How to Install a Double Pole Switch

What You'll Need
Double pole switch terminal
Slotted screw driver
Digital volt meter or an electrical tester
Insulated gloves
Rubber boots

A double pole switch isn’t difficult to install if you have a basic understanding of electricity and how it works. There are two types of switches: a single pole, which controls only one circuit, and a double pole that controls two circuits controlled by one button, lever, or knob.

Installing a double pole switch isn’t double the trouble. It’s relatively easy as long as you follow the instructions and/or diagrams and follow safety procedures.

Step 1 – Gather Materials

Get all of your materials together. When purchasing the switch, be sure it is a double pole versus a single pole switch. If in doubt you have the correct switch, ask a sales representative at the home improvement center. A double pole switch should have the Double Pole Switch Terminal (DPST) clearly outlined.

Step 2 – Instructions and Diagrams

Have all instructions and diagrams necessary for the installation readily available for reference.

Step 3 – Cutting the Power

Before starting the project, turn off the power at the circuit breaker. If the circuits are not clearly labeled or you’re not sure which circuit is the correct one feeding the room/area where you’ll be working, turn off the power to the entire house.

Step 4 – Voltage Detector

Use the voltage detector to check that there is no electricity running through the wires. It is imperative that you check, periodically, throughout the installation process that no electricity is registering. It’s also important that anyone else in the house does not inadvertently “flip the circuit breaker switch” while you’re working.

Step 5 – Removing Existing Switch

Use the slotted screw driver to remove the face plate and the screws on the metal tabs holding the switch in place. Carefully pull the switch out of the electrical box exposing the wires. There should be three or four wires. Each will be attached to screws located on the switch.

Step 6 – Wire Determination

Each wire has a designated color. The neutral wires are usually white and connect to the silver screw on the side of the switch. The hot wire, may be black or red and connect to the gold or copper screws on the side of the switch. Grounding wires may be yellow, green, or bare copper and connect to the green grounding screw located on the bottom of the switch.

Step 7 – Diagrams

It would be beneficial to take a picture of the wires showing their placement on the switch, or draw a quick diagram. If you become confused, refer to the picture or diagram.

Step 8 – Detaching the Wires

You’re now ready to detach the wires that are screwed to the terminals. Use the slotted screw driver to unscrew the screws. Keep the wire in its curved, clockwise direction for easy reattachment. Once removed, you’ll see that the tip of each wire attached to the terminal is bare. This connection allows for a complete circuit, meaning the electricity will run from the source and through the wire to the switch.

Step 9 – Attaching a Double Pole Switch

Now that everything is disconnected and the power is still off, it’s time to reconnect the wires to the new switch. It’s important that you connect the wires to the new switch exactly as they were connected to the old switch. If you get confused, refer to your photo or diagram for wire locations.

Step 10 – Testing the Hot Wire

After connecting all of the wires to the new switch, you should turn the power on and test the device before completing installation. If the switch operates correctly, turn off the power and finish switch installation by securing the metal switch tabs with their mounting screws to the electrical box.

Step 11 – Connecting the Wires

Make any adjustments to the switch before installing the face plate. Verify the switch is straight and aligned properly, then finish the installation by installing the face plate and corresponding mounting screws.

Step 12 – Reconnecting

Turn on the power to verify switch operation.

Whenever you are doing a DIY project, safety is at the top of the list and when working with electricity, safety is especially important. Follow the manufacture’s guidelines and recommendations, follow the instructions carefully, and ensure the power is turned off and no one has access to turn it back on without your knowledge.