Our house is about 25 years old, though we have lived here less than 2.
Our master bath has a dual light switch, one for the main light bar over the sinks and one for the lights above the shower stall and tub. These are both oversized rocker switches with a slider to dim the lights.
If we leave the lights over the shower and tub on for an extended period of time – an hour or so – the switch will be noticeably warm to the touch. It does not seem to warm up any further by leaving it on beyond this. The wall switch does not have an internal backlight when it is off.
The lights on the circuit are an in-ceiling "can" light over the shower and a gaudy gold chandelier over the tub. Would replacing either of these help alleviate the problem?
I have not noticed this problem with the switch for the light over the sinks, though we don't typically leave that one on as long. This circuit consists of two bars of 6 bare-bulb globe lights each.
I am relatively confident that the switches are not original to the house, though the light fixtures themselves probably are. (Edit: Looked at them again this morning, and I'm less confident that the chandelier is original – the medallion is a slightly different color from the ceiling, so it either wasn't painted or was installed later.)
Should I be worried about the operating temperature of the switch?
Best Answer
It is perfectly normal for it to be warm. If it's HOT, you might be over capacity.
If there is more than one dimmer in a single box, you generally need to snap off the fins on the side(s) to get them to fit. With less heat sink surface area, they can't dissipate the heat as well, so the capacity is reduced. This is known as "de-rating."
In a nutshell, a typical residential dimmer rating works like this (For incandescent lights):
Both fins intact = 600W
One side fins removed = 500W
Both side fins removed = 400W
Here's a link to a typical manufacture's "manual" for one of these devices:
http://www.homedepot.com/catalog/pdfImages/cb/cb27dfa7-40a6-4788-9112-c2a619a4b2e0.pdf
Top of page 1 - "Important Notes": Item 7 reads "It is normal for the Dimmer to feel warm to the touch during operation."
At the bottom of page two, there's a chart that shows de-rating info and ratings for other types of bulbs (non-incandescent)
That's as thoroughly and definitively as I can answer your question! There's also a toll-free number for Lutron at the bottom of that page. I believe they are the leading manufacturer of residential dimmers. dp