I guess the point of my post wasn’t that you need a new post to create a tag (which is fine, tagging this particular post would be useless), but that the actual tag they recommended we use doesn’t even exist and it doesn’t seem you can just create tags willy nilly.
I came to this forum this morning looking for answers why 2 of my v1 switches died. Looks like everyone else is having the same issues.
I swapped them out with IP44 Outdoor plugs (still v1)
I’m confused by the Dimmer 2, I see it doesn’t require a neutral wire. However, does it work out the box with no neutral to are additional components/part required to make it work?
The Dimmer 2 works without a neutral but requires a minimum current flow so there is a voltage drop across the electronics. If the minimum current isn’t met, external components are needed to bypass the light being controlled so more current can flow.
It is all on their website.
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I was almost ready to pull the trigger on 10x shellys, especially now the Shelly dimmer just got certified
But – I stumbled across this thread showing the shellys get hot. Very hot. Shelly 2.5 getting hot to touch (63°C external case) - should I be worried?
So I’m now concerned by having them in a wall surrounded by insulation and starting a fire. Eg 40 degree day, in wall temp could be 70-80 degrees (I was going to get them installed behind the light switch, as in ceiling installation would be tricky)
Has anyone installed these in wall?
Do they aeotec or Fibaro get hot? I could potentially spring for these, but the are 3x the cost, and I’d need to get a zwave stick
As long as the device operates within its specifications and has certification, what is there to worry about? The safety cut out is at 90 degrees so it well within spec.
It has been designed by engineers to fulfil design requirements which have been achieved.
They have been sold worldwide yet there have not been any safety alerts or recalls. I’d be more worried about the sparky who installs them. 
Within specifications could still mean a 90 degree heat source within an insulated wall. That is the part to worry about
Heaps of photos of sonoffs going up inside wall cavities (I know they aren’t as good as Shellys, but the heat / insulation principle still stands)
There’s been a few dimmers melt recently on the Shelly Facebook group. They identified an issue and updated firmware
90 degrees is hot for humans but not for a lot of electrical/electronic devices or wood, plaster, insulation, or anything else used in house construction. Remember the book ‘Fahrenheit 454’,the temperature at which paper will burst in to flames.
125°C is the usual limit for silicon junctions. Because of the thermal resistance between the junction and the component package, the package temperature limit is usually a lot lower. I’d say if your dimmer enclosure was reaching 90°C you have a legitimate concern.
Silicon semiconductors are prone to thermal runaway. The hotter they get the more they conduct, so they get hotter, etc… until failure.
Yes, but the temp sensor on the PCB will shut it down when the board hits 90 degrees. The likelihood of the case reaching 90 degrees is remote. I reiterate; 90 degrees won’t set anything in house construction on fire.
As has already been pointed out this is not the normal operating temperature of the device.
At best you are advising people to destroy their devices, electrolytic caps wont last long at those temperatures.
At worst you are relying on a fail-safe that may not work. Especially if those electrolytic caps I mentioned have dried out causing excessive ripple and failure of the sensing circuit to do its job.
Tom, I don’t want to argue, however, there are many 125 degree C rated electros and they are far more common than in the past. If there is an abnormally high temp, I think Shelly may be more interested in keeping their market without burning down houses.After all, this is the only market they have.
And without opening one and checking, you are only guessing that they are not building down to a price.
You’re right there is nothing to argue about here.They should not be operating at 90°C.
That’s a challenge; I’m going to buy one and crack it open.
While I agree that electronics do tend to operate in what seem like quite high temperatures in their internal components (Pi 4 anyone?), I’d be wondering what exactly a dimmer or relay would be doing that would heat it to have an external temp of 63… and how much power would be being wasted by that.
My Aeotec Nano switches only get externally to 29C, and that’s on the one with 100w of bulbs attached, and the light circuit that has a comparable light load on it without one of the switches only operates about 2w less when on. It would be interesting to see a power comparison on a load with and without one of these, to see if they make have a cost in long term power wastage.
Probably wouldn’t be much of a difference, but still be interesting to see…
From that linked thread, the enclosure was hitting 63 degrees c, and the pcb was reporting 80 or so.
So I acknowledge that it’s not the enclosure hitting 90, but rather the pcb.
But if it’s hitting 63c in a well ventilated environment with 30c ambient temp - what about inside an insulated wall with western sun at 40c ambient temp??
Is that aeotec hitting 29c by measuring the external enclosure? Or is that an internal sensor reporting it?
Either way seems pretty safe
Switching losses for the dimmer ending up as heat mainly.