# "3 way switches" what does that mean?

I want to change my house switch’s for smart ones but I have this question, does it mean they can do 3 switches in parallel? Because any video I’ve seen showing it off they only show 2 switchs.

Another question I have related to those smart switches, if I have a 6 gang can I have 2 or 3 different parallels connected to it?

I’m trying to get started on these smart house/ smart lighting topic but the lighting topic in specific is confusing me a lot.

3-way (and 4-way) is a name used in the US (and possibly Canada and other countries) for the way light switches and lights are wired. A 3-way configuration is 2 light switches to control a light. These are not your normal on/off switches. The switches have an additional traveler terminal. When the switch is switched, instead of breaking the circuit, it redirects power from the common or input terminal to a different terminal. Depending which of the 3 switch position configurations (both up or both down) turns on the light or one up and one down turns off the light.

So if you have a light that can be controlled by more than one switch, you need a smart switch that is specifically made for 3-way circuits (it will say so on the box or in the install instructions).

You might find certain smart switches (Shelly and a few other Zwave or Zigbee products) that have multiple channels. These devices can do “parallel” circuits as you call them. But really each channel is its own light switch/circuit.

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In the UK 3 way switching is also known as intermediate switching. Googling this term yields lots of examples. Using intermediate switches along with a standard 2way switch at either end allows for many switches to control a single light. (3way, 4way etc)

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Which is a good point. To help you properly we need to know where you are. Power is wired very differently in different parts of the world.

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Like Nathan said that’s a good point, my bad, I’m in Brazil, we do pretty much the same as UK, intermediate switch is also one of our terms here, difference being our 3-way means 3 switches controlling a single light.

In Brazil to get some variety and some decent prices we need to get these types of stuff on AliExpress (AVATTO, MOES, GIRIER, SONOFF,…). Since those smart switches do intermediate switch through apps, do I need to find switches that explicitly say they do 4-way or would it just be a software type of limitation where inside Tuya for example I would be able to do “infinite” amounts of intermediate switches?

My understanding of these smart 3-ways is that one of them get fully wired, the other one just gets energy and I connect them through the app, so I was wondering, can I get 3 switches, 2 of them just wired with energy, connect the main, fully wired switch to one of them through the app, and then connect the energized ones together controlling the lights?

Since my English is not the best, idk if I did a good job explaining my other question, for example, I have one light switch that’s got 2 of it’s 4 gangs(idk if that’s the right term) in you guys 3-way, so one controls the kitchen lights and the other one is controlling our dining room lights, am I capable of doing that inside the app with those smart switches?

It can depend on the wiring that is used in your country. One gang means one switch control one light, two gang one switch control two lights. I’m talking about wired connection from a switch to a light.
One way or multi way switches means that they are working as a one switch controlling one light or two or more switches controlling one or more lights like ie. light on stairs.
I have multiway switching in my house. It’s setup using three switches and I needed to call electrician to rewire electrical wires.
One switch is main switch meaning it does physically control lights, others are slave switches connected only to live and neutral wire for power. They physically doesn’t control anything,
To make it work you have to use that as a light group or create automation ie. when switch 1 is on switch 2 and 3 is on or pair it in an app if you using app to work as one switch.

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Perfect, so they can do not only 3-way, they can actually do multiway switching? If I got your comment right you have a 4-way switch setup through the app right? About the gangs, through the app, can I set more than one gang on each switch to do different multiway switching, can I get one gang set to multiway switch the kitchen lights and one gang to multiway switch a different light?

Yes you can have multiway switching if you are using it over an app or home assistant.
You are mixing thing here. You can have a smart switch controlling your kitchen light. It’s a one gang one way switch. You can set it up in home assistant if you turn on kitchen light turn on dinning room light and hallway light. It doesnt have anything to do with switch wiring.
Multiway switching just mean that you have two or more switches controlling one light bulb.
The app problem with multiswitching is that you have to use the same switches using the same communication protocol.
In home assistant you can mix them as you like.
I have multiway switching where one switch is zigbee switch and two of them are wifi switches.
In app you can’t do that.

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I see, I’m sorry, I’m having a bad time explaining myself here, what I’m trying to say is:

Assuming they’re all the same protocol, same brand, all that, is there a limitation to the slave switch? can it do different multiways on more than one of its gangs to different master switches?

Like for example a 4 gang switch where 2 of those gangs as multiways to different masters and the other 2 gangs of these switch are just fully wired one way, no slaves. Is that possible?

Assuming they’re all the same protocol, same brand, all that, is there a limitation to the slave switch?<

No, at least no for home assistant. For app I don’t know.

can it do different multiways on more than one of its gangs to different master switches?<

You can only have one master switch, all other switches in the same control group are slave switches. If you understand me.

Like for example a 4 gang switch where 2 of those gangs as multiways to different masters and the other 2 gangs of these switch are just fully wired one way, no slaves. Is that possible?

You can have only one master switch and that is it.
For simplicity let say this.
You have hallway and two switches that can turn on/off one light bulb.
One switch is in the beginning of hallway and other is on the end.
You want to replace old switches with smart ones.
One of switches will be master switch, meaning it is connected to live neutral and light wire and can turn on/off light bulb.
Other switch will be slave switch. It’s connected to live and neutral for power but it can’t turn on/off light. When you filp this switch nothing will happen. To make it work with master switch you have to enable in app multiway control, or something similar, for those two switches. Then they will work as one switch and you will be able to turn on/off light bulb from switch 1 and switch 2.

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I think I understand, maybe, so just to make sure I got these photos, I have yet to look the wiring inside to confirm which one is slave/master and even if both slaves are on the same switch but, assuming that’s right, I wouldn’t be able to set up something like that on smart switches?

Apparently I can’t upload more than one media on the same post

Let’s start with. What you CAN do will be directly related to exactly what device you are able to locate. What devices are available to you are a function of both what you can use in your country and availability.

So first. You need to determine what controls you can actually get.

I say this because multi ‘gang’ (using quotes because gang has different meanings in different countries) switches like the ones you have (multiple physical buttons in one vertical switch) have been difficult to manufacture and very expensive because of current state of miniaturization and power handling. (in fact the max ive seen in a single device is two loads.)so you may run into that issue.

You may also run into an issue where you see the ‘perfect’ device and it runs on US 110 power and frequency but it won’t work in your country.

So first start by building a good map of the switches. Then I’d look at what switches are available in your Geography and finally then see how they match up.

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Look you should check this out with an electrician. Explain him or show him my post how to wire those switches. The switches you need is something like this
You see on back of them that you have basically three connectors. Live, neutral and light wire. Other L2, L3 connectors is for connecting more than one light bulb to one switch.

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