How to Use Extension Cords Safely
Homeowners are plugging in more electronics and appliances than ever before. Older buildings typically have fewer outlets than newer construction, and many people use extension cords to access electricity in an area without available outlets.
Overloaded extension cords, however, can overheat and start fires. According to the National Fire Protection Association (NFPA), an average of 1,780 fires are caused by extension cords every year.
Follow these safety guidelines to protect yourself, your family, and your home the next time you use an extension cord.
Choose the Right Extension Cord Type
Extension cords only allow a certain number of amps to flow through them, depending on the diameter of the wire inside and the length of the cord. If you plug in multiple appliances that draw more amps than the extension cord can support, it can overload and cause a fire.
You should always check the manufacturer’s instructions to see how many amps an appliance uses before plugging it into an extension cord, but here’s a general summary of different types of cords and what appliances they can support:
- Light cords have two prongs (no grounding pin) and can be used for lamps, smart devices, and other electronics that draw up to 7 amps. (For reference, an iPhone charger draws about 2.2 amps.)
- Medium cords have two prongs and (most of the time) a grounding pin. They can be used for larger electronics like TVs and desktop screens that draw up to 10 amps.
- Heavy cords always have two prongs and a grounding pin and can be used to power appliances like yard tools that draw up to 15 amps.
NOTE: Some appliances that produce heat—like space heaters and hair dryers—are unsafe to plug into any extension cord. Manufacturers usually note if an appliance can be plugged into an extension cord on the packaging.
When using an extension cord outdoors or in a damp environment, make sure the cord is outdoor-rated. This means that the cord is water-resistant and GFCI-protected. GFCI (ground-fault circuit-interrupter) cords and outlets reduce your risk of electrocution.
Inspect Extension Cords Before Each Use
Extension cords are wrapped in resilient materials to protect the wires from damage, but you should still check your cord before each use. Any sign of damage means the cord is unsafe to use.
Here’s what you’re looking for when you inspect an extension cord:
- Exposed wiring, especially near the plugs
- Nicks or melted sections along the length of the cord
- Chew marks made by a pet or rodent
- Missing or misaligned grounding pin
Avoid Common Extension Cord Mistakes
Keep the following tips in mind each time you use an extension cord:
- Never run an extension cord through snow or standing water.
- Try to plug extension cords into GFCI-protected outlets, especially in damp areas. (GFCI outlets have “test” and “reset” buttons.)
- Do not plug an extension cord into another extension cord (also called “daisy chaining”).
- Never cover extension cords with rugs, furniture, tape, or other material.
- Avoid plugging multiple appliances into a single cord. It’s easy to overload the cord, which can cause overheating.
- Never remove a grounding pin or bend the prongs on an extension cord to make it fit in an outlet.
- Do not run extension cords through doorways or holes in the floor, and don’t nail or staple them to the wall.
- Never use an adapter to convert a grounded cord (two prongs and a pin) to an ungrounded cord (two prongs).
Unplug & Store Extension Cords with Care
If unplugged and stored correctly, extension cords can last for years. Here’s how to take care of your cords:
- Unplug cords that are not in use. Extension cords always draw power when plugged in.
- When unplugging, pull the plug rather than the length of the cord.
- Wrap your cords neatly so they’re less likely to get damaged between uses.
- Discard older cords with non-polarized prongs (two prongs that are exactly the same size and shape).
