I need help understanding how to control one smart light from 5 different wall switches without installing a Shelly behind each switch.
My idea is to keep the light always powered and use wall switches only as inputs, using something like a Shelly I4 in detached mode.What I don’t understand is how to wire 5 physical switches to a single Shelly I4 (or similar), avoiding the need to install one Shelly per switch.
Is it possible to connect multiple wall switches (5) to a single light?
What is the recommended architecture (I4 + Shelly 1 / 1PM / - Are there wiring diagrams or videos showing this exact use case?
You can do it exactly the same as you would wire light without shelly, you just need enough wires. This picture shows wiring, you just eliminate light bulb and connect red and black directly to shelly input:
Note that you can insert as many middle switches (cross ones) as you want (in series), it’s only important that first and last ones are three-say, as on the picture.
Note however that if you do it this way and, say, you’ll have light on with switches and you turn it off via HA - then light will turn off, but for turning it back on with switches you’ll need to toggle any switch twice (first to “off”, then back to “on), which can cause a mess…
A better option would be to use momentary swithces(like those for door bell) and wire them in parallel to shelly.
Additionally: if you are using multiple dumb switches to control 1 (or multiple at once) lights, you just have to install 1 smart switch which adds additional options to that 1 physical switch as if you were controlling that switch manually.
In theory, this is correct. in practise, it’s not always quite so simple if you don’t know how your lighting circuit is wired. I would always say (as would others here) that if you’re not sure about wiring, please consult a qualified electrician who will be able to either fit it for you, or explain how your lighting circuit is wired.
Essentially, you need to find which switch is the one that actually feeds power to the light. In any lighting circuit where there is one light and multiple switches, there is one switch that feeds power to the light while the rest, in effect, just switch power to that final switch. You need to find that last switch and fit the Shelly there. Then any other switch just povides a trigger to switch the Shelly. Your additional switches don’t actually need to “switch” at all, because all you need is a trigger to switch the Shelly. So the additional switches can be smart buttons on the wall, or a button on a dashboard.
Alternatively, if you have space at the light itself, and power at the light, you can fit the Shelly directly at the light position then trigger it from all your additional switches. There is more than one way to achieve this, which is why it may be better to consult an electrician if you’re not sure.
BTW, once you find that switch and fit the Shelly, it’s helpful for later to label the light’s switch wire so you can easily revert back to manual switching if you need to. There’s nothing worse than opening an enclosure and being faced with a bunch of wires and trying to figure out which one goes to the light.
Whatever you do, remember safe isolation before disconnecting anything.
You’re absolutely right. I was writing and thinking as electrician, assuming that all wiring would be made from scratch (or at least checked in detail). But if someone is not a skilled electrician i absolutely agree that it’s best to leave it to professionals.
Thanks, I will follow your advice amd contact a professional.
Just one question - I think I have space on the light itself and power at the light. Which shelly should I buy?
Thanks
I think that in this solution, you should be aware that your physical switches will loose their functionality if the light was switched off by the relay.
Dump the mental restriction of physical connection between the devices. Once they are all smart/ logical, the switches as sensors (whether you wire one physical switch to one smart device, or five of them to a smart device and get five entities, or replace them individually with smart devices - ultimately you make them smart), and your light as the controlled device, you have freedom within HomeAssistant to control them however you want.
Logically connect them, via automation. Mix and match however you want.
One press, two, long press, morse code, tied to presence sensors, timing out, fading, time of day, you now have the power.
Warning. It may cost, both in devices, wiring, and also futzing around.
