Dimmer issues

[mi38k 4]

Hello all,

it has been almost a year since I started dealing with Walli Dimmers and make them work flawlessly. First thing that surprised me was that when bulb is dimmed (I have tried LED and incandescent bulbs), I can see some very very slight fluctuation in light intensity, but in the end (after some research and also information from users here) it seems, that it may be caused by voltage fluctuation in power grid, which is something this kind of dimmer cannot avoid.

 

But the main issue I am trying to deal with now is that LED bulbs connected to Walli Dimmer in trailing edge mode (recognized by calibration) do flash (go to 100% brightness and back in fraction of second) from time to time when dimmed. It is not any kind of flickering, strobing or so, it is just one quick flash and every time all bulbs connected to the same dimmer do it at the same time. I have several dimmers with various LED bulb brands (including OSRAM which I consider one of the best), some with Bypass 2 and some without, but all behave similarly - they flash when dimmed. But frequency of flashes is different for each dimmer, so in other words, all bulbs connected to a single dimmer flash at the same time, but flashes occur at different times for each dimmer (just to rule out some power grid disturbances like ripple control or so). It is also not dependent on time of the day - they just do it like once per few seconds to 10 minutes (so not entirely regularly).

 

But when I force the dimmers to work in leading edge mode (of course the ones without Bypass 2), the bulbs work well without flashing. I had them set like so for more then half year without any issue. I just noticed that the dimmer is a little warm to touch when dimmed - not hot by any means, but just warmer than when turned off or at 100% brightness, but after some research I found out that it is normal for dimmers to get warm. The problem is that I recently got overheat warning after having the dimmer like 3 hours in the dimmed state (not the longest time I ever had, but this time it just overheated). I have discovered that one of 6 LED bulbs connected to the dimmer (about 55 W in total) is flickering when looked at via phones camera). So theoretically it could cause some weird current spikes and heat the dimmer more, but I cannot know this for sure. Also the leading edge as such (based on what I have researched) is causing current spikes when connected to LED bulbs just from its nature, so it is causing more stress to bulbs and dimmer and can cause more heat.

 

So, basically I would like to if anyone have similar experience with flashing or (over)heating, or if anyone have any remarks or theories what could cause what and what to try. I would by very thankful just for anything :).

[Tim__ 112]

Hey there, sounds like you've done a lot of research and investigating already, including reading my tutorial on troubleshooting flickering lights.  You've also had 6 months of flicker free operation which is great.  My Dimmers do get warm but not concerningly so. Given you've suddenly got a problem, and you can see one flickering light, I would suspect that the light has gone faulty and it should be replaced. To confirm, you could disconnect just that one and see if the warning goes away.

[mi38k 4]

Hi @Tim__, thanks for the reply. Sure I have went through your tutorial tips post, it is a great one :). As you suggested, I am leaning towards the setting the leading edge again with the faulty bulb replaced and give it a go.

 

Anyway, I will still be glad for any other experience with dimming the LED bulbs - it might help also others in future.

[jakub.jezek 350]

@mi38k do you have 3-wire (L in, N, L out) or 2-wire (L in, L out) installation? I observed more flickering to 2 wire installations. And better result (flicker reduction) id Bypass 2 is connected near the bulbs.

 

On 1/23/2023 at 10:04 AM, mi38k said:

I have discovered that one of 6 LED bulbs connected to the dimmer (about 55 W in total) is flickering when looked at via phones camera)

I would recommend to play with parameter 38. Also electronics compared to other lights may differ from batch to batch. I have encountered this issue and needed to replace that bulb with one of the cold spares.

[mi38k 4]

Thanks @jakub.jezek. I have 3-wire installation, forgot to mention it in my original post. I have tried to play with the parameter (177 in ma case, as I have Walli version) just a little bit - tried always ON and also few other values. Do you think it would be worth to try let's say all 255 values?