Buzzing

Hi
My problem:

1. The Cbus dimmer module buzzes very loudly i dont know if thats normal

2. The downlights although quiet when on full level, as soon as you dim them, u can hear a very anoying buzzing sound coming from them... The room has low 2400 ceilings and is very quiet so its realy noticable and totaly unaceptable

***I hope this isnt normal and that something isnt right and there is something that can be done about this. This is the first room that has been wired and i have already bought all the cbus for the whole house already!

Connectioned so far:
*A single 8output L5508D1A dimmer to 16 x 50watt downlights and 2x 20watts uplights

Output 1 - 2 downlights
Output 2 - 2 downlights
Output 3 - 2 downlights
Output 4 - 2 downlights
Output 5 - 4 downlights
Output 6 - 4 downlights
Output 7 - 1 uplight
Output 8 - 1 uplight

Each downlight is conected to a single atco ted-70 transformer
It has been wired by a licensed electrician

Thanks
David D

 

Are the modules (dimmer module) still loud on 100% as well?

 

???

 

Try buying a few really good quality LV globes and see if the noise goes.
Unfortunately good quality = $
Make sure you put the same globe in all fittings on a channel / switched cct. I have seen situations where cheap globes act as a light source and a speaker

 

As I was told, this is, unfortunately, normal when an Leading edge electronic dimmer connecting to electronic transformers. It happens to me since the first day and there is no solution whoever I asked. The normal case is that no noise at 100% and louder it gets when more dimmed it gets. (if buzzy at 100%, there is something wrong). Leading edge of the electrical wave has a lot of noise so it is the "problem" with Leading edge, I guess. People said it happens to all electronic leading edge dimmers. Normally I hear the noise at the dimmer rather than the tranformers. So, maybe using magnetic tranformers may help, or use some "more inductive" electronic tranformers. SO the principle is, if you can't change dimmer, change the transformers. Try a few before changing too many. One more note, make sure the 4 LV channels do not overload the channels with any new transformers in practice.

 

Hi
The dimmer module buzzes loudly whether the globes are dimmed or not
I have 6 more dimmers to connect i can only imagine how loud that is going to be
At least the dimmers are in an enclosure inside a cabinet

The downlights are quiet when at full level
And then buzz ever increasingly as you dim them
Although even to dim just slighly the buzzing sound is completly irritating

At full britness these globes are just too bright
They are 50watt Osrum titan globes
HOPEFULY these are cheap **** globes and i can swap them for something else
Even though i bought all the gear over a year ago im probibly ****ed
I will try 35watt globes and maybe i can get away with not dimming them
Ill have to ask my light supplier
However this defeats the whole purpose of advanced mood or scene lighting capabilities
To have some an electrified zapping sound above your head
I cant beleive this is aceptable in any way!!!

I bought 95 x atco ted-70 transformers becasue they were recommended on the cbus transformer chart
And its taken me 2 years to build this digital studio and this zapping sound is rediculous
Theres no way this system can go in the bedrooms and dinning rooms
But everything has been cableda already...

I need to know if dynalite and other brand lighting company have this same issue
Its completly rediculous
They shouldnt even be in business none of them
They should invent something that doest sound like its frying your ears off
And until then pull all their **** off the market
Atleast put a warning on the box
This is going to sound like a 24/7 bug zapper
Buy at your own risk

Hopefuly something isnt installed corectly or the globes i bought were not suitable
Then ill make a full apology

But if this is a known problem and there is no solution for this i want a full refund of all the cbus gear

This is bull****

DAVID D

 

Ill post photos of the instal soon also incase you can pick something up

Here is just some more information incase u notice something that could cause this problem:

The transformers maybe too close to the globe?
The transformers are wired to the downlight without the small clear plastic block
By this i mean the 150mm cables coming from the ceramic block above the globe go directly into the transformer
Which sits on the ceiling maybe only 100mm away from each downlight
The Transformers do not go into plugbases but are hardwired to the 1.5 power cable going back to the dimming zone junction box and then on to the dimmer

The dimmer is wired from an 8amp mcd in the cbus enclosure which is wired back to a 10amp rcd in the mains enclosure all in 1.5 power cable
The buzzing sound from the transformers(like a flock of bees) is immediate upon any dim level
Not related to overheating in the ceiling area etc etc

Do you think anything above would contribute to the noise...

Thanks
D
D

 

Are the transformers resting on the ceiling plaster, if so it will tend to amplify the the sound.

You need to get them up and sitting on something that stops the vibrations from transferring. No doubt someone else will know the best stuff to use.

 

This is very strange...

Hmmm - you need to really do some tests : Is the noise coming from the LIGHTS, transformers, or are they causing interference with other devices ?

I have never "heard" of a 12V light globe causing a buzz... I guess it MIGHT happen, but you'd have to really listen hard... how quiet is the space, is it truly a "digital studio" ?

The transformers shouldn't buzz at all, I've definitely heard it happen with wire-wound but never with electronic trannies.

What colour are the transformers... are they blue and white and marked "Speedy" or are they completely blue?

I'm just making sure that you haven't somehow got some Trailing Edge dimmable transformers, because if that was the case then you would get exactly the symptoms that you describe....

Try a test in "free air"... separately wire up ONE lamp, tranny and dimmer channel, put say 2m of cable between each component. then dim that and see which is truly making the noise.

If it's the dimmer, then something seriously faulty. If it's the transformers, then try a different brand. I doubt it's the lamps, but try swapping that to a different brand too.

If all is quite in the "one-of-each" test, then you are going to have to investigate the difference in the real installation

Hope that helps, John

 

Thanks for replying john

*just one thing first up with your test, can I have the tranny 2 meters from the lamp?
atco told me 300mm was the max distance recommended? (more info lower down)

So far the only thing connected in the room are the downlights
I have no power to anything else connected
The room is completly empty

Becasue this is a new renovation
And we have 3 phases
The only other thing on the same phase at the moment is the hotwater tank
Rheem 250liter duel element optima

I have the blue and white marked transformers with speedy ted-70
I bought them all over 1 year ago
My sister has my camera so as soon as i get that back ill take some photos

Ill try the tests you suggest and write back with what happens
Thanks for the advice and the positive outlook that the transformers shouldnt be making this sound
Your not lying to me to make me feel more hopeful are u man

Im happy to fully appologise to cbus if something else is at fault here
But that day is not today

I just went backupstairs to listen
Its not like a 747 flying overhead...
It is very faint buzz above ambient noise when your standing in the room
It was worse at night becasue the room was quieter
However if u get on a step ladder and go closer to the downlight
You can hear its very loud in the ceiling!
Ive always planned to soundproof and ventilate the computers
I will be useing in the rooms
I know they are going to be a problem
But its something i expected
And hopefuly i wont hear them
Because im putting them in cupboards
That are ventilated to a false wall
Which act as plenum boxes for a bulkhead style Split system Daikin aircon
So heat should be removed from around the computer
Anyways
To now have to contend with the downlights zapping me from above isnt cool

Here is a pic of one wall in the room
You can see 2 of the offending downlight oppenings
When i took the photo the downlights wernt pluged in yet

http://www.t666.com/davidd/townhouse/room1/speakerwallmay2006.jpg

A desk is going along that wall matching the bulkhead width
And a large cupboard is going on the right side up to the studwork

I can try having the transformers wired back
Onto the clear plastic expansion terminal block that came with them
And then to a longer 1.5cable
To get them further away from the downlight and hole oppening
But how far can they go before its too far
Atco told me 300mm was the maximum
If the transformer is further away from the downlight
Will its operation sound become even louder?!
You can see in the bulkhead the sound can just as easily come through the grill
Most of the other ceilings are a 120mm false ceilings
Theres no where for the sound to go but down through the hole
I could put an 8mm foiled sheilded unburnable mat
Between the 13mm gyprock and transformer
But i think its just the proximity of the transformer to the hole
Not sound transmition thru vibration although it might help
What i needed was a vertical sound partition in the ceiling void
Between the hole and the transformer so the high frequncy couldnt bounce directly down the hole

But ill do more testing to confirm whats making the noises and so forth as you suggest


Thanks
David D

 

A bit of info

Hi David,

Regarding the cable length between the Trannies and the lamp: This is limited to a relatively short distance, as the output of virtually any electronic tranny is high frequency, i.e. about 20kHz, and if the cables between the tranny and the globe are long, they can act as aerials and cause radio interference on other equipment, especially if that other equipment does not fulfill the required immunity specs. However, for testing purposes I would not worry about that.

Next, I agree with John that a globe itself will hardly cause a noise, also the Osram Titan is a top brand (or has been) and should not cause trouble. However, the light fixture itself may resonate...

What is not 100% clear to me is whether your dimmer is in the ceiling, and simply wired from the C-Bus enclosure, or whether it is mounted in the C-Bus enclosure, which is hopefully in a different room, such as your garage? Should it be in your ceiling cavity, then you will need to move it out of there.

Regarding your earlier sentiments about the noise from L/E Dimmers, this is totally normal and will be the case with any make and model of L/E Dimmers. Trailing Edge is different in that transistors are used for the internal switching purposes, as opposed to Triacs, and Triacs are unfortunately noisy.

I hope that this will help a bit,

Cheers
Thomas

 

As Thomas said, the lead length between tranny and lamp is restricted to prevent EMC (Radio Interference).

Normally, the transformers themselves are marked with the maximum length - I always use 2m as a guide... but there ARE electronic transformers available that can be mounted further away. But since you already have the transformers, I wouldn't worry about that for now.

After you do some testing, you should be able to determine what is making the noise... as I mentioned before I've never personally heard any noise with electronic transfomers, but I did have a problem in my own kitchen years ago

The installation was done in about 1988, when LV was very new and the downlights ONLY cost $45 Trade each. To save money, I used a single Atco 200VA wire-wound transformer, connected to a HPM Leading Edge dimmer. That transformer DEFINITELY buzzed loudly when it was dimmed. Originally I had it screwed onto the ceiling beams (supporting the plaster), but found that if I used longer wires and screwed it to the roof truss instead, then the noise was un-noticeable.

So, tell us what you find in your testing so we can get a solution sorted out !

JC

 

Atco Possums

I mainly use the Atco possum transformer and so far have had no problems with them. The only time I have ever heard any noise was when I was testing an installation and only had one connected to the output of a 2A dimmer, when dimmed it made a slight buzzing noise but when I loaded the channel up ( 5 trannies) the problem vanished i.e./ no noise from either the trannie or the dimmer module. These were in a fairly sound proof room - 200mm stud walls with sound check insulation and 16mm plaster and double glazing to all windows. Also the ceiling was made in two layers - top layer 16mm firecheck plaster then 100mm gap and lower layer was 6mm plaster. You could hear a fly fart in this house but their was no discernible noise coming from any part of the lighting. So I think I can definately say that the problem does not lie with the C-bus product. Do you honestly think the product would have made it this far if one of its by products was irritating noise? Perhaps a simple query next time without the rant and rave.

 

Thomas,
The dimmer module is in a clipsal enclosure in a cupboard in a hall
I dont think ill be able to hear it when the cupboard doors go on i just was checking if it was ok that the dimmer was buzzing very loudly as soon as the lights turn on (dimmed or 100%)

John i cant do the test till monday now when my frend comes back. Today he came and had a look and said everything looks good but he also noticed the buzzing. Hes prety much 100% sure its the transformers buzzing. One weird thing is 2 downlights in particular (dimzone1) are much louder than the rest, perhaps double as loud as the other zones... cant work this one out. Some high up dood from clipsal may be coming also to have a look so ill let you know what the deal is however quite alot of people seem to think its acepted that transformers buzz, i dont know why this is. its sort of like me saying aliens come and abduct 99% of the population every night but noone seems to think its strange. ive never been involved with lighting b4 so i had no idea of this but i think its stupid that a light should make a buzzing noise. Ive never noticed lights buzzing before in my life, and then i went downstairs and this elchepo crap desk lamp i was using makes a buzzing sound also, maybe until you actualy get involved with installing the lights you dont realize that the anoying buzzing sound in the back of your mind is actualy coming from the lights... or maybe most people have higher ceilings with large noisy roof spaces and probibly cant hear it. hopefuly thats not the case tho cuz that wont help my situation. Actualy tomorrow i might just pull a downlight fitting and transformer down through the ceiling and have a listen, thanks for your advice.

Pbelectrical

"Do you honestly think the product would have made it this far if one of its by products was irritating noise? Perhaps a simple query next time without the rant and rave"

I dont care, do u think im lying? my transformers are buzzing and the only thing i have connected is cbus with the transformers that were recommended by cbus
A couple people in this forum already have said they hear the buzzing and recon its normal (which i dont want to acept) but maybe the reason u cant hear it is you are fully deaf


The neo switches look sick its like my room is part of starship enterprise but i dont want the lights to sound like a nuclear reactor whenever they r turned on

Thanks to all for the constructive messages tho, maybe this can b solved...

d
d

 

T666, in my experience I have heard quite a few lights, dimmers and transformers buzz and carry on long before the likes of c-bus so it came as no surprise to me that when clipsal and other manufacturers introduced electronic lighting control systems and their leading edge dimmers there would be some issues, especially now with the popularity and benefits of cheap electronic transformers. I have bench tested a few of the transformers on the clipsal compatibility chart and most have quite a noticable hum regardless of what most maunfacturers of the transformers claim. The problem at this point is has been explained already - Triacs in the electronic leading edge transformers. Some of the transformer manufacturers are working on bringing new leading edge electronic trannys to market that are much improved such as the osram redback etc. but even they are not perfect all the time.

I can have the same combination of components work flawlessly in one installation and not in another. Could be more transmission noise in particular areas than others or the electronics are not exactly identical from tranny to tranny, who knows? There are many variables, namely electronics.

Personally I have atco iron core trannys controlled via c-bus in my own house and none of them hum at any level of dimming and never have. Maybe I was lucky? But I don't think so.

PS, it isn't just the Clipsal installations that have trouble with electronic transformer hum. I have also worked with Hpm I-control and Dynalite.

PPS, It is TOTALLY unacceptable to be able to hear transformer or dimmer hum from the living spaces in any building and contrary to what others may say, I do not consider it "Normal".

 

Cool man
Im only 1/3 thru fininshing this house so ive just put up with it for now
As is i cant hear the lights over the computer that is just temporarily under the desk instead of in a special cabinet

I still didnt pull down some lights and listen to where exactly what the noise is coming from. Ill do that soon but its goto be the transformers its heaps easy to do i just been lazy

One thing i defnetly can say is 2 particular transformers are way louder than the rest. I will swap them out and see if different transformers are as loud...

Maybe the batch of atco ted-70 i got are dodgey...
I didnt like the build quality of the terminal points...
They are weak and flimsy when u tighten the screws as apposed to the osrum or atco possum...

My problem is i bought all the gear over a year and a half ago...
But only just got to instal stage so i think im stuck with it
But that dont mean im not going to make some noise myself
Cus i bought these transformers cuz cbus specificly recomended them over other ones



ill report back soon

Peace
D
D

 

I only use iron-core in my own house for this reason. Where I worked previously we ONLY recommended Iron Core on Dimmers for exactly the same reason. Iron-Core = no hassles. Most other experienced Lighting Companies will agree. Who cares about 9W lower watts loss if it generates 100W worth of grief !

However, very very soon MEPs (Minimum Energy Performance) Standards will be in force for LV Trannies, and the old black Atco TM50's will no longer be legal.

As I understand it, the solution to the WHOLE THING is to use the correct dimmer (Trailing Edge) for these capacitive loads. A good way of testing would be to try a Trailing Edge Transparent wall dimmer, or even a Trailing Edge C-Bus Wireless dimmer. Who knows, it might just be that there's nothing wrong with the Transformers at all.

Funny that the price for Leading Edge and Trailing Edge is the same for C-Bus Wireless, but there is a difference between the 32E450LM and the 32E450TM (trailing=dearer)

Anyway I keep referring to the lack of Trailing Edge Wired C-Bus modules, and CIS keep saying they are working on it....

JC

 

Egad. I must be getting grumpy in my old age.

"Who cares about 9W *LOWER*" ??? Virtually all the lights in my place are only 11W each *TOTAL*. So your ADDITIONAL "wasted" power is 80% of my entire lighting load!

(No, I don't live in a dark, dingy cupboard - these 240V CFL lamps may take a minute or two to come up to full brightness, and may not be quite as flexible in the dimming department, but I have >120 of them in here and it is, in my opinion, better lit (and certainly more evenly lit) than most places I've seen done with halogens. And the upside is, even with ALL the lights on, I'm still only pulling a little over a kilowatt out of my batteries - and most nights its under 300 watts including a high pressure sodium flood out the front!)

 

LOL, Ross ! Good call !

It's amazing how little light (wattage) you really *need* isn't it ? The human eye is an amazing thing, no matter how bright OR dim (within reason) you light things up, the eye automatically adjusts so that you can see !

A lot of people don't like the "spotty-ness of LV dichroics, in which case the CFLs are a much better (and cheaper to run) alternative. Pity that most people (builders especially) cannot understand that those LV dichroic lamps were designed for highlighting (effect lighting) and NOT for general illumination.

JC

 

As an aside - the Osram rep called me today about a job with about 200 x Osram Redbacks that were buzzing on C-Bus.

I noticed that the Redback is 110nF and a DinRail dimmer can only handle 300nF - so that means that you can only use TWO per channel. That's only 120VA worth, or half of the dimmer rating.

Osram rep is gunna check how the job is wired... but I bet ya that they've wired 4 trannies per (1A) channel.

John