Extension cords seem simple to use--but if the cord is the wrong size or type for a job, or if it's improperly used, it can cause a fire. Some local codes forbid extension cord use because they're considered a safety hazard.
An extension cord is intended only for temporary duty--unplug and store it after each use. Don't run one where it may be tripped over. To avoid a severe or fatal shock, never use one near water.
Here are some dos and don'ts about choosing and using an extension cord:
--Be careful when buying an extension cord. Just because it has several receptacle ends doesn't mean that it can carry more current than the outlet into which it's plugged. As a general rule, don't plug more than one item into an extension cord.
--Most extension cords are marked with a rating in amperes (also called amps or simply abbreviated "A"). Look at the nameplate. If not listed and you know the wattage, divide by 110 (household voltage) to obtain amperage.
--Never exceed the ampere rating.
Also be aware that the longer the cord, the greater the drop in current. That can reduce an appliance's efficiency. A 25-foot cord, for example, has to be heavier than a 6-foot cord performing the same task.
An extension cord contains a pair of wires, each covered with heat-resistant plastic insulation and wrapped in a plastic or rubber sheath. The cord is equipped with a male and female plug. If there is a three-prong plug, the cord also contains a third, ground wire. Plug this type of cord into a grounded (three-hole) plug. Use only three-wire extensions for tools and appliances that have three-wire cords.
--If you must use an extension cord for a refrigerator, freezer or some other electrical unit that draws substantial amounts of current, make sure it's a heavy-duty, three-wire type.
--The thinner the cord, the lower its capacity for conducting electricity. Wiring in electrical cords is rated by numbers. The lower the number, the larger the wire and the greater amount of current it can safely carry.
--A lamp-type cord usually contains a number wire. Don't use it for any device that draws more than 7 amps.
--Heavier-duty numbers 16, 14 or even 12 should be used for devices that draw higher amounts of current.
--If an extension cord feels warm to the touch, replace it with a heavier one.
--If at all possible, avoid using extension cords in a workshop. If using one is unavoidable, make sure that the cord has a three-prong plug and is at least a number 14 or heavier.
--Hook the cord slack on a long spring screwed into the ceiling above your workbench to keep extension or power cords out of the way.
--If the cord has frayed insulation or a bare wire, replace the entire cord. If the plug is damaged, replace it with a new plug that has the same or greater current-carrying capacity.
--Remove an extension cord from an outlet by grasping the plug body. Otherwise, wires may tear loose and result in a shock or a short circuit.
--Store folded cords in napkin rings or toilet paper tubes, or hang on an old tie rack wrapped with masking tape.