Greetings, I’m trying to install a Shelly 1 to automate outdoor lights in an old house build (build around 1920 in Germany).
My problem is that a shelly requires more than two wires, however the light switch that I want to automate only gets 2 wires from the wall (as seen in the image below).
Is there anything i could do without ripping the wall open and looking for where the wires come from and go? As well somewhere there do needs to be the connection to the “house” and also the connection to the outside lamp.
If you don’t know what you are doing, messing with mains power lines is usually not a good idea.
Usually you would put the Shelly 1 behind the wall switch where you would have four wires. Two coming from the mains power and two going to the light. You’ll need to add an additional wire to go from the switch to the Shelly.
Notice, you must know the difference between the neutral and the hot. I strongly suggest that if you don’t understand the diagram above that you hire an electrician because wiring it up wrong will likely break the shelly at best and start a fire at worst, not to mention electrocution dangers.
Yes I do understand enough of wiring and electricity for it not to be a dangerous.
I understand that the conditions are not how it is usually done. Otherwise i would not have asked. Which is why I asked whether I would need to rip open the wall and put new wires down or whether there would be another way.
You picture describes a somehow normal old wiring, where only the hot wire (L) from mains is running to the switch and from there running to the light. Looking at the light, you will still see three wires arriving.
Your only chance will be to check where cables exist in the wall and provide a new neutral (N) wire to the place there the switch is.
Only other solution will be removing the switch and put the Shelly directly at the lights place (in the lamp or behind) Gut in that case, you will lose the ability to use a physical switch.
And please keep in mind, that this sort of wiring isn’t (and never was) allowed.
Many electricians did it this way to save money, but blue is only allowed to be the neutral.
Maybe there is a junction box (Abweigdose, Klemmdose) above the switch to put the shelly 1 in (well, it’s not very likely to have enough space in it ).
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