We just noticed that our dining room light (on a dimmer switch which is usually at full throw) is flickering. Reasoning that it may be due to the energy saving bulbs in the kitchen (probably the same circuit), I turned off the kitchen light to prove my theory. Yes, the flickering stopped.
But, what is cauing this? I should add that the kitchen light emits a high-pitched sound which seems to eminate from the kitchen switch (which has a sliding dimmer-like device beside a conventional switch - at full throw). At first, I thought the squeal was from the lighting fixture, but it seems to be from the switch.
What’s up with (a) the flickering? (b) the squeal? Should I be concerned that the energy saving bulbs are a fire hazard? Note: There are two of these energy saving bulbs in the kitchen light fixture. Each claims to throw off 100W.
Since you’re noticing the sound near the switch, my first thought would be to pull the switch out. If you’re handy with light electrical work, replace the switch with a regular one (or just pull the switch out connect the two wires), then turn the power back on and see if it still does it. I’m guessing your dimmer is dying.
Does it ALWAYS flicker, or just sometimes?
PS For the sake of easiness, you might just want to swap out the bulb first. Actually, if you still have the packaging, make sure the bulb is compatible with a dimmer, it might not be.
Most compact fluorescent bulbs can not be dimmed, especially older ones. It sounds like your kitchen dimmer is expressing its displeasure by squealing.
The solution is to go back to standard incandescent bulbs or find dimmable CFLs.
Do not use CFs with a dimmer. Even if the dimmer is on full brightness. I learned this the hard way.
A couple years ago I installed four CF’s in a ceiling fan’s light kit. The light was controlled by a dimmer switch. I knew CFs were not supposed to be dimmed, but I figured I would simply keep the dimmer on full brightness. Boy was I wrong… each CF bulb burned out within two weeks.
I didn’t understand why they burned out. I had always assumed that the complete sine wave was passed through the dimmer switch when the brightness control was set to 100%. So I connected a resistive load to a dimmer switch and measured the voltage signature as a function of brightness level using an oscilloscope. Even at full brightness, the voltage did not resemble anything that looked like a sine wave. There were huge spikes and dips in the voltage, which meant the voltage had a lot of high frequency components. These components are what probably killed the CF bulbs.
Lesson learned: only use a standard switch on a circuit with CF bulbs.
After I posted my reply, I realized that by “energy saving bulb” you probably meant compact flourescent. I can tell you (at least with standart flourescent) they will make the dimmer emit a buzzing sound.
So, you have three choices, regular bulbs, a regular switch or CFLs designed to be used with a dimmer.
BTW, my understanding is that it isn’t a dangerous situation, it just won’t work.
