Best solution for dimming LEDs

Hi folks,

I've just put some 16W LED down lights with Tridonic dimmable drivers on an L5508D1A. The performance isn't great - dimming is OK, but I occasionally get boughts of flickering (more like pulsating) in the evenings.

Is there a good solution for dimming LEDs on CBus? I'd prefer to keep the dimmer unit, so I was thinking it may be worth trying a Clipsal 5001LD driver. If not am I better of with a universal dimmer or a 0-10V analogue output unit?

Cheers,

Jon

 

A question with no answer

Hi jonw
There is no "best" solution.
The solution depends on the either the dimmer type OR the LEDs & Drivers you have- there are soooo many variations, and how much you want to spend v's how much hair you want to pull out.

LED is NOT and Incandescent light source. Phase cut dimmers were made to control variations of an Incandescent light source. LED is not "plug & Play" as an incandescent light source was.

LED manufacturers are trying to make dimmable drivers that work on phase cut dimmers, but as they were not originally designed to work together, so often there are annoying side effects as you are experiencing.

The L5508D1A is an leading edge dimmer, so you need to find a driver that will work with a leading edge dimmer. That is in an ideal world.
As product development is moving so fast, a brand that worked made last year, the same part made this year, may not work.

So the recommended action is find and test an LED luminaire and matched driver that will work on your dimmer type.
From memory these should work:
Pierlite starburst, LED lighting Evo 50, Gamma (most models) Earlier Osram (check current). The best is supposedly the Lumitex Baricade.
I would expect the current Clipsal ones work on their dimmers too.

Happy lighting

 

Hi Jon

Could you please give a brand and product number of the LED's and drivers which are flickering.
Someone might have had experience with the fittings.

Even if they haven't I'm sure it will be helpful to everyone here.

I don't have a lot of experience with all the various brands of LED.
But I do have some Pierlite Starburst Star2 3000K in my office and a bedroom.
The light output is reasonable compared to a 50w halogen (700Lm).
Pierlite has excellent listings for approved dimmers and number of fittings per channel.

The 10 fittings have no problems with dimming or flickering on the 8 channel leading edge dimmer.
They have run without any failures for 2 years now.


Regards
Daryl

 

Hi JonW,

......and if all else fails, you can possibly try one of these.

Regards,

Brad

 

Thanks for the advice guys. I ended up getting a couple of the 31LCDA load correction devices to try out, and they've made a significant improvement.

The LED downlights are from Wattsaver - they're DL7-1400s. Stephen @ Wattsaver has been really helpful getting this set up, and he's keen to have a product that works well with C-Bus. He lent me a mix of different colour temp units with different drivers to try out. I like the colour of these lights (I've got the Natural white 4000-4500k units) and they're seriously high output, so I'm keen to keep these units rather than go with an alternative manufacturer.

I'm using their premium driver, which is a Tridonic unit. As I pointed out before, when I had four drivers on a single channel, I'd get flickering fairly regularly. That seems to have been resolved by the LCDs. Also, the dimming range has improved - for example, I have an input programmed with two keys for on/up and off/down. Before I installed the LCDs, dimming down too far would switch the lights off, but now it just dims to an acceptably low level. I had programmed the ramp rate to immediate on/off to avoid the flickering during the ramp - I'll set that back to a 12s ramp now and see how that goes.

I've also installed an LCD on a circuit that has some cheap LED GU10s from ebay, also connected to a dimmer channel. They were still glowing when switched off, and that seems to be fixed too.

Cheers,

Jon

 

Good to hear that about the 31LCDA, Jon.

I found if I have 3 or more GU10 ebay LED downlights, none of them flickered when the dimmer circuit was off.