Dimmer Switches

Aug 26, 2005 7 Replies

I have 5 downlighters in the bathroom that have 50w High voltage halogen lamps in them (GU10).



I had a dimmer switch on them. I can't remember what it was rated at but it was above 250w. The switch only lasted a few months and then burnt itself out. The switch was old so may just have been a coincidence that it burnt out but it was pretty scary for my wife to find that at the top of the stairs there was a smell of burning plastic but she couldn't see what it was. The smoke had been going up the void in the wall!!!



Is there a specific dimmer switch I should be fitting?



Cheers


In article , Steven Campbell writes

A bigger one

They normally give a special rating for running halogen lamps, e.g.

250W (100W halogen) or something like that

You need a bigger dimmer. Halogen bulbs (and that includes mains voltage halogens - both the GU10 type and the normal bulb replacements) are much harder on the dimmer than conventional incandescent bulbs.

(Halogen bulbs take more current than normal bulbs when at low temperature).

Most decent dimmers will explicitly state a halogen rating. E.g. 250W (150W halogen).

If no rating is given, it's best to avoid using that type of dimmer at all. However, I've had no significant problems by using 40% as a rule-of-thumb (e.g. no more than 100W of halogen light on a 250 W dimmer and 150W on a 400 W dimmer).

I think you'll struggle to find a dimmer than explicitly states compatability with 250W of halogen light. If you do find one I'd love to know - I've got 300 W of GU10s on one circuit in my living room (and they're a bit harsh when trying to relax).

Perhaps swapping out the 50W bulbs for 35W ones may solve both the dimmer problem, and the excessive light problem.

Mark

temperature).

Thanks for the info. Although I'm sure the last dimmer was 400 or 500watt. I'd have thought that would have been more than enough.

Anyone any links to a appropriate dimmer.

Thanks again.

Steven.

Take a look at the following URL at TLC:

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catalogue at
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dimmers (perhaps just those listed in the halogen section?) have been 're-rated' for halogen use hence they cater for upto 500W (or 600W for the IR/touch type). Available in all the usual finishes too.

Mathew

Get an MK 'intelligent' dimmer. These have soft start and intelligent overload control suitable for Mains halogens;

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16 and 17 of pdf file

If you check specs of dimmers, you'll find they're rated for GLS lamps. Change to near any other type, and the rating may be halved - or even more.

It's certainly possible to make dimmers that could cope with any type of filament lamp, but then they'd be more expensive.

Thanks guys for all your helpful advice. I'll have a look at the MK 'intelligent' dimmer that Tim Morley suggested.

Thanks again.

Steven.

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