When the nearest electrical outlet is so close, yet so far away, an extension cord can put the power right where you want it. But there’s a big difference between bringing a cell phone charger to your bedside and firing up a treadmill in front of your TV. When you need a few extra feet, choosing the right extension cord is a matter of safety.
Keep It on a Short Leash
The handy thing about extension cords is that they allow you to put the power virtually wherever it’s needed, but that doesn’t necessarily mean that longer is better. The longer an extension cord is, the lower the delivered voltage. This not only means you lose electrical efficiency by the foot, it could mean your desired appliance doesn’t even receive the voltage it needs to run properly or safely.
Part of choosing the appropriate extension cord is choosing the shortest possible cord for the job at hand. This not only conserves energy, it may allow for the use of lighter-duty cords. But once you know your needed length, you need to match the heft of the cord to the power of your appliance.
Appliances and devices have amperage ratings, which can usually be found printed on a tag or plate on the device itself. Extension cords are likewise categorized by gauge, with lower gauges corresponding to more heavy-duty appliances. Most household extension cords range from 18 gauge to 8 gauge; to match your appliance to the right cord, use an extension cord amperage chart like the one found here.
Read the Fine Print
There are even more factors to consider besides length and gauge, and among the most important is whether an extension cord is rated for outdoor use. If an extension cord not rated for this is used outside, it’s at risk of overheating and potentially causing a fire.
Outdoor use ratings are conspicuously noted on packaging for new extension cords, but they’re often printed right on the cord jacket, designated by the letter “W”. If you see the letter “S” instead, you know that cord is rated for general use.
Higher-end extension cords can also come with helpful features, such as indicator lights that show whether there’s power flowing through the cord. This can be important when using extension cords to power things that could potentially be dangerous, such as power tools.
Other extension cords may have ground fault circuit interrupter (GFCI) features, which help prevent accidental electrical shock, or connection boxes, which help prevent cords from accidentally becoming unplugged from their devices.
No matter what type of cord you choose, there are a few basic safety precautions you should always observe. Never chain multiple extension cords together -- always upgrade to a longer cord if you need more length. And before using an extension cord, check it thoroughly for damage. Discard it if there are tears in the jacket.
It’s also important to be mindful of where every foot of your cord lies. Don’t run them across walkways where they could present a tripping hazard. And avoid running them under carpet, through doorways or anywhere where they could be damaged by traffic, friction or pinching.
Extension cords are for temporary use only. If you need to extend power on a more permanent basis, that’s a simple job for your licensed, local electricians.