Dimmer Switch Smoking

Your lucky your house didn't go bad with it

According to DaveR :

If it's been fine until the smoke, it's probably going bad. If there's a wiring fault (ie: a short), dimmers usually fry instantaneously[+]. It would be highly unusual for a wiring fault to only draw enough current to make the dimmer overheat without going kaboom.

You should also check the wattage of what the thing is driving. Most dimmers are limited to 500-600W, and some to 300W. If this is a new installation, or you recently relamped the circuit with higher wattage bulbs, I'd strongly suspect a simple overload, which you can resolve by choosing a higher capacity dimmer, or reducing the quantity/wattage of the lamps.

Check the wattage regardless of whether it's a new circuit or new bulbs.

In any case, once a dimmer starts to smoke, I'd replace it.

Just replace the switch, first make sure that the total load is less than the rated capacity of the switch.

Don't try to fix the switch or continue to use it. If you like, I suspect that Lutron may replace it free if you send the damaged one back to them. Again only if it was controlling a circuit within it's rated value.

Thanks for the advice. This dimmer was newly installed (professionally) 3 years ago and it has been working fine until recently. I did see the occasional spark when turning on the switch but I was told this is common in the Skylarks and not necessarily dangerous. None of the bulbs have been changed. It is a 600W dimmer driving exactly 6 100W bulbs.

I guess I will just replace the switch.

According to DaveR :

Uprate the dimmer to something beefier - say, 1KW, or, lower the wattage of the bulbs. Ie: switch to 75W quartz halogen - more light, less power.

I don't like devices run at their extreme limit. It'll probably run warm all the time, and the lifetime will be shortened (as it was).

Probably...?

Well, I think he meant "maybe". :-)

I thought he meant "almost certainly."

:-)

Smoking is bad for dimmer switches. Get the Patch or some nictoine gum, and try to get it to use that.

If it won't, get rid of it and get a new switch. Why should you be responsible for its eventual medical bills.

Remove NOPSAM to email me. Please let me know if you have posted also.

It's common knowledge that dimmers run on smoke. When the smoke leaks out, they stop running.

Lutron has agreed to send a new switch and pay for shipping the old one back, even though it is out of warranty. Great customer service!

smoke....fire.......bad...........

Yea. I once wrote them about the possibility of getting a small plastic part that have broken off, also out of warranty. They called me as soon as they got the letter and wanted to know what color the switch was. I tried to explain that it was an internal part and the color was not important. They explained they did not have the part, but wanted to send me a new switch.

They cost a little more and I would not normally worry about a broken switch, but I still appreciate their effort to provide a level of customer service not normally seen.

Even running well within limits a solid state controller can be damaged by an incandescent lamp burning out with a "tungsten arc". That happens occasionally when the filament opens and an arc starts through the vaporized tungsten between the broken ends. That arc burns back along the two filament pieces until it's consumed them, with the current increasing while that happens. It all takes place faster than Jill Robinson, and sometimes it's enough to blow a conventional 15 or 20 amp glass fuse, but they seldom last long enough to trip a breaker.

If you've ever flipped on a light switch and had the bulb blow out with a bright flash, you've seen one. Better brands of incandescent bulbs used to have a fuse built into one of the internal bulb leads which was intended to blow when a tungsten arc occured, but a lot of the cheapies don't bother with them.

I used to have trouble with several table lamps in out home which I'd fitted with solid state "touch switch" dimmers. Every once in a while a bulb blew with a tungsten arc and took the dimmer with it. I solved the problem by fitting fuseholders with 2 amp quick blow 3AG fuses in each lamp. I've had a few bulbs fail and blow the fuses, but the dimmers were saved.

Jeff

Replace it Be sure your load is not too high If the load is not too high, contact the manufacturer. They should know about the danger and will likely send you a free dimmer too.

DO NOT reinstall that thing !!!!

You are pushing the limit, and there is some significant probability that doing so has taken its toll - maybe in combination with transient surges in line voltage. Keep in mind that lots of these things are made by low bid contract manufacturers and plenty of low bid devices probably barely qualify as passing testing.

I would replace the thing, and do so with one rated much more than 600 watts, or else reduce the load. The triacs in dimmers get plenty hot at

- Don Klipstein ( snipped-for-privacy@misty.com)

If you are using longlife or vibration-resistant or 130V 100 watt incandescent, or ones other than "Big 3" (GE/Sylvania/Philips and their store brand ones with same/similar lumen and hour ratings), then you could be able to downsize to 75 watts - and they may not have to be halogen.

I agree on that one!

- Don Klipstein ( snipped-for-privacy@misty.com)

I talked to Lutron about a client's Skylark and they seemed very nervious that it was run at 600W. They asked if the heat sink tabs had been removed on the front. Definately replace the unit up to 1000W or bulb at 75W max as above. Richard

Seems strange to me that a device should be rated at 600W and yet be "pushing its limits" at that load. I would think the rating should be somewhat conservative.

Nevertheless I don't doubt that my 600W load probably had something to do with the problem. I will pull out one of the 100W bulbs which I really don't need, and then eventually replace the rest with 75W which should be sufficient for this room.

I have a bunch of other 600W Skylarks in my home but thankfully they are all pushing 300W or less.