Advice on LED lights on my CBUS system please.

Hi all. New member. I have read a number of posts on this topic, but I am not clear on the answers, so some advice from the pros on this forum would be great.

I recently purchased a large home, 5 years old, with CBUS2 in it, and halogen down lights everywhere. Over 200 of them in the home. I have 2 x 8 channel CBUS dimmers, 2 x 4 Channel dimmers, and a couple relays controlling all the lighting. the most amount of down lights on a channel is 8 down lights, which is in the open plan kitchen.

I wanted to look into changing all the bulbs over to LED MR16 as they blow out over time. On the weekend a couple in the kitchen over our sink blew, and the wife always complains about low light, so I though I would try a couple LED's. So I purchased 2 x Philips Master dimmable 7W, 60 degree, 715ma, 4000k cool white globes and popped them in. So these now sit on channel of an eight channel dimmer, with 6 other halogen bulbs on the one channel. So the channel has 8 lights in total, 2 now are the philips led and 6 are normal halogens.

They seem to work well. Nice and bright white as the wife wanted. They can dim down to about 3-4% and right up to 100%. When I get to 4% or lower, One LED seems to be brighter than the other slightly and sometimes only one turns on. Not that that is a problem as we never really dim below 35%.

But my question is, will changing over to LED be a problem for the CBUS system ? Will it cause damage ? Is it Dangerous ?

Can I over time as my lights blow replace all the halogens with LED ?

I would replace with what potentially is considered quality product - Maybe Philips Master or the eqiv Osram. Lights not on a dimmer and just a relay, I might try the more generic Philips Essential globe as there is no need to pay for a dimmable globe. If it is OK to go with LED MR16 globes, do you guys suggest any better replacement product that the top end philips or Osram ? There are so many out there and I am sure that many are just cheap chinese junk. While others might be very good chinese quality ?

Is changing to LED safe ? I dont want to damage the CBUS system as obviously that would be more expensive to replace a dimmer

Any advice please as I really don't know - I am not an electrician and I am not technical in anyway - I just know what I read on good forums like this and try to learn what I can from here.

 

Hi Johncbus

(edit) Assuming the channels are not already overloaded changing the bulbs to the 7W Philips is probably not going to increase the load on the dimmer but is not something I would recommend due to the fact you will still have old transformers.


I wonder what sort of halogens you had since those 7W Philips LED's aren't very bright.

Maybe you meant 8 lights come on with a single key press?
8 halogen downlights on a single channel of the 8 channel dimmer is almost certainly too many for the 1A dimmer.
There is also a maximum capacitive load which can be connected to each channel of the dimmer and with electronic transformers the number of transformers per channel is usually reduced.
Perhaps you have iron core transformers, which would work nicely with the dimmer or perhaps you have a mix of iron core and electronic.
That could explain the differences in brightness you mentioned.

Just like 50W MR16 lamps, iron core transformers are phased out.
No one is going to know which transformers you have or how many fittings per channel without looking.

Minimum dimming levels can be programmed into the dimmer to avoid some problems with flickering or other issues at low levels.

If you read the forum you will see that dimming LED's can be somewhat problematic.
Some brands work well though with specific minimum and maximum numbers of LED fittings per channel.
Some manufacturers supply this info, some don't.
There can be different results for each different type of dimmer.


There are two types of dimming methods used by CBus, leading edge and universal.
All 8 channel dimmers are leading edge.
Some but not all 4 channel dimmers are universal dimmers and automatically select leading or trailing edge operation depending on the load.
Universal dimmers have a higher load rating per channel.
Feedback on this forum suggests what works on a leading edge dimmer might not necessarily work on well on a trailing edge dimmer and vice versa.

Don't discount the option to swap the dimmers with relays for as much of the home as you can be happy with.
It makes the selection of LED fittings so much cheaper and easier.

200 fittings is a significant investment.
There should be some good savings on energy costs and many LED options which will allow more or less light output than your halogen fittings in the colour temperature of your choice.

My advice is talk to an experienced installer in your city.

 

Hi Daryl. Thanks for the advice.

Just to clarify a few points - The Philips LED's are very bright. Awesome actually. Much better than the halogens.

Yes, 8 light come on with a single key press. The Dimmer is 8 channels, and on this particular string of lights I refer to in the original post, 8 lights come on when using the one channel in the open plan kitchen, of which 2 of the 8 are now the Philips LED while the other 6 are regular halogens.

I will check what types of transformers are in the ceiling on the weekend. I don?t know the name or brand, but I have seen them when putting the new LED's in and they are gold and green in colour. So that may give a clue to you of what type and brand they are.

Daryl your advice on swapping dimmers for relays is a good idea. There are many areas of the house like hallways and outside where I do not need dimmers. The lights have never ever been dimmed. In fact the only place we use the dimmers are living areas, bedrooms, and the bedroom hallway as a night light on motion sensors for the kids

In your opinion Daryl, Given the Philips bulbs seem to play really nice with the Cbus dimmers, would it be a problem over time replacing the blown halogens with LED ?

My main concern is should the LED lights be avoided as there is potential damage that can be caused to the cbus system? Or are they safe to use?

I just don?t want to put these things in only to find in a few months? time they have caused damage to the cbus system which becomes a double whammy - You pay top dollar for energy saving LED's, then have to pay top dollar to replace damaged cbus components - Forget about any payback using LED's over time as you just blew that potential saving fixing what you just damaged!

Thanks for your advice and guidance Daryl

 

Hi John CBus

Perhaps I supplied too much information but I was trying to explain in some detail the various factors which need to be taken into account.

Changing the lamps and therefore reducing the load on the transformers is unlikely but not beyond the realm of possibility to cause some unexpected results.

I doubt there is a person on this forum who can advise whether your LED bulb, will work with any particular transformer, with various number of lamps per channel on the 2 different types of dimmers.

That is why I suggested you get someone experienced in CBus out to look at it.
I think they will probably suggest replacing the complete unit with transformers designed for the particular LED.

They could check if there is spare relay channels to change some areas from dimming.
If required they can adjust the minimum dimming levels of the dimmer.

These are some of the reasons why you want to get someone out there before spending a lot of money on LED bulbs.

 

Thanks Daryl. Understand where you are coming from. It is a bit of a minefield, hence I guess why the information out there regarding this situation is so varied and vague

That coupled with so few truly knowledgeable electricians who understand cbus and what to do with it. I know in my situation I have had to undertake much of the programming and learning about it myself. I do most of my own basic toolkit programming as the few people who I have come across that are willing to work with cbus really only know how to run wires and connect stuff up - they don't know the detail of what works with what and how to program. I guess it is a very specialized area

Perhaps another approach would be to totally get rid of the transformers, and get GU10 tails and run 240v GU10 LED's. That way the whole transformer thing goes out the window.

What does everyone think - Is moving to GU10 and straight 240V easier and more straight forward than worrying about MR16 and transformers all the time ?

 

I think CBus compatibility in GU10 is even worse.
GU10 LED's also have a power supply but it is built into the already warm lamp.
With LED's, if the fitting fails you are realistically going to replace the whole thing.
Assuming it is plugged into a surface socket it makes little difference if it is GU10 or MR16 with a separate power supply.

In the power level you are looking at I would recommend looking at these.
http://www.pierlite.com/au/87173/starburst-crystal-eco#.VaYnWUkVhaQ
They are a specific type of lamp in that they have a fairly narrow beam and are what I would call low glare fittings.

Lots of people use other brands on CBus with success but for me I like the Pierlite products.
They come with trims but I have used them in old MR16 fittings.
Maybe you won't like the price but they have documented CBus dimmer compatibility specs link on that page and come with a 3 year warranty.
Replacing the lamps in your existing fittings doesn't.

Having said that, when doing your sums I would work on a 3 year life span.
My opinion is that the energy savings will almost pay for the fittings but probably not.

The real gain is the convenience of having lights which work for a long time between touching them.
Whether you are able to buy an identical replacement in 3-5 years time is something else to consider (eg have a few spares if you install 200 of anything).

 

Thanks Daryl again for your reply. I will have a look at the pierlite

The cost is not the issue. I don't mind paying more, paying once, and doing it right. What's that old saying "measure twice, cut once" so to speak.

More so the lure of the led lights was that they are supposed to last longer, be a little brighter, and lower power consumption. And the island of trialling the current crop of mr16 halogen replacements is really just to move over to led bit by bit as all the current halogens I have die and need replacing. But like I said, I didn't want to go ahead and start changing without advice, just in case damage would be caused to the cbus.

Thanks for all your advice. Hopefully soon enough I can come across an electrician in Sydney who knows cbus properly.

 

You probably won't need 200 dimming compatible LED's if you can get some of the areas which don't really need to be dimmed onto relay channels.

Pierlite supplies specs and they will want to be followed to get a good result.
I'm sure your local installer will have experience with brands other than Pierlite too.

I see you like the 4000K Philips LED's.
4000K LED's do output more lumens and also due to the colour look visibly brighter.
However 3000K is much closer to the colour temperature of your existing halogens.

Halogen lamps have an even lower colour temperature when dimmed eg more red to yellow.
Barring a few rather specialised fittings LED's have a fairly constant colour temperature when dimmed.

Opinions vary but I would be reluctant to install a 4000K LED in a dimming application for aesthetic reasons.
In my opinion 4000K can be nice for a kitchen, office, bathroom or laundry but not so great for a lounge room or bedroom.
The difference is even more noticeable when dimmed.

Another question is whether it is worth having different colours and types of lamps throughout the house.

Have a good think about the lighting effect you want.
3000K is much closer but still a whiter light than the halogens.

These are the sort of things to discuss with your installer.

Due to excellent contribution on this forum I suggest you include noushouse.com.au in your search for a local expert.

 

Thanks again Daryl.

Yes agree on the 4000 globes - Only used those over the sink in the kitchen - The wife likes the extra brighness. But definitely would not consider that brigh in a bedroom or hallway. But en-suite, bathrooms, even laundry the 4000k have a place.

Had a look at my transformers on the weekend. They are a brand called possum - gold and green in colour. So they might be an aussie brand given the name and colouring.

I stumbled across noushouse. Might hit them up.

thx

 

You could also ask Tridonic ATCO.
The Possum transformers did have specs for CBus so they might be able to tell you if there is any problem using the LED bulbs.

 

Hi Johncbus
I just found this
"Please note: Not suitable for LED lighting - Please choose the Redback Transformer with LEDs"

http://www.electricalproducts.com.au/atco-possum-transformer-with-flex-and-plug.html

If that is correct I would definitely be looking for some new matched fittings, supplied and installed by someone who is familiar with CBus dimmers.
They are going to have to count the number of fittings per dimmer channel and identify the type of dimmer.
It's not rocket science but needs to be done properly to get predictable results.

I really think you can do a lot better than those LED bulbs anyway.
There are 3000K LED fittings which will put those Philips to shame for brightness in the kitchen.
Which ones will work well on various CBus dimmers for your existing fittings per channel no one can say until they have a look.

 

Hi Daryl

Mate - really generous of you to spend your time answering so many questions and looking things up. Thank you so much.

Now that I know the transformers I have also been googling them a bit to see what else can be dug up.

Interesting to see the differing opinions out there. You can understand why there is so much misconception, or lack of clear single minded thought on the subject. There really is no one standard to stick to for Sparkies. It's all very new, and trial and error, and testing.

Just out of interest, have a look at this website. It tests both Possum and Redback transformers with Philips, Brightgreen and other LED bulbs, just in general - not related to CBUS at all.

The test results seem to imply both redback and possum work well and are stable with LED lights. Just some interesting reading.

http://www.ledbenchmark.com/faq/Transformers-Output-and-Compatibility.html

 

Hi John,

I have ATCO possums, and most recently, after trying a few 'retro fit' options, retaining the possums... and not having a lot of joy with the setup overall... decided to look for replacement units, however retain the 'fixtures' on the roof.

I ended up going with a few brightgreen products.

For 70mm units (non-gimbal)
D700NF - works well as long as there are more than 3 units per channel (any less than this and the dimming channel fails to turn off properly, due to low load or capacitance), but with 3+ works fine... dimming range is around 20-100%, with a slight 'flare up' on turn on, if turning on to a low initial dimming level (say <40%). but nor real flickering whilst going through the dimming range. I am experimenting with adding some capacitance to channels with <3 units... I will post my results.

For premium upgrade or for gimbal units
D900 - works really well... however a complete replacement is required if going from 70mm up to 90mm, not to mention cutting out the roof.
These unit worked well with only 1 unit per channel, dimming range probably ~10-100% with no noticeable flickering... a really nice unit, however a bit more expensive than the rest.

I am really happy with the product so much so that I am now happy to recommend a reliable replacement to my customers, as I was reluctant to do so in the past due to the inconsistency in behaviour of some units.

Good Luck

Grant

 

Using JCC

We have C-Bus and have used a mix of Click Inceptor (non C-Bus) and JCC LEDs, the non C-Bus are controlled by relays.

The JCC's work really well and their 7W LED is fully fire rated an IP protected for use in bathroom ceilings, the profile is low and the rating means you do not need a hood when used with Celotex or similar.