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What Does A 2-Way Dimmer Switch Mean?

While installing a dimmer switch in your home is relatively easy, you just need to ensure you get the right type for the job at hand.

This isn’t exclusive to dimmer switches. It’s the same as when buying a light switch.

It all comes down to whether you want the lights to be controlled from a single switch or if you want the option of controlling them from two different places.

A 2-way dimmer switch (called a 3-way in the US) lets you connect a dimmer switch to a secondary light switch so that you can control the lights from either. They’re designed for safety and convenience, so you don’t have to cross a dark room to reach the switch.

There’s a bit more to explain here, so let’s look at:

  • The different types of dimmer switches and their wiring
  • The benefits of a 2-way/3-way switch
  • How to wire a 2-way/3-way switch

Different Types of Dimmer Switch Wiring

Switches with dimmers in the collection of wall

When you’re looking for a dimmer switch for your lighting setup, and you’re doing your initial research, you may see that there are some called 1-way (or one-way) switches, some called 2-way (two-way), and some called 3-way (three-way).

Except that there are actually only two kinds of switches.

It just depends on where you live in the world as to what they’re called.

A dimmer switch will be designed to work independently or in conjunction with another switch.

That’ll impact how many terminals it has.

Dimmer switches designed to be the only switch on a circuit are called single-pole.

However, they’re also called 1-way switches in the UK and the European Union or 2-way switches in the US.

They have two terminals – an ‘in’ and an ‘out’ essentially – so the mains power is connected to the switch, and then the switch is connected to the bulb.

Dimmer switches designed to work alongside a second switch on a circuit – where you can control the light from either switch – are called a 2-way switch in the UK and the EU or a 3-way switch in the US.

They have three terminals – one called a ‘common’ and then two ‘travelers.’

Instead of being traditional on/off, where the circuit is broken, think of it as two different channels the current can run through, almost like switching a railway line.

A little bit confusing, yes?

A 1-way UK/EU switch is the same as a 2-way US switch, while a 2-way UK/EU switch is the same as a 3-way US switch.

There’s no real reason for the difference.

It’s just how they’ve been named in each area.

The only time you need to be aware of the difference is if you’re ordering your dimmer switch from a global website like Amazon.

Make sure it has the right number of terminals/wires for the job you want.

Benefits Of 2-Way/3-Way Switch Wiring

Man Turning Down Electrical Dimmer Switch

To be clear, I will explain the benefits of a switch designed to be used in a multi-switch circuit.

That is a 2-way switch for my European readers or a 3-way switch for my US readers.

These are the benefits compared to a single-pole switch (1-way in Europe, 2-way in the US).

For ease, I’m just going to refer to those as single-pole from now on.

So a 2 or 3-way switch is meant to be used in any circuit where you want to be able to control the lights from more than one location.

The example commonly given is at the top and bottom of a staircase, but it could be just different entrances to a room.

The way these are wired up, it’s better to think of the switches as having two different channels – say “1” and “2” – instead of “on” and “off” positions.

When both switches are in the same position – so in “1” or in “2”- the light will be switched on.

If they are misaligned, the circuit is broken, and the light is switched off.

This benefit is that you can always control the light from either switch.

You don’t need to turn both to “on” for it to work. You don’t need to walk up or down a dark staircase to reach the light or walk through a dark room.

The dimmer function always works when one of those switches is a dimmer.

The dimmer will have a switch and a slider or a dial.

As long as both the dimmer’s switch and the second regular switch are in the same positions, the light will be as bright as the dimmer’s dial or slider.

The one slight disadvantage is that you can only control the brightness from the one dimmer switch.

Generally, you can’t use dimmers for both switches, it won’t work, although there are some special dimmers that you can buy that both work on one circuit.

Related: Do Dimmer Switches Control Volts Or Amps?

How To Wire A 2-Way/3-Way Dimmer Switch?

3-way dimmer with switch

Wiring a 2-way or 3-way dimmer switch isn’t too tricky, though it can get confusing if you get lost.

It’s a good idea to label wires if you get a little confused.

For the sake of this guide, I’m going to use the dimmer switch as the one closest to the circuit breaker, but it doesn’t matter.

If the circuit runs directly to the regular switch instead, then that will work too – just swap the steps around.

  • Connect the mains power to the common terminal on the dimmer switch
  • Connect one of the traveller terminals on the dimmer switch to one of the traveller terminals on the second, regular switch
  • Connect the second traveller terminal on the dimmer to the second traveller terminal on the regular switch
  • Connect the common terminal on the regular switch to the load – the light bulb.

If the switches have ground wires, these should be connected to the ground cables. These are either bare copper or green/green and yellow.

Then the neutral wire from the bulb just needs to connect to the neutral on the main wiring line.

Most dimmer switches don’t have a neutral, but regular switches can – if they do, connect them to the neutral line.

Also read: Why Are Dimmer Switches So Expensive?

Final Words

While the naming conventions get a little confusing between the US and European standards, the main guidance still stands.

A 2-way or 3-way dimmer switch lets you control your lights from more than one place in your home, which is much more convenient.

It’s safer, too – no need to stumble across a room hoping there isn’t an obstacle in your way.

Do you have any 2-way or 3-way dimmers installed?

Have you been considering adding dimmer switches to your home?