Walli Dimmer LED bulbs fluctuating brightness level

[mi38k 4]

Hello, I have Walli Dimmer connected in 3-wire installation to a light with 3 dimmable LED bulbs (3x14W) and when I set brightness let's say below 50 %, I can see the light to slightly changing the level of brightness - like if the dimmer is having hard time to maintain the desired level. Lower the brightness set, the more apparent the fluctuancy is. It is not like flickering where the bulbs would be flashing, there are just a small changes in brightness. Is it normal? Would Bypass 2 help in this case?

 

In fact I have two exactly same connections in two rooms and both behave the same way.

 

Thanks in advance for any responses.

[mi38k 4]

So, bypass did not help and behavior is still the same. If I am watching the power consumtion I can even see the changes in it. Is this normal when dimmed? I think the consumption should be stable as well as the light intensity. @m.roszak, @A.Socha may I ask you for some input here? Or @jakub.jezek, do you please have some similar experience from your installations? Thanks in advance!

[m.roszak 556]

@mi38k, hello!

I would assume that this has something to do with the fluctuations in the grid or usage of ripple control.
Normally it behaves strangely in 2-wire installations but may have an impact for 3-wire also.

In parameter 177:

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You are able to tweak how the algorithm work.
You can try to disable it altogether or reduce the time of the correction.

Let me know how it went. 

[mi38k 4]

Thanks @m.roszak, this is something I have already tried, or at least I have tried values 0 and 255 and behaviour is still the same. Do you think that some other number in interval 1-254 would have some effect? Also, this is not something that would be happening at some exact time, it is just general behaviour of all my Walli Dimmers with various bulbs and also with or without bypass.

[m.roszak 556]

If this parameter was set to 0 and didn't worked - this is not it.
I will share this topic with our HW team.

I assume that you checked if there are no actions send from the gateway to the module?

[mi38k 4]

Yes, definitely no action from HC3 that would change the brightness. The brightness level set is still the same, only thing that changes is the "real" brightness and power consumption. Anyway, thanks @m.roszak for sharing it with your HW team.

[Tim__ 125]

@mi38k have a look at this post, and the post within it:

 

 

[mi38k 4]

Thanks @Tim__, I have actually found this post an also there are some other posts dealing with this kind issues, but I have tried everything mentioned there without success. Only thing that remain is continuously try to change bulbs, but so far I have tried like 4 different and all doing the same...

[Tim__ 125]

Sounds like the problem could be in your electricity grid.  You'd need specialist equipment to monitor it and see if the voltage is fluctuating or there is interference.  If you manage to solve it, post back here

[mi38k 4]

Thanks @Tim__, somehow I hope you are not right :). But do you mean like oscilloscope and looking at the sinus wave?

[mi38k 4]

Also one think I did not mention - I have tried the dimmer also with the incandescent bulb (@m.roszak maybe also useful information for you and your team), and it behaves more or less the same - no problem with full brightness, no fluctuations at all, but at lower levels, it starts fluctuating. If there was problem in the electric grid, wouldn't I see the fluctuations also in full brightness?

[m.roszak 556]

LEDs generally has full brightness with usage of 30-40% of the sinus, so on full brightness you probably won't see anything as for fluctuations. 

[mi38k 4]

@m.roszak: true, true, that is why I tried incandescent bulb as well, which does not have this kind of LEDs characteristics :).

[m.roszak 556]

If the problem exists also with incandescent it really looks like a grid problem.

[mi38k 4]

@m.roszak: Even if the fluctuations on incandescent bulb are happening only at low dim levels? Not very good news for me

[m.roszak 556]

It will be problematic to diagnose, I know.
Our HW team is aware and already planning some test internally - they may reach out to you for some additional information if necessary. 

[mi38k 4]

@m.roszak: Perfect, thank you, just let me know if anything is needed.

[jakub.jezek 353]

@mi38k, check if you see on those bulb if electronic part is different. Color of PCB can suggest that. Happened to customer. During the test I replaced bulb for same one and it started to work. LEDs are tons of problem for Mosfet type dimmer in case you have multiple bulbs.

[mi38k 4]

@jakub.jezek thanks for the reply. Unfortunately there is no nondestructive way to see bulb's internals, but the fact it behaves similarly also with incandescent bulb would suggest that the LED bulbs themselves will not be the only problem.

[jakub.jezek 353]

@mi38k, I tell you what I tell other electricians. Connect it on table. Get

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, connect it, plug it to wall plug and test it.

 

In case of our dealer we were able to see color of PCB in LED bulb, so that was when we suspected different electronics.

[mi38k 4]

@jakub.jezek, could you maybe share link to the bulbs you have good experience with? Maybe it would be worth another shot. But yeah, connecting it to the wall plug might at least tell me if the problem is in the light circuit or if it behaves the same way in the plug circuit.