Led lights not turning off completely on Fibaro FGD-212

[tnpet2]

Hi there,

I'm having some problems with the Fibaro FGD-212 dimmer module that my Philips Led lights 3.5 watt (5x so total 17,5 watt) will not completely turning off. You still see that the lights are burning with a very amount of light.
I'm using a 2 wire system, I've tried it with the Fibaro Bypass 2 buth my light goes flicker than and my Fibaro FGD-212 Dimmer 2 is not visible anymore in Domoticz (he will not get any response of the device).

The lights will only go completely off during the Calibration process....

Thanks already for your help!

BR Roy

[niceandeasy]

Take out one LED bulb and replace it with an incandescent light bulb, so your dimmer will see a 'normal' load.

If you try to dim LED-based lighting by using a dimmer in the 230V mains supply, unwanted effects can be expected. Surely when you're operating your dimmer outside of it's limitations: the user's manual of that dimmer states that a LED load should be at least 50 Watts.

The only way to dim LED-based lighting properly is to use a PWM dimmer in the low-voltage DC lines.

[Bikey]

Take out one LED bulb and replace it with an incandescent light bulb, so your dimmer will see a 'normal' load.

If you try to dim LED-based lighting by using a dimmer in the 230V mains supply, unwanted effects can be expected. Surely when you're operating your dimmer outside of it's limitations: the user's manual of that dimmer states that a LED load should be at least 50 Watts.

The only way to dim LED-based lighting properly is to use a PWM dimmer in the low-voltage DC lines.

That is only partly true. Yes, the dimmer needs a minimum load, but I am using this dimmer with two configurations with only 220V led bulbs and even with a minimum of 20 Watts it works fine if you connect the neutral wie as well.

If you use the 2-wire configuration the dimmer gets/"steels" the current for itself from the wire to the lamp so with very efficiënt lamps this can ben seen as a small glow/flickering in the off state. If you have a higher load connected this becomes unnoticeable as the current is distributed over all lamps and you don't need the 3-wire set-up.

[tnpet2]

Hi,

Thanks for the reactions!
I'm going to get the neutral line as well to the dimmer module!

BR Roy

[uppervillage]

Hey guys,
got same problem but with 3 wire setup.
dimmer was connected and lights stayed on 1% even when turned of.
Placed the dimmer between it and the lights went out as they supposed to.
but now when the lights are on they flicker from time to time.
Any ideas?

[niceandeasy]

Well,
I've seen this all, when I was still using 230V dimmers:
- LEDs that don't turn off anymore
- Flickering, from time to time
- 80% of the brightness scale is in the first 20% of the dimmer scale.
- Total failure

That's why I made the switch to 12Volt PWM.
But yea, you cannot always do that in existing light ornaments. In such case, you'll need to experiment with different setups, use different dimmable LED bulbs, use high-quality dimmers with neutral connection (3-wire), operate them within the limits set in the user manual and maybe even add a resistive load.

Some low-quality 230V LED bulbs are lighting up very dimly when off, if they are on a simple on/off wall switch, because of the coupling between the live and switch wires (brown and black) from ceiling junction box to wall switch box.

Flickering might indicate that the ornament has an electronic transformer that is rated for 12V halogen, not LED. So if you're trying to dim an ornament that has a transformer and 12V LED bulbs, originally fitted with halogen bulbs, you might want to replace the transformer.
(as I was told by a lamp salesman)

I have an ornament with 15 12V10W halogen bulbs on a dimmer. I replaced all of the halogen bulbs with cheap 1.5W LED bulbs. The thing turned into a stroboscope. I had to replace 4 LEDs for halogen, to make it operate normally. Even then, every now and then: flickering.
One day, I took it off the ceiling, ripped out the electronic transformer and replaced it with a small 12Volt 3 Amp power supply and a PWM dimmer in the 12V line and replaced the 4 halogen bulbs for LED. And of course, I took out the mains dimmer. Works as a charm, ever since.

[qbic2007]

@niceandeasy : adding a resistive load may sound like the obvious, but electronically it does not make sense.

You would need to dissipate like 20W or more to get the result you want.
A) The power you save from using leds is wasted over this resistor.
B) Also dissipating 20W in heat? Costly and heavy resistor.

The better solution is to put a ~400nF (high voltage, at least 400V) capacitor parallel over the dimming terminals. This will force the dimmer (triac) to open on each fase.
If it buzzes you need a small resistor in series. Some experimenting might be necessary to find the right combination (dimmer - cap - resistor).

No this will not cause a shortcut.
This is the same as the 'fibaro dimmer bypass' and others have inside.

But I agree, 12V PWM dimming is still a much nicer solution, if possible.