Hi. I recently wired up can lights in my basement. Each light is a 75 watt halogen bulb. There are 6 of them on the switch.

There is a 15 amp breaker with 14 ga wire. The switch is one of those fancy 3-way dimmer switches with the green LEDs on the side that indicate the brightness of the lights. The switch says it handles up to 600 watts. My math says I'm using 450 watts, 75% of peak load.

From the power source, the power goes to an outlet, where it is pig tailed and up to the switch. From the master switch, my travellers go to the secondary switch, and also from the master switch, power goes up to the first light. From the first light, I did a parallel circuit to the rest of the other 5 lights in succession.

My concern. Tonight I noticed the dimmer switch on the master switch a little warm. Nothing too alarming, but the metal part that screws to the plastic box was downright hot!

Is this normal? I checked and doublechecked my wiring before I finished up. All the lights work as I expect. The secondary switch is normal temp, not even a little warm.

If this is not normal, I can post a detailed description of my wiring. I did it according to the instructions...

Thanks!

Just a follow-up, I turned the lights off, did some work upstairs for a half hour or so and went back down. The switch and metal plate are normal temp. Not sure if this is useful information or not! :-)

I will try to run the lights at a dim setting tomorrow and see if the switch heats up...

Thanks,
Trip

I have used 3 way dimmer switches, and never had them get hot. Unless the connections are loose, I think the switch is defective. I would return it and try another one.

Dimmers getting warm is normal, it should even mention this in the instructions.
The front plate is made of aluminum to dissipate the heat. Larger dimmers 1000 watss and larger have fins to eliminate the heat created.

By all means check all connections, even change the dimmer.

The amount of heat can be subjective, and what may be normal may be alarming.

The rating of your circuit and load is fine. No dimmer shall be loaded more than 80% of rated load.

Hope this helps.

Kevin

In both the military and college they said not to load something more than 50%. You see voltage spikes can occur that double the voltage when you first turn a circuit on, or off (or produce transient currents). Secondly the best engineering practices say that for longest life you use a 12.5% load. Because it would take a lot to get 8 times as much voltage or current or both out of a device. Remember that both voltage and current matter when dealing with power (measured in Watts).

Most applications 40% or 50% load is okay. The more you load a circuit the sooner it burns out. Also note the electrical wiring you are using must be physically able to let enough charge reach the item loading. Example: a too thin cable can never jump start between cars because not enough current (charge passing through a point every second) is getting to the "dead" (low) battery.

If your wires are not connected properly (loose?) then you are shorting to the faceplate, and that will heat it also, and be a dangerous fire hazard.

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Originally Posted by triptrop

Hi. I recently wired up can lights in my basement. Each light is a 75 watt halogen bulb. there are 6 of them on the switch.

There is a 15 amp breaker with 14 ga wire. The switch is one of those fancy 3-way dimmer switches with the green LEDs on the side that indicate the brightness of the lights. The switch says it handles up to 600 watts. My math says I'm using 450 watts, 75% of peak load.

From the power source, the power goes to an outlet, where it is pig tailed and up to the switch. From the master switch, my travellers go to the secondary switch, and also from the master switch, power goes up to the first light. From the first light, i did a parallel circuit to the rest of the other 5 lights in succession.

My concern. Tonight I noticed the dimmer switch on the master switch a little warm. Nothing too alarming, but the metal part that screws to the plastic box was downright hot!

Is this normal? I checked and doublechecked my wiring before i finished up. All the lights work as i expect. The secondary switch is normal temp, not even a little warm.

If this is not normal, I can post a detailed description of my wiring. I did it according to the instructions...

thanks!

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... is to turn the dimmer full on and see if the faceplate gets cooler. If it does and you are satisfied with the temp (recalling the suggestions to replace the unit) then all is likely to be normal and leave it as is.