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OSHA - Improper use of extension and flexible cords

image Joann Natarajan, Compliance Assistance Specialist OSHA Austin, TX

DALLAS/FT WORTH - The normal wear and tear on extension and flexible cords at your site can loosen or expose wires, creating hazardous conditions. Cords that are not 3-wire type, not designed for hard-usage, or that have been modified, increase your risk of contacting electrical current. The most commonly found defects are:

 

 

 

Strain Relief  29 CFR 1926.405(g)(2)(iv):
    To reduce hazards, flexible cords must connect to devices and to fittings in ways that prevent tension at joints and terminal screws. Flexible cords are finely stranded for flexibility, so straining a cord can cause the strands of one conductor to loosen from under terminal screws and touch another conductor.

Cord Damage 29 CFR 1926.405(a)(2)(ii)(I): A flexible cord may be damaged by door or window edges, by staples and fastenings, by abrasion from adjacent materials, or simply by aging. If the electrical conductors become exposed, there is a danger of shocks, burns, or fire.

Durability 29 CFR 1926.405(a)(2)(ii)(J):
    The OSHA construction standard requires flexible cords to be rated for hard or extra-hard usage. These ratings are derived from the National Electrical Code, and are required to be indelibly marked approximately every foot along the length of the cord. Examples of these codes are: S, ST, SO, and STO for hard service, and SJ, SJO, SJT, and SJTO for junior hard service.

Grounding 29 CFR 1926.405(a)(2)(ii)(C):
    Extension cords must be 3-wire type so they may be grounded, and to permit grounding of any tools or equipment connected to them.

Wet Conditions  29 CFR 1926.405(j)(1)(v): When a cord connector is wet, electric current can leak to the equipment grounding conductor, and to humans who pick up that connector if they provide a path to ground. Such leakage can occur not just on the face of the connector, but at any wetted portion. Limit exposure of connectors and tools to excessive moisture by using watertight or sealable connectors.

How Do I Avoid Hazards?
•    Use factory-assembled cord sets.
•    Use only extension cords that are 3-wire type.
•    Use only extension cords that are marked with a designation code for hard or extra-hard usage.
•    Use only cords, connection devices, and fittings that are equipped with strain relief.
•    Remove cords from receptacles by pulling on the plugs, not the cords.
•    Continually audit cords on-site. Any cords found not to be marked for hard or extra-hard use, or which have been modified, must be taken out of service immediately.
natarajan.joann@dol.gov
512-374-0271 x232


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Author Info

Melissa Jones-Meyer dfweditor@constructionnews.net