how warm is warm for a dimmer?

[timtheenchanter]

We have just had our social club function room refurbished, with the addition of halogen downlighters in the ceiling (approx 18) all mains voltage, plus 3 PAR cans (stage lights) of 300W each (again halogen lamps).

they are on seperate dimmers ie one for the PARS, one for the downlighters, but the dimmers get what i would call hot rather than warm, they are OK to touch with the front of your hand, but you cannot keep the back of your hand on them, this happens regardless of the position of the dimmers.

they also buzz, alot more than the ones i have at home.

is this heat, and buzz just due to the high load, or do they need replacing with something of a higher rating, if so we can get it done asap as we haven't paid them yet!

 

[daytona]

they shouldnt get that hot mate now way.
many things could cause this but the obvious one is overload.get them checked.its easier than putting out a fire .

dont pay him until they dont get too hot!

 

[daytona]

alsoi know you said they are all mains voltage but even so thereare types of light that are not suitable for dimming.others can be dimmed only with special equipment

 

[timtheenchanter]

thats what i thought, but wanted a second opinion.

the downlighters are just the normal halogen down lighters with 50W GU10 lamps

If i am correct in thinking that the load of halogens should be doubled to get the correct rated dimmer?

ie, 3x300W=900W, so a 1800W rated dimmer would be needed.

 

[Adam_151]

Is this a stage dimmer? most would not bat an eyelid at those sorts of loads!

And yes, normally double the rating of TH fittings when selecting a dimmer unless the specs of the dimmer say otherwise

 

[very_pointy_ears]

Also bear in mind that there's probably a maximum power you should draw for any given faceplate size regardless of the dimmer rating.

I recently bought a couple of Richmond 500W grid dimmers and in the sheet that came with it, it said that you should not go more than 500W total load across all dimmers in a 76x76mm faceplate, for example (which is actually big enough to fit two of these dimmers), due to heat dissipation.

Disclaimer: I am not an electrician.

Cheers,
Kingsley.

 

[timtheenchanter]

no these are not stage dimmers, they are just normal push on/off, turn to dim type dimmers, single gang, with 2 mounted side by side in seperate 40mm boxes.
I was a little concerned when I saw it as I wasnt aware you could get such highly rated standard dimmers.