Shelly Plus 1Pm with 2way switch wiring, can't figure it out

Hey HA-enthusiasts!

Starting my smart home journey with some hardware that I thought would be quite easy to install. But apparently I was mistaken.

I’m trying to install a Shelly Plus 1Pm in my living room where there is a 2 way switch. They are wired in this way.

But I’ve been told that the shelly needs to be installed at the last switch, so in this case the second one.
What I also learned is that the shelly needs a permanent phase: L.
So I pulled an extra cable to the second switch from the first to provide that.
And a Neutral wire is also available at the second switch.

So at the first switch I have a brown L. 2 black switching wires and an N.
At the second switch I have the permanent L that I added, I have the O ( output to the lights), 2 black switch wires and an N.

So in theory I should have everything I need, right?!
Yet I can’t seem to get it to work. The shelly works, setup was easy and I can control the light with the shelly app.
But I seem to be doing something wrong wiring the switch(es) to the Shelly, because either only one switch works, or both don’t. But I can’t get the 2 switches to work in combination with the shelly…

The switches I’m using are Niko 2 way switches. Like these with the L, 1 and 1’ contacts: Base for a two-way switch or two-way pull switch 10 AX/250 Vac, plug-in terminals

First switch is wired like this:
L------------------------ 1------------------------------------------1’
L 230V. Black switch wire. 2nd switch wire

The second one like this:
L-----------------------------------------1------------------------------------------ 1’
Output to lights.-----Black switch wire.-------2nd black switch wire

I’m hoping someone can provide me some insights. Because I’ve been staring at the diagrams for too long and I think my brain is broken. Because I can’t see the solution…

Thanks in advance❤️

(excuse me for formatting, posted on mobile)

You must use 3-way switches wired like this:

Thanks @stevemann.
But since someone told me that it would be easier to do with buttons instead of switches, I made a little test set up to see if that would work.

In this picture, with just one push button, it works like it should. I can turn the light on/off with the app and with the push button and any combination.

But now how do I wire the second push button in?
And right now the Shelly settings are: input mode - > button and relay type - > momentary.
That should also be okay when the second button is wired in?

I’m not an electrician but your first wiring scheme look to me like alternating switch wiring.
And it is if there was dumb switches.
The thing with smart switches is fairly simple. You need one main switch that control the light and have live neutral and light wire connected to it. All others are dumb switches that have only live and neutral connected to it for power. Light is turned on or off by automations ie. when switch 1 is on turn switch 2 on etc.

What happens with two buttons in parallel?

If I wire the second pushbutton the same way, parallel and on the same connections on the button, it doesn’t work. The second button does nothing…

I think tomorrow I will try with another Shelly. Or just order some 2PMs. They’re more expensive, but it seems like those might make it easier…

This makes no sense. If a button works as you want, then more buttons in parallel will also.

Standard connectign three (or more) switches require two “three-way” switches ( first and last) and one (or more, hundred if you want…) “four-way - cross” ones in the middle. The basic princicple is very easy to understand:

So, if you’d like to connect that way you’d need and external relay (with NO - C - NC contact) connected to shelly. Since this is not a practical option it’s easier to connect a light to shelly only (as you’d have only light and shelly), then get a bunch of pushbuttons and connect them parallel to shelly’s input, so whichever pushbutton you press you will toggle the lights.

A good side of an option with relay is that if shelly goes bad you’ll still be able to turn on (or off) the lights with other two switches, while good side of second option is that you don’t need a relay, but nothing will work if shelly goes bad.

1 Like