Buzzing dimmer

[sosa]

I've recently installed 16 low voltage downlights on a 1000w dimmer now the only problem is the buzzing coming from the dimmer ia unreal the downlights i'm using are:
http://www.jcc-lighting.co.uk/products/interior/downlights/lv+halogen+downlights/fireguard
the transformers i'm using are:
http://www.allaboutelectrics.co.uk/20-60va-lv-lighting-transformer.html
And the dimmer i'm using is:
http://www.theinternetelectricalsto...d-dimmer-georgian-brass-twin-plate-1279-p.asp

I've also changed the lamps to 35w but this hasn't really had much effect.

Can anyone suggest anything to stop the dimmer from buzzing so much?

 

[ban-all-sheds]

I suspect you mean Extra Low Voltage downlights, not Low Voltage?: //www.diynot.com/wiki/electrics:voltage-bands

In which case:

1. Are the transformers dimmable?
   
   
2. Are the dimmers suitable for use with transformers?
   
   
3. Even if 1 & 2 are yes have you matched the leading-edge/trailing-edge characteristics of dimmer and transformers?
   
   There is a little known compatibility issue with dimming ELV lighting "transformers" (in quotes because they aren't actually transformers, which is why the problem arises)
   
   Dimmers do not work by lowering the peak voltage, they reduce the RMS voltage by simply chopping out part of the waveform - they either turn on part way through each cycle (leading edge, or phase-delay) or turn off part way through (trailing edge, or phase cut), and what the dimmer does must match what the transformer needs.
   
   So you might have a "transformer" that is labelled as suitable for dimming and you might have a dimmer switch that is suitable for use on ELV power supplies but you still need to match the leading/trailing edge characteristics of each.

Disclaimer - I've not looked at the links in your post which may answer some or all of these....


What sort of room is it that's large enough to require 560 - 800W of lighting but small enough or used in a way that means all the lights on one switch is OK? That's more than I've got for the entire ground floor of my house...

Also, did you know that dimming halogen lamps shortens their lives, and saves very little electricity?

 

[kevindgas]

did you buy the standard item (link 3) or the special dimmable ones?

 

[sosa]

I suspect you mean Extra Low Voltage downlights, not Low Voltage?: //www.diynot.com/wiki/electrics:voltage-bands

In which case:

1. Are the transformers dimmable?
   
   
2. Are the dimmers suitable for use with transformers?
   
   
3. Even if 1 & 2 are yes have you matched the leading-edge/trailing-edge characteristics of dimmer and transformers?
   
   There is a little known compatibility issue with dimming ELV lighting "transformers" (in quotes because they aren't actually transformers, which is why the problem arises)
   
   Dimmers do not work by lowering the peak voltage, they reduce the RMS voltage by simply chopping out part of the waveform - they either turn on part way through each cycle (leading edge, or phase-delay) or turn off part way through (trailing edge, or phase cut), and what the dimmer does must match what the transformer needs.
   
   So you might have a "transformer" that is labelled as suitable for dimming and you might have a dimmer switch that is suitable for use on ELV power supplies but you still need to match the leading/trailing edge characteristics of each.

Disclaimer - I've not looked at the links in your post which may answer some or all of these....


What sort of room is it that's large enough to require 560 - 800W of lighting but small enough or used in a way that means all the lights on one switch is OK? That's more than I've got for the entire ground floor of my house...

Also, did you know that dimming halogen lamps shortens their lives, and saves very little electricity?

Sorry yes i did mean ELV, and in answer to your questions yes the transformers are suitable for dimmers and yes the transformers are dimmable but i what do you mean by 'have you matched the leading-edge/trailing-edge characteristics of dimmer and transformers?'

And yes i agree it is alot of light but the customer was adamant on having that many.

 

[sosa]

did you buy the standard item (link 3) or the special dimmable ones?

If it is link 3 you are refering to then yes i bought the dimmer.

 

[sosa]

Sorry ban-all-sheds after reading through your post again i kind of understand it a bit better so what your saying is i should get a dimmer that is recommended to be used with the transformers?

 

[Taylortwocities]

No. He means get a dimmer that is designed to be used with the transformers that have been installed.

There is a big difference.

Just because it says "Dimmable transformer" does not mean that it works with any dimmer.

 

[sosa]

No. He means get a dimmer that is designed to be used with the transformers that have been installed.

There is a big difference.

Just because it says "Dimmable transformer" does not mean that it works with any dimmer.

Right ok thanks well as seen as i have jcc downlights and jcc transformers i've rung the jcc tech helpline and am waiting for a return call.

 

[securespark]

The link I clicked was for a Steeple tx, not JCC??

http://www.allaboutelectrics.co.uk/catalog/product/gallery/id/540/image/16753/


Quote from the dimmer link:

Please note standard dimmers do not dim wire-wound transformers, choose the Intelligent Dimmer (IQ Dimmer). The standard dimmers also do not dim fans and inductive loads, choose the Intelligent Dimmer (IQ Dimmer) or look at Fan Regulators for these awkward loads, (please check with manufacturer that appliance is dimmable).

 

[sosa]

The link I clicked was for a Steeple tx, not JCC??

http://www.allaboutelectrics.co.uk/catalog/product/gallery/id/540/image/16753/


Quote from the dimmer link:

Please note standard dimmers do not dim wire-wound transformers, choose the Intelligent Dimmer (IQ Dimmer). The standard dimmers also do not dim fans and inductive loads, choose the Intelligent Dimmer (IQ Dimmer) or look at Fan Regulators for these awkward loads, (please check with manufacturer that appliance is dimmable).

Sorry yes your right, its from the jcc lighting shop though. So according to that quote if i were to get an IQ dimmer then this should stop the buzzing, because at the moment it is dimming the lights but just buzzing quite loudly.

 

[slup]

Is it one big circuit or can you split it up?

It strikes me as a lot of lighting to have on one single circuit. That load on a dimmer is almost certainly going to buzz - there is little you can do about it.

On the other hand, you may just have a rogue particularly noisy dimmer - that does happen from time to time.

Also, it's generally best to match transformers and dimmers from the same manufacturer as you can be fairly sure that they have been tested, if not designed, to work together.

 

[johnnykc]

Is it one big circuit or can you split it up?

It strikes me as a lot of lighting to have on one single circuit. That load on a dimmer is almost certainly going to buzz - there is little you can do about it.

Spot on slup.....

 

[ban-all-sheds]

That should not be the case.

From an operational POV it's probably daft to have all those lights on a single switch, but then the customer has shown that he's no stranger to daftness by having that type of lighting in the first place.

BUT - if a dimmer manufacturer says his product can cope with 1000W of ELV lighting then it must cope with it, and making a loud buzzing noise does not count as coping.

If the product matching recommendations are followed and the dimmer still buzzes under a load which although heavy is within the published specification then it's a Trading Standards issue - the seller of the product needs to be prosecuted.

 

[sosa]

That should not be the case.

From an operational POV it's probably daft to have all those lights on a single switch, but then the customer has shown that he's no stranger to daftness by having that type of lighting in the first place.

BUT - if a dimmer manufacturer says his product can cope with 1000W of ELV lighting then it must cope with it, and making a loud buzzing noise does not count as coping.

If the product matching recommendations are followed and the dimmer still buzzes under a load which although heavy is within the published specification then it's a Trading Standards issue - the seller of the product needs to be prosecuted.

Well i've been waiting for a call from jcc all day and haven't recieved one yet but as soon as they recommend a dimmer to use i'll change it to that and let you all know.

 

[johnnykc]

That should not be the case.

From an operational POV it's probably daft to have all those lights on a single switch, but then the customer has shown that he's no stranger to daftness by having that type of lighting in the first place.

BUT - if a dimmer manufacturer says his product can cope with 1000W of ELV lighting then it must cope with it, and making a loud buzzing noise does not count as coping.

If the product matching recommendations are followed and the dimmer still buzzes under a load which although heavy is within the published specification then it's a Trading Standards issue - the seller of the product needs to be prosecuted.

But Varilight don't suggest using that many transformers on a 'standard' dimmer......I think the maximum is 5 and even then they suggest quality electronic transformers!

But I know you don't type without thinking BAS so i'm just clarifying that your comments were directed at the seller of the products.