Anyone suggest what the life expectancy of a 12" 8W fluorescent tube
should be? They seem to be lasting about 6months here with around 12hrs
a day use, much less than standard 5' 58W tubes.


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http://www.stopblair.eu/

bof at bof dot me dot uk

bof wrote:

Anyone suggest what the life expectancy of a 12" 8W fluorescent tube
should be? They seem to be lasting about 6months here with around 12hrs
a day use, much less than standard 5' 58W tubes.



Osram: 4500 hours "service life", 8000 hours "lifespan".

Philips: Don't say.

GE: Warmwhite 5000 hours "rated life".

GE: Coolwhite 8000 hours "rated life".

In article ,
bof wrote:
Anyone suggest what the life expectancy of a 12" 8W fluorescent tube
should be? They seem to be lasting about 6months here with around 12hrs
a day use, much less than standard 5' 58W tubes.

Probably down the to the driver. I've found those small tubes last as well
as any other.

--
*Remember not to forget that which you do not need to know.*

Dave Plowman London SW
To e-mail, change noise into sound.

On Nov 8, 1:07*pm, bof wrote:
Anyone suggest what the life expectancy of a 12" 8W fluorescent tube
should be? They seem to be lasting about 6months here with around 12hrs
a day use, much less than standard 5' 58W tubes.


I gather some ballasts do treat the tubes poorly.


NT

In message , Dave Osborne
writes
bof wrote:
Anyone suggest what the life expectancy of a 12" 8W fluorescent tube
should be? They seem to be lasting about 6months here with around
12hrs a day use, much less than standard 5' 58W tubes.


Osram: 4500 hours "service life", 8000 hours "lifespan".

Philips: Don't say.

GE: Warmwhite 5000 hours "rated life".

GE: Coolwhite 8000 hours "rated life".

Thanks, the current and previous tubes were Philips, but seems like
there's a problem, I can only guess it's with the driver unit.

--

http://www.stopblair.eu/

bof at bof dot me dot uk

In message , "Dave Plowman (News)"
writes
In article ,
bof wrote:
Anyone suggest what the life expectancy of a 12" 8W fluorescent tube
should be? They seem to be lasting about 6months here with around 12hrs
a day use, much less than standard 5' 58W tubes.

Probably down the to the driver. I've found those small tubes last as well
as any other.

Maybe I'll try another unit, see if there's any improvement, though it
may be cheaper just to keep feeding the current one tubes.


--

http://www.stopblair.eu/

bof at bof dot me dot uk

On Mon, 9 Nov 2009 17:58:29 +0000, bof wrote:

In message , Dave Osborne
writes
bof wrote:
Anyone suggest what the life expectancy of a 12" 8W fluorescent tube
should be? They seem to be lasting about 6months here with around
12hrs a day use, much less than standard 5' 58W tubes.


Osram: 4500 hours "service life", 8000 hours "lifespan".

Philips: Don't say.

GE: Warmwhite 5000 hours "rated life".

GE: Coolwhite 8000 hours "rated life".

Thanks, the current and previous tubes were Philips, but seems like
there's a problem, I can only guess it's with the driver unit.

Looking at small tubes (up to 20W) a couple of days ago, there was in some
cases a factor of 2 between electric and electronic, with the latter being
better.
--
Peter.
The head of a pin will hold more angels if
it's been flattened with an angel-grinder.

In article ,
bof writes:

Anyone suggest what the life expectancy of a 12" 8W fluorescent tube
should be? They seem to be lasting about 6months here with around 12hrs
a day use, much less than standard 5' 58W tubes.

Lots of possibilities.
How do they die? http://en.wikipedia.org/wiki/Fluores...mp#End_of_life

Poor control gear can have two detrimental effects on tube life.
Firstly, if it doesn't preheat the electrodes, these will wear
significantly at each switch-on. If a tube is switched on for less
than about 3 hours each time, tube life is generally limited by
the number of switch-ons rather than operating period.
Secondly, the current waveform (or more specifically, the "crest
factor") has an impact on the electrode life whilst the tube is
running. Good control gear has a low crest factor. Crappy high
frequency control gear (such as in a cheap torch) often has a
high crest factor and will wear a tube out quickly.

There are also lots of low quality tubes around in these sizes,
where there are many uses such as emergency lighting where the
tubes will never be operated long enough to reach end of life,
so short life doesn't matter.

What sort of control gear (or fitting) is it in?

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

In message , Andrew Gabriel
writes
In article ,
bof writes:

Anyone suggest what the life expectancy of a 12" 8W fluorescent tube
should be? They seem to be lasting about 6months here with around 12hrs
a day use, much less than standard 5' 58W tubes.

Lots of possibilities.
How do they die? http://en.wikipedia.org/wiki/Fluores...mp#End_of_life

Poor control gear can have two detrimental effects on tube life.
Firstly, if it doesn't preheat the electrodes, these will wear
significantly at each switch-on. If a tube is switched on for less
than about 3 hours each time, tube life is generally limited by
the number of switch-ons rather than operating period.
Secondly, the current waveform (or more specifically, the "crest
factor") has an impact on the electrode life whilst the tube is
running. Good control gear has a low crest factor. Crappy high
frequency control gear (such as in a cheap torch) often has a
high crest factor and will wear a tube out quickly.

There are also lots of low quality tubes around in these sizes,
where there are many uses such as emergency lighting where the
tubes will never be operated long enough to reach end of life,
so short life doesn't matter.

What sort of control gear (or fitting) is it in?

Bog standard (I assume) electronic mains powered surface mount white
box, pretty non descript really.



--

http://www.stopblair.eu/

bof at bof dot me dot uk

In article ,
bof writes:
In message , Andrew Gabriel
writes
In article ,
bof writes:

Anyone suggest what the life expectancy of a 12" 8W fluorescent tube
should be? They seem to be lasting about 6months here with around 12hrs
a day use, much less than standard 5' 58W tubes.

Lots of possibilities.
How do they die? http://en.wikipedia.org/wiki/Fluores...mp#End_of_life

Poor control gear can have two detrimental effects on tube life.
Firstly, if it doesn't preheat the electrodes, these will wear
significantly at each switch-on. If a tube is switched on for less
than about 3 hours each time, tube life is generally limited by
the number of switch-ons rather than operating period.
Secondly, the current waveform (or more specifically, the "crest
factor") has an impact on the electrode life whilst the tube is
running. Good control gear has a low crest factor. Crappy high
frequency control gear (such as in a cheap torch) often has a
high crest factor and will wear a tube out quickly.

There are also lots of low quality tubes around in these sizes,
where there are many uses such as emergency lighting where the
tubes will never be operated long enough to reach end of life,
so short life doesn't matter.

What sort of control gear (or fitting) is it in?

Bog standard (I assume) electronic mains powered surface mount white
box, pretty non descript really.

Not enough info to provide a useful answer.

Most of these I see are still mains magnetic ballasts and a starter.
Only tend to find electronic control gear in those with very slim
bodies (similar profile to the tube itself).

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

On Sun, 15 Nov 2009 22:22:16 +0000 (UTC), Andrew Gabriel wrote:

Bog standard (I assume) electronic mains powered surface mount white
box, pretty non descript really.

Not enough info to provide a useful answer.

Most of these I see are still mains magnetic ballasts and a starter.
Only tend to find electronic control gear in those with very slim
bodies (similar profile to the tube itself).

From limited searching, it would seem to be worth getting the electronic
ballast as the life of the tube can be twice as long as with the old type
of ballast.
Old-type ballast are a bit like NiCd batteries: still hanging around
although long superseded.
--
Peter.
The head of a pin will hold more angels if
it's been flattened with an angel-grinder.

In article , Andrew Gabriel
writes

Only tend to find electronic control gear in those with very slim
bodies (similar profile to the tube itself).

Are they any good? Fitted an "Eterna" one from B&Q (intended for under-
cupboard use in kitchens) in a display in a local pub a few weeks ago,
it's probably on 12 hours a day, and has already failed.

--
Mike Tomlinson

In article ,
Mike Tomlinson writes:
In article , Andrew Gabriel
writes

Only tend to find electronic control gear in those with very slim
bodies (similar profile to the tube itself).

Are they any good? Fitted an "Eterna" one from B&Q (intended for under-
cupboard use in kitchens) in a display in a local pub a few weeks ago,
it's probably on 12 hours a day, and has already failed.

I've fitted a few "Eterna"s, and no failures yet.
I would not expect them to be same quality as Orsam,
Philips, Tridonic, Helvar, etc ballasts, but it should
last longer than that.

I fitted many of the Omnicron ones before they vanished.
These fail to shutdown when the tube dies, and carry on
running the tube in cold cathode mode, until the heat
melts through the glass or makes the lampholder melt and
drop the tube out (both of which have happened). I could
imagine them starting a fire if fitted close to something
combustable.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

In article , Andrew Gabriel
writes

I've fitted a few "Eterna"s, and no failures yet.

Thanks. Have a replacement tube but not yet fitted it.

I would not expect them to be same quality as Orsam,
Philips, Tridonic, Helvar, etc ballasts, but it should
last longer than that.

Yes I've used more expensive fireworks which lasted longer.

I fitted many of the Omnicron ones before they vanished.
These fail to shutdown when the tube dies, and carry on
running the tube in cold cathode mode, until the heat
melts through the glass or makes the lampholder melt and
drop the tube out (both of which have happened). I could
imagine them starting a fire if fitted close to something
combustable.

Lovely. One to look out for.

--
Mike Tomlinson