Return to the Lighting Forum | Post a Follow-Up

 o
Dimmer Problem

Posted by javachik (My Page) on
Tue, Nov 16, 10 at 6:55

I had a handyman (licensed for "simple" electrical work, but not master electrician) hang 3 new ceiling light fixtures and install dimmer switches on 2 of them (a 5-bulb and a 2-bulb). Each of the fixtures is rated for 100w incandescent bulbs, which I used. However, the dimmer switches get hot at full power and lower power. I replaced the 100w bulbs with 75w bulbs. Same problem. Any suggestions?


Follow-Up Postings:

 o
RE: Dimmer Problem

I am no electrician, but what are your dimmer switches rated for.


 o
RE: Dimmer Problem

The dimmers as installed are rated for 500w.


 o
RE: Dimmer Problem

Is the box the dimmers are installed in plastic? You might have the installation revised so that they're in an oversized METAL box. That will help to dissipate the heat better.

The phrase "licensed for 'simple' electrical work, but not master electrician" makes me suspicious. Just what does t his mean? I'm not a pro myself, but as I understand it, either he's a licensed electrician or he isn't. Maybe Brick or one of the other pros here can speak to this.

In any case, I'd want to be sure he or she was properly licensed. In most cities it's illegal for an unlicensed person to do electrical work on your house.


 o
RE: Dimmer Problem

We are licensed, bonded and insured master electricians in Dallas. Don't know where you live, but we have never heard of any one being licensed for "simple" electrical work.

In our area, even an apprentice or journeyman has to work under a master. Only a master electrician can pull permits.

However, none of this doesn't answer your question on this or the electrical board.


 o
RE: Dimmer Problem

davidr - An oversized box may be called for.

In regard to the handyman licensed do to simple electrical and plumbing work... He is a licensed contractor by the state of Virginia. That licensure does in fact allow him to do electrical and plumbing work without being licensed as an electrician or plumber. The state does not, however, give any guidelines to the extent of the electrical or plumbing work he can do. I know he works with a master electrician on jobs requiring installation of wiring for new electrical services in the house. Installing a dimmer is something I know I could have done (did it before), but it was convenient to have him do it when installing the new light fixtures that were too heavy for me to do by myself.

The consensus seems to be that the heat I'm experiencing is normal..

Thanks for all the replies!


 o
RE: Dimmer Problem

I have installed several dimmers in our home and countless dimmers in other people's homes. None of them have any heat to the touch what so ever. If what you are experiencing is considered normal, more power to you. No pun intended.


 o
RE: Dimmer Problem

Hello there,

Some lower quality dimmers may get warmer than other ones due to not having a good enough heat-sink built in to the dimmer (ie, thinner metal brackets, or none). But they shouldn't be hot to the touch (danger!). You might also check to see what the de-rating information is for the dimmers you have if you have a ganged wall-box. Some 500W dimmers may only be rated for 250 watts once they're in a wall-box with other dimmers/switches. One more thing; make sure the wiring connections are secure and that there's no arcing going on.

I also know that in my state and neighboring ones, a handyman can get what's called a "Limited Electrical License". That means that they can replace existing fixtures and switches but can't do any wiring or new installs.


 o
RE: Dimmer Problem

"I have installed several dimmers in our home and countless dimmers in other people's homes. None of them have any heat to the touch what so ever. If what you are experiencing is considered normal, more power to you."

Larger dimmers (1000 W) even come with fins on the front surface and a metal cover (they cannot be used with a regular switch plate.

Dimmers dissipate heat on controlling the current to the load (though unlike an actual rheostat they do not dissipate a lot of power).


 o
RE: Dimmer Problem

The heat in the dimmer definitely sounds like trouble. None of ours are even slightly warm. One area in the attic of our new house (heating & air area) got hot - it turned out the unit was faulty. It could be a bad run of dimmers - lots tend to have the same problem.


 o
RE: Dimmer Problem

"The heat in the dimmer definitely sounds like trouble."

It sounds perfectly normal for something dissipating less than 10 watts.


 o
RE: Dimmer Problem

A full-on triac has a voltage drop of about a volt. The larger fixture here is using 3.125a, so the dimmer might be dissipating about as much power as a night light bulb. I'd expect it to be warm, but not I-can't-touch-it hot.


 o
RE: Dimmer Problem

davidr - Good comparison. A night light bulb gets too hot for me to touch (ouch!). The dimmer just gets noticeably warmer than the switch it's next to. Definitely not ouch hot.


 o
RE: Dimmer Problem

The dimmer just gets noticeably warmer than the switch it's next to. Definitely not ouch hot.

That's fine. You're OK.


 o
RE: Dimmer Problem

The heat build up you feel on your dimmers can be caused by a number of factors.
Inexpensive "imported" dimmers are usually rated at 500 watts, and even then are suspect.
Even good quality 600 watt dimmers, like Lutron or Leviton, can be come warm as the total load approaches the maximum rating.
If your dimmer is installed in a gang of switches, the maximum load is reduced to 500watt or 400watt, depending on how many of the metal heat sinks are popped off for gang mounting.
Your problem can be solved by reducung the bulb wattage further, replacing the dimmer with a good quality dimmer, or installing a 1000 watt dimmer


 o
RE: Dimmer Problem

"...replacing the dimmer with a good quality dimmer, or installing a 1000 watt dimmer."

These units have better heat sinking, and are designed to operate with higher temperatures.


 o Post a Follow-Up

Please Note: Only registered members are able to post messages to this forum.

    If you are a member, please log in.

    If you aren't yet a member, join now!


Return to the Lighting Forum

Information about Posting

  • You must be logged in to post a message. Once you are logged in, a posting window will appear at the bottom of the messages. If you are not a member, please register for an account.
  • Please review our Rules of Play before posting.
  • Posting is a two-step process. Once you have composed your message, you will be taken to the preview page. You will then have a chance to review your post, make changes and upload photos.
  • After posting your message, you may need to refresh the forum page in order to see it.
  • Before posting copyrighted material, please read about Copyright and Fair Use.
  • We have a strict no-advertising policy!
  • If you would like to practice posting or uploading photos, please visit our Test forum.
  • If you need assistance, please Contact Us and we will be happy to help.


Learn more about in-text links on this page here