Hey electricians! Flourescent bulbs with a dimmer?

I just moved into my new place. The former owner had the house wired up with all kinds of 75 and 100 watt floodlights and dimmer switches. Quite attractive actually. I can only imagine that the electric bill in this place was enormous.

Anyway in the old house, I used nothing but flourescent bulbs to cut my electricity costs and I want to install them here.

Question, is there any problem with using the dimmer switches with flourescent bulbs? If I turn the juice down is there any chance that it have an adverse impact on the bulbs, like blowing them up or starting a fire?

You can’t use dimmers with flourescent lights. You’ll have to have the switches changed.

IANAElectrician, but generally speaking, dimmers just plain don’t work with fluorescent lamps.

You know how, when you turn them on, they sort of do a tick-tick-flash-flash thing, rather than starting off dim and fading up to full brightness* - that’s because they’re really only ever on or off; there’s no in-between dimmed state they can be in - either there’s enough energy for them to function, or there isn’t, and if there isn’t, they don’t light up at all.

*(OK, I know they get brighter as the phosphor warms up)

You can get compact fluorescent bulbs that work with normal incandescent dimmers. You should be able to find them at Super Home Mega stores near you.

I’m not sure what would happen with regular bulbs and a dimmer, but I’ve recently been obsessed with getting fluorecent bulbs all over my house (not until I find some that start up instantly though), and have seen at least three types of bulbs at Rona that say on the box that they work with dimmers. IIRC, one was a flood-type light too. Assuming you’re in the 'States, I’d bet any large home renovation store would carry them.

Before you buy a bunch, make sure they fit your light sockets though. The ballast on some bulbs is fantastically small, but others won’t quite fit in the smaller recessed sockets (like in my overhead fan, for instance) :smack:

I’m not an electrician, but the house I rent has a very similar setup. I tried to find information on this in the past, and it seemed like there were some special flourescent bulbs that were built to work with dimmers (I assume that they have multiple elements and some sort of voltage stepper/transformer built into them), but it was hard to tell if they’d really work.

I hope there is a good solution to this.

I have tried compact florecents on a dimmer, they just flickered. As mentioned there are some that can be dimmed.

I guess I was less interested in whether or not the lights will actually dim and more interested in whether I will burn my house down due to some inherent incompatibility of flourescents and dimmer switches.

Some dimmers have an an on/off switch in addition to the dimmer. Mine do not so turning the lights off is more or less dimming them until they don’t shine any more. If there is a potential hazard then I will go replace them. However, if there is no problem, then the only danger is with me trying to do anything electrical in my house.

TCP edison base fluorescent lamps will work with some dimmers, but may encounter difficulties when turned down too far. There are also some CFLs which look like a standard A19 incandescent lamp, but are fluorescent and dimmable. Rather than a big box-see your local lighting supply outlet or go smurfing on teh intarwebs.

So why can fluorescent tubes glow in an induced EM field but not run with a dimmer? couldn’t they be rigged to have full power to start, and then run at reduced power?

The circuitry has to adjust the power output on a flouresent bulb. Most flouresents adjust the ouput in the unit it’s self and require the the power isn’t on a dimmer. Aparrently some are now being made with circuitry compensate and allow for an external dimmer. There are different types of dimmers nnow and I wonder if the bulbs require a certain type. Some of the new one’s don’t drop the voltage with a resistance, but pulse the power on and off for different amounts of time.

Zackly. This is why you shouldn’t use an incandescent dimmer to vary the speed of a ceiling fan-the motor doesn’t like the reduced voltage it’s seeing from the dimmer. Use fan speed controls for motor loads, and dimmers Listed and Labeled for fluorescent loads. Doing otherwise voids the UL of the product and as such is a NEC violation.