3 way smart switch wiring diagram plus#

A second bundle (four-wire) should contain three colored wires (black, white, red) and a copper (bare). These link the switch to your light fixture.

3 way smart switch wiring diagram plus#

One three-wire bundle will have two colored wires (black, white) plus one of bare copper. Besides their direction of entry the wires are constructed the same way. Here, both wire bundles should enter the electrical box from its top side. They connect the switch in this box to the other switch in box 2.īox 2. The other 4-wire bundle will enter the box from the top and have three colored wires (black, white, red) and a copper (bare) one. These wires come from your home's main electrical panel (usually in the basement below) and provide power to your lighting circuit. This three-wire bundle should consist of two colored wires (black, white) plus one of bare copper. In box 1, one of the wire bundles enters the box from the bottom. It will help you deduce their origin and ultimately identify them.īox 1. If so then the direction wires enter each box is important. Let's call each box 'Box 1' and 'Box 2.' We'll also assume that, like mine, the boxes you're working inside are on a floor above the basement. Inside each of the two electrical boxes you should see two bundles of wires. This step-by-step is reflective of a common wiring scenario and the one in my own home. I must stress that there are many possible ways a set of three-way light switches can be connected. You should now have a good view inside each box. If not you'll have to switch more breakers off at the main panel until the warnings stop. Once your pen gives the all clear you can proceed. Learning to use this tool is a valuable skill. This gadget can sniff out voltage and amperage of electrical circuits, components and connections. Of course if you need to measure the actual voltage of live wires, a multimeter is the way to go. If the pen starts to flash and sound its alarm then watch out! There's likely high voltage (120 volts) electricity running nearby. With your voltage pen turned on, tap the edges of the switch. Just to be safe, use a voltage pen to check for a live current. In my case, the old switches had exposed terminals so I made a mental note to tape them later. Unscrew these screws then remove the plates covering each switch.Ī common practice is to wrap switch terminals with electrical tape once their wires are connected. There is often a pair of screws holding each faceplate in place, at the top and bottom.