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OSHA 30: Subpart K Electrical Standards for Construction

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In a previous article that was posted on December 14, 2016, we gave an overview of OSHA’s 30-hour training course. You can read that article here:

The OSHA 30-hour Construction Industry Training course covers several specific topics. However, there are certain topics that OSHA may require contractors to complete extra training on based on the industry that the person participating is associated with.

Contact your local OSHA office to determine whether you are required to participate in extra training as part of the OSHA 30-hour Construction Industry Training course. More information can be found at

Subpart K Electrical Standards for Construction (29 CFR part 1926, subpart K) training overview:

GFCI monitors the difference in current flowing into the “hot” conductor and out to the grounded neutral conductor. The difference (1/2 ampere in this case) will flow back through any available path, such as the equipment grounding conductor, and through a person holding the tool, if the person is in contact with a grounded object.

Subpart K training is particularly important to those working in the HVAC industry as it outlines rules and regulations in regard to the assured-equipment grounding-conductor program which mandates the use of  warning labels and marks to alert employees to hazardous electrical conditions; and tags to warn against energizing circuits and equipment on which employees are working. Accordingly, these standards prevent deaths and severe injuries among construction employees caused by high-voltage electrical hazards.

K-1 What are the most frequently cited serious violations?

  1. 1926.403(a)-Electric equipment must be approved by an OSHA accepted laboratory or agency.
  2. 1926.403(b)-Electric equipment must be free from recognized hazards and used in accordance with manufacturers and approval agency instructions.
  3. 1926.403(I)(2) & (j)-Live parts of electric equipment operating at more than 50 volts must be guarded from contact by an approved enclosure or by other approved means. (See §1926.405(a)(2)(ii)(E), (a)(2)(iii), and (b) for specific guarding requirements for lamps on temporary wiring, for temporary wiring over 600 volts, and for electrical boxes, respectively.)
  4. 1926.404(b)(1)-Employers must provide either ground-fault circuit interrupters or an assured equipment grounding conductor program.
  5. 1926.404(f)-Electric equipment must be grounded under the conditions and in the manner given in Subpart K.
  6. 1926.405(a)(2)(ii)(J)-Extension cord sets used with portable tools and appliances must be of the three-wire, grounding type; and flexible cords must be designed for hard or extra-hard usage.
  7. 1926.405(g)(2)(iv)-Flexible cords must be provided with strain relief.
  8. 1926.416(a)-The employer must determine the location of electric circuits that might be contacted during the course of work and must implement measures to protect employees from accidental contact.
  9. 1926.416(e)(1)-Worn or frayed electric cords and cables may not be used.

K-2 What are effective control measures that can be used to control the hazard listed in K-1?

  1. Make sure that electric equipment is listed or labeled by an Agency or testing laboratory acceptable to OSHA.
  2. Use electric equipment in accordance with the manufacturer’s instructions. Install electric equipment with exposed live parts inside approved enclosures, or install exposed live parts in such a manner that unqualified employees cannot readily gain access to them (for example, by installation at a height of 8 feet or more above the floor).
  3. Make sure that all non-double-insulated electric equipment is equipped with a grounding conductor. Maintain the equipment grounding conductor in good, operable condition.
  4. Provide either ground-fault circuit interrupters (see illustration K) or an assured equipment grounding conductor program (which includes the regular testing of all equipment grounding conductors) to protect employees from ground faults.
  5. Use only three-wire extension cords sets, which provide an equipment grounding conductor. (This applies regardless of whether they are used “only” with double-insulated tools and equipment.) Use flexible cords and cables that are marked with one of the following types: S, SC, SCE, SCT, SE, SEO, SEOO, SJ, SJE, SJEO, SJEOO, SJO, SJT, SJTO, SJTOO, SO, SOO, ST, STO, STOO, G, PPE, or W.
  6. Provide strain relief where flexible cords are connected to devices and fittings to prevent pull from being applied directly to joints or terminal screws.
  7. Determine, by direct observation, by inquiry, or by the use of instruments, whether energized electric circuits are present in a work area where they might be contacted by employees. Deenergize and ground the circuits or guard them, or use insulation to protect employees. Inform employees of the presence and location of these circuits.
  8. Inspect flexible cords for damage, and discard or repair any that are worn or frayed or that have damaged insulation.

K-3 What work practices are needed for protection against electrical hazards?

  1. Maintain a 10-foot-minimum clearance from overhead power lines (§§1926.416, 1926.550(a)(15), and 1926.600(a)(6)).
  2. Use barriers or other forms of guarding when live parts of electric equipment and circuits are exposed (§1926.416(b)(1)).
  3. Maintain electric equipment in good condition (§§1926.416(e)(1) and 1926.431).
  4. Lockout and tag electric circuits that are to be deenergized (§1926.417).
Ruben Porras

Posted In: Safety

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