Got light where you need it? Probably not. No house seems to have exactly the right lights, in the right place, with convenient, safe switches. Even if a plug-in hanging lamp is where you want it, built-in wiring is safer, more convenient, and easier on the eyes. And it can, as in our example, be fitted with a dimmer switch.
In this improvement, we'll look at some basic electrical techniques, and then add a light near an electrical outlet. The hard part about running cable is getting through walls without destroying them; always try to run cable through an unfinished area, like a basement, attic, or garage.
Running cable through finished walls can be frustrating. Wires get stuck. The fish tape you use to pull wires through the wall gets stuck. Be creative. Visualize where the fish tape is going, and why it's hung up.
Basic Electrical Jargon and Safety
Working with electricity is not tricky, but it can be dangerous. If you are inexperienced or uncertain of what you are doing, consult a more thorough treatment, such as the chapter on electricity in The Complete Idiot's Guide to Home Repair and Maintenance Illustrated. The following jargon and basic rules will help keep you out of trouble:
Hot wires (usually black, sometimes red) carry incoming electricity.
Ground (white, often called neutral) wires take electricity back to the utility.
Equipment grounding conductors (usually bare copper, sometimes green) are a safety system that allows electricity to return if something goes wrong.
Supply wires enter a box and bring electrical current.
Current is the flow of electricity.
What size box do you need? To prevent overheating, the National Electric Code restricts how much junk you can jam into a box. The capacity, in cubic inches, should be marked on each box. Here's how to calculate the box size needed:
|Each hot and neutral wire||1|
|All ground wires||1|
|Each switch and receptacle||2|
|All wire clamps||1|
Multiply by 2 (for 14-gauge wire) or 2.25 (for 12-gauge wire). Result: minimum box volume required, in cubic inches.