How to Choose the Right Electrical Extension Cord

Choose the right electrical extension cord

It’s always great when you have an electrical outlet next to you, especially where it is convenient and you need to use the devices while they are connected. However, if you aren’t lucky enough to have an electrical outlet where you want it, you can always use an electrical extension cord.

Most people put very little thought when purchasing an electrical cord. It is a low involvement purchase and many don’t realize how dangerous it can be if you purchase one with the wrong sizing and specs. As per the U.S Consumer Product Safety Commission, the electrical cords can pose safety hazards within our homes. In fact, there have been many accidents due to its usage and it is known to kill 50 people each year. 4000 people sustain serious injuries as a result of electrical cord-related accidents and it is also a fairly common cause of residential fires.

Most accidents that happen due to electrical cords can be avoided by using safe and sturdy cords that do the job without any risks.

How do Extension Cords cause accidents?

In order to know how accidents happen due to extension cords, it is important to understand how they work. Extension Cords comprise of a bunch of insulated wires and have a plug on either side of them. The electricity flows through the wires to produce heat. However, when the electric current in the wires is excessive, overheating can happen resulting in the plastic insulation melting and being damaged. This causes short circuits and can start a fire.

This problem should ideally not occur if the extension cord is of the right quality. When an appliance is plugged into an outlet with the help of a factory cord, the current flowing through it should be a per the electricity demand of the appliance. If it’s higher than the demand and exceeds the safe load capacity of the extension cord, it can end up being dangerous.

How to select an Extension Cord according to its Length, Size and Type?

Electrical extension cords come in different sizes and types. When you’re choosing one, there are two factors that should be kept in mind; one is the electric load capacity of the extension and the other is its ability to transmit the electrical current appropriately.

In order to measure if the cord can fulfill the above mentioned criteria, have a look at the wire gauge and length of it. The wire gauge refers to its diameter or thickness. It determines how much current can be carried through it and the extent to which the wire can heat up during the function.

Length, on the other hands determines the voltage drop and the amount of voltage lost through resistance in the cord wires.

There is a numeric that identifies the gauge of a wire known as the American Wire Gauge (AWG). It is a rating of the copper wire diameter where the lesser the number, the thicker is the cord. A 12 AWG of a 120 volt cord means that there are 12 gauge wires in the cord and can be used with electric source of 120 volts.

When the voltage of electricity is dropped due to the resistance in the wire, its extent is regulated by the length of the wire. If the wire is long, the voltage drop will be higher also. Long Extension Cords have a lower capacity than their shorter counterparts even if the AWG rating of both is the same.

To explain this, take the example of an extension cord that is 18 AWG meant for 5 to 7 amperes of electric load and has a length of 25 feet. If you want to get the same load rating with a cord that is 50 feet long, the cord should ideally comprise of larger 16 AWG wires. To avoid voltage drop, it is advisable to use short extension cords. Try our "Build Your Own Extension Cord Builder" to build your ideal extension cord.

Extension Cords for Light Duty Devices and Electrical Appliances

For Light-duty devices, Light-duty extension cords work best. They should not be used with anything that requires more power and are best suited to work with lamps, clocks and appliances with similar power needs. Don’t use them with heat generating appliances as it will draw heavy electrical load. These extension cords come with only two plug prongs. There are no prongs for a third wire or for grounding.

Light-duty extension cords that are 25 feet use 18 AWG wire, whereas cords that are 50 and 100 feet long use 16 and 14 AWG wires, respectively. They draw up to 7 to amps of power and should be used with light electrical devices so as to no exceed the load capacity of the cord and avoid mishaps.

Extension Cords for Medium Usage

Extension Cords meant to take medium capacity load are grounded extension cords with plug prong to support the grounding and a third wire. They can be used to power television, computers and devices that require not more than 10 amps of power. The 25 feet cords use 16 AWG wire whereas 50 and 100 feet cords use 14 and 12 AWG wires, respectively.

Extension Cords for Heavy Usage

If your electrical appliances want to draw 10 to 15 amps of power, then heavy-duty extension wires are the right choice. They usually include a third wire and plug prong required for grounding and come with plugs containing three slots so that grounded appliance cords can be connected to them.

Cords that are 25 feet long use 14AWG wire, cords that extend 50 feet use 12 AWG wire and cords that are 100 feet long use 10 AWG wire. It is always a good idea to comply with the manual instructions of electrical appliances for extension use.

GFCI Protection

Some extension cords come with built-in GFCI Protection which helps to inhibit any shock hazards that may occur. If the cord is being used outdoors, in the basement or any space where there is moisture, it is best that the cord falls has a ground-fault circuit interrupter or is connected to a GFCI protected electric source.


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