My dimmer melted on a load of 25W

[apmadsen 0]

This morning, a circuitbreaker went off, and at first I just turned it back on. It was first when I noticed, that I couldn't turn off the lights that I decided to check out the dimmer, and what do you know - it had melted (see attached image).

Now, the load was only at around 25W, which is 1 x bypass module, and 2 x Philips LEDbulb D 12-60W E27 2700K A60 (MASTER), so why did this happen?

I've noticed that the bulbs produce a significant humming/buzzing, both when used with a dimmer or a constant load, but could this have an effect?

I'd like to hear if anyone else have any experience with melting dimmers, and/or the LED bulbs. I cannot be the only one fearing electrical fire, can I?

Please login or register to see this attachment.

[hvb83 1]

I remember there was somebody else on here who also had a melted dimmer. If I recall correctly he also had LED's on it. Don't know if that has something to do with it?

[Guest spazpeker]

has one of your bulbs developed a dead short ?

[apmadsen 0]

Well the bulbs are working fine now, so I don't think so, but as I wrote, they are doing an annoying humming, so I won't rule out the bulbs being the culprits.

I'm using other dimmers without problems:

1: 4 x 42W halogens

2: 5 x 4W LED + 1 x bypass

3+4: 1 x 100W incandescent

[Dalle1985 16]

It is the interaction between the LED and the TRIAC dimmer. In my opinion, triac dimmers should only be connected to purely resistive loads (ie. Incandesent bulbs).

With this type of light, you are constantly pulsing the bulb on and off and each time it is turned on, the load will spike to a very high load. This can damage the TRIAC in the dimmer to the point where the tansistors break down and let through a huge current... Which makes it melt. The high current is also the reason for the noise in the dimmer (it will always make a noise, but it should not be noticeable in a normal wall mounted install.

If you want dimmable LED bulbs, buy Hue bulbs or use a dimmer purposebuilt for it. Because this CAN happen with any triac dimmer.

**EDIT**

I've added a picture describing what I'm trying to explain above. Basically, each time the TRIAC cuts the power at opens again, the lamp will draw a large current and then settle out. This isn't a problem usually as the spike is very short and only happens when the lamp is turned on. But as the dimmer turns it on and off 100 times pr second (in europe, 120 in the states), this creates a huge load on both the dimmer and the lamp itself which will have a significant shorter than normally expected lifte.

Please login or register to see this attachment.

[apmadsen 0]

Well I actually tested and confirmed noise in a normal wall mount yesterday, so I'm not so sure that the dimmer is to blame.

Also, the setup with the small Philips LEDs are working fine...

[Guest spazpeker]

i have 9 fibaro dimmers all connected to meggaman 6w LED bulbs, one of the dimmers has 30 bulbs connected and works fine

i have had one bulb fail and this caused no damage to anything else

[deanrparry 19]

I had 3 x gu10 50w halogens take one of my dimmers out! Not even led!

[hkmod25 0]

It is very interesting.

If you looking on official Philips WEB site for this lamp, they say that unit can be used "with most leading edge (triac) dimmers:

Please login or register to see this link.

But. Here is pdf for recomended combinations:

Please login or register to see this link.

As you can see from the list: ELKO RS16/400 GLI PH dimmer marked as NOT compatible.

But from ELKOs own manual it is an Leading-edge Triac based dimmer unit:

Please login or register to see this link.

I think, Philips are not correct here...........

[UrSv 6]

Well, "most" does not include all dimmers so Philips may very well be correct...

[deanrparry 19]

Best check my smoke sensors

Please login or register to see this image.

/emoticons/default_icon_smile.gif" alt=":-)" />

[Guest Kuuno]

Read the second page. Also other modules...

[ivan.ruban 3]

I remember there was somebody else on here who also had a melted dimmer. If I recall correctly he also had LED's on it. Don't know if that has something to do with it?

Thank you, hvb83, for mentioning it. It was actually me who had problems with dimmer connected to LED+bypass. My post is here:

Please login or register to see this link.

I appreciate if somebody can write a comment in this topic to move it up. I cannot do that since I was the last person who left a comment.

The funniest thing is that I got my second melted dimmer+bypass yesterday!!! Details are in the last comment. And now I have just found your post as well - interesting coincident.

Please login or register to see this image.

/emoticons/default_icon_wink.gif" alt=";-)" />

What relates to dimmer, both my dimmers got stucked after this. In the first case it stucked in "always on" position, in the second case from yesterday in "always off". I had no humming/buzzing at all in my case.

What relates to LED lamps. I have checked in the first case and the LED still works. But what is different, LED flickers a bit when it is ON now. Anyway I sent LED also to Fibaro and hope they will investigate. Nevertheless support adviced to send dimmer as a warranty request. Thus I don't expect any investigation in reality.

Please login or register to see this image.

/emoticons/default_icon_sad.gif" alt=":-(" />

In my case I blame LED or bypass. In both 2 cases bypass was short cuted! apmadsen, can you check with ohmmetr if it is the same in your case? It can be actually a bypass causing the problem.

But of course it can be also a LED. I tried to find the specification for IKEA dimmable lamp, that I use, in order to check if it's compatible with Fibaro dimmer. But I have not found any specs unfortunately. And in IKEA support they have not understood what I want from them

Please login or register to see this image.

/emoticons/default_icon_biggrin.gif" alt=":-D" />

has one of your bulbs developed a dead short ?

In my case the lamp is working, it is bypasses with dead short in both case. That's why I also suspect bypass actually.

It is the interaction between the LED and the TRIAC dimmer

In my case as I wrote there was no strange noice. Nevertheless I assume my LED lamps can be incompatible with dimmer - you comment and diagram explains quite clear why we can have troubles.

I had 3 x gu10 50w halogens take one of my dimmers out! Not even led!

Hmmm, than we have a candidate N3 whom we can suspect! Dimmer!

Another funny thing is that I use this dimmer

Please login or register to see this link.

with absolutely the same IKEA lamp. Dimmer costs 19 euro and works already for half a year. It uses also no neutral, has a local switch. The only difference is another wireless protocol - 433Mhz, which is a single-direction simple protocol in comparison with ZWave. Antother difference, dimming is not as linear as in Fibaro dimmer. But otherwise it's a cheap wireless dimmer that works with 10W LED without any bypass as a charm and is fire safe.

Please login or register to see this image.

/emoticons/default_icon_mrgreen.gif" alt=":mrgreen:" />

[apmadsen 0]

Okay, I just rechecked the LED humming, and it seems that it's only noticeable when connected to a dimmer, and not when connected to a relay or a simple wall plug.

I checked the bypass, and it showed an impedance cycling from 0 to 10K Ohms - I guess this is normal for an IC circuit, right?

[Dalle1985 16]

I can only repeat what I have already stated, dimmers and LED bulbs should not be used together unless dimmer and light has been designed together. It is correct that the bulb power supply is also a TRIAC type component, as this is the main power supply for electronics connected directly to power mains. But the mode of operation is different for the bulb and dimmer. And it is the interaction between these two components which might cause problems. What i wonder is how the bypass works. If that is just a resistive load, it will reduce the harmonics between lamps and dimmers. If it is some piece of electronics, it might just make things even worse.

[apmadsen 0]

What i wonder is how the bypass works. If that is just a resistive load, it will reduce the harmonics between lamps and dimmers. If it is some piece of electronics, it might just make things even worse.

Well I think it's some kind of IC circuit, because the impedance cycles from 0 to 10K - but then again, my electric knowledge is fairly outdated so, it might be something else.

However, I can say that the dimmer works really well with Philips LEDLuster bulbs. I currently have 2 configurations: 5 x 4W E14 + bypass and 4 x 4W E27 + bypass.

Funny thing is, that while they are rated as 25W equivalent, my opinion is that they are almost as bright as 40W...

[ivan.ruban 3]

I can only repeat what I have already stated, dimmers and LED bulbs should not be used together unless dimmer and light has been designed together.

Thanks Dalle. I also thought about incompatibility between LED lamp and Fibaro dimmer from the beginning. That is why I posted a question in my original post "Anybody who used LED+bypass for a long time (>6 months)? What lamp model do you use?" I hope people can share names of their lamps that works stable with dimmer. We are all interested in that!

But since still nobody commeted my post

Please login or register to see this image.

/emoticons/default_icon_sad.gif" alt=":-(" /> , it means nobody will se my question. The post I meant is:

My post is here:

Please login or register to see this link.

I appreciate if somebody can write a comment in this topic to move it up.

Anyway, I created another topic instead and hope to collect some answers there :-> :

Please login or register to see this link.

However, I can say that the dimmer works really well with Philips LEDLuster bulbs

Thank you very much! Now I know which lamp I will test the next.

Please login or register to see this image.

/emoticons/default_icon_wink.gif" alt=";-)" />

[Dalle1985 16]

I think it might be down to small errors in the electronics of either component. It might be something that doesn't call for the component being rejected, but the two components together interact together in a way that causes problems. I only know that it is not seen as good customs to mix a triac powersupply and a triac dimmer. 9 out of 10 probably won't be a problem... But it might be the 1 out of 10 that lights your house on fire.

As apmadsen wrote, it took out his circuit breaker. This is because the circuit breaker was overloaded by a huge power spike.

[apmadsen 0]

On a side note: Has anyone experienced short single flickers when using the dommers? As it happens ultra fast and in my peripheral vision, I'm not entirely sure that the lights are the true source, but I could swear that it has happened several times, with both normal and LED lights.

[biggles 0]

Sure, I have the ultra fast single flicker from two of my dimmers. Both are from the newer batches.