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How To Install A 3-Way Switch

How do you wire up a 3-way switch?

What wires go where on a 3-way light switch?

With a three-way switch, three wires connect the pair of switches—two black “traveler” wires and a third “common” wire. When the circuit’s power is turned on, any of these may be “hot,” depending upon how the switches are toggled.

What is the common wire on a 3-way switch?

The black (line) wire connects to the common terminal of the first 3-way switch. A 3-wire NM connects the traveler terminals of the first and second 3-way switch together. Traveler wires are interchangeable on each switch. The common terminal of the second 3-way switch connects to the light fixture(s).

What color wire goes to the black screw on a 3-way switch?

The black screw has the black (common) wire that runs up to the light through the yellow cable. The two grounds are connected together and then to the green ground screw on the switch. To summarize, the black screw gets either the wire from the electrical panel or the wire going to the light.

Where does the white wire go on a 3-way switch?

The black “hot” wire enters the switch on the left. Three-way wire(which includes red, black and white wires) runs from the switch on the left to the switch on the right, with the white wire carrying ground and the red and black wires carrying the output from terminals in the left switch.

What happens if 3-way switch is wired wrong?

Usually when a 3-way switch fails, lights can be toggled on and off at one switch, but not the other. If one of the two 3-way switches toggles the light(s) on and off, the other 3-way switch has probably failed. Follow these steps to find which switch is bad. Toggle each switch until the light come on.

Why does my 3-way switch only work one way?

The way a 3-way switch works is that there is no On and Off. So, if power is going to the first common and the first switch is Up, then power goes down the top traveler until it gets to switch 2. If that switch is Up as well, then power goes from the Up traveler to the switch 2 common and on to the light.

Does 3-way switch need to be grounded?

A three-way switch has four different screw terminals on its body: Grounding screws on switches were not always required, so if you are replacing an old three-way switch, you may find one without the grounding screw. The two lighter, brass-colored screws are called the traveler screws.

Can you use 2 wire for a 3-way switch?

Two three-way switches (s.p.d.t.), four diodes, and two wires also enable three-way switching action. If you only have a two-wire cable to work with, you can still hook up a three-way switching circuit for your garage, or hallway, to enable you to turn a light on and off from either of two different locations.

What is a 3-way switch used for?

A 3-way switch is one that allows you to control a ceiling light (or other electrical fixture) from two separate locations. Common scenarios would be 3-way switches located at both the top and bottom of a stairway, or having 3-way switches next to doors in a room with two entry points.

Does the hot wire go on the top or bottom of a switch?

Attach the white wire from the light fixture, which is now the hot wire, to the nut at the top right of the switch. Attach the red wire from the light fixture to the nut at the top left of the switch. Connect the bare copper wire to the green nut at the bottom left of the switch.

What wire is connected to the black screw?

A black or red-hot wire usually connects to a brass-colored screw terminal or black wire lead on electrical devices. A white neutral wire usually connects to a silver-colored terminal or white wire lead.

Does the black wire go to the gold screw?

Black (Hot) goes on the smaller prong side or white to silver screws, black to gold screws. Ground (bare wire) to green. 3) Strip wires, about an inch.

Why can’t you mark the on and off positions on a three-way switch?

Why can’t you mark the on and off positions on a three-way switch? The switch is inaccessible. It is important for the electrician to figure it out by himself.

At what terminal of 3-way switch we connect wire going to the load?

The common terminal is the “bridge” between the power supply and the load (typically a light fixture). With this in mind, the wire that attaches to the common terminal is either (1) a hot wire from the main board or (2) leads to the load (fixture).

What color is the common wire?

Red, Black, and White are the colors of switch wiring for three-ways. Red and Black are connected to the switches if the White is used for neutral. The White is often referred to as Common, but the colored wires are also used as hot wires.

Is a Dead End 3 way legal?

The 2011 does not allow a dead end 3 way- a neutral needs to be present in most situations. There is nothing against using a dead-end 3-way. You can use a 4-wire to get a neutral in the far box.

What is a dead end three way switch?

A ‘dead-end’ 3-way is one which only has one cable in the box. the xx/3 from the other switch. The feed and switched circuit are both in the other box. Dead-ends are perfectly legal.

What is a switch leg circuit?

The switch-leg portion of electrical circuits controls the flow of electricity to lights or receptacles. The type of circuit wired for a switch depends on where electricity is delivered to the circuit: at a switch or at the light or receptacle.