About failed CFLs (pics)

[J Tiers]

OK, several pics, of a failed "curly tail" CFL, bought from Home Depot, their older "nameless brand name". Note that there is NO heatsink whatsoever on the devices. Also NO air vents of any consequence in the case.

The design seems to be essentially a type of "Royer" oscillator, or other "flip-flop derived" oscillator, as there is a small toroid, a larger inductor or transformer, and a pair of transistors with no discernible drive circuitry or control IC. The small toroid might reasonably be assumed to be the saturating inductor.

Once device catastrophically failed, splitting its case wide open (pic3), and heating/burning several other components (pic 2, etc).

A hole was apparently also burned in the tube. In the last picture (see the second post below, bless this BBS program.......with a brick) there is visible a hole in the tube near the base, at which point the tube cracked through. The hole may have been made by the filament getting full voltage and burning out, then arcing, generating enough heat to melt the glass locally. The pressure difference may have made the hole through the melted glass. It probably cracked when it cooled.

This one actually failed fairly cleanly, without fanfare... I smelled it, and it was not acting right, although it was still lighting. However, it seems that it SHOULD have totally quit with the damage it sustained internally. It is NOT right that it should have continued to "work", without blowing an internal fuse, or the like. It could only have been lighting by a small current going thru due to 60Hz leakage.

The other one (so far) shot out sparks, and might have caused a fire if not seen and shut off. I haven't cut it open, I'm saving it as evidence. I needn't have cut this one open, apparently they are only "snapped" together, and are not glued or positively held.

The one positive thing I see is that they didn't suffer a breach of the case. The plastic must be fairly good at resisting heat

[J Tiers]

The last pictures including hole in the glass.

The CFL in question is a "Commercial Electric" brand, sold by Home Depot up until a year or so back.
Model CBPESL23TM, SKU#368-875
marked 23W, 380 mA

NOT marked to indicate a problem with operating base up, which is how 95% of the CFLs in my house are operating..

[dp]

No doubt that thing is headed for the hazardous waste disposal as we speak? he said tongue in cheek.

[J Tiers]

T'ain't hazardous anymore..... the mercury all evaporated through the crack!

We have flourescent recycling, as well as general hazmat, but this one is also being kept for evidence.

[nheng]

You have pushed my emergency response button This cr-p is amazing and the public sits there and lets it be shoved down our throats.

I bought a half dozen Sylvania 40w and 60w from Lowes about 3 - 4 weeks ago. Would you believe that 2 have already failed? Of 3, 2 tube workshop lights bought from Home Depot in the last 2 years, 2 have become intermittent. They will go dark and then come back on a while later.

Are you comfortable leaving your house with one of these cr-p lights on?

We can't allow our homes to go up in smoke while these AMERICAN companies push for every penny of savings at our expense.

Oh yeah, of those 6 Sylvanias, a third one takes about 3 seconds to turn on at all now, making a buzz as the inverter circuit trys to start up.

You, J.T. and others, need to get images like this into the hands of the PUBLIC and POLITICIANS.

You've just reminded me J.T. ... I will be calling Sylvania Customer Service and hopefully their quality and maybe their engineering departments.

[lazlo]

As some may remember from the amusing Safety Harness thread, I'm an avid rock climber. A couple of years ago I bought a finger training board to hang in our game-room (basically a pull-up board with various one- and two-finger holds).

So I swing by the local Home Depot to pick up some 5/16" lag bolts (as per the manufacturers instructions) to anchor the board into the wall studs. I hang the board up, go for my first finger hold, and one of the bolts shears right across the head. (!)

I'm 190 lbs, and let's give the bolt the benefit of the doubt that my momentum doubled the load to 400 lbs of dynamic stress, spread across two 5/16" bolts.

Scary stuff. I don't buy nuts or bolts at Home Depot anymore...

By the way Jerry -- was the CFL UL listed?

[nheng]

I found this site by Googling for "cfl failures". It has a concise summary of cfl failures and more.

http://sound.westhost.com/articles/incandescent.htm

This is a quote from one of the links at the above site. It is in regard to Sylvania failures and the INCREDIBLE reply from UL.

" ... I did receive a reply from UL (Underwriter's Laboratory) and they stated the smoking and overheating was a common occurrence for this type of lamp at end of life."

So UL is going to guarantee where there's smoke there ISN'T fire ???

[daveo]

I had one do the same exact thing!

[J Tiers]

Originally Posted by lazlo

By the way Jerry -- was the CFL UL listed?

UL E170906

Fcc symbol also

[jacampb2]

I have had several of the CFL's burn up in much the same way. Some have melted the base, I have had several melt through the bulb in the exact same way that yours did, but with a much bigger hole melted in the glass. I have 18 47w(I think, 150w equivalent) in my shop. I always assumed it was due to metallic dust in the shop. Mine do have ventilation holes in the plastic. Seeing that yours are doing it in your home though, may rule out my theory.

I normally just take mine back to home depot and get them replaced. I have probably been through 50 bulbs in the 3 years they have been there.

Later,
Jason