Help please - DALI a good idea for a new house?

To be able to reliably dim LED's, and to simplify wiring set up, would it be a good idea to set up a new house build with C-Bus plus LED's on a DALI, with a gateway C-Bus to DALI? Or is this unnecessarily complicated for just a house. What disadvantages would there be.

And I guess cost would be a problem - very approximately, how much would a LED downlight plus DALI dimmable driver be?

Many thanks!

 

Hi MSupp,

You should check out Clipsals new SILC system, its just been release and might suit what you are trying to achieve and be cheaper than a full cbus / dali setup..

Cheers..

 

Hi Msupp
It is not difficult to find CBus dimming compatible LED downlights.
They have been available for years from companies like Pierlite.
Using lights with specs and following the specs is easy.

When dimming fluros, DALI is a good choice.
Large format LED downlights and high end dimmable LED oyster lights exist.
They are not cheap but DALI is the common control system.

Aside from initial install, maintenance costs need to be considered.
As you probably know each DALI fitting has its own DALI addresses and programmable settings.
The homeowner has to be prepared and able to find someone to program a replacement fitting when it breaks.

The DALI ballast is more expensive to purchase as well but this can be somewhat negated by reduction in CBus output units.

Another thing which could be seen as a DALI disadvantage is when it comes to ramps and push button dimming.
For push button dimming CBus has to pass the commands to the DALI bus.
In my experience the ramping is nowhere near as smooth and controllable as push button dimming using CBus dimmer output units.
For dimming such as scenes or perhaps a slider on a touch screen where the lights are ramped to a level this is not a problem.

A couple of plus points for DALI is the huge reduction in switchboard real estate required.
Potential for reduced cabling.
The ease of installing extra individually controlled fittings if required later.

 

If you want to dim LED strip lighting then I've used successfully on a few jobs the DMX controller. If it is LED downlights then DarlyMc is spot on.

I set it up so the power supply is controlled by a relay so when the lights are off they are off at the relay, not just the DMX off state. This saves a bit of power and should increase your power supply longevity. Just link your DMX dimming group to the logic in the relay and the macro dimming function in toolkit makes you LED strip work like any normal dimming light - no response time lags I've noticed.

The power supply connects into a DMX control box which has a single, daisy chained, cat5 cable linked from the cbus DMX controller to to all areas of the install which needs dimmed LEDs. If its a new install then the extra DMX cable is usually insignificant to run. As mentioned I use cat5 and have no issues with runs around 100 meters - cheap. You can also use a more heavy duty DMX cable.

The cbus DMX controller has 12 channels; a single White LED run only needs one channel - so you can have 12 areas dimmed separately if so desired.

DMX control boxes are cheap and DMX integration is easy to do from toolkit.



More LED discussion here - http://www.cbusforums.com/forums/showthread.php?t=7166

 

Hi Ambro
The response I was talking about with DALI specifically relates to push button dimming.
Do you use pushbutton dimming on your DMX?
I thought it might be a similar result.

 

Hey DarylMc,

Yup; a normal dimming macro from any key input unit to turn on a relay and dim up a DMX channel seems to work the same as a dimmer module in regards to lag.

However - I've found all LEDs always have to be tweeked at their low end so they don't 'jump' into their ramping up - which gives the illusion of lag when dimming from off. Most LEDs I've used start in the range of 5-15% power load before they start to shine.

 

DMX is a (relatively) fast streaming protocol and so has much less of an issue with things like ramping, compared to DALI. Basically that is what DMX was designed for, DALI on the other hand is a slow command based protocol, so once you take C-Bus that is also a slowish command based protocol and have it control another slow command based protocol you get awkward things happening with real-time ramp commands.

 

In terms of the OP,

I use DMX for all LED control, unless it is in an office environment where the 'remote' re-addressing abilities of DALI is more suited to that and dimming isn't such an issue.

Have a look at this thread as well:
http://www.cbusforums.com/forums/showthread.php?t=11837&highlight=DMX

J

 

Thanks jboer - good info to know, I learnt something new today

 

Hi jboer
Thanks for that information too.

 

Clipsal load correction device can solve these problems with some drivers.... especially if you only have 1-2 LEDs on a circuit.

http://updates.clipsal.com/ClipsalOnline/Files/Brochures/A0000268.pdf

 

I've not tried DMX, but DALI works very well in this situation from my experience.

0-10v is another option, but I've not had good results. Jumpy/stepped dimming, non linear and the lowest setting is typically 10%+

 

Also reduced 240v cabling costs, especially if you have a lot of circuits and the switchboard is not close.