Transformer help please

Hi
I have been asked to look an installation for a guy who has some low level lighting transformers in his system.

Kitchen
5 100W Halogen Lamps on 1 2 Amp Dimmer channel

Bedroom
3 not sure of the loading

Wardrobe
1 lamp

Not been down to see it yet but he seems to be having problems.

The kitchen 1 lamp out of the fives flashes on and off
The bedroom same again with 1 lamp
The wardrobe the same again

This is usually when he just turns them on to 100%, if he uses the dimmer function they seem to work OK.

Myself I cant see how this can be the cbus, software or hardware, if it was a channel problem all lamps on the channel would be affected to my way of thinking.

I am thinking its a transformer problem

Any thoughts from anybody.

Thanks
Mark

 

Kitchen
5 100W Halogen Lamps on 1 2 Amp Dimmer channel

That channel is overloaded - say the transformers are electronic then they'd be about 6W loss each, so the total load is 106x5 = 530W, and the dimmer is only rated for 480W !

But as you summise, it's unlikely that the dimmers could be causing the problem because it'd affect ALL the units on that channel.

Regarding the flashing, it might be an incompatibility between the Leading Edge C-Bus dimmers and the transformers. However if that's the case it'd tend to be affecting all the lights... although there definitely are small differences between units even of the same brand / type. Note that the C-Bus dimmers still "chop the waveform" when running at 100% - they are still sort-of dimming even when they are not dimmed, and that can cause problems for some devices (not many).

But the most likely cause is overheating of the transformers. Check with the client if the flashing is occurring immediately, or after the lights have been on for a while. Most electronic trannies have a thermal cutout, and it's not hard to exceed that temp if the electrician has covered then with insulation, they are between 2 floors of a house, or mounted directly under a flat metal roof.

So check the "frequency" of the flashing - every few minutes, every second, or a flickering ?? This will really help isolate what may be causing it.

The only solution for overheating is to remote-mount the transformers - get them out where they can breathe. Note that most electronic trannies have a max Ta of 50C, so that's the maximum ambient they can handle (which is easy to exceed in a roof space here in a Australia).

I've also had instances of bad connections causing flashing - but since there are 3 on one site that's highly unlikely.

Hope that helps - but I'd recommend a bit more detective work before you go to site if possible.

John

 

Thanks John your a star.

I will see what else I can find out.

Regards
Mark

 

A bit more information

Hi Guys
one light in the bedroom flashes-about 12 times when 1st switched on-then operates as normal-if switched on and off again

This has got to be a transformer problem hasnt it.
I will try and get the make etc

Regards
Mark

 

Ummm... I can't see how C-Bus could make the light flash like that unless it was deliberately programmed.

One thing that I found very handy for troubleshooting this kind of thing is the C Bus Toolkit Application Log. You need to do it on-site, while you are connected to the network and after you have scanned all devices etc.

In the tree view (left side of screen) open Network > Applications > Lighting > Application Log.

Test a few things and make sure it's logging, then use the button to Clear Log. Then deliberately do whatever makes the problem occur - you can instantly see what C-Bus events are happening (eg: the On and Off events that might cause a flashing).

Also consider that in the bedroom, all the lights are probably on 1 output channel and are wired up together. If this is the case, then it can only be the transformer or a bad connection that is causing the flashing to occur (otherwise all the other lights would be flashing too, eh?

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Re: transformer overheating, it's unlikely that the lower ambient temps (winter in UK) will be a factor, but don't discount the stupidity of some installers. I am thinking that maybe a transformer is sitting on a poorly insulated steam pipe, or bolted to a chimney ? ? ?

Good luck anyway, and charge by the hour to fix it