C-Bus and LED Dimming using Tridonic Ballast

Hi,

I am new to this forum and very new to the C-Bus scene.

I am trying to put together a C-Bus system which is capable of dimming an LED light fitting. The LED light runs at a 700mA constant current @ 240V and I believe the Tridonic LCAI 030/700 one4all ballast is able to serve the purpose.

The question is how i can interface this ballast using C-Bus.

I figure i would need a C-Bus L5508RVF 8-channel relay (there are 5 lights in this room) + a C-Bus L5504Auxiliary contact unit which has connection to the C-Bus light switches.

Am I able to just connect the tridonic ballast to the 8-channel relay or do i need additional hardware?

Many thanks
J.L.

 

Hello JL
Is this the one you are looking at?
http://www.tridonic.com/com/en/products/7002.asp
It does DSI, Dali and switch dim.
If you go down that path my preference would be Dali but it's a whole new concept if you've never done it and quite a bit of work to program the ballasts.
I would not think they are suitable to connect to a C-Bus relay since the "All 4 One" units are designed to be powered all the time and switched by one of the 3 methods I mentioned.
If you have no existing C-Bus you might want to look at the switch dim wiring arrangement and use a 30 series momentary mechanism for on off and dimming.
http://www.tridonic.com/com/en/download/data_sheets/DS_TALEXXconverter_LCAI_30W_en.pdf
Before you get too excited you may want to check price and availabilty also.

 

It sounds like you have an LED lamp that requires a constant current supply of 700mA @ 24V (not 240V). If you're only looking to switch it on and off (no dimming) then there are a lot cheaper options out there than that Tridonic ballast. All you need is a 700mA constant current power supply, and these can be had fairly readily for not much money.

The only reasons you would use this Tridonic ballast would in the cases where you want to dim the LED using DALI, DSI or the switchDIM input. With this ballast you have those 3 different options for interfacing. This ballast isn't designed for having it's power turned on and off to switch the load, as would be the case if it's inputs were connected to a C-Bus relay unit; it's designed for being permanently powered and having one of it's control signal inputs tell it what to do.

If you want to learn all about DALI, then you can use that interface. The corresponding C-Bus interface is the 5502DAL C-Bus DALI interface.

If you don't want the hassle of configuring a DALI network then you can use the DSI interface on the ballast with a C-Bus DSI Dimmer, however this is an expensive solution.

You might be able to connect a C-Bus relay up to the switchDIM inputs on the ballast, giving you on/off and dimming control of the lamp, but you won't get any status feedback onto C-Bus if you go this way, so C-Bus won't be able to tell you if the light is on or off.

The C-Bus switches communicate with the C-Bus dimmer using the pink C-Bus cable, so you don't need the L5504AUX Auxiliary Input Unit. It would only be required if you want to use some other non-C-Bus dry contact switch to also control the lights.

I think you've probably figured out by now that this is not the way to go. If you don't want to dim then your best option is going to be a simple mains-powered constant current LED driver, with it's input connected to a C-Bus relay. This will be cheaper, simpler and more reliable than the Tridonic ballast, as the Tridonic ballast is really intended for use with a DALI or DSI control system.

 

Thanks DarylMc and Newman for your help.

@DarylMc: yes. that is the exact same ballast i am thinking to use. According to the LED light manufacturer, that ballast is the suitable one to use for dimming purposes.

I am also aware of the switchdim feature and i have successfully implemented that previously using the standard clipsal bell switch....but this is not so suitable for my current situation.

@Newman: Thanks. I now understand that the ballast is designed to be always powered on and not switch on/off by C-Bus. So i guess my strategy has to change a bit.

This is for a hotel room application. I need the LED lights to be individually dimmed and i wanted to have a key tag control device inside the room that will automatically kill the LED lights when the key tag is removed. I also need a bedside control panel to control all the room lights at one location...hence i feel C-Bus is the best way to achieve this...although not with the dimming control of the LED lights..

Any other ways i can achieve this objective? I am open to any suggestions.

Thanks again
J.L.

 

I would connect the key card switch to a C-Bus Bus Coupler with Scenes. When the card is inserted you can set a scene to set the appropriate lights to the desired levels and, when the card is removed, turn all the lights out with another scene.

Regarding the bedside control panel... what you use will depend upon the constraints imposed on you by the job spec and what exactly they're looking for. It could be ordinary C-Bus Switches, it could be a DLT, it could be a Touchscreen or it could be a custom switch panel with dry contact switches all wired up to an auxiliary input unit. Any of the above will work.

For the dimming of the LED light, there are a lot of dimmable LED lights out there that will take a regular phase-control dimmer supply, saving the need for an intermediate control system such as DALI/DSI/DMX. There's a lot of variation in how well they dim though, so test first carefully before making a commitment to buy too many. LED lights that are phase-control dimmable will certainly be the simplest to install and could work out to be your cheapest option too.

If you have no need at all for dimming then an off-the-shelf constant current LED driver wired to a C-Bus relay would do the trick.

 

Thanks Newman. U have given me a lot of ideas to go forward.

Does C-Bus have any dimmer system as part of the product range? perhaps i can find an LED light that can work with C-Bus's own dimmer.

 

Hello JL
I havent used any led lighting myself but if you search the forum for led you will find a few threads about various led fittings and their operation on C-Bus dimmers.
What sort of led fittings were you looking at?

 

C-Bus has 4 and 8 channel Leading Edge as well as a 4-channel Universal dimmer that are DIN mounted. There are other larger capacity dimmer families available in the C-Bus range but I suspect they're not really what you're looking for.

A couple of posts here and here that discuss dimmable LEDs. Search and you will find more.

 

@Daryl: I am looking to use the 3S LED downlight...it is a sydney based company..dont have the catalogue with me right now but i was told it is a pretty good LED fitting...and reasonable price too.

@newman: I will research those threads this weekend. Thanks for your help again.

 

Hi Daryl,

I'm heading down the same path myself, and got an experimental setup going. You can connect a C-Bus DALI Gateway directly to the Tridonic driver, which then connects directly to the LED lamp. You will need a DALI USB interface to program the addresses of the DALI drivers.

The drivers are hard-wired into the power, standby power consumption is 1 or 2 watts, so work out whether that is a significant cost. Conversely, avoiding an intermediate dimmer probably increases efficiency when the light is on.

An alternative to Tridonic is eldoled, the distributor is cutter.com.au. These may have better economics as they have multiple LED output terminals. I'm just talking to them now, haven't actually tried it.

I'm interested in other comments on this approach and anyone who has put it into practice...

 

Hello Russsh
I have a site with 50 dali ballasts running 18W fluros in downlights and oyster fittings.
The power consumption while the lights are off is a concern and while I havent actually measured it the customer is quite satisfied with the power bill.
With Dali, the saving on switcboard real estate is significant.
It promises real savings in wiring since you can loop from light to light, as many as the circuit will take up to 64 fittings.
Then a second circuit can control another 64 and all within 4 din modules worth of CBus equipment or 8 including power supplies and the breakers.
I wasn't game enough to wire the lights that way in case some other method of control was required in the future, so I ran the 5 cores out on a per room basis.
Support for programming the ballasts at the time was hard to find but I did get some good help from Tridonic.
One of the several issues I had was resumption from power loss.
Some of the ballasts could be programmed to resume in the off state and some would always resume in the on state.
Tridonic told me their new ballasts have that feature but it would certainly pay to ask.
CBus is rectifying the state of the lights after power loss now but it takes quite a few minutes.
Another issue I came across was because I used a dali group address for the rooms on top of their individual ballast address.
I have some trouble getting the right status feedback if I want to say use the touch screen to kill just a few individual lights in a room.
The reason I operate the rooms as Dali groups was because I was using standard key inputs and it was the only way I could think of to turn on 10 lights at a time.
There is probably a way around that but I haven't got to it yet.
Also the response to dimming can be problematic since you have a ramp programmed in the CBus key iput and a Dali ramp programmed into the ballast.
I have ticked the CBus Dali Interface match ramp rates and it is not too bad but I think there can still be some jumping of the level after you release the key.
If the job required ramping to a level for scenes etc this would not be a problem.
Aside from these issues the customer has ended up with energy saving dimable lamps and not even a lamp failure in 3 years.
I think Dali ballasts could go quite well with LED since you have a control method which doesnt require compatability to any particular type of dimmer.
As you say the cost might become more reasonable if you can drive multiple fittings.
Good luck

 

Standby power is 1-2W ? what kind of driver? I think it is not well designed.
usually the standby power of ballasts or driver can reach 0.1-0.5W easily.

 

Hello Russsh
Thanks for the link.
The prices seem good for those drivers.
Which one were you looking at and what are you going to use for the DC supply.

 

Hi Samluo, that's what is quoted for the Tridonic drivers, for a "LCAI 50 W 1050 mA N020 DALI" it is quoted as "< 2W". Which drivers are you referring to? Are they available in Australia (with regulatory approval)?

Thanks DarylMc for a few things to watch out for. Regarding Eldoled - I'm looking at the ones with integrated AC input (SOLOdrive and DUALdrive) so they shouldn't need a separate AC to DC supply. Best to ask them directly regarding approvals though.

 

Less complicated way to dim a LED

Hi JL
from your intended use: a hotel room, I think that installing a mains dimmable LED on a C-Bus L5504D2U, with C-Bus providing input signal control will be a lot simpler solution. If you use Dali to do the ballast (output) control then, you still need something "nice" to do the input control, you may need a whole different program. There's not as much variety/ options in the Dali input control as you have with C-Bus, and in a hotel how it looks counts.

Essentially the mains dimmable LEDs have been designed to simply retrofit dichroic/ halogens on a "ordinary" dimmer in a domestic situation. The good ones though are suitable for commercial installations where they will typically run longer. They have a purpose built DC driver which is critical to the longevity of the lighting system. Make sure you get a warm white 3000K colour, again because how it looks counts. There are a plethora to choose from and I have tested many. Many of the more common ones would not satisfactorily dim with only 1 unit connected to a new trailing edge dimmer. The best I've found so far are:
Lumitex Baricade http://lumitex.com.au/products/led-downlights/ ( A local Perth company for you)
LED Lighting EVO50 http://www.ledlighting.com.au/EVO50.html
Both are from reputable companies and I have used the products on commercial projects. Both are about $80ex GST at selected wholesalers.
That way you can keep it simple!

 

I see the driver have many function,0-10v and more. usually DALI driver can consume less than 0.5watt in standby mode. good design can reach 0.1watt.