PDA

View Full Version : Question about flourescent bulbs + dimmers



7rider
10-16-2007, 03:27 PM
Okay. Totally OT.
We have recessed lights switched with dimmers.
We're thinking of replacing the bulbs (all now, or just as they burn out) with flourescents.
However, flourescents generally (always?) can't be used with a dimmer.
So what happens if you put a flourescent flood in a lamp that has a dimmer??
Will it light, but not dim?
Will it not light?
What happens if you mix flourescent and regular bulbs on the same circuit (i.e., the switch turns on 4 lights in a row)?
Inquiring minds want to know!
Thanks!

onimity
10-16-2007, 04:28 PM
I was curious too and tried this. :)

The result of my experiment was that at when the dimmer was all the way on (full brightness) everything was fine. But as I tried to dim it, the bulb flickered horribly. It was technically still lit, but totally unbearable.

So I used it as a good excuse to replace all of the non-dimmer standard bulbs with CF bulbs, and I'll use the out-of-service standard bulbs to replace the bulbs that burn out on dimmer switches.

Just remember that you shouldn't put CF bulbs in the garbage when they (eventually) burn out; they contain a small amount of mercury so you should take them to a special recycling center. Fortunately that is very infrequent with the bulbs.

Anne

smilingcat
10-16-2007, 07:47 PM
ARRGHHHH!!!!

Flourescent light on a dimmer is a big NO NO! Dimmer's do some really bad thing to the voltage on the line and there is circuit, called a ballast, which is used to light the flourescent bulbs. The ballast can't handle the voltage from the dimmers and both the flourescent light bulb and the ballast can be damaged permanently.

This is about as simple as I can explain. Please don't plug CFL lights into a socket with dimmers.

I work with some really geeky engineers who wear flood water pants with white socks. No pocket protectors nor masking tape across the bridge of their glasses. Still, they are really geeky!! Gawd, if I were married to one of them, I would be so embarrassed on how they dress. :eek:

Smilingcat

onimity
10-16-2007, 08:18 PM
ARRGHHHH!!!!

Flourescent light on a dimmer is a big NO NO! Dimmer's do some really bad thing to the voltage on the line and there is circuit, called a ballast, which is used to light the flourescent bulbs. The ballast can't handle the voltage from the dimmers and both the flourescent light bulb and the ballast can be damaged permanently.

This is about as simple as I can explain. Please don't plug CFL lights into a socket with dimmers.

I work with some really geeky engineers who wear flood water pants with white socks. No pocket protectors nor masking tape across the bridge of their glasses. Still, they are really geeky!! Gawd, if I were married to one of them, I would be so embarrassed on how they dress. :eek:

Smilingcat

Ok, I appreciate the simple explanation, but the bulbs I tested specifically stated that they could be used with dimmer switches. They nevertheless flickered horribly when dimmed, as I'd heard was the case with these bulbs. I wouldn't use them in a dimmer, but they work find when not dimmed. Your mileage may vary.

Nice to hear about the sartorial ineptitude of your colleagues, though. I am doubtless described the same way, but I like to think I have qualities better than my fashion sense. No engineer would ever masking-tape a pair of glasses, BTW. Duct tape holds so much better.

Anne