Fibaro 212 with direct power connection and LED non-dimmable lamps


Hopefully someone can give me a quick answer on this. I have a ceiling lamp in my lounge where the power actually comes from it being plugged-into a 13A power socket with a plug in the garage. I currently use a timer socket to switch it on and off; it’s powered like a desk lamp I guess.

I want to set this up instead like a smart lamp so I bought a Fibaro Dimmer 2 (212). Having reviewed the diagram and realising I don’t have a switch at all, I believe the wiring of the Dimmer 2 can be done in the ceiling and should be as simple as this:

Firstly, can I have someone else agree it’s that simple please?

Next, my lamps are non-dimmable (LED). I read on the forums that it may be used as a switch with non-dimmable light sources but when I look on the details on Vesternet they state this must be in a 3-wire connection… So if this is the case, then my connections need to look like this I think:

So secondly, can I please have an OK on that?

But then I realised that because I’m using LED bulbs, the total draw is only about 10W [BTW, how infuriating it is that - despite all the LED lights now - switching and dimming manufacturers are STILL making devices with minimum wattage of 50W!] so I thought I needed a Dimmer Bypass 2. But again on Vesternet I see they have stated this on the Dimmer 2 page: "The Fibaro Dimmer 2 and Dimmer Bypass can only be used with lamps that are ‘dimmable’. So, it seems like I cannot use these devices at all because even though my LEDs could be used by the Dimmer 2 itself, the addition of the Bypass 2 means it won’t work as they are not dimmable.

Thirdly, could I please ask for confirmation of this incompatibility?

The final question is that actually my bulbs are 12V so the 230V power feeds I am talking about in teh diagrams are actually going to/from the transformer (which is non-dimmable) so in these connections I treat the transformer as the lamp.

Fourthly then, will the set-up programme of the Fibaro Dimmer 2 mess my transformer with it’s test cycle or will that either be ok or can I tell it to go straight to an on/off configuration?

So to summarise, my current perception is I have a binary answer on the transformer/12V question and then I can only get around the other limitations by either:

  1. upgrading my (7) LEDs in that fitting to use a combined draw of over 50W (and no need for the Bypass 2) or

  2. upgrading all 7 LEDs in that fitting to be dimmable if I want it all under 50W (and use the Bypass 2)

I’d really love to know what to do now and thanks in advance for your help for this rookie.


Agree about using a smart socket being easier, however forsome of your questions:

The Dimmer 2 does work with 2 wire installation but the way it works is passing a small current through the bulb (by having a high internal resistance in the Fibaro) to keep itself powered. To do this the bulb or load should be dimmable,though in many cases this will still work if not dimmable. If you have a very low wattage load then you need a bypass in order to ensure that the low current passing through the bulb does not turn it on (since for a 5W LED, even a few milliamps will make it glow lightly).

A 3 wire installation is better in most circumstances given you can do it fairly easily.

For the transformers, then it is the transformer that must be dimmable as the lights are just 12V ac and will be fine to dim. The setup process on the Fibaro should not damage them as the Fibaro should quickly workout that the transformers are not dimmable. If you have 7 individual transformers and you want to be able to dim them then I would suggest removing them and just replacing with a dimmable LED (the energy savings do add up if they are currently halogens), but if you have a single transformer for all lights then it is easier to just replace the transformer.

Hi Robin. Your statement that “I have a dimmer 2, in a 3-wire setup, without a bypass, running an LED driver less than 50W without any adverse effects” is good enough for me to move forward and try it, thank you.

The comment about the smart socket is a good one. The main reason is that the socket is in the garage where there is no Wifi signal from my router. As my Smartthings hub is adjacent to the router I assumed the ZWave or ZigBee signals would also not reach that far. There was also something about ‘trying another bit of kit’ that intrigued me. along with it seeming such a waste to by a £50 socket for the garage :slight_smile:

Your point here, alongside Robin’s comments above mean I will give this a try.

I’ll go for the 3-wire set-up - so the Neutral can act as bypass - and with my current bulbs and the (single) transformer for the light fitting. I’ll see what happens.

At last I got around to setting-up my dimmer! It works with wiring configuration diagram 2 above.

I used the recommended code provided on the other thread: Fibaro 2 Dimmer (212 not 211)

I have one problem which is that the Smartthings app does not appear to correctly register/maintain the status of the lamp. For example, if I tap to switch it off, the status goes to “TURNINGOFF” but never goes to “OFF”. If I leave the app and come back to it, the button shows as “ON” but the light is off; and it then takes two taps to turn it on again: the first turns it from “ON” to “TURNINGOFF” and the second turns it to “TURNINGON”.

Is this a problem with the code I have installed? Anyone else have this problem?

Yes thanks, Robin. Actually, on checking I am using the one you recommend. The issue appeared to be that it has a few config options that are not filled-in after discovery and once I had found the config area and entered values for them it worked. Something about protection status and max and min values. Anyway, entered values that looked sensible and the app now shows the On and Off statuses as hoped for. I have a working Fibaro Dimmer 2 module (doing just on-off as I’ve got LED on a non-dommable transformer). Disappointingly, Google Home doesn’t recognise this device.