Asked by: Zulfiqar Coba
technology and computing computer peripherals

How do I hook up a 3 way light switch?

Last Updated: 12th March, 2020

20
Directions for Wiring a 3-Way Light Switch Yourself:
  1. Turn off the correct circuit at your electrical panel.
  2. Add an electrical box for the second three-way switch in the basement.
  3. Feed a length of 14-3 type NM cable (or 12-3, if you're connecting to 12-gauge wire) between the two boxes.

Click to see full answer.

In this regard, what is the common wire in a three way switch?

The switch wiring for three-ways is normally Red, Black, and White. If the White is correctly used for neutral, the connected switching wires are Red and Black. The White (neutral) is often referred to as Common, but the colored wires are both used as Hot wires, alternately as the possible switch positions are made.

Likewise, does it matter which wire goes where on a light switch? Properly you should have a black always hot wire bringing power in and a red wire going to the light. Red means the line may be switched. Sometimes electricians go cheap and use black instead of red. If your switch has a “LINE” marking, the always hot wire goes to this.

Moreover, how does a 3 way light switch work?

"3-way" is the electrician's designation for a single pole double throw (SPDT) switch. The switches must create a complete circuit for current to flow and the bulb to light. When both switches are up, the circuit is complete (top right). When both switches are down, the circuit is complete (bottom right).

Is the common wire red or black?

The faceplate of a single, one-way switch has two terminals: "L1" is the terminal to which the neutral core wire is attached - the blue wire (traditionally black, before the change). "COM" or "Common" is the terminal to which the live core wire is attached - this is the brown wire (formerly red).

Related Question Answers

Dovydas Simmen

Professional

What is the red wire in a 3 way switch?

If the switch box is metal, it also must be pigtailed to the grounding wires. The cable run linking the two switches is made with 3-wire cable. The black and red wires are "travelers" and are connected to the traveler screw terminals on the two switches.

Oum Koppauner

Professional

Is one wire always hot on a 3 way switch?

The hot wire leading from the 3-way switch circuit will have no power, since all power must travel through the switches. If one of the black (hot) wires does have power, then that is the wire for the "always on" plug.

Sabrine Zhernosek

Explainer

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

The black wire from the circuit breaker panel gets attached to the black screw on the 3-way switch. The black and red wires from the white cable running between the switches get connected to either of the two brass screws on the switch. On the other end, the two white wires are wire nutted together.

Faust Opgenvorth

Explainer

Is common wire white or black?

White. The "common" is the "neutral" or "ground" wire, depending on the type of circuit. In normal US residential wiring, you'll have a black "hot" wire, a white "neutral" or "common" wire, and a green or bare "ground" wire.

Serafina Kien

Explainer

What color is common wire on 3 way switch?

A or B). The switches will be identified by a label on the common terminal and/or the terminal screw will be a different color. Make sure to wrap black electrical tape around the ends of all white wires used as travelers between the three-way switches.

Dorie Wepierre

Pundit

What color wire goes to Common?

The most important wire to get right is the one connected to each switch's common screw terminal. This is the "hot" wire (usually colored black, but not always), and it brings the power from the source and delivers it from one switch to the next and to the light fixture.

Charles Polster

Pundit

What is the difference between a 2 way and 3 way switch?

A two-way switch (2 connections to the switch, not including ground)turns lights on or off from 1 location only. A three-way switch (3 connections to the switch, not including ground) can turn lights on or off from 2 locations.

Mette Unzilla

Pundit

Do both switches need to be 3 way?

No, you can use each switch for a different 3-way circuit. I also have one TP-Link 3-way switch and a Dimmer 3-way switch in the same circuit, NOTE: To use a dimmer, you have to have the TP-Link smart switch on the HOT side of the two 3-way switches.

Rimantas Zharov

Pundit

Can you use a 2 way switch for 3 way?

Yes, you can use 3-way (#UK: #2-#way) as 2-way (UK: 1-way) #switches. 3-way switches are spdt (single pole #double #throw) with 3 screw terminals, and regular switches are spst (single pole single throw) with 2 screw terminals. Just pick the correct two contacts and you are good to go.

Liyong Stubbs

Pundit

What is a 3 way wiring?

A three-way wall switch is a common type of light switch that makes it possible to control a ceiling light or other electrical fixture from two different locations in a room. The three-way switch is a variation of the standard single-pole switch, which controls a light only from one location.

Syed Simion

Teacher

How do you troubleshoot a 3 way switch?

Here's a fail-safe process to fix a three way setup that isn't working:
  1. Turn off the breaker controlling this light.
  2. Disconnect all wires from both of the 3-way switches (but do not unwrap or un-nut any of the twisted wire bundles, or disassemble any other switches).
  3. Turn the panel breaker back on.

Krystin Beyschwang

Reviewer

Can I connect red and black wires together?

In 220-volt circuits, red wires are the secondary live wires. Like black wires, they can be used in some types of switch legs. They are also used to connect hardwired smoke detectors to the home's power system. It's possible to link two red wires together or a red wire to a black wire.

Siny Aufterbeck

Reviewer

How do you wire a light switch and outlet in the same box?

Connecting Separate Devices in a Double-Gang Box
The same three options exist when wiring separate devices. To have the switch control just the outlet, connect the hot circuit wire to one of the switch terminals, and then connect the other switch terminal to the brass terminal on the outlet with a short jumper wire.

Ouadia Neumeister

Reviewer

How do I know which wire is neutral?

The only way to be absolutely sure that you have found a neutral wire is to check the voltage (110V/120V) between the white wire and the "hot" (usually black in color) wire in the box. In a standard switch/dimmer, the "hot" is using one of the two wires connected to the switch.

Suleman Matties

Supporter

How many wires can be in a junction box?

Counting Wires in Electrical Boxes
Each switch, outlet, or other device counts as two wires.

Nayan Bascompte

Supporter

Where does the neutral wire go on a light switch?

The white (neutral) wire connects to the silver screw, or you place it in the back wire hole on the same side of the device as the silver screw. The black (hot) wire goes to the brass screw or into the hole in the back of the device on the same side as the brass screw.

Joanie Schlutt

Supporter

What is common wire?

A common wire is a more general term and simply refers to the 0 Volt wire of a circuit, either electrical or electronic.

Beatrix Kroess

Beginner

How do you wire a 3 wire outlet?

Avoid backstabs (they're not reliable) and never use 12AWG on a backstab.
  1. Ground terminal: a bare (or green) wire.
  2. screw 1: a white wire.
  3. screw 2: nothing, but if the tab between 1 and 2 has been broken, a white wire.
  4. screw 3: a black wire.
  5. screw 4: nothing, but if the tab between 3 and 4 is broken, a black wire.