404, OSHA requires that junction boxes, cabinets, and outlet boxes be installed so they provide suitable enclosure, protect conductors and connections, and be accessible for inspection and maintenance. See 1926.404.

• Boxes and enclosures must be of the correct size and type for the wiring and equipment they contain and must be securely mounted.
• Covers and doors must be in place to prevent accidental contact and to protect wiring from damage.
• 1926.404(b)(1) specifically requires accessible placement and installation to minimize hazards.

Reference: 1926.404; see 1926.404(b)(1).

Under 1926.403, yes—employers are required to provide disconnecting means for electrical equipment where necessary so circuits and equipment can be de-energized for safe operation and maintenance. See 1926.403.

• The disconnecting means must allow workers to remove power before servicing equipment to prevent electric shock and arc-flash hazards.
• Disconnects should be clearly identified and accessible in order to safely isolate energy sources during work.

Reference: 1926.403.

Under 1926.402(a), compliance with NFPA 70-1984 will generally be deemed compliance with OSHA 1926.403–1926.408, but employers must meet any OSHA provisions specifically retained (e.g., 1926.404(b)(1) and parts of 1926.405(a)(2)(ii)), and OSHA enforces federal OSHA standards regardless of local code differences. See 1926.402(a).

• If a local electrical code imposes more stringent requirements than NFPA 70-1984, employers should follow the more protective requirement; OSHA enforces federal standards and may cite for violations of OSHA regulations even if local code differs.
• The NFPA 70-1984 "deeming" provision is not a substitute for meeting OSHA requirements that are explicitly retained by OSHA in the standard.

Reference: 1926.402(a).

Under 1926.402(a), the installation safety requirements in 1926.402–1926.408 do not apply to existing permanent installations that were in place before the construction activity commenced. See 1926.402(a).

• However, hazards arising from interaction between new construction activities and pre-existing electrical installations (for example, damaged wiring or exposed live parts created by construction) can still create OSHA safety issues, and employers must protect workers under applicable OSHA standards and the General Duty Clause.
• If work modifies or extends an existing permanent installation, the new work may be subject to 1926.403–1926.408.

Reference: 1926.402(a).

Under 1926.403 and related provisions, employers must ensure electrical installation and servicing are performed by qualified persons who understand the hazards and required protective measures. See 1926.403.

• A qualified person is someone trained and knowledgeable about electrical work and the safety-related practices, including recognizing electrical hazards and implementing controls (grounding, PPE, lockout/tagout where applicable).
• Using qualified personnel helps ensure wiring methods, overcurrent protection, and disconnecting means are correctly installed to protect workers.

Reference: 1926.403.

Under 1926.404, junction boxes, outlet boxes, and similar enclosures must be provided with covers or closures to protect the wiring and to prevent accidental contact when they are not in use. See 1926.404.

• Covers prevent exposure to energized parts and protect wiring from physical damage, moisture, and debris.
• Keeping boxes covered is part of installing equipment to minimize hazards as required by 1926.404(b)(1).

Reference: 1926.404; see 1926.404(b)(1).

Under 1926.405(a) and related safe-work practices, employers must ensure that circuits and equipment are de-energized and properly isolated before performing work that would expose employees to electrical hazards, and that overcurrent protection is restored or alternate protective measures are in place before re-energizing. See 1926.405(a).

• If overcurrent protection must be removed for service, qualified persons should carry out appropriate lockout/tagout and temporary protective measures to prevent accidental energization and protect workers against shock and arc flash.
• Restore overcurrent protection before placing equipment back into service unless another safe, documented procedure is used.

Reference: 1926.405(a).

Under 1926.402(b), installations used for the generation, transmission, and distribution of electric energy—including related communication, metering, control, and transformation installations—are not covered by 1926.402–1926.408. See 1926.402(b).

• That exclusion means large-scale generation and distribution systems are addressed elsewhere (for example, specific power generation standards or Subpart V for power distribution and transmission lines).
• Note the explicit exception: portable and vehicle-mounted generators used at the jobsite remain covered under these sections.

Reference: 1926.402(b).

Under 1926.404(b)(1), OSHA requires that electrical equipment be installed to provide safe and accessible working space, which includes clear access in front of panelboards and equipment for operation and maintenance. See 1926.404(b)(1).

• Maintain required clearances so workers can safely operate, inspect, and service equipment without reaching over energized parts or working in cramped conditions.
• Proper working space reduces the risk of accidental contact and allows safe use of tools and personal protective equipment.

Reference: 1926.404(b)(1).

Under 1926.403, employers must protect wiring and cables from physical damage by using appropriate wiring methods, conduits, cord grips, raceways, or positioning to avoid hazards. See 1926.403.

• Cords and cables should not be run across walkways or work areas without protection (covering or routing out of traffic) to prevent abrasion, crushing, or trip hazards.
• Where exposed to potential damage, use conduit, armor, or other approved methods to protect conductors.

Reference: 1926.403.

Under 1926.402(a), OSHA retained specific parts of 1926.405(a)(2)(ii)—namely subitems (E), (F), (G), and (J)—so these portions are not covered by the NFPA 70-1984 deeming rule and remain mandatory OSHA requirements. See the deeming compliance note in 1926.402(a).

• These subitems address specific overcurrent device arrangements, identification, grounding, or protective measures that OSHA chose to retain; employers must comply with these OSHA provisions even if they follow NFPA 70-1984.

Reference: 1926.402(a); see 1926.405(a)(2)(ii).

Under 1926.402(b), construction, alteration, or repair of power distribution and transmission lines is covered by Subpart V of 29 CFR 1926, so you should consult Subpart V for those activities. See 1926.402(b).

• 1926.402–1926.408 do not apply to generation, transmission, and distribution installations addressed in Subpart V.
• For tasks like power-line construction, refer to the specific requirements in Subpart V to ensure compliance and worker safety.

Reference: 1926.402(b) and 1926.

Under 1926.403, employers must guard live parts against accidental contact by using approved enclosures, barriers, insulation, and by locating equipment to prevent inadvertent contact. See 1926.403.

• Use covers, cabinets, and barriers to prevent access to live parts.
• Ensure proper insulation and grounding are in place, and maintain clearance distances for both workers and equipment.
• Provide training and lockout/tagout procedures where de-energizing is necessary for servicing.

Reference: 1926.403.

Under 1926.404, yes—electrical equipment installed outdoors must be suitable for the environment and protected against weather and moisture in accordance with approved wiring methods and equipment ratings. See 1926.404.

• Use weatherproof fittings, enclosures rated for wet locations, and proper sealing on outdoor junctions and connections.
• Select materials and installation methods intended for outdoor exposure to prevent short circuits, corrosion, and shock hazards.

Reference: 1926.404.

Under 1926.405(a), employers must select overcurrent protective devices that are appropriate for the conductors and equipment they protect, which means sizing protection devices consistent with conductor ampacity and equipment ratings. See 1926.405(a).

• Correct sizing prevents overheating of conductors and reduces fire and shock risk.
• Overcurrent devices must be coordinated so they protect conductors under foreseeable load conditions.

Reference: 1926.405(a).

Under 1926.402 and related sections, OSHA enforces the electrical installation rules for construction activities, and you can read the standard text at the 1926.402 main page. See the broader construction electrical requirements at 1926 and the linked sections 1926.403, 1926.404, and 1926.405.

• Use these official OSHA pages to review the exact requirements, interpretative notes, and associated citations.

Reference: 1926.402 and 1926.