Extension Cord Reference Guide

Extension cord reference guide: Selecting the right power cord

Updated September 5, 2023
By Cody Papenfuss, Supplier Development Manager - Lighting and Electrical | David French, Associate Product Manager - Lighting and Electrical

Construction worker carrying electrical cord

Extension cords are great when working with gear that isn’t battery operated. They provide a consistent power source that allows for constant usage without having to worry about a battery dying or malfunctioning.

Using an extension cord properly, though, isn’t as easy as “just plugging it in.” There are several factors to consider when procuring an extension cord: the safety of workers, the environment, and the item itself.

The bottom line, when using an extension cord you want to ensure the cord’s specifications match what the device or object needs in order to function. If the extension cord supplies too much power to the device, it could overheat or malfunction, and the cord could begin to melt. On the other hand, if the extension cord supplies an insufficient supply of electricity to the device, then the device could malfunction and become permanently damaged.

So how do you know what type of extension cord to buy?

These terms and suggestions can help you power devices while keeping your team safe.

Amps: Measure the flow of electrons through the wire, “current.”

Amps decrease as wire length increases due to lost capacity.

Voltage: Measures the electrical force required for electrons to move.

Watts: Measure the amount of electricity used.

Wattage is usually printed on an electrical device’s label, instructions, or in the owner’s manual.
On an extension cord: amps, voltage, and watts are printed on the UL or ETL tag.

Gauge: The capacity of the extension cord to conduct electricity and power the device (even-numbered).

All gauges are measured in terms of American Wire Gauge (AWG).
16 AWG (low), 14 AWG, 12 AWG, 10 AWG (high).
The higher the gauge, the thicker the conducting-inner wire (thicker overall wire). Plug / Connector Type: 2-prong plug ("/2"), or 3-prong grounded plug ("/3").

Extension cord reference guide: Selecting the right power cord

​So how do you know what type of extension cord to buy?

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So how do you know what type of extension cord to buy?