Single-Pole Switches
What Is A Single-Pole Switch?
A single-pole switch controls only one outlet or built-in fixture from one location, say your bedside lamp or overhead fan. It will have two screws of the same color holding in place two black (hot) wires. The white wires will be capped with screw-on wire connectors or taped with electrical tape. The bare or green wires are ground wires (in a grounded switch).
Tip: The exception to the single-pole wiring described above is when a switch sits at the end of a circuit—instead you will find one black and one white wire, but they are marked that way only to confuse you. In reality, both wires are hot (black), but some brain surgeon decided to coat one in white insulation to make it easy to tell them apart—thanks a lot! It is helpful to wind a small piece of black electrical tape around the white wire to remind you.
Replacing A Single-Pole Switch
To replace a single-pole switch, turn off the power to the circuit. Remove the faceplate and unscrew the small screws holding the switch in place. Gently pull the switch out far enough that you can test the switch with a circuit tester to make sure the circuit is cold. Once you know the power is definitely off, remove the switch from the switch box without disconnecting any of the wires.
Testing A Neon or Standard Circuit Tester
To test using a neon or standard circuit tester, do the following:
- Not to be redundant, but first disable the switch at your breaker box!
- Hold the tester by the insulated areas only.
- Hold one probe against the bare copper grounding wire. Then one at a time, touch the other probe against each of the terminal screws. If the bulb on the end of the circuit tester lights up at any point, the circuit is still live and needs to be disabled.
- Disable the circuit at your breaker box and try testing it again.
Once you know the power is off, you can quickly test the switch for problems using a continuity tester, just to ensure that the switch is actually at fault. If your switch needs replacement, the process is simple enough that it will make you feel quite competent. It is a great starter project for the electrical newbie.
Loosen the terminal screws and unfasten the wires. Take the switch with you to the hardware store and buy a new one that has the same amp and voltage ratings as the one you’re replacing.
Tip: If your home has solid aluminum wiring, (the switch will be marked CU/AL or AL/CU) replacing switches and outlets should be left to an electrician!
Once you have the appropriate replacement switch, check to see if you need to strip the wires. Once you have clean wire ends, curl them clockwise around the terminal screws and secure them in place by gently tightening the screws.
Reinsert the switch into its open switchbox, careful not to crowd or bend the
wires. Secure the switch with its anchor screws. Replace the cover plate and
restore power. Viola!
