Why is my dimmer switching making my switch plate hot?

Question

I have a Lutron dimmer switch hooked up to 8 recessed lights. I know that the dimmer switch is at least 600watts. Each of the 8 recessed lights is 65watts. Is it normal for the dimmer switch to make the switch plate hot after a couple of hours of being on? Thanks for your help.

Answer 1

Josh M has it right on. Also you could get a 1000 w dimmer and don't break any of the "heat sink" side blades off as they reduce the capability of the switch to dissipate heat.

Good luck - an afterthought have you checked the existing switch to see if any of those aluminum ears on the top, bottom and sides have been broken off of the top, bottom and sides. This has the effect of the cooling and will de-rate the 600w down to a much lower rating. ( I think I remember the de-rating value is stamped on each of these snap off leaves) If there isn't any of these left on the switch, then they have been snapped off and the 600w rating is much less and you may be in trouble. Be safe and check it ! ! !

Answer 2

Yes, it is normal for dimmers to get hot.

Answer 3

The dimmer switch is basically a variable resistor. It consumes part of the power, being fed to the circuit, so that the lights have less and aren't so bright. If you put your hand next to a light bulb you'll feel the heat from it. This is due to the energy being consumed, Only about 2% of the energy is given off as light, the rest is released as heat. The dimmer has no light producing element so ALL the energy it consumes is given off as heat. Some solid state dimmers have heat sinks built in which help to dissipate the heat but even they get warm. With eight bulbs you're running the dimmer near max load. A lighter load would lessen the heating effect. It isn't a good idea to run one that heavily loaded.

Answer 4

Yes, it's normal for the dimmer to be generating a fair amount of heat.  No real cause for concern there, as long as you're sure that each bulb is only 65 watts, and the dimmer is rated at 600 watts.  With 520 watts currently connected, you're pretty well maxed-out.  You certainly wouldn't want to add any more lights to the circuit; nor would you want to use higher-wattage bulbs.  Assuming that you're using incandescent (standard) bulbs, have you considered going with compact fluorescent bulbs?  You'll get similar light output while decreasing your watt usage (i.e., saving electricity).  And to top it off, it will cool that dimmer switch off some.

Answer 5

A dimmer switch is not a variable resistor.  It is usually a triac or other active circuitry where you are varying the waveshape to reduce the voltage.  A variable resistor would consume much more power than you would like and would be much hotter than your dimmer switch now is.  However to answer your question, yes it is normal for them to heat up, but you should not have any problem holding your hand on it.  If it is hotter than that you need a higher power dimmer switch.

Answer 6

Yes.  A dimmer switch is nothing more than resistor (although not a fixed one, but has changable settings). To maintain the wattage of the bulbs, the only thing that can be increased is the amperage. The voltage stays the same and as you dim the lights, the amperage increases, making the switch warm to the touch.