Help wiring up Fibaro FGS-222 Dual Relay Switch to existing switch

ok, so in the instruction link you posted above. The first set of diagrams, that shower the dimmer. You want to wire to the left one.
As mentioned before you need to identify the supply/feed cable to the switch. and the load cable going to the light/s.
then connect up as in the drawing. Feed conductors going to the central pair and load external pair. Blues to ‘N’ Browns to ‘L’.
Then just connect the switch terminals to the pair, next to the 3V terminal. not to the 3V terminal.
polarity on this shouldn’t mater.


I’m going to give this a try at weekend. I’ll need two new wires right from the Aeon to the switch? Which one goes to Common?

doesn’t matter.

How come it doesn’t matter? I still want the ability to use the physical switch? Or is it just that the way the aeon works means any of those 2 outputs can go to either Common or L2? Is that what you meant by polarity?

Yeah, the switch terminals on the Aeon are just looking for an open/close situation.
It can’t distinguish from a standard switch what way round anything is.

So I got this partially setup this morning. I have it working without the physical switch because I don’t have wire available to feed from the Aeon to the switch. Its a bit disappointing that I’ve had to feed the antenna out of the side of the switch due to the fact that the switch and its plate are metal. I have the Aeon z-wave repeater only 10 feet away too!! I gather this is probably a common problem but not ideal.

Have you tried using it with the aerial fitted inside?
My fibaro ones work inside mine with metal back boxes and face plates. They are all quite close though would say 10ft on average.

Just try and keep it tucked away from the mains cabling, especially were the live neutral conductors don’t run parallel with each other.
you might also find it works better horizontal or vertical.

If you still have issues, you should be able to remove a small amount of material down one side of the back box for the aerial. That the face plate should still cover.

well done, enjoy your new toy.

I tried the aerial inside originally and it didn’t register any actions from the app. Have ended up feeding it through the side sandwiched between another switch so its not so visible. As I replace more of these switches they may start to work inside the wall units.

On a separate topic I have a new project :slight_smile:.

It is to implement some automation in my master bathroom by means of auto-switching on lights when motion is detected and controlling a loft extractor fan (which is continually running) when humidity reaches a certain point.

I’m starting first with the automation of the 6 halogen lights. I took a look at the light switch at weekend and there’s two wires, see pic below.

I understand there isn’t a neutral here so this got me thinking, I could use the Fibaro dimmer but thinking a bit further, I remembered I had access to the wiring in the loft (its an attic room) via the crawl space either side.

Figuring that the 6 downlight must be fed from the ring at some point I came across the following.

The first downlight is fed through this block

So my understanding is the power is 240v down to 12v and that is what each of these green transformers do. I guess my question is, can I place an Aeon Micro Smart switch here so I can control the bathroom down-lights?

On the Aeon I’m assuming its the same approach as the other light switches, blue/brown (from the first pic) to the outside inputs on the Aeon and a live/neutral that supply power to the central inputs on the Aeon. Which ones though? There’s multiple blues and what looks to be two lives (dark browns)??

Also, I need to retain the use of the switch. Which wires would go to the signal connections? I see the switched live with the brown sleeve connects to the live in the connector block that feeds the live in the down-light circuit.

Hopefully this works, and is legible. Not used OneNote for this before.

Did you pair it to the ST hub close by before?
I take it, it works fine now its outside?

First question is because these can some times not work right if the pairing/registration is done to far away.

I paired it when wired to the wall near a z-wave repeater. It works fine outside. It did take a while to find the device through Smartthings to be honest. Its working fine now and I haven’t experienced a failed command with it but the aerial is still outside. I have found some wiring to feed from the switch to the Aeon so will retry it again at weekend.

Do you think I should un-pair, move the hub closer, re-pair it before enclosing it?

That’s more helpful thanks.

I still have a few questions though…

Step 1 : Correct in assuming it’s both L and N from these two wires that feed into Load L & N?
Step 4 : Does this apply for both browns and both blues to the AC L and N?

This allows me to retain the use of the light switch right?

Step 1; Yes both sets 2x L + 2xN
Step 2; Yes same again 2xL + 2xN

Yes, by wiring up as I showed the switch will operate the relay.

Probably not if it’s working ok outside. Was just a thought.

Ok brilliant. The Aeon should be here in time for weekend to fit it. I also purchased a junction box to keep all this tidy as the one there won’t be big enough.

Next question is about the extractor fan and its isolator switch. Can a relay be fitted to work with a physical isolator switch?

I will say no here, as the fan isolator is a safety isolating item. and has to meet cert BS standards as such. I have a feeling the relay wouldn’t meet these. Among others being able to secure if the off position. As this could be switched on from the APP. it would be very hard to work on the fan with it safely isolated.

What I would do, is put it on the supply side of fan isolator switch. Disconnect the switched supply to Isolator and leave safe. (connector block etc).
Then use the relay to create the switched supply to the fan. But connect it through the isolator switch. I.E. connect it to the terminal you removed the switched supply from earlier.

The colour black as Switched supply is only for drawing it could be the brown.
You could also supply the isolator a neutrall from the load side of the relay.

How would I know what the switched supply to the isolator is? Here’s a pic of the isolator :

The isolator doesn’t appear to have the amount of cabling in your diagram, it has L, N and G and both of these are then fed via the isolator to the fan.

The closest white wire feeds through to the fan which can be seen below.

Could I not place the relay on the fan by connecting up the current L and N wires to the relay (AC Power) and then feed the Load to the current wiring arrangement in the bottom picture? So effectively, the relay sits between the white cable currently connected to the fan and the terminal block on the fan.

The isolator will still act as a cut off point for power to the relay and the fan.

Or is this just the wrong way?

What you suggest would work.

That’s not a standard fan. is the cable you talked about switched though, as it could just be a boost function. and would turn off in such a case. stopping power to the relay. this would then give you issues.

If it is just a constant trickle fan and the supply is permanent then it would work fine.

It is a Vent Axia multi-vent. Its constantly on and reacts to rising humidity I.e. showers, baths. It extracts from the master bathroom, a en-suite (not used) which isn’t separated from the bedroom, a utility and WC room. My problem is that is it constantly extracts so heat is being lost. It only really needs to be on when humidity rises in any of those rooms so I plan to place multi-sensors (light, humidity etc) in each of these rooms, these will trigger a multi-vent relay on and kick the fan into action when a threshold is met.

So its always operating in a low speed mode (you can hear it extracting in those rooms) and then cycles through medium and high until humidity drops. The humidity sensor is on the fan unit itself which is situated in the loft.

The only on/off function is the isolator switch (which I never used because I don’t turn it off).