An extension cord can make it easier to use a lamp, tool or appliance where an outlet is out of reach. The important word is temporary: a cord is a short-term connection, not a replacement for an outlet installed where you need one.
Used incorrectly, cords can overheat, get damaged or create a tripping hazard. A few checks—before plugging in and while the cord is in use—can help you avoid the most common problems. If a cord, plug or outlet looks damaged, stop using it. Don’t try to repair electrical wiring yourself.
Start with the cord’s rating
Extension cords are not all interchangeable. Before buying or using one, look at the label or packaging for its intended use and electrical rating. The cord must be suitable for the appliance and the place you plan to use it. If you cannot read the rating or are unsure whether the cord can handle the load, choose a properly rated cord or ask a qualified electrician or the appliance manufacturer.
Pay attention to the appliance’s instructions as well. Some appliances, including many portable heaters, are meant to plug directly into a wall outlet. Follow the manufacturer’s directions rather than assuming an extension cord is acceptable. Never connect a cord to equipment if doing so would exceed the rating of the cord, outlet or appliance.
A longer cord can be more convenient, but length and construction affect what a cord is designed to handle. Don’t choose one by appearance alone or assume that a thicker-looking cord is automatically the right match. Use the product’s markings and instructions.
Check the cord before plugging it in
Look along the full length for cuts, cracks, crushed spots, exposed wires or damaged plugs. Check that the plug fits firmly and that its blades are not bent or loose. Don’t use a cord with missing grounding parts, or one that has been modified to fit an outlet.
Keep cords away from places where they can be pinched, crushed or damaged: under rugs, beneath furniture, through doorways or across busy walking routes. A rug can conceal wear, while a closing door or heavy furniture can press on the insulation. If you need power in a location where a cord would have to cross a walkway or be hidden, consider a safer arrangement instead of trying to disguise the cord.
Keep cords away from water and damp areas unless the product is specifically rated for the intended conditions. A cord labeled for outdoor use is not automatically suitable for every wet or demanding job; follow its instructions and the tool’s instructions. Don’t use an indoor-only cord outside.
Avoid daisy-chaining and overloaded connections
Plug a cord directly into a suitable wall outlet unless its instructions specifically allow another arrangement. Don’t connect one extension cord to another to reach farther, and don’t plug power strips or other multi-outlet devices together to create more sockets. These workarounds can make it easier to draw more power than a connection is designed to carry.
Adding outlets with a power strip does not increase the electrical capacity of the wall circuit. Check the ratings of the connected devices and the strip, and follow the manufacturer’s directions. If you regularly need several cords or a strip in one area, that’s a sign the room may need a better permanent outlet arrangement. A qualified electrician can advise on options.
Keep the cord where it can be seen and inspected. Don’t bundle or cover it with bedding or other material while it is powering equipment, and don’t leave it where someone can trip over it. Unplug a cord by gripping the plug, not by yanking the cable.
Use outdoor cords only as directed
For outdoor equipment, choose a cord marked for outdoor use and rated for the job. Inspect it before each use, keep connections out of standing water, and follow the instructions for both the cord and the equipment. Don’t assume that an outdoor label makes a damaged cord safe, or that a cord can be left outside indefinitely.
When you’re finished, unplug and store the cord as its manufacturer recommends. Avoid tight knots or sharp bends that can damage it. A cord that has been run over, pinched or exposed to harsh conditions should be checked carefully before it is used again.
Know when to stop
Unplug the cord if it becomes hot, smells unusual, sparks, or makes a crackling sound. Stop using it if a plug fits loosely, the insulation is damaged, or the outlet shows signs of scorching. Don’t touch exposed wires or attempt to patch a damaged cord with tape. Replace it, and have a qualified electrician assess a damaged outlet or recurring electrical problem.
If a breaker trips or a fuse blows when you use an appliance, don’t keep resetting it or switch to a higher-rated protective device. The circuit may be overloaded, or there may be another problem that needs attention. Unplug the equipment and seek qualified help if the cause isn’t clear or the issue recurs.
In short, use an extension cord only for a suitable, short-term connection; match it to the appliance and conditions; and keep it visible, undamaged and within its rating. If you find yourself relying on one day after day, the safer fix is usually to address the need for a permanent outlet—not to make the temporary cord permanent.
