Kevin Lindley, FRSA Self Insurer’s Fund Safety Consultant
Electrical extension cords are a tool often used in the construction industry, even when the condition of the cord is not completely acceptable. Extension cords are a vital device used to transfer power from one source to another: a remarkably simple tool for a very simple purpose. To safely use an extension cord, be sure to know the differences in their capacities.
Contractors must purchase the correct extension cord for the job. The Occupational Safety and Health Administration (OSHA) has mandated that construction contractors must provide and use a minimum 12-gauge exterior rated extension cord on all jobsites – residential and commercial. A 12-gauge extension cord is rated for heavy-duty use, can handle up to a 20-amp capacity and is suitable for cords up to 150 feet in length. Contractors are not permitted to daisy chain or connect multiple extension cords to one another. The power source should be located no more than 100 feet from the operation. Cheaper extension cords, although still 12-gauge, have a fairly thin outer jacket which may allow the interior wires to flex and twist, creating broken wire filaments. Avoid purchasing cheaply made extension cords just because they cost less.
Contractors must inspect extension cords prior to each use. Damaged cords must be completely removed from the jobsite, disabled so they are no longer able to be used or plugged into a power source or tagged out-of-service in the field. OSHA requires that a damaged cord be removed from use. Roll the cord up and place a tag on the cord indicating that it is damaged and out of service, then return it to the office for further action (i.e., repair, replacement or disposal). Damage can include but is not limited to missing ground pin or plug, broken connector(s), jacket separation from the connector(s), cut in the jacket, exposed wires in the cord and jacket or cords used beyond their capacity, causing the cord to become overheated.
In construction, all electrical devices and cords shall be plugged into ground fault circuit interrupter (GFCI) at all times. Not all residential buildings have exterior GFCI outlets. Homes constructed before 1971 may not have them present as currently required. Also, not all outlets on a power generator are necessarily GFCI protected. Some generators require the unit to be grounded in order for the GFCI outlets to work properly. GFCI portable adapter outlets are sold at many retailers. The amperage limits should be confirmed prior to purchase and used with some equipment such as Leister heat guns. When portable GFCI adapter outlets are used, they should be plugged directly into the power source, not at the end of an extension cord. Do not daisy chain portable GFCI protectors or power extension strips to one another. While being used, there are a few simple precautions for electrical extension cords:
■ Do not use a damaged extension cord or plug it into a damaged electrical outlet.
■ Do not use indoor extension cords in an exterior condition.
■ Avoid placing extension cords through puddles of water; especially avoid placing connections in water.
■ Do not run extension cords through unprotected doorways, holes, walls or floors.
■ Do not staple or nail an extension cord to a wall or any other surface.
■ Fully plug the extension cord into the outlet or power source.
■ Avoid creating a knot with the extension cord and your tool. Instead, create a loop and allow slack at the connection or purchase a connection securement device.
■ Do not cover extension cords with combustible materials or equipment.
When an extension cord is in use, a fire extinguisher must be present on the job. Electrical fires are classified
as a Type C fire hazard. OSHA requires a fire extinguisher anywhere a fire hazard is present. ABC rated fire extinguishers are the most recommended type of fire extinguisher to have available because they have more versatility.
For additional reference, type A fire hazards are combustible materials such as cloth, wood, cardboard, paper and plastic. Type B fire hazards are liquid materials such as gasoline, grease, oil, roofing adhesives and solvents or cleaners. An ABC rated fire extinguisher can be used on a type A, type B or type C fire. The size of the fire extinguisher will determine the size of the fire the extinguisher is rated to extinguish.
A 4A60BC fire extinguisher is also commonly referred to as a 20-lb extinguisher. They are capable of extinguishing a Type A fire with the equivalent of four gallons of water and have the 4A rating. A 4A60BC extinguisher is also rated to extinguish a 60 square foot area of a type B or type C fire, with the 60BC rating.
Larger fire extinguishers have the capacity to extinguish larger fires. OSHA does not mandate a certain size fire extinguisher to be present, unless torching roof activity or hot roofing asphalt activities are taking place. When roofing torches are being used in any capacity, a minimum of two 4A60BC fire extinguishers shall be readily available within 10 feet on the operations at all times. When operating an asphalt kettle, two 4A60BC extinguishers are required to be within 25 feet of the kettle and an additional two 4A60BC extinguishers are required to be readily available on the roof where hot mopping activities are present.
Extension cords are a essential piece of equipment. They should be adequate to provide the power necessary
for all the equipment the cord is supplying power to, inspected prior to use, properly used and should always be used with safety in mind. When good extension cords are purchased, cared for and used properly, their lifespan will be extended and continue to provide power to the equipment as needed.
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