Extension cords can provide a convenient way to connect devices and appliances to outlets that are far away. However, not all devices and appliances are safe to use with an extension cord. Overloading an extension cord with too many high-wattage devices, or plugging in the wrong types of electronics, can be a fire hazard. Knowing what should and should not be plugged into an extension cord is important for safety.
What is an extension cord?
An extension cord is a short, removable power cord that can be plugged into a permanent electrical outlet to add length and allow devices to connect in locations further away from the outlet. Extension cords are available in various lengths and wire gauges. The longer and thicker the wire gauge, the more current the extension cord can safely carry.
Extension cord safety tips
Here are some important safety tips to keep in mind when using extension cords:
– Only use extension cords rated for indoor or outdoor use, as applicable. Outdoor cords are more durable.
– Check that the extension cord is rated for the total wattage of the devices plugged into it. Don’t exceed the rated capacity.
– Unplug and inspect extension cords periodically for damage. Discard and replace damaged cords.
– Don’t run extension cords through walls, under rugs or carpets, or anywhere they can become a tripping hazard.
– Don’t overload extension cords with too many devices.
– Don’t plug extension cords into other extension cords. Use a single cord of the proper length.
– Don’t knot cords or cover them with anything that could cause overheating.
Devices that should not be used with extension cords
There are certain types of devices and appliances that require too much electricity to be powered safely through an extension cord. Using these with an extension cord can easily overload the cord, create voltage drops and arcing, overheat the wires, and start electrical fires. Devices you should avoid plugging into extension cords include:
Major appliances
Examples:
– Refrigerators
– Dishwashers
– Washing machines and dryers
– Electric stoves and ovens
– Air conditioners
– Space heaters
– Microwaves
These large household appliances pull a lot of current and need to be plugged directly into a wall outlet designed for their high wattage requirements. Even though some extension cords are rated for over 1,000 watts, major appliances can have starting or operating wattages exceeding this.
Televisions
Large screen televisions, even flat screens, use a substantial amount of electricity. They are also at risk of voltage drops over an extension cord that can damage the TV or cause performance issues. TVs should always be wall-mounted or placed so they can plug directly into a wall outlet.
Computers
Desktop computer systems with a monitor, CPU, speakers, modem, and other peripherals can draw over 500 watts in regular operation. Laptop power adapters may be rated for over 200 watts. Computer equipment is also sensitive to any voltage fluctuations from overloaded extension cords. Computers should be plugged into surge protectors that are then directly connected to a wall outlet.
High-wattage medical devices
Medical devices like oxygen concentrators and CPAP machines use high amounts of power. Any voltage variability can affect their operation and be dangerous for users. Medical devices need to be plugged into dedicated electrical circuits as required.
Power tools
Power tools like circular saws, miter saws, table saws, and drills require several hundred watts or more of sustained power. Extension cords may not be rated to handle the start-up current surge that occurs when some power tools first turn on. Power tools should be plugged directly into wall outlets.
Air conditioners and other cooling devices
Window air conditioning units, portable ACs, swamp coolers, and large fans use hundreds of watts of power. They require a dedicated high amp circuit for proper operation and should not be connected with extension cords.
High-wattage lights
Large halogen work lights and other high-wattage light fixtures can exceed the safe capacity of extension cords. Plug these directly into wall outlets or a single extension cord that’s rated for their load. Don’t string multiple cords together.
Appliances that are generally safe for extension cords
Here are some types of smaller devices and appliances that typically can be used safely with properly-rated and configured extension cords:
– Table lamps and floor lamps
– Clocks and small mirrors
– Phone and tablet chargers
– Radios and small stereo equipment
– Small TVs under 40 inches
– Game consoles and streaming devices
– Printers, scanners, and other small office equipment
Using extension cords safely
To use extension cords safely:
– Choose the right gauge and length cord for the power needs of the devices used. Longer and thicker cords support more wattage.
– Ensure the total wattage plugged into any one extension cord does not exceed the cord’s rated capacity. Read labels carefully.
– Do not overload outlets and power strips at the end of extension cords.
– Only use grounded extension cords with 3-prong plugs for grounded appliances.
– Inspect cords periodically and replace any damaged, loose, or frayed extension cords.
– Position cords so they will not be tripping hazards or subject to damage.
– Never cover cords with rugs or run them through walls or under doors.
– Do not plug extension cords into each other. Use a single cord of the proper length.
Conclusion
Extension cords are very useful for providing power to electronics and devices that need to be located far away from permanent wall outlets. However, they must be used properly and safely. Avoid overloading extension cords and do not use them with major appliances, televisions, computers, medical equipment, power tools, or other high wattage devices. Be sure to choose the proper gauge and rated capacity extension cord for the expected electrical load. With reasonable precautions, extension cords can be used safely and effectively to add length to your electrical connections.