Wiring of 2-way switch with Shelly Plus 1/2PM

Hardware
1

Hi.

In my home, most lights are wired up using 2-way light switches. I struggle to find a solution to integrate the Shelly switch and still have all the physical switches work normally.

Here is a sketch of the original wiring in the house:

image
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My goal is to retain the original functionality of the 2-way switches and add the Shelly on top of this. Does anyone see a clever way of realizing this, without pulling additional cables in the walls?

Thanks in advance!

2

The best solution for integrating the Shelly, that I could come up with is this one:

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This wiring allows me to use switch 1 or the Shelly remotely to turn on and off the light. When I use switch 2, I can override the Shelly/switch 1 and turn everything off.

A variant of this solution is to wire both brown cables in switch 1 to the output port of the Shelly. Then switch 2 is non-functional.

3

Assuming you read the Shelly documentation on wiring, I did a quick search for your issue on Google and come up with this. Is it of any use?

I use a lot of these 1PM’s but not in a 2 way setup.

4

You can just replace the original switch with momentary type, so you don’t need to pull new cable

5

Thank you for this suggestion. I saw this one, but unfortunately, for me, the circuit for the switches is also used to power the lightbulb, unlike in the setup they have in this post. Hence, this does not work in my case.

6

Not sure that I want to switch out my light switches for momentary ones (I’m just renting). But this blog made me realize that I can just use a Shelly 2PM instead. I can wire up the two switch outputs to the two switch inputs and the brown wires to the two Shelly outputs. This means that I can use the Shelly 2 for only one circuit, but at least it would be fully functional.

Too bad, I now bought myself a bunch of Shelly 1s :stuck_out_tongue:

7

It is an old post, but in case you remember: did it work ? how is the logic between two independent relays managed with a common output?

Thanks!

8

Hi All,
Here is the solution that I have working in my house.

Here is the current details of using Shelly Plus i4 and Shelly 1 Plus Wi-Fi Relay Switch used to change a standard double switched light circuit into a smart light with the original switches still working when used.

2 Way Switching
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The attached diagram shows the original and completed wiring, and all that is then required is a single automation to ensure that both switches continue to work as expected, plus the HA switches also work with voice commend or screen action as required.

The Automation is generated using the UI, and I have included images of the UI setting, as well as the resulting YAML code. At the time of writing this post I am running Core 2024.10.2, Supervisor 2024.10.2, Operating System 13.2 and Frontend 20241002.3 on A Raspberry Pi 5/64b with 256MB ram.

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then do
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alias: Dining Room Light Toggle
description: ""
mode: single
triggers:
  - entity_id:
      - binary_sensor.dining_room_switch_two_input_0
      - binary_sensor.dining_room_switch_input
    trigger: state
    to: null
conditions: []
actions:
  - action: light.toggle
    metadata: {}
    data: {}
    target:
      entity_id: light.dining_room_light

This wiring requires active/neutral at both switch points, which most modern wiring (in Australian houses) has as standard. Older wiring standards are best automated by use of a single Shelly 1 Plus Wi-Fi Relay Switch at the light fitting, with the light fitting requiring active/neutral and switch result to correctly wire the Shelly 1 Plus Wi-Fi Relay Switch and light. Wiring for this method is not included in this post.