Switch Wattage Rating

TipsyMcStagger

I'm installing Lightolier low voltage track-lighting. The Lutron dimmer switch for electronic LV transformers is rated at 300w.

Is this rating referring to the wattage rating of the bulbs? There will be six 50w track heads for a total of 300w.

Thanks.

Tipsy

joed

Dimmer is too small for that. A 300 dimmer should not be used to control 300 watts. You should have some wiggle room. The nest size up should be used, probably 600 watts.

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TipsyMcStagger

Thanks for the reply...Lutron does not make a 600w dimmer (in this style) for LV electronic transformers.

I just installed six recessed lights with magnetic transformers. The Lutron switch I got for those is rated for 600w.

What is the risk of running the 300w switch with a 300w load? Early failure?

Tipsy

nap

lot's of heat.

I have seen a dimmer actually catch fire from being overloaded.

TipsyMcStagger

Is it overloaded if it's at the rated limit?

I would think not?

Tipsy

frenchelectrican

Sure I have see it few time they will get super hot inside espcally right on rated wattage.

There one trick that you may prolong the life of the dimmer is put a metal switch plate cover on it.

It will act like heat sink to help a but I can not garranunite it will work espcally if you are right on the limit of the dimmer.

Merci.
Marc

nap

then you would think wrong. When I said overloaded, it was a bit of a misstatement. It was overloaded because it could not handle the load applied. It was not overloaded because of the load compared to the rating.

the one that caught fire actually was not beyond it's rating. It was on a job (all engineered and everything). I noticed it was hot one day and said something to the boss. He kind of blew it off as it had been spec'd and was actually within it's rating. When I say hot, I mean it was hot enough I did not want to leave my hand on it.

anyway, one day we come to work and find a melted dimmer. Luckily it was in a metal box and there was apparently not enough flames to catch the sheetrock paper on fire. It ruined the carpet that was below it though as molten metal and plastic fell onto it. (there was no trim plate on it as the room was not finished yet)

I have always found it better to upsize a dimmer if you are getting near the max rating.

joed

It is never a good idea to run a dimmer at it's full rated wattage. 80% is good limit, but it is not a rule.

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