When you’re already frazzled, few things are as irritating as being unable to flip on the single-pole switch in the bathroom or closet as you’re trying to find the item that you’re sure was right there. If you have around 15 minutes to spare, some common tools, and an extra single-pole switch on hand, you can have your new switch up and running in no time so you won’t have to search around with a flashlight to locate your essentials. Follow these steps to learn how to wire a single-pole switch like a pro.
Prepping to Wire a Single-Pole Switch
Working with electrical wiring can be a complex project, but that isn’t the case with single-pole switches. The most important part of your preparation is making sure you know how to work with electrical wires.
Safely Working with Electricity
Dealing with electricity without the proper precautions and knowledge can have fatal consequences. Improper wiring poses fire safety hazards, while directly working with wires can cause electrocution if you’re not sure how to shut off the electricity and check that there’s no electrical current flowing through the wires. It’s important to only take on electrical projects if you feel confident in your ability to safely manage electrical circuits, and call in a local electrician to do the job if you don’t.
Turn Off the Breaker Box
Never try to work with electrical wiring while your electricity is running. Instead, go to your breaker box and turn off the circuit breaker for the room where you’ll be wiring the single-pole switch.
Check for an Electrical Charge
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Shutting off the power doesn’t mean that the electricity is completely gone from the wires. Likewise, your breaker box could have mislabeled circuits, meaning your switch hasn’t actually been shut off. To be on the safe side, use a multimeter to check for voltage before you start working with the wires. Here’s how to check for voltage:
Make sure your multimeter is set to AC voltage.
Choose an outlet connected to the same circuit as your single-pole switch.
Push the black probe into the multimeter’s common jack.
Push the red probe into the AC voltage port.
Put the other end of the black probe into the outlet’s neutral slot or “wider” prong.
Put the end of the red probe into the other plug’s slot, called the hot slot.
Look at the reading to see if there’s power.
Once you’ve confirmed the power is off, you can move to the next step.
Remove the Wall Plate
Depending on the type of screws, you’ll need to use a Phillips or flathead screwdriver to loosen the wall plate and gain access to the single-pole switch. Set aside the wall plate and screws in a location where you won’t lose them.
Take Out the Existing Switch
To remove the old single-pole switch, you must disconnect the switch from the three wires that make up the circuit. Holding the wires, loosen each of the three terminal wires. For tightly twisted wires, you may need to use wire-twisting pliers to loosen them.
Inspect the Electrical Wires
Before you replace the switch, you’ll want to get your detective hat on and inspect the electrical wiring for signs of damage—pay close attention to the ends of the wires and use a flashlight. This step is especially important if you’re replacing an old switch because it’s not working properly.
If you come across wires that look damaged by rodents, have a strong burnt smell, look scorched, are frayed and too short to clip, or are in some other poor condition, you’ll want to hire an electrician to conduct a closer inspection and, if necessary, replace old wiring. If the wiring is only frayed, you can DIY a simple fix in the next step.
Prep the Wires
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Frayed wires don’t necessarily mean a visit from an electrician. In many cases, frayed electrical wiring just needs a little extra TLC before they’re ready to go. To prepare frayed wires for a new light switch, trim them down with wire cutters until there is no fraying, then use a wire stripper to expose around 1/2 to 3/4 inches of wiring.
Connect the Wires to the New Switch
The most challenging part of this project is connecting the wires to your new switch. Thankfully, single-pole switches only have three wires, making it easy to tell them apart and connect them to the correct terminals. Follow these steps to correctly install the new switch:
Create a hook with each exposed wire.
Using wire-twisting pliers, locate the green ground wire and wrap the hook clockwise around the green terminal screw.
Tighten the screw using a Phillips screwdriver.
Connect the other two wires to the two remaining terminals by following the same steps—on a standard single-pole switch, these two wires can be used interchangeably.
Secure the Terminal Screws
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Securing the terminal screws with electrical tape prevents the single-pole switch from short-circuiting inside the box. Take your electrical tape and wrap it around the switch body until the terminals are fully shielded.
Insert the Switch into the Box
With your new single-pole switch completely set up, you can now insert it into the box. Gently fold the wires into the box, and then push the switch in so that it’s in front of the wires. Avoid letting the wires pop out from the sides of the switch, as the sides of the wall box can interfere with the terminal screws.
Replace the Wall Plate
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Retracing your first steps, reinstall the wall plate, and secure the screws using a screwdriver. If you’re using a labeled toggle switch, make sure that the toggle switch is right-side up to avoid confusion.
Test Your Switch
Before you give yourself a pat on the back and call it a day, turn the power back on and test the light switch to ensure it works. If the light doesn’t turn on, turn the power back off, then check that the wire terminals are fully connected to the correct terminals before turning it back on to test again.
Should You DIY Wiring a Single-Pole Switch?
Wiring a single-pole switch yourself is a straightforward project, but there are circumstances where you might not want to do it yourself. If there’s wiring that’s damaged beyond repair, faulty wiring, or if you don’t feel comfortable DIYing a single-pole switch, play it safe by contacting a professional electrician near you.
Frequently Asked Questions
No, it doesn’t matter which of the two wires goes on each of the two switch terminals. Just be sure to put the ground wire in the correct terminal. The ground wire is either green, bare copper, or green with a yellow stripe. The other wires are hot wires and are typically black. They can be used interchangeably.
Single-pole switches are simple circuits designed for lower voltages. As such, they don’t require the complex wiring of switches that need to supply power to larger devices and appliances. This is why single-pole switches commonly go in bathrooms, closets, and other small rooms that power a low-watt light fixture. One wire creates the circuit from the power supply, the other goes to the fixture, and the final wire provides safety mechanisms through grounding.
