Remote Living > Lighting

What kills CFLs?

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pyrocasto:
I've had 2 CFLs less than a year or so old go bad now. One happened after I put a light sensor on it, so when the sun came out it would turn off. When it was near light or near dark it would flicker alot, which caused it to last a couple of weeks max before it died.
Now, I have another one that was used in our garage for almost a year and it apparently died as well. Under normal use, they are supposed to last 6000-10000 hour right?
Both of these were either Lights of America, or GE brands so they werent flea market for $1 brands.
Anyone else have any problems with CFL longevity?

DanB:
I think lots of on and off is bad for them - I think your light sensor was definitley a culprit.
Strong magnetic fields...  Ive learned that they dont like to be stuck to tools with strong magnets.  Sometimes a strong magnet will just make them not light up while near the strong magnet, sometimes it kills them for good!

fishfarm:
Your post got me curious because I have used several in my house for more than 5 years without a problem (they are GE). I found a CFL FAQ and as usual, learned something. They don't recommend using them with sensors or timers unless designed for that application.
"Customers are advised to exercise caution and diligence when selecting timers and photocells for use with CFLs. Photocells contain a silicon chip that converts radiant energy into electrical current. Most photocells today do this in a manner that is incompatible with CFLs, resulting in a shortened lamp life. Timers are devices that allow trickle voltage to cycle through the lamp when it is off. This causes the lamp to try and start itself when there is not the proper supply voltage present. This also shortens the lamp life."
"In both cases CFLs are labeled as unsuitable for such use, because the user would not realize the average rated life from the bulb when used in this manner. Using CFLs in a manner inconsistent with their design voids any warranty. Customers should only use timers and photocells that are rated for use with CFLs."
http://www.penlight.org/pages/faq_pgs/cfl_faqs.html

jimjjnn:
Cold also causes failure as most CFLs electronics are cold sensitive. There are some CFLs that are designed for outdoor cold weather use. I used a CFL as a porchlight for ten years . Then my daus started turning it off every day. It lasted only a year more. Not real sure that was reason for failure or end of life. Turning CFLs off and on is biggest reason for failures as the same porchlight CFL inside and being turned off and on fails in less than a year. I tried the autmatic turn on sensor and found that there is a voltage drop across the sensor. Lost 2 CFLs in 6 weeks before I read the instructions for the Sensor.It stated that lights would be dimmer cause of this and said "Do not use for FLOURESCENT lights". I have 2 globe shaped CFLs that are in a bathroom that is not used that often and they are still burning after 10 years.

Just sold house so I won't be able to see how long the last now.

crashk6:
Looks like you've had a quick lesson in combination of electronics.
Yes it's true, a standard CFL should never be used with timers, dimmers, photocells, or computerized ambient light building controll systems. And can cause an electrical fire if improperly mated. But then so can any device if improperly deployed.
However there is hope, first I'll tackle your photocell issue, there are photo cell fixtures that are designed as florescent fixtures or to work with CFL's. Before replacing the whole fixture for one of the previously mentioned units you may wish to try one other route.

Look for a "dimmable" CFL or one certified to work with incandescent light controlls... these particular bulbs have a much more sophisticated voltage sensing electronic ballast and may solve your photo cell trouble... but all photo cell circuts are a smidge different so I can't guarantee it will work in you particular fixture... but it works for 80% of the ones I've fitted. The others simply don't light up... I only had magic smoke from one, but I already knew it would happen... Why some people ask for your expertise then ignore it and insist the opposite must be done is beyond me!
Anyway, and as the name implies dimmable CFL's may be used with most light dimming systems.
However timers are just as tricky as photocells as some will pass voltage and some will not. About two years ago I had to solve these same issues for my mother who rang me complaining her plant lights were eating up huge amounts of power... my first suggestion was a large wall of triple glazed window with thermal shades... I was even willing to speak with her landlord who for the record has been very understanding about all the other "wacky" changes... she didn't bite on that one...
She wanted electric lighting but wanted to switch the plant lights to fluorescent to save on usage, this was all logical to her as she had been using fluorescent for years for everything else... but there was a catch she wanted it to all be automatic... that's right... a timer!

The solution here was a fully digital appliance timer.. an appliance timer of this type is different from a mechanical lighting timer, as it uses a rely to switch things on and off. It is also has very low standby consumption and doesn't play with the voltage at all.

I mounted track lighting with large style fixture heads and installed dimmable CFL flood lamps in those to prevent the short ripple from the relay and the reactive current from the "shop light" type fixture over her african violet table from blowing the ballasts. And so far everything is behaving.
Anyway enough of this.. hope it helps a bit,

--

crashK6

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