The fascinating world of extension cords

If you're like me, and I know I am, your extension cords are patched every couple of feet with black electrician's tape. Is this safe? No. Is there a way to make it safe? Sure. Use the cord to re-weave your patio furniture.

If you haven't scarred your extension cord by running over it with your lawnmower, you may have yanked on it enough times that the insulation is fractured and frayed where the cord disappears into the plug. Instead of replacing the entire cord, you can just install a new cord cap (plug). This is a cinch - SAFETY ALERT - assuming you've unplugged the cord at the outlet.

Quick Fix

1. Buy a replacement plug (either male or female, depending on which end of the cord you're repairing) that's rated to match the amperage of your extension cord. (If in doubt, cut off the plug and take it with you to the hardware store).
2. If you haven't already done it, cut the plug off using wire cutters or a sharp knife.
3. Carefully cut the outer cable jacket to reveal an inch of each of the wires: black, white and green.
4. Cut away the fibres that comprise the filling material.
5. From each of the three wires, strip a half-inch of insulation.
6. Twist the exposed strands of wire to keep them from fraying.
7. Slide the plastic housing onto the cord (I always forget this step in my hurry to get to the screwing).
8. Attach the wires in exactly the following order: black wire to the brass screw terminal, white wire to the silver terminal, and green (ground) wire to the green terminal. TIP: Wrap the copper wire around the screw terminals in a clockwise direction to prevent it from slipping off the terminal as you're tightening the screw.
9. Close up the housing, and bingo, you're back in the game.

Gauge before beauty

If you need to replace an extension cord, know your options. Some are longer, some are thicker; which matters most? Choosing is an intensely personal matter. Here are some guidelines:

The copper wires that are hidden inside a heavy-duty outdoor-rated three-prong extension cord come in a range of gauges (diameters). You can learn to use the word "gauge" with confident abandon by understanding that the larger the wire, the smaller the gauge number. This system is called the American Wire Gauge System, and was devised many years ago by some illogical nutbar and now we all have to live with it.

Another thing to know about gauge is that the smaller the gauge number, the more current the cord can carry. For instance, the fatter wires in a 10-gauge cord can power higher wattage appliances than the skinnier wires in a 16-gauge cord.

Length or width?

The heavier your appliance's demand for voltage, the lower the cord's gauge should be. But you have to consider the cord length too. The farther you get from the electrical outlet, the less voltage reaches the motor of your appliance, because of resistance over the length of the cord.

For example, I once tried to power a fridge on a movie set with a 100-foot extension cord. The fridge was supposed to be full of cold drinks for the crew, but nothing in that fridge got cold. Ever. It was as if the fridge was trying to suck current through a tiny straw, and just couldn't get enough. We dragged the fridge closer to the outlet, installed a shorter, lower gauge cord, and the pop got cold.

All appliances are stamped with how much wattage is consumed when operated, and the manual might even suggest what length and gauge of cord to use with your power tool or appliance. Some appliances indicate power usage in amps, rather than watts. Here's a Grade 10 Physics tip: If your appliance uses 5 amps at 125 volts, then its wattage rating is 625W (5x125).

The more voltage your equipment needs, the lower the cord gauge you need, so know your user profile. You'll need a lower gauge cord for equipment that works against a heavy load, like hammer drills boring into concrete, or electric lawn mowers cutting through extension cords.

Burning for it

Trouble can start when you hook two or three shorter cords together to make the length you need. Voltage gets lost along the way through resistance over the length of the combined cords. In addition, every time the current hits another plug connection, the voltage drops a little. If the motor doesn't get enough voltage, your appliance or power tool may run for a while and then burn out, or it may just hum but not actually engage, making you think you need an expensive repair when in fact you only need a lower-gauge, and/or shorter, extension cord.

If you have trouble remembering the counter-intuitive American Wire Gauge System, use this handy comparison: When you habitually consume a high number of calories you are likely to state your weight as being less than it actually is. It's the same with extension cords: the higher the voltage they transport, the more modest they are about it.