Newbie Hardware Question/s

I apologize for the simplicity of these questions and if this is not the correct forum for such a post.

I plan to install a CBus system in my home. I am currently renovating, so it will be a retrofit. I plan to have a new electrical meter box installed with a distribution panel in the laundry, and had planned to install the CBus system next to the distribution panel in a DIN enclosure. I have a few questions regarding CBus hardware selection.

1. If I wish to control (dim) say 7 or 8 low voltage halogen downlights and have them on the same circuit - should I be installing for instance the L5504D2A or L5504D2AP rated at 2 amp per channel (4 channels) versus the L5508D1A or L5508D1AP rated at 1 amp per channel? (I guess it depends on the type and number of transformers I plan to use). Do I use 1 transformer per halogen or do I use 1 larger transformer to drive the 7 or 8 halogens?

2. What type of relay unit would I use to control my pool pump/filter? Do I have the pool pump/filter hooked to a suitably rated GPO which is then switched using a suitable CBus relay?

3. Is it possible to control the automatic water level pool pump with CBus; that is, have the pool water level read by CBus and when the pool water level drops to a particular level to have the pool filled automatically.

Thanks in advance, and again sorry if this is an inappropriate post.
D

 

Dak,

Your questions are quite valid for someone starting out with C-Bus. You've at least done your homework. Everyone does things differently as there is always more than one way to skin a cat. For my home installation:

1. I use L5504D1A with 240V, 50 W halogens. There are pros and cons for using 240V halogens. Check out these threads.
http://www.cbusforums.com/forums/showthread.php?t=89&highlight=240v+halogen

http://www.cbusforums.com/forums/showthread.php?t=1020&highlight=halogen+240V

For me, I don't want transformers as they are another thing that can go wrong and I also don't have to worry about the transformer being compatiable or not with the dimmer. This means that per channel I can safely connect 4 x 50W halogens (Total of 0.84 Amps) per channel. I've never looked at the efficiency of the 12V transformers so I couldn't tell you whether it is safe to connect 4 or not to a 1 amp channel. Lots of people will have done this and can provide advice.

2. I've got my pond pump connected to a GPO activated via L5512RVF. That way if you need to maintain the pump you can easily disconnect it.

3. I'm far from a CBus guru, but I am struggling to think how you would control the pump via levels without using the Logic engine in a PAC or Colour C-Touch. The problem is that you need to "latch" the output on when the level is low and "unlatch" when the level is high. Someone will have done this before. You can buy cheap dedicated controllers to do this. If you use a PAC you would connect your levels via an auxilliary input unit. L5504AUX.

And of course you will get a licensed electrician to at least connect all of this up for you ....

Cheers, CC&C.

 

Thanks CC&C for the reply and for the info regarding pros and cons of 240V vs 12V Halogens. I think I will go the 240 V route as you say it will provide one less thing that may go wrong.

And yes I will definately have my electrician wire the relays / dimmers / loads etc, I'll have a go at the low voltage side of things. Its just that I like to have everything clear in my mind, so that when the electrician suggests anything I can converse with him with a little knowledge under my belt.

Thanks again.
Dak

 

Gday Dak,
Theres pro and cons for the LV and 240 V Downlights.Only what ive found but i would be careful using 240v in high use areas . Any lighting rep . not a light shop sales person will probably tell you that the globe life can be a problem due to the heat thats generated around the lamp . We have 40 x 3 light rails instaled in a commercial situation that the client supplied the lighting for against our advice . They are now paying the price, they are forever replacing globes and are sorry theyt put them in.By al means use them for your project but be prepared for the sparky to not be very sympathetic if you have problem with fitting that you supplied.
When selecting LV Fitting for cbus jobs please consult your sparky befor purchasing to avoid a Problem called capactive loading on the dimming channels . All tranformers have different loadings that vary from 33 nano farads to 150 nano farads,some even worse. I think from memory din mount dimmers have a max cap loading of 300 nano farads . Over loading of the channels causes instability inthe dimming of the channels , They flicker like candles when you dim them down.I Have had a experience recently when the builder supplied the Lights for a job and asured us that the tranis were compatible . however the tranis he supplied after investiagtion when the problem developed had a cap loading of 100 nano farads so it doesnt take many to over load the channels.Trust me it easier to pay a bit more for a good trani ( 33 Nano Farads ) and avoid all problems all together

 

Two quick notes

First on LV versus 240V halogens, there is both a colour temperature difference and a focus difference on these two sorts of lamps, I find the mains versions as "insipid" compared to LV. Whether that matters or not is, of course, a personal opinion. I mostly only notice it when the two sorts are near each other...

Secondly, in terms of controlling odd stuff like pool levels, although you have CBus it may not be the most cost effective, simple, or understandable (read long term maintainable) approach, I'd advise you to evaluate a tradeoff against those cheap small PLCs that enable a fit and forget solution to be built. If integration is needed just use relay contacts between the two control systems. Examples of makers of these ickle PLCS include Siemens Logic!, Crouzet, perhaps even Schneider (owners of most of Clipsal) have one these days... yep, found it, the Telemechanique Zelio Logic. Or perhaps someone makes an off-the-shelf box?

 

Thanks for the additional comments Nick and dbuckley.

Nick: The install is a residential environment, not commercial, however I guess there is still a difference between high, moderate and light use even in a residential application. I have a dedicated theatre room which is taking shape (renovations - very slow process), I guess it would be a "light" use area as most of the time the lights will be off. There is a large play/pool room which I would like to have illuminated quite well - and I too have noticed the light "quality" between the 12V and the 240V halogens. It seems a much "cleaner,crisper" light from the 12V - perfect for the play/poolroom. Other areas would probably fit into the moderate use category - so lamp life is of importance.

I assume that the ATCO Possum transformers are OK to use as they are in the "recommended" datasheet from CLIPSAL.

How big physically are these transformers? Does anybody have any comments on these transformers?

Obviously it will be important to maintain accessibility to these transformers in case of faliure! Ive had my upstairs LV Halogens installed for approx 4 years and have changed the odd globe, but not had a problem with a failed transformer as yet.

dbuckley: thanks for the comments RE pool equip control. Its sounds like its far simpler to find a dedicated pool control system.....fit and forget sounds like a much more favourable outcome.

Thanks again

 

Dak, Just a folllow-up on your pump control via levels. Here is details of a brand that I have used before. Quite simple, not sure of the cost, there are lots of other brands around as well

http://www.multitrode.com.au/products/level_relay_alarm/overview.cfm

I agree with the comments about colour and globe life with respect to 240V vs 12Volt. I made my decision with the assumption that 12 Volt Halogens gradually improved in colour and globe life and I'd anticipate that 240V (being relatively new when compared to 12Volt) will also improve with time as well. I also note that in 5-10 years time we'll mostly be using LED's anyway. (I already do for some applications.)

Cheers, CC&C.

 

Thanks CC&C.

Had a look at the MultiTrode, looks like it could be just the thing.

 

Have used thousands of these transformers and have not had any problems thus far. Approx size 100mm long 50mm wide 32mm thick and they fit thru a standard 70mm downlight cut-out so access to them is not normally an issue.

On Cbus installs where we don't supply fittings I stipulate that these transformers are to be supplied.

 

240V Halogen = WHAT THE ???

Hi everyone,

I absolutely stunned and amazed that "professional" people who spend time and $$$ on a complex lighting control system like C-Bus would even CONTEMPLATE using GU10/GZ10 240v Halogen lamps !

A comment was made earlier in this thread about "not having a transformer = one less thing to go wrong" - that is utterly mind-boggling. When was the last time you heard of a (good quality) lighting transformer failing ? Compare that with the last time you heard of a C-bus device fail

The 240V halogens are (technical) disaster - the lamp life is terrible (rated 2000hrs, but max 1000hrs is being optimistic in a real-life installation). No professional in the lighting industry would use or recommend them (refer previous comment by (ex?) employee of Osram).

The filament in the 240V lamp is very thin - that makes them fail faster due to fragility and tungsten evaporation (normal use), and they are very susceptable to over-voltage too. The 12V filaments are thicker and sturdier but also much shorter, which leads to the biggest problem of the 240V... efficiency, light output and beam control.

Apart from the lower operational efficiency, the 240v filament is so "large" that most of it is not within the optimal "focal point" within the reflector. Therefore, you can only get wide-beam 240V, which are rated at around 35 degree beam. The closest common 12V lamp to that is a 38 degee (EXN).

OK - so how bad is the output of the 240V ? Using Osram 2005/06 catalogue figures for Candela (brightness) at centre of beam :

240V GU10 Metal Reflector = 950 cd
240V GZ10 Dichroic Reflector = 900cd

12V Cheapest EXN (Decostar) = 1450 to 1500cd
12V Best Standard EXN (Titan) = 2200cd
12V IRC EXN (current best practice) = 2850cd

Therefore, without going into complex lighting maths - to get similar effective light in the room you need to use 3 TIMES as many 240V lamps as the 12V IRC, or 60% more than the cheapest Osram 12v lamp.

Alternatively, using 20W IRC lamps you get 1000cd (more than the best 240V), so even allowing for transformer losses you can at least DOUBLE the efficiency of the installation for the same light level !

Or, you could use 60 degree IRC lamps (50W 1430cd or 35W 1100cd) and space them about twice as far apart for the same light level...

There is a very good reason why the majority of installations use the "more complex" 12V lighting systems... it's the overall lifetime cost of the installation that matters, not the initial purchase price per unit !

I hope that clarifies it for you guys - if you need further information, advice or assistance please advise.

Cheers, John

PS: I haven't mentioned the poor light distribution, excessive glare, etc from the 240V, that's another problem of them

PPS : Osram are having extreme difficulties supplying IRC lamps at the moment, but let's not "go there" in this discussion

 

I feel sure I should post something here agreeing with what you say, but instead I'm just gonna put on a flak jacket and hide in a hole.....

 

Gee, didn't mean to "open a can of worms".

I really appreciate the input / comments here.

I can only speak from an end user point of view, not from a lighting professional point of view, but there is a real difference (positive difference in my view) in the "quality" of light from the LV halogen vs the 240 v halogen.

As an end user, wanting to install a lighting system which will provide the "best" light quality with as little maintenance for a reasonable price point is of paramount importance.

My concern was the reliablity of the transformers, but after the replies in this thread, and after some detailed discussions with "lighting professionals" on the Gold Coast, the atco possums seem to be as reliable as they come.

The only thing , I think I need to do is to reconsider the number of actual LV halogens I'm going to connect to each channel of the L5504D2A. I think I probably need to reduce the number on each channel, thinking more about it, i've probably gone a little overboard. (Might give everyone severe sunburn whilst the light are on).

I'm a little concerned about the inference about CBus components and their failure rate vs failure rates of good quality transformers. I'm hoping as an end user that the failure rate for CBus components is the same as any other electronic equipment, that is, dependent on the installation quality and the environment that the gear is expected to run in.

Again, thanks for the input.

 

Howdi Dak,
If your concerns had any validity then the noise level raised on this forum would indicate it. As the silence would deafen the most abused ears known to rock music, be assured, there are no known issues with reliability or the quality of C-Bus dimmers.

 

Yeah, thanks Ross,

Talking alot to colleagues who have CBUS installations, and not heard concerns about the reliability. Infact most people who I have spoken to say the system is transparent - just as it should be. "Push the button, and things work"......I guess thats a little simplified, but you get the idea !

Dak

 

Err - thats it.

Thats what spending $$$$ gets you over spending $$.

 

I hope that doesnt become one of those notorious quotes that people use as an example, (like the pink cable in the mortar), when they are trying to say: "wow, that really was a dumb thing to say".

Maybe I should have written "Push the button .........etc"

 

Hi again,

For quality of light, efficiency andmaintainence - DEFINITELY use Low Voltage !

**************

Sorry to create a fuss - I did not mean to imply that C-Bus was "unreliable" - my analogy was mainly to counter the previous post about using 240V and not adding a transformer to make the lighting system more "reliable".

I made the comment about C-Bus reliability because I have a faulty L5508D1AP on my desk - the first one I've seen, but annoying nevertheless. I reckon our company sells between 500 and 1000 x Electronic Lighting transformers per month, and I can't remember ever getting a faulty one (in the past few years at least) !

If only the lamps (or indeed the Mains Power) was as reliable as the transformers !

Cheers, John