The Golden State: Where & How to Live, Secure, Visit, Enjoy and Thrive in California
Practical Electricity And House Wiring
Installing Switches.—To install a switch on an existing outlet which is not controlled by a switch, simply run 2-wire cable from the outlet to the desired location of the switch. The switch is connected to the two ends of the cable at that end. At the opposite end, cut the wire that leads from the fixture to the black wire in the outlet, and solder the new ends, obtained by cutting, to the two ends of the cable which runs to the switch.
If you have an outlet that is controlled by a wall switch, but want to have it controlled from another point in addition, run 3-wire cable from the present switch to the new switch.
Throw away the single-pole switch and substitute for it a 3-way switch and connect as shown in Fig. 227. Note that of the two wires which ran to the original switch, one now connects to the single terminal on one of the 3-way switches, and the other is extended to the single terminal of the second switch.
Sometimes as in basements with plastered ceilings, it is desirable to run exposed cable from a flush outlet, to a new exposed outlet. An "extension ring" is used and Fig. 228 shows the necessary steps.
Wire Sizes
In Chapter 5 were covered the more ordinary problems encountered in determining the proper sizes of wire in everyday wiring. In this chapter will be discussed the more difficult problems, although as usual the difficult problems become simple if the principles involved are completely understood.
The gauge or number assigned to wires used in all residential and farm wiring is always stated in terms of a standard gauge which has two different names: the American Wire Gauge (AWG), or the Browne & Sharpe (B & S). The bigger the number, the smaller the wire. It must be understood that the gauge number refers to the size of the wire without insulation—the size of the copper wire inside the insulation. Fig. 46 showed the actual diameter of common sizes of wire, and the table in Chapter 5 gives the actual diameters in fractions of an inch.
