Wire a Single-pole Switch

Photo of a Single-Pole Switch
Single-Pole Switch. Timothy Thiele

Every home has many single-pole switches in it. They are used for lighting, disconnects for furnaces, garbage disposers, and other things needing something to turn on and off a 120-volt circuit. Learn how easy it is to wire a single-pole switch. This simple how-to will have you turning lights on and off in no time. With a few choice electrical tools and these instructions, you can change or install a single-pole switch in a short period of time.

Difficulty: Easy

Time Required: 15 Minutes or Less

Here's How:

  1. How To Wire a Single-Pole Switch - Turn Off the Power First!
    Broken switches can short out, leave you susceptible to live parts and increase the chance for electrical shock. As with any electrical repair you may perform, safety should be your number one concern. Turn off the circuit you will be working on and double-check it with a circuit tester or voltmeter. Never assume the circuit is off! This applies to new and existing electrical installations.
  2. How To Wire a Single-Pole Switch - Remove The Existing Switch (If Necessary)Remove the switch cover plate by removing the two screws. The switch is now exposed. Remove the two screws holding the switch in place and carefully pull out the switch. This is the time to take the tester once more and triple check to see if the circuit is off. Test from the green ground screw or the metal box to the two brass screws on the switch. If there’s no power then you can continue. Loosen the two brass screws and the ground screw. Remove the switch and discard it.
  1. How To Wire a Single-Pole Switch - Strip The Electrical Insulation From The Wires
    If this is a new installation, strip 3/4" of the insulation from the wires to make the connections.
  2. How To Wire a Single-Pole Switch - Connecting the New Switch
    Bend the ends of the wire into a half moon shape to go around the screws. First tighten the bare copper or green wire to the green ground screw. Next connect the two black wires to the remaining brass colored screws. Always tighten the half moon shape towards the right and in a clockwise motion. This will insure that the connection is good and tight.
  3. How To Wire a Single-Pole Switch - Electrical Tape for Added Safety
    Once the connections are secure, I like to wrap the switch with electrical tape as an added safety measure. This eliminates the switch from coming into contact with the side of the box. Now, press the switch into the box for a test fit. You may have to adjust the wires in the box to make everything fit. Tighten the two screws into the box, keeping it as plumb as can be. Replace the switch cover and tighten its two screws. There, you have done it!
  1. How To Wire a Single-Pole Switch - Turn On The Power And Test Switch
    Turn on the circuit at the breaker panel and test to see if everything is working. The switch should turn the light on and off. Be sure that the light switch is installed properly by looking at the toggle part of the switch. It should say "on" and not "off". If so, you have completed your “light duty” of the day!

Tips:

  1. Use more expensive, quality switches that are more durable.
  2. Make sure all electrical connections are tight.
  3. Twist the wires around the terminals in a clockwise motion so the wire tightens around the screw. Otherwise, the loop of the wire will open when you tighten the screw.
  4. Make sure the switch is rated for the amperage of the circuit breaker it is connected to.
  5. Use the appropriate electrical tools for the job.

What You Need:

  • Single-Pole Switch
  • Screw Drivers
  • Wire Strippers
  • Electrical Tape