Q: REGARDING T-8 4 FT LAMPS OVERHEATING

[pinb...@comcast.net]

Hello, was in the store the other day. wife was shopping i was bored
as usual. Looked up and saw plastic dripping from one of he 4ft tubes
in the store. One of the lamps had failed. this was the 4ft type
thinner octron bulbs i believe . the lamps had a plastic cover which
was red hot almost on fire where the end of the bulb was as the bulb
was failing. I looked at other lamps that were in the store and all
had these plastic covers on them. The ones that were burnt out also
had melting on the ends . Just wondering if this is normal for these
lamps to get that hot upon failure. I know the older t-12s didnt get
that hot. jr

[RBM]

<pinb...@comcast.net> wrote in message
news:e66381ce-2d2d-4159...@t54g2000hsg.googlegroups.com...

From my experience, I've found many fixture sockets don't make good contact
when the plastic tube cover ends are used. When this occurs, the arcing
causes the ends to melt and the lamps ultimately go out

[ransley]

On Jul 18, 3:10 pm, "pinbal...@comcast.net" <pinbal...@comcast.net>
wrote:

You should call that store , when they fail they start fires. I have
heard of several large fires caused by bad ballasts.

[RBM]

"ransley" <Mark_R...@yahoo.com> wrote in message
news:b7a1fb4d-6888-41c9...@y21g2000hsf.googlegroups.com...

Fluorescent ballasts for the last 30 years or so, have had thermal cutouts
built into them, to prevent overheating, but prior to that, it was common
for them to smolder and smoke

[DanG]

If these are exposed bulbs that could fall to the floor if broken,
they have been slid inside a plastic tube to catch the broken
stuff. They are more liable to be T5s than T8s. The plastic
sleeves must not be quite the right type. If the bulbs are that
new, I'm sure they have electronic ballasts, not tar filled
magnetics. I am not aware of failure mode crating additional
heat.

--
______________________________
Keep the whole world singing . . . .
DanG (remove the sevens)
dgri...@7cox.net

<pinb...@comcast.net> wrote in message
news:e66381ce-2d2d-4159...@t54g2000hsg.googlegroups.com...

[pinb...@comcast.net]

On Jul 19, 7:53 am, "DanG" <dgrif...@7cox.net> wrote:
> If these are exposed bulbs that could fall to the floor if broken,
> they have been slid inside a plastic tube to catch the broken
> stuff.  They are more liable to be T5s than T8s.  The plastic
> sleeves must not be quite the right type.  If the bulbs are that
> new, I'm sure they have electronic ballasts, not tar filled
> magnetics.  I am not aware of failure mode crating additional
> heat.
>
> --
> ______________________________
> Keep the whole world singing . . . .
> DanG  (remove the sevens)

> dgriff...@7cox.net
>
> <pinbal...@comcast.net> wrote in message

>
> news:e66381ce-2d2d-4159...@t54g2000hsg.googlegroups.com...
>
>
>
> > Hello, was in the store the other day. wife was shopping i was
> > bored
> > as usual. Looked up and saw plastic dripping from one of he 4ft
> > tubes
> > in the store. One of the lamps had failed. this was the 4ft type
> > thinner octron bulbs i believe . the lamps had a plastic cover
> > which
> > was red hot almost on fire where the end of the bulb was as the
> > bulb
> > was failing. I looked at other lamps that were in the store and
> > all
> > had these plastic covers on them. The ones that were burnt out
> > also
> > had melting on the ends  . Just wondering if this is normal for
> > these
> > lamps to get that hot upon failure.  I know the older t-12s
> > didnt get

> > that hot. jr- Hide quoted text -
>
> - Show quoted text -

surprisingly, these are t8's. the fixtures all look to have been
retrofitted from t-12's. They must have the electronic ballasts
because the failed lamps are singles and are completely off not
flickering like the t-12's did when failed. I just thought the
electronic ballasts had some type of overheat protection to shut the
fixture down in case of overheating. doesnt seem like the sockets are
failing. All lamps have these plastic tubes on them. The failed bulbs
have the 3" dark spot on the bulb ends and all of them the plastic is
charred or melted /burned away in this area on the tube. Like I said I
saw a bulb that was flickering on its way out, tube plastic red hot
dripping on the floor. told cashier she was more concerned with her bf
on her cell. I Had to catch a movie with wife.

[RBM]

<pinb...@comcast.net> wrote in message
news:0f6d2727-dfe9-4c56...@h17g2000prg.googlegroups.com...

The electronic ballasts do have thermal protection. It's not the ballast
that's overheating.