running fluorescent light w/ one tube dead?
Nate Nagel
fluorescent fixture w/ a dead tube... specific application is my desk
light, it's a (very old) Dazor "floating fixture" deal that well
predates electronic ballasts. Uses two F15T8 tubes and I don't have any
floating around. OK to use as is until I can get some or should I
scavenge around the house for another lamp that will produce acceptable
light? I anticipate being snowed in tomorrow so running to the store is
not an option, I'll likely be splitting my time between being at my desk
and shoveling.
nate
--
replace "roosters" with "cox" to reply.
http://members.cox.net/njnagel
Pete C.
You sure you have the correct tubes in it? As far as I know, electronic
ballasts well predate T8 fluorescent tubes. T12 would be more likely if
the fixture is really old.
Nate Nagel
Pretty sure, there's a few of the same lights but with clamp bases
floating around at work (presumably for back when they had draftsmen
that used paper and pencils) and they use the same tubes.
Actually I "solved" the problem by remembering that there were some
under counter lights in the kitchen that we never use and it turns out
that they use the same size tubes, so I appropriated one of those until
I can go out and get some more.
Don Klipstein
>
>Nate Nagel wrote:
>>
>> just curious if there are any long-term negative consequences to using a
>> fluorescent fixture w/ a dead tube... specific application is my desk
>> light, it's a (very old) Dazor "floating fixture" deal that well
>> predates electronic ballasts. Uses two F15T8 tubes and I don't have any
>> floating around. OK to use as is until I can get some or should I
>> scavenge around the house for another lamp that will produce acceptable
>> light? I anticipate being snowed in tomorrow so running to the store is
>> not an option, I'll likely be splitting my time between being at my desk
>> and shoveling.
>
>ballasts well predate T8 fluorescent tubes. T12 would be more likely if
>the fixture is really old.
15 watt tubes came in both T8 and T12 sizes, with T8 being more common.
15 watt T8 is a long-standing and traditional size, probably dating back
to the 1950's or so.
17 and 32 watt T8 are newer, but they predate common use of electronic
ballasts. However, they were hardly used except with these modern
electronic ballasts.
- Don Klipstein (d...@misty.com)
Don Klipstein
>just curious if there are any long-term negative consequences to using a
>fluorescent fixture w/ a dead tube... specific application is my desk
>light, it's a (very old) Dazor "floating fixture" deal that well
>predates electronic ballasts. Uses two F15T8 tubes and I don't have any
>floating around. OK to use as is until I can get some or should I
>scavenge around the house for another lamp that will produce acceptable
>light? I anticipate being snowed in tomorrow so running to the store is
>not an option, I'll likely be splitting my time between being at my desk
>and shoveling.
If a 120V fixture has two F15T8 tubes, and one tube can light while the
other is dead, and it well predates electronic ballasts:
Chances are it has two ballasts. That makes it safe to run only one
bulb.
I would remove the dead bulb or the starter for it, unless the fixture
has "manual start" (a "start" button and an "off" button and no starters).
Beware of a dead bulb glowing only at its ends, even if only a dimmish
orange, in a preheat fixture due to a stuck starter. I have known a
ballast to catch fire from that.
- Don Klipstein (d...@misty.com)
N8N
> In article <hkt99l0...@news2.newsguy.com>, Nate Nagel wrote:
> >just curious if there are any long-term negative consequences to using a
> >fluorescent fixture w/ a dead tube... specific application is my desk
> >light, it's a (very old) Dazor "floating fixture" deal that well
> >predates electronic ballasts. Uses two F15T8 tubes and I don't have any
> >floating around. OK to use as is until I can get some or should I
> >scavenge around the house for another lamp that will produce acceptable
> >light? I anticipate being snowed in tomorrow so running to the store is
> >not an option, I'll likely be splitting my time between being at my desk
> >and shoveling.
>
> If a 120V fixture has two F15T8 tubes, and one tube can light while the
> other is dead, and it well predates electronic ballasts:
>
> Chances are it has two ballasts. That makes it safe to run only one
> bulb.
You're correct in that it does have two ballasts. I did not realize
this until after I posted, however. I'd just acquired said fixture
when I posted, and one of the tubes that came with it died almost
immediately. I discovered two separate ballasts in the base when I
cleaned it up and gave it a coat of wax. It must be really old,
because it apparently was used in a time when architects, draftsmen,
etc. could smoke at their desks :/ I guess that explains the use of a
coppery brown paint color, it hides the tar stains...
>
> I would remove the dead bulb or the starter for it, unless the fixture
> has "manual start" (a "start" button and an "off" button and no starters).
> Beware of a dead bulb glowing only at its ends, even if only a dimmish
> orange, in a preheat fixture due to a stuck starter. I have known a
> ballast to catch fire from that.
It does in fact have two buttons, and you have to hold the "on" button
down for a second to "start" the tubes.
I just went ahead and ordered two new tubes for it, because it was
easier than fighting my way to any of the local hardware stores, and
also I could get "full spectrum" tubes online. As I said in my
previous post, I found that the under cabinet lights in my kitchen
used the same tubes, so I appropriated one of those as a temporary
measure, so I've been able to keep using the desk lamp - but thanks
for the reply in any case.
I take it that since you prefaced stating that it was safe to use by
telling me that it probably had two ballasts, that that means it's
generally a bad idea to use a fixture with multiple tubes on a single
ballast with a bad tube?
nate
Nate Nagel
check this out...
was just sitting at my desk, with the lamp we've been discussing lit...
noticed that one of the ballasts was humming up a storm, enough to be
not only noticeable but also mildly annoying. Disassembled base again,
and removed both ballasts, thinking I'd insulate them from the metal
with a little friction tape. Here one of them had one of its leads
pinched between the core and the base of the lamp! I rearranged those
wires, and also went ahead and put some friction tape on the top and
bottom of the two ballasts. Nice and quiet now!
Wonder how many years it was buzzing? It's got a two-wire,
non-polarized cord, so it has to have been quite a few! (which
introduces the possibility that had it been left like that for another
50 years or so, someone might have gotten an unpleasant surprise,
depending on exactly how it was wired...)
Now why, may you ask, am I messing with a probably 50 year old desk
lamp? 'cause it's the one I wanted, and I'm too damn cheap to pay $300
plus for a new one, that's why.
bud--
IMHO you want a ballast tight against an enclosure to transfer heat out
of the ballast, and don't want to do anything that would add thermal
insulation to the ballast.
--
bud--
Don Klipstein
wrote:
>On Feb 10, 7:10�pm, d...@manx.misty.com (Don Klipstein) wrote:
>> In article <hkt99l0...@news2.newsguy.com>, Nate Nagel wrote:
>> � I would remove the dead bulb or the starter for it, unless the fixture
>> has "manual start" (a "start" button and an "off" button and no starters). �
>> Beware of a dead bulb glowing only at its ends, even if only a dimmish
>> orange, in a preheat fixture due to a stuck starter. �I have known a
>> ballast to catch fire from that.
>
>It does in fact have two buttons, and you have to hold the "on" button
>down for a second to "start" the tubes.
That fixture is in good shape for bad tubes.
>I just went ahead and ordered two new tubes for it, because it was
>easier than fighting my way to any of the local hardware stores, and
>also I could get "full spectrum" tubes online.
Hope you get as much light as you want... Let us know if you do. Full
spectrum fluorescents produce less light than ones with color rendering
index mid-80's or less.
> As I said in my previous post, I found that the under cabinet lights in
>my kitchen used the same tubes, so I appropriated one of those as a
>temporary measure, so I've been able to keep using the desk lamp - but
>thanks for the reply in any case.
>
>I take it that since you prefaced stating that it was safe to use by
>telling me that it probably had two ballasts, that that means it's
>generally a bad idea to use a fixture with multiple tubes on a single
>ballast with a bad tube?
Now that I am putting some thought into that one...
Multiple tubes, single ballast, non-electronic ballast...
I can't think of any situation where a bad tube does not knock the
other(s) out or dim, nor any situation that endangers the ballast.
If one of 2 tubes on a 2-tube ballast conks out and the other is very
dim as a result, prlonged dim operation may cause extra wear on the good
tube. If you see any orange end glow, prolonged operation that way is
sometimes hard on the tube. One thing to watch for - if one tube is out
and the other is dim, or if they are unequally very dim, the
glowing/brighter one is not always the good one.
- Don Klipstein (d...@misty.com)
Nate Nagel
> In<7e67e416-8668-414a...@15g2000yqi.googlegroups.com>, N8N
> wrote:
>
>> On Feb 10, 7:10 pm, d...@manx.misty.com (Don Klipstein) wrote:
>>> In article<hkt99l0...@news2.newsguy.com>, Nate Nagel wrote:
>
>>> I would remove the dead bulb or the starter for it, unless the fixture
>>> has "manual start" (a "start" button and an "off" button and no starters).
>>> Beware of a dead bulb glowing only at its ends, even if only a dimmish
>>> orange, in a preheat fixture due to a stuck starter. I have known a
>>> ballast to catch fire from that.
>>
>> It does in fact have two buttons, and you have to hold the "on" button
>> down for a second to "start" the tubes.
>
> That fixture is in good shape for bad tubes.
>
>> I just went ahead and ordered two new tubes for it, because it was
>> easier than fighting my way to any of the local hardware stores, and
>> also I could get "full spectrum" tubes online.
>
> Hope you get as much light as you want... Let us know if you do. Full
> spectrum fluorescents produce less light than ones with color rendering
> index mid-80's or less.
Well, you thought I wouldn't remember, but I did :) the tubes arrived
today, and they're just marked "F15 T8 5500K Full Spectrum" and they're
actually rather attractive in terms of light color and how they make the
crap on my desk appear, and they seem to be at least as bright as the
old tubes of questionable age and functionality that I had before :)
Granted, I'm using two 15W tubes to illuminate a standard sized office
desk, so it's gonna be bright no matter what.
nate
>
>> As I said in my previous post, I found that the under cabinet lights in
>> my kitchen used the same tubes, so I appropriated one of those as a
>> temporary measure, so I've been able to keep using the desk lamp - but
>> thanks for the reply in any case.
>>
>> I take it that since you prefaced stating that it was safe to use by
>> telling me that it probably had two ballasts, that that means it's
>> generally a bad idea to use a fixture with multiple tubes on a single
>> ballast with a bad tube?
>
> Now that I am putting some thought into that one...
>
> Multiple tubes, single ballast, non-electronic ballast...
>
> I can't think of any situation where a bad tube does not knock the
> other(s) out or dim, nor any situation that endangers the ballast.
>
> If one of 2 tubes on a 2-tube ballast conks out and the other is very
> dim as a result, prlonged dim operation may cause extra wear on the good
> tube. If you see any orange end glow, prolonged operation that way is
> sometimes hard on the tube. One thing to watch for - if one tube is out
> and the other is dim, or if they are unequally very dim, the
> glowing/brighter one is not always the good one.
>
> - Don Klipstein (d...@misty.com)