HOME WIRING REPAIRS IN THE REAL WORLD

Enlarge Image Image Gallery Left: A typical ceiling light box. Many wires are joined here, but for replacement, focus on the wires connected to the light. Middle: a common wiring scenario. Notice how the double terminals on the receptacle function as a splice between the incoming and outgoing hot (black) and neutral (white) wires. With only one ground terminal (top), the receptacle needs a short pigtail ground wire, which is wirenutted to the ground wires of the two cables, plus another pigtail attached to the metal box. On a plastic box, the second pigtail is eliminated. Right: A ground fault circuit interpreter (GFCI), with TEST and RESET buttons. (ILLUSTRATIONS: THOMAS MOORE)

ENERGY AND ENVIRONMENT

by Patrick Maxwell

Basic Tools and Accessories

If you're like most people, when the weather turns cold, gray, and damp, you turn inward. I'm not talking about transcendentalism; I'm talking about your house. Late fall is the perfect time to consider all the in-home repairs and upgrades you've left on the back burner during the busy growing and harvesting seasons. With this in mind, you decide today is the right day to replace that broken light fixture just inside the back door. You already have the new light (you bought it last year, remember?), and those fix-it-yourself shows on TV make its replacement look like a ten-minute no-brainer. But as you remove the fixture coverplate, the gray fall light does not reveal what you saw on TV; it reveals a tangled mess of perhaps ten or more individual wires connected with as many as four or five wirenuts. Why, there's even some red wires in there! And where's the simple "black wire-to-black wire" and "white wire-to-white wire" scenario you saw in the fixture instructions?

For simplicity's sake, I'll focus my advice on three projects homeowners are likely to attempt: (1) replacing a light switch, (2) replacing a receptacle, and (3) replacing a light fixture. Later, I'll give you some tips on methods that are common to all three of these endeavors, as well as other wiring projects.

To save time, you should have the tools, accessories, and replacement devices on hand before starting the actual work. The basic tools for electrical work include needle-nose pliers, a pair of linesman's pliers, tools that cut and strip wire, a utility knife, various screwdrivers, and a test light or multimeter. Some typical accessories include things like wirenuts of different sizes, electrical tape, grounding screws or clips, and short pieces of copper wire for making ground connections. As for the devices, that's where I start giving you some of that advice I promised. To select the proper light switch, first determine if it works alone or in conjunction with another switch or switches to control the light. If it works alone, it's a simple, single-pole switch. If you can operate the light from two locations, the switch (or switches, if you replace both of them) you'll need is a three-way switch. Don't let the term "three-way" confuse you; it refers to the way the switch itself works, not to the number required to do the job. A light that can be controlled from more than two locations uses two three-way switches, plus a four-way switch for each additional location. In this instance, the only way to determine whether the switch is a three-way or fourway switch is to remove the switch's coverplate and see how many wires connect to it. A three-way has three connected wires and a four-way has four (excluding any ground wire). How many switches should you buy? The answer in the first case is obvious, but in the second and third cases it depends on your situation.