Hi, I’ve got two non-dimmable 5W LED spotlights controlled by a single toggle switch which I want to add to my Smartthings and looking for advice on best way to do this. I’m in the UK and I’ve got no neutral wire at the switch.
I’ve tested wiring a Fibaro Dimmer 2 at the switch but although the calibration returns Green the lights just constantly turn on and off when I turn on at the switch or via ST. That suggests to me the load is too low for the Dimmer 2 although happy to be corrected.
So I believe I have two options:
Use the dimmer bypass
Wire a relay or Single Switch 2 above the ceiling where there will be (?) a neutral wire
I don’t have a bypass module at the moment but I do have a first gen relay and a Single Switch 2 and I have access to the wiring in the ceiling for the spotlights so I’d like to try and explore option 2.
I’m very familiar wiring at the switch but could do with some guidance on how I wire in the ceiling. How do I identify the neutral wire? Is there always a neutral wire in the ceiling? And how do I wire up the relay/Single Switch 2?
I’ve included a photo of the wiring I have access to for the spotlights in case that helps. Any help would be appreciated!
You can’t use nondimmable lamps with a dimmer module without a neutral wire. The physics are different, so the flickering is to be expected regardless of the load. You need to use dimmable lamps or change to the Fibaro switch instead of the dimmer.
Since the nondimmer model does require a neutral, then you would have to move it. (There’s always a neutral somewhere to complete the circuit, it just doesn’t have to be at the switchbox and in the UK it typically isn’t.)
But switching to dimmable lamps might be easier, it just depends on the models you have.
Edited to note the correction given below. The Fibaro dimmer is indeed unusual in that it has parameter settings to convert it to something that can be used with non-dimmable lamps: but only in a three wire configuration.
I’m sure you’ve got much more knowledge and experience than me here but with the custom DTH I’ve got for the Dimmer 2 there is a parameter 32 to enable an “on/off mode” and also a parameter 34 to disable soft start. So making those changes basically allows me to use the dimmer 2 with non-dimmable bulbs - technically. Curiously, I notice those parameters are not present in the standard Smartthings handler for the Dimmer 2.
Interesting though - I didn’t think to test this. I’ll change the bulbs out for dimmable ones and then retry the Dimmer 2 and see if I still get the problem. If not, that would be a much lower hassle solution!
I’ve just tried with 2 dimmable bulbs but now when I run calibration it returns a red light so I guess the load is too low and/or my bulb models don’t play nice. I’ve got the Aurora bulbs. So I guess I’m back to square one - if I can get some guidance on how to find the neutral wire and how to wire a Single Switch 2 above the ceiling I can give that a go…
Sorry for the confusion. The Fibaro dimmer manual says it can be used with non-dimmable lights (with the appropriate parameter settings) but only in a three wire configuration.
It may be used as a switch with non- dimmable light sources (in 3-wire connection).
I’ve edited my post above.
But from your testing it sounds like you’ve run into both issues: you need dimmable lamps and you need to meet the minimum threshold.
Normally there would be a neutral at the ceiling rose, but I don’t know enough about UK wiring to know how it works when there are two lamps which are probably operating in serial. Hopefully someone from the UK will respond with a more helpful answer.
That’s OK - although I did manage to get the Dimmer 2 to work with some outdoor lights where I had wired it in the same 2 wire configuration and the load was fairly low. It’s just the spotlights it doesn’t seem to like.
OK no problem. I’ll wait for someone from the UK to hopefully shed some light…thanks for getting back.
You should really test this out, but based on what I can see this would be the usual setup.
Earth - Self explanatory.
Two blues in - This is the neutral for your lighting circuit. One comes in from the previous room or the circuit or the breaker and the other goes to the next room in the circuit.
Three browns - This is you live in and live out and the live to the switch.
Blue with tape. This is the switched live return from the switch
You can see your lamp connected across the switched live from the switch and neutral. The other cable is the other light on the same switch.
OK thank you so at least I have access to where the neutral is. So I have a first gen Fibaro relay switch and wiring diagram for that in a wall switch is below. I guess next question would you be able to provide some instructions on how I would wire it into the ceiling connections? And presumably if it is wired into these connections successfully it would control both lights, not just one?
N - terminal for neutral lead
L - terminal for live lead
IN - input terminal for load power supply
Q - output terminal of the load
S2 - terminal for key no. 2
S1 – terminal for key no. 1 (has the option of entering the device in
learning mode)
B- service button (used to add or remove a device from the system)
Like I said you should really test the connections to confirm.
Earth - Self explanatory.
Two blues in - Would connect to N on the module and the blue from your lamps.
Three browns - Would connect to L on the module and IN for a Fibaro relay switch
Blue with tape. Would connect to S1 on the module
Q on the module - Would connect to the Brown from the lamps.
This would control both lights.
Please be careful and if you’re not confident then don’t do it.
Thanks. I definitely won’t take any risks but if I can understand it like I did the dimmer 2 wiring at the switch I thought I could do it.
Sorry to press but some clarifications please…
So with a new piece of wire I connect one end to N on the module and the other end to the port on the terminal block which is on the opposite side of the two blues in, i.e. the neutral to the lamp?
Again with a new piece of wire I connect one end to L on the module and the other end to the free port on the terminal block on the opposite side to where the three browns are coming in? And then also create a loop between L and IN on the relay?
Again with a new piece of wire I connect one end to S1 on the module and the other end to the same port that the blue with tape wire is connected to?
Again with a new piece of wire I connect one end to Q on the module and the other end to the switched live to my lamp, i.e. the same port as the brown wire on the other side of the blue with tape wire?
So with a new piece of wire I connect one end to N on the module and the other end to the port on the terminal block which is on the opposite side of the two blues in, i.e. the neutral to the lamp?
YES
Again with a new piece of wire I connect one end to L on the module and the other end to the free port on the terminal block on the opposite side to where the three browns are coming in? And then also create a loop between L and IN on the relay?
YES
Again with a new piece of wire I connect one end to S1 on the module and the other end to the same port that the blue with tape wire is connected to?
YES, or just put the blue wire with the red tape into S1
Again with a new piece of wire I connect one end to Q on the module and the other end to the switched live to my lamp, i.e. the same port as the brown wire on the other side of the blue with tape wire?
NO, just put the brown wire form the lamps into Q
Forgive me for saying it though, but based on those questions, I am not sure you should be doing this.
Thanks sir. I will use a tester and if I’m not convinced I will leave it for an electrician to do. I’ve just got a load of time on my hands right now so thought I’d make use of it but obviously need to be sensible.
@siwilson thanks very much for your help, after plenty of checking and testing I wired up the relay and got it working!
I have one more set of two spotlights and this time a Single Switch 2 to wire them to and would appreciate some guidance please. Looks to me the wiring for the Single Switch 2 is similar to the Relay, the only bit I’m not quite understanding is what connects to the L next to the S2 on the module? Does it connect to one of or either one of the ports where the brown live wires are connected on the terminal block?
Below is a photo of the wiring and apart from the L next to the S2 on the module, from my understanding the wiring would be:
N on the module connects to port on terminal block on opposite side of two blue neutral wires
L (next to Q) on the module connects to port on terminal block on opposite side of two brown live wires
Remove the blue switched live return wire (far right of photo) from the terminal block and connect to S1 on the module
Remove the brown switched live to my lamp from the terminal block and connect to Q on the module
You can ignore the second L next to S2. It’s just a Live out for the switch so if you have live to the switch already you don’t need to use it.
N on the module connects to port on terminal block on opposite side of two blue neutral wires
Yes - N on the module goes to Neutral and in your case the left hand block with 4 blue wires in it already.
L (next to Q) on the module connects to port on terminal block on opposite side of two brown live wires
Yes - L is Live in for the module. second to left on your block.
Remove the blue switched live return wire (far right of photo) from the terminal block and connect to S1 on the module
Yes - Connect the blue far right to S1
Remove the brown switched live to my lamp from the terminal block and connect to Q on the module
Yes
These connector blocks don’t have ‘sides’. Each pair of connections is one connection so it does not matter which side you go into from an electrical perspective. just put then in the ‘side’ that’s easiest.
Lastly, make sure all those earth leads are covered in earth sleeving and connected together into the block. The ones coming from the ceiling should also be twisted together before you put them into the terminal block.
@freddyq
The following article would seem to dover your requirement. It uses a Fibaro relay with a single standard latching light switch to provide on/off control of lights and there are diagrams for both 2-wire and 3-wire options.
In your case you would locate the relay in the ceiling.
Fantastic - got it working! Wiring was all fine, had more issues getting the Single Switch 2 to reset and add, I’ve read elsewhere that attempting inclusion using the B button doesn’t always work which seemed to be the case with me but luckily using the toggle switch worked.
I also couldn’t factory reset the module - the manual states there should be a Yellow menu option for reset after Purple but my module would only go from Turquoise to Green to Purple and that’s it. No matter what I tried I couldn’t get the Yellow option to show. In the end it didn’t matter but odd behaviour nonetheless.
Incidentally, is the standard Smartthings DTH for the Single Switch 2 the best one to use?
Thanks a million @siwilson for the wiring guidance with all this - I thought at one point I wouldn’t be able to get control of the lights I wanted to but all good now
