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Posted to alt.home.repair
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Where is my problem with this flourescent lamp?
In article , Peter wrote:
On 4/26/2010 5:44 PM, Don Klipstein wrote:
In , Peter wrote:
On 4/24/2010 9:10 PM, The Daring Dufas wrote:
wrote:
On Sat, 24 Apr 2010 11:57:29 -0400, wrote:
SNIP to here to edit for space
I was able to pull off the rotating shade, unscrew the bulb socket,
pull it out about 2", and observe a 1" glass bulb that looks almost
like a neon bulb with an opaque mercury-like metallic coating on the
inside of the glass bulb. There are 2 wires coming out of the base of
this little bulb, 1 connected to the black, and the other to the
white power wires that enter the base of the socket. Perhaps this is
the hard-wired starter? There are no markings on it at all. I
reattached the bulb, plugged in the fixture, and turn it on while
observing the little glass bulb. Nothing at all; no glow, no sparks,
no "tink" "tink" "tink". What do I replace it with?
Try an NE2 bulb? That's what used to be in the old starters.
ERRRRRRR! Wrong! I would suggest you find an old florescent starter
and take it apart, carefully break the glass off the silvered bulb
and you will find a heat activated bi-metal switch. A little searching
of The Interweb will help you learn how it works.
TDD
Follow up:
I cannibalized an unused FS-2 starter I found in my "junk box" and wired
in it's glow bulb in place of the defective glow bulb I clipped out. To
my surprise anddisappointment, when I replaced the CFL bulb, plugged in
the fixture and turned it on, the fixture and the glow bulb both
continuously flickered. I waited about 5-10 seconds to see if it would
stabilze; it didn't. I turned off the fixture, waited about 10 seconds,
tried again with the same result. I then added the capacitor from the
FS-2 in parallel with the glow bulb (as it was wired within the FS-2).
Same behavior.
Should I assume that the glow bulb from the FS-2 is mismatched to this
circuit (although the CLF is 18W and the FS-2 is rated for 14, 15, and
20W bulbs), or that something else is wrong in the circuit? Should I buy
a starter with a higher rating and try again with that?
This is a bit of a surprise to me. I have a fair amount of experience
with homebrewing and hacking of preheat fluorescent lamp fixtures, and the
behavior suggests to me that the starter is re-glowing too easily from the
voltage needed to fire the lamp.
This may be from the ballast skimping on current - that can make
starting crankier, and then the fixture can get fussier about starters.
You may be able to fix this by using a different FS-2 or FS-2 variant
starter, preferably one rated to start 22 watt lamps (along with lower
wattages).
Also, proper grounding may make a difference. Did you remove any during
your troubleshooting and repair attempt?
Winding a few turns of bare wire around the bulb, over the filaments,
has some chance of making the bulb easier to fire. This has to do with
capacitive coupling through the glass, so that a very small amount of
current does not have to go through the full length of the bulb. That may
make the gas in the bulb "break down" more easily.
There is even a remote chance that reversing the leads of the starter
will make things better. If ionization in the bulb occurs more easily on
one half-cycle of AC than the other due to polarity of the electrode on
the "hot side", then reversing the leads of the starter may make a
difference. I have seen starters having a polarity when used with DC.
Also try reversing the plug, to reverse hot and neutral, if the plug
blades are the same width. (I forget already whether or not you said the
plug blades were equal width or not.) And check for hot-neutral reverse
at your outlet - that does affect a few cranky fluorescent fixtures.
Don,
As far as grounding is concerned, I did not need to remove any special
grounding, and replaced everything exactly as it had been, including the
foil lined rotating shade, only substituting the cannibalized innards of
the FS-2 starter for the glow bulb that I removed. (The original glow
bulb did not glow when I applied power. The one from the FS-2 glows
lavender). This has become a long thread with multiple side arms. You
probably missed some of my previous posts were I stated that the
fixture's power plug is 2 prong polarized, and I've checked the wall
receptacle with a 3 neon lamp circuit tester designed to detect open
grounds, open neutrals, reversed connections, etc. (it checks "correct
wiring".
One clue that I failed to mention to date is that the original glow bulb
was substantially larger (both longer and greater diameter) than the one
from the FS-2. Does that help you make a recommendation to me of which
model starter I should purchase and cannibalize to try in place of the
one from the FS-2?
That does not tell me much. I have seen very different shapes and very
different sizes of bulbs inside FS-2 starters, depending on their brand
and maybe when they were made.
--
- Don Klipstein )
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