Best value solution for dimming/Tunable White

[livingpure]

I really don't understand how this is some help for the thread starter

It shows that light planning is not as simple as it sometimes might seem and allows him to reflect what requirements he wants for his lights.

High CRI without TW should sometimes be a better option than High CRI with TW? Why?

The range of lamps with good light quality, but without TW, is much larger, so you get much more options. It's also possible that mostly you'd like a colour inbetween the TW range and you choose a non TW lamp to avoid the pinkish light. Price might also be a reason.

Be careful when looking at CRI values. Often manufacturers mention just one value, but actually this is only an average of some CRI values. For example R9 is important as it considers "strong red color", but it's neglected for calculating average CRI.

[FrankMaier]

No, I'm not recommending to mix white light out of RGB! For better TW you can, for example, use a warm white AND a cold white AND a green LED

But you can't just put an additional green LED in the room. This green LED must be located on the PCB itself, directly next to each cold and warm white LED. And I doubt anyone here intends to build their own PCB for their lamps. Additionally do you need an adapted dimming curve, ... (probably what's the Pi LED patent is all about) I really don't understand how this is some help for the thread starter.

or something like PiLed (which does not use traditional RGB either)

You're right, they are using red, mint and blue, instead of red, green and blue.

I'd also disagree, high CRI / light quality and no TW can sometimes be a better option than TW (even with high CRI)

High CRI without TW should sometimes be a better option than High CRI with TW? Why? If you can have both, then it's always better. And if you don't want to mix it, then just don't mix it (don't use HCL) and just turn on the cold white or the warm white, depending on daylight or night.

But sometimes there's no need for TW. (maybe outdoor lightning)
And sometimes there's no need for a high CRI LED. (toilet, basement, outdoor lightning, hallway, ... ) (But honestly, for me, high CRI is only important in the kitchen, bathroom and office. But that's also due to the fact, that high CRI LED products are very rare.)

[Crashman]

I like having Tunable White in almost all of my rooms. But yes, in mixed light conditions you can notice a shift to pink using standard 24v TW LEDs. It is visible, but not as bad as you may think. It is more important to me, to have bright and cold white on cloudy days and warm white in the evening. The nearer you are at the native led color (either warm white or cold white), the lesser the pink shift.

[livingpure]

No, I'm not recommending to mix white light out of RGB! For better TW you can, for example, use a warm white AND a cold white AND a green LED or something like PiLed (which does not use traditional RGB either)

I'd also disagree, high CRI / light quality and no TW can sometimes be a better option than TW (even with high CRI)

[FrankMaier]

ergo14 I described my installation in post #2 (centralized power supply, 24V supply cables from the distribution to the MDT LED controllers which are placed on top or close to the LED panels. This requires both the 24V cable as well as the KNX cable to the LED panels.)
You might also consider to install the LED drivers in the distribution, too. That way you don't need the additional KNX cable.
You could also install the 230V line to each LED panel and place a decentralized 24V supply and driver, ... and use DALI.
....

livingpure LED becomes complicated if high light quality is desired.
And high CRI TW is better than low CRI TW or high CRI and no TW and this is thousand times better than 99% of LED installations consisting of low CRI and fixed low color temperature LEDs.
Of course, white light created by mixing blue, green and red LEDs can give the best light. But not with some RGB stripes or other cheap solutions. It's also less efficient and much more expensive.

There will always be something better.

[livingpure]

TW becomes complicated if high light quality is desired as two different LEDs won't be enough to avoid reddish colours in the colour spectrum in between the two LEDs. Hue uses a green LED to avoid this, Kiteo uses PiLed.

[ergo14]

I use MDT drivers.

Can you point me to MDT drivers? Maybe I not understanding things correctly and I'm confused here but MDT LED controllers need to be fed with 24v voltage for leds correct?

And DALI LED driver takes 230V + DALI +/- and then outputs the right current/voltage that matches the luminary, is that correct?

[FrankMaier]

I use MDT drivers.

[ergo14]

That's why I choose the more expensive variant with drivers close to the LEDs. It also allowed me to have a higher cross section in the supply line to each LED group and finer control in those LED groups. But all of this depends on your installation.

That makes sense - can you recommend me some led drivers that you use?

[FrankMaier]

Yes it is safe, a lot of people do it. Most often up to 50m are allowed.

However:
If you intend to use a high PWM frequency it will become problematic the longer the cable is. e.g. Enertex LED Dimmsequencer:
@488 Hz and up to 50m cable length, max current 15A
@1200 Hz and up to 50m cable length, max current 7A

Regarding cross talk:
No idea. I haven't seen any well-grounded statements. I personally don't like the idea of having an unshielded high current high frequency cable across my room. That's why I choose the more expensive variant with drivers close to the LEDs. It also allowed me to have a higher cross section in the supply line to each LED group and finer control in those LED groups. But all of this depends on your installation.

[ergo14]

Thanks, I'm not an electrician (a specialist will do the wiring for me) - is it safe for me to use 24V strips and luminaries having the dimmers in cabinet? The cables all go together in big bunches there. Is cross talk something I should worry about? I don't think the furthest cable should exceed 30m - most of them should be shorter.

[FrankMaier]

My approach for tunable white with HCL: KNX only

Central Enertex LED Power Supply (160W, 100 Euro)
MDT LED Controller (AKD-0224V.02 (1 TW channel, 100 Euro) or AKD-0424V.02 (2 TW channels, 160 Euro)) close to the LED. (One could also use the REG variant, which is cheaper.)

In the end, however, the price will be similar, maybe slightly cheaper than DALI.

[ergo14]

Hi,

In my house we want to have about 12 circuits with dimmable tunable white lights, preferably implement HCL, some night time lighting.
All the luminaries would be LED based, my wife wants the dimming to be smooth and good quality. Some circuits would consists of 3-4 led tubes (probably with Deep TW Constaled), some would be some bigger hanging luminaries, two led strips.
Everything is wired in a star and the luminaries have 5 wire cables available - the destination to the electrical
cabinet should be between 10-25m.

I've been reading a bit about possible approaches here and it seems that to me that the most common approach would be to
use DALI or DMX.

And for that if I understand correctly I need to have a DALI gateway + a 2 channel TW DALI led driver like EldoLed or Lunatone for each circuit.
So for ~12 circuits it seems to me that I'm looking at spending ~1200euros just for the controlling part.

- Are there other approaches that I'm missing? I've been reading about LED controllers and Meanwell KNX drivers, maybe there are others I'd like to avoid 2 buses if possible.
- Can I put all the drivers in the electrical cabinet if the lights would be 24V - all the cables would be bunched together? Or should I put the drivers in the ceiling - I don't have much space approx. 7cm there.
- Maybe Philips HUE would be cheaper - if so how can GIRA X1 controll it, can it access Zigbee bridge?
- What happens if one of light sources break - I then need to get exactly the same type of source - and can't mix anything otherwise something might burn/get damaged?