Extension cords: dos and don’ts
Just because it reaches the outlet, it still may not be the right one for the job
Everyone buys the cheapest, longest cord they can find, but that old 100′ 16-gauge cord can damage your expensive power tools, which are designed to work at 120 volts.
Here’s the problem: The longer the cord, the more resistance in the wire, and the more the voltage drops. Under heavy load, when you plug in, say, an air compressor or a circular saw, the voltage drops even more. Voltage drop will cause the tool’s motor to overheat and, eventually, to burn out. That’s why cord size is important.
- Buy thicker extension cords and use the shortest one that will reach. The lower the gauge, the thicker the wire and the less its resistance. Cords are commonly sold in 16-, 14-, and 12-gauge sizes. To protect your tools, 12-gauge is best.
- Use a GFCI-protected receptacle outdoors.
- Bury extension cords or use them as permanent wiring: They’re for temporary connections only.
- Use a damaged extension cord. You can replace the plug or receptacle end safely, but if the cord itself is damaged, buy a new one.
- Cut off the ground-pin.
This article was originally published on January 14, 2011