Electrical - Replacing a 3-way switch

Replacing a 3-way switch
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Introduction

There are many reasons to replace a light switch. For example, your current switch may not match the décor in your room or the color of your walls. Maybe it is old and unreliable. Either way, it is a relatively quick, inexpensive and simple project.

A 3-way switch allows you to control one or more light fixtures from 2 locations. The basic principles of a 3-way switch are shown in the figure above.

Electrical basics are easy to understand, but working on electrical projects can be hazardous. You should always take the proper precautions - turn off the circuit you are working on and use tools with insulated handles.

• Beginner - 30 to 45 minutes
• Intermediate - 20 to 30 minutes
• Advanced - 15 to 20 minutes

Make sure you turn off the circuit you will be working on. Locate the breaker or fuse and properly disable.

If you are using a plastic workbox, connect any ground wires directly to the switch.

Make sure you connect the wiring to the correct terminals on your new switch. Use the same relative connections from the old switch. If this doesn't work, you may need to use "trial and error" until the wires are connected correctly.

Use insulated tools as an extra safety measure.

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1.	The first and most important step is to turn off the circuit that you will be working on. Find the right breaker in the breaker box and flip it to the "Off" position. If you have a fuse box, find the right fuse and remove it completely from the panel. (Figure 1)
2.	You can verify that the correct circuit has been turned off if the light controlled by the switch no longer works.
3.	Remove the old switch plate.
4.	Remove the old switch from the workbox. (Figure 2)
5.	Unscrew the wiring from the old switch. (Figure 3) Note the position of the wires as you remove them. It will help when you connect the new switch. (Figure 4)
6.	There are 3 wires that you will need to connect to the new switch - the common terminal that goes to the light or comes from the breaker box, the two hot wires and the ground wire. The neutral wire will not be connected to the switch.
7.	Attach the 3 wires to the new switch. Figure 1 will help you understand the basics involved. Refer to wiring diagram that came with the new switch to make sure you are using the proper terminals. Loop each wire so that it wraps around the screw in a clock-wise direction. (Figure 5) This will keep the wire from slipping off as you tighten the screw. (Figure 6)
8.	The neutral wire should be spliced to the wiring that continues on to the next switch or to the light workbox.
9.	The ground wire should be connected directly to the switch if you are using a plastic work box.
10.	Wrap electrical tape around the switch so that it covers all of the screw heads on both sides. (Figure 7)
11.	Bend the wires in a zigzag pattern so that they easily fold into the workbox. Push the switch into place. Adjust the switch so that it is perpendicular to the floor. Tighten the two screws that hold it in position.
12.	Install the new switch plate over the switch. (Figure 8)
13.	Switch the breaker back on (or re-install the fuse). Test the new switch to make sure the installation was successful. Make sure you test the other switch used for this light. This will ensure that the new switch is properly wired.
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Shopping List

Materials Needed
•	3-way switch
•	Switch plate
•	Electrical tape
Tools Needed
•	Screw driver
•	Needle nose pliers
•	Utility knife

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