I found this schematic since i have this problem with a third switch inbetween.
Regarding the schematic, can someone explain how this works? If the Shellys state is off , O (blue) should have no power. How can the switches work then?
The source is a german YouTube Video and he shows that its working.
Hello,
If it is a Shelly 1L gen3 from official docs does not look correct.
The output for switches is Sx and the input are S1 and S2.
As it has no neutral so there is a leak towards neutral wire on the output load to ensure power to the relay, so it might work but not according to the documentation.
Hi thanks for your reply.
Its indeed a four year old source using a gen1 Shelly 1L. He also mentions using the bypass to prevent flickering.
If its really based on leaking power it doesnt sound very reliable.
Heres the showcase
Thanks
The official Shelly site has wiring schemes for both 1 & multi-way switching, for each of their devices.
Why are you using a random 4 year old source instead of the manufacturer guides?
I found none in the official Shelly docs where I can solve the problem that the live wire is only available at the first switch and the lamp wire is only available at the last switch which is typical for older german Kreuzschaltungen.
Between the first and last switch are only two wires available and all official Shelly solution’s would require three.
I had 2 instances in my house that are exactly like the one presented in this diagram ( I used exactly the same picture 
). Both working perfectly reliable since ~3 years, no issues. Indeed the trickery of this setup is related to not having neutral available (so bypass required if power leak is too small) and actual load source and receiver being connected to different switches.
If you have 3 switches setup, it might not work properly, since Shelly 1L works here with both switches configured as edge switches, eg. 1L toggle light based on each of switches toggle, which might mean it is unrelated to their combined state - both might be on, off or in on/off combinations. So in fact you are using here existing wiring to create setup with 2 independent switches rather, that using it in real 2-way or 3-way setup that on any switch toggle also toggles power delivery.
Thanks,
the comments in the original source suggest that the same circuit doesnt work with the shelly 1L gen3 anymore, so i have to look for other solutions. Replacing all switches with toggles would work with existing wiring.
Im still wondering, since other diagrams for the shelly 1l gen3 suggest for example connecting S1 to the switches input and the switch output to Sx, is live internally connected to S1 and S2?
Hello,
You are reporting
[quote=“morkar, post:5, topic:962382”]
the last switch which is typical for older german Kreuzschaltungen
[/quote], I am not german speaking so I might have not understand it correctly but isn’t it usually a three switch configuration? Two two way rocker and one invertor?
If you are in this situation it might need a different wiring then the one I will suggest here below.
You need to do something like the following
If I understood correctly your wiring you need to add a wire for the shelly output to lamp.
If you want to detect from HA what switch has caused the triggering of the ON/OFF you need to wire one switch to S1 the other to S2.
At this point if you are unsure and you are not an electrician I would ask to some professional.
About the voltage on SX I don’t know but for sure there is some voltage going around.
Can you confirm which Shelly 1L Gen you actually have?
Hey,
I don’t have a Shelly 1L yet. I encountered the problem after trying to integrate my second floor lighting. If there is a solution I will get a Shelly 1L gen3 since it’s the current version and it’s the only Shelly working without neutral at the switch.
You are correct. I didn’t know the correct english term and was typing on my phone. This is my lighting circuit on the second floor
So it’s indeed two rocker switches and one intermediate/4way switch inbetween.
I’m still confused of the terminology since there seem to be multiple english words for the switch types, sorry for that.
I’m Shelly fan, but your wiring setup would be better match with Sonoff Magic Switch mode.
Hold up, you said you have a 3rd switch so you got a 3 way switch setup?
Then you should use this example instead
Another easier solution without rewiring or switch replacement is sonoff basic r4/v5
Unfortunately extra wiring is not an option for now.
I did not know the Magic Switch Mode thing from Sonoff. This looks indeed like a better solution than complex wirings with Shelly 1L. Thanks!
If extra wiring is not possible, Magic is likely the best choice. Shelly 1L gen3 docs don’t confirm any of the circuits proposed above.
