I have permanent standard 40W 48" fluorescent fixtures in the bathroom (1)
and kitchen (3) installed by the builder 14 years ago (I have owned house
for 5 years). Recently, a bulb in the bathroom failed. Until I could
purchase a new bulb, I "borrowed" a bulb from the kitchen to use in the
bathroom. It works just fine.
Meanwhile I bought a two pack of GE kitchen and bath bulbs. I replaced the
missing bulb in the kitchen fixture. There was some flickering at first but
that went away. The next day, the fixture suddenly went out although the
other fluorescent fixtures on the switch stayed on. I replaced the new bulb
with the second new one and still had problems so I put both new ones in. It
worked fine for a few days, then suddenly went out again. When the switch is
turned off overnight, it comes back on again.

Some facts:
The fixture worked fine until I borrowed the bulb.
I have not tried shutting light off for shorter than overnight (It has only
been a few days).
I have had problems with the two new bulbs and with each of the new bulbs
paired with the old bulb.
It is a pain to get to the bulbs so I hate just moving bulbs around for
"fun".
I know the ballast could have suddenly had problems but it seemed so
coincidental.

Any suggestions?

John Pezzano

some additional facts:

There are no starters on these fixtures

The lights have a noticeable delay turning on vs. the other fixtures on the
same switch,

John

"John Pezzano" wrote in message
...
I have permanent standard 40W 48" fluorescent fixtures in the bathroom (1)
and kitchen (3) installed by the builder 14 years ago (I have owned house
for 5 years). Recently, a bulb in the bathroom failed. Until I could
purchase a new bulb, I "borrowed" a bulb from the kitchen to use in the
bathroom. It works just fine.
Meanwhile I bought a two pack of GE kitchen and bath bulbs. I replaced the
missing bulb in the kitchen fixture. There was some flickering at first
but that went away. The next day, the fixture suddenly went out although
the other fluorescent fixtures on the switch stayed on. I replaced the new
bulb with the second new one and still had problems so I put both new ones
in. It worked fine for a few days, then suddenly went out again. When the
switch is turned off overnight, it comes back on again.

Some facts:
The fixture worked fine until I borrowed the bulb.
I have not tried shutting light off for shorter than overnight (It has
only been a few days).
I have had problems with the two new bulbs and with each of the new bulbs
paired with the old bulb.
It is a pain to get to the bulbs so I hate just moving bulbs around for
"fun".
I know the ballast could have suddenly had problems but it seemed so
coincidental.

Any suggestions?

John Pezzano

But why suddenly would it have problems just when I put in new bulbs? It
worked fine with old ones.

Remember, replacing the bulbs is a pain - replacing the fixture (might as
well go the whole way and likely just as cheap) would be even more
difficult.

John

"Meat Plow" wrote in message
news
On Mon, 05 Feb 2007 15:32:30 -0500, John Pezzano Has Frothed:

I have permanent standard 40W 48" fluorescent fixtures in the bathroom
(1)
and kitchen (3) installed by the builder 14 years ago (I have owned
house
for 5 years). Recently, a bulb in the bathroom failed. Until I could
purchase a new bulb, I "borrowed" a bulb from the kitchen to use in the
bathroom. It works just fine.
Meanwhile I bought a two pack of GE kitchen and bath bulbs. I replaced
the
missing bulb in the kitchen fixture. There was some flickering at first
but
that went away. The next day, the fixture suddenly went out although the
other fluorescent fixtures on the switch stayed on. I replaced the new
bulb
with the second new one and still had problems so I put both new ones in.
It
worked fine for a few days, then suddenly went out again. When the switch
is
turned off overnight, it comes back on again.

Some facts:
The fixture worked fine until I borrowed the bulb.
I have not tried shutting light off for shorter than overnight (It has
only
been a few days).
I have had problems with the two new bulbs and with each of the new bulbs
paired with the old bulb.
It is a pain to get to the bulbs so I hate just moving bulbs around for
"fun".
I know the ballast could have suddenly had problems but it seemed so
coincidental.

Any suggestions?

John Pezzano

Change the ballast.


--
Pierre Salinger Memorial Hook, Line & Sinker, June 2004

COOSN-266-06-25794

On Mon, 5 Feb 2007 15:32:30 -0500, "John Pezzano"
wrote:

I have permanent standard 40W 48" fluorescent fixtures in the bathroom (1)
and kitchen (3) installed by the builder 14 years ago (I have owned house
for 5 years). Recently, a bulb in the bathroom failed. Until I could
purchase a new bulb, I "borrowed" a bulb from the kitchen to use in the
bathroom. It works just fine.
Meanwhile I bought a two pack of GE kitchen and bath bulbs. I replaced the
missing bulb in the kitchen fixture. There was some flickering at first but
that went away. The next day, the fixture suddenly went out although the
other fluorescent fixtures on the switch stayed on. I replaced the new bulb
with the second new one and still had problems so I put both new ones in. It
worked fine for a few days, then suddenly went out again. When the switch is
turned off overnight, it comes back on again.

Some facts:
The fixture worked fine until I borrowed the bulb.
I have not tried shutting light off for shorter than overnight (It has only
been a few days).
I have had problems with the two new bulbs and with each of the new bulbs
paired with the old bulb.
It is a pain to get to the bulbs so I hate just moving bulbs around for
"fun".
I know the ballast could have suddenly had problems but it seemed so
coincidental.

Any suggestions?

Older ballasts are only for 40 watt bulbs unless marked for 34 watt
lamps. If the new bulbs are 34 watt lamps, they will draw too much
line current and the ballast may be tripping the thermal cutout which
must then cool. Ballasts may have to be replaced or 40 watt bulbs
used. Label on the ballast will be the source of an answer.
--
Mr.E

Consider the following assume the only thing you did to the fixture in
one calendar year was to replace one lamp. Now, if something fails in
the fixture within that one calendar year, the chance of that occurring
on any specific day is 1:365. Hey! The lottery is at 23 mil! How many
tics are you going to buy at 1:365 odds of winning? Thought so...
JR

John Pezzano wrote:
I have permanent standard 40W 48" fluorescent fixtures in the bathroom (1)
and kitchen (3) installed by the builder 14 years ago (I have owned house
for 5 years). Recently, a bulb in the bathroom failed. Until I could
purchase a new bulb, I "borrowed" a bulb from the kitchen to use in the
bathroom. It works just fine.
Meanwhile I bought a two pack of GE kitchen and bath bulbs. I replaced the
missing bulb in the kitchen fixture. There was some flickering at first but
that went away. The next day, the fixture suddenly went out although the
other fluorescent fixtures on the switch stayed on. I replaced the new bulb
with the second new one and still had problems so I put both new ones in. It
worked fine for a few days, then suddenly went out again. When the switch is
turned off overnight, it comes back on again.

Some facts:
The fixture worked fine until I borrowed the bulb.
I have not tried shutting light off for shorter than overnight (It has only
been a few days).
I have had problems with the two new bulbs and with each of the new bulbs
paired with the old bulb.
It is a pain to get to the bulbs so I hate just moving bulbs around for
"fun".
I know the ballast could have suddenly had problems but it seemed so
coincidental.

Any suggestions?

John Pezzano




--
--------------------------------------------------------------
Home Page: http://www.seanet.com/~jasonrnorth

Both are F40. The old one is F40RES (residential). The new ones are F40T12
(kitchen and bath). I have used the new ones in the other fixtures
intermixed with the old bulbs in the past with no problems.

John

wrote in message
...
On Mon, 5 Feb 2007 15:32:30 -0500, "John Pezzano"
wrote:

I have permanent standard 40W 48" fluorescent fixtures in the bathroom (1)
and kitchen (3) installed by the builder 14 years ago (I have owned house
for 5 years). Recently, a bulb in the bathroom failed. Until I could
purchase a new bulb, I "borrowed" a bulb from the kitchen to use in the
bathroom. It works just fine.
Meanwhile I bought a two pack of GE kitchen and bath bulbs. I replaced the
missing bulb in the kitchen fixture. There was some flickering at first
but
that went away. The next day, the fixture suddenly went out although the
other fluorescent fixtures on the switch stayed on. I replaced the new
bulb
with the second new one and still had problems so I put both new ones in.
It
worked fine for a few days, then suddenly went out again. When the switch
is
turned off overnight, it comes back on again.

Some facts:
The fixture worked fine until I borrowed the bulb.
I have not tried shutting light off for shorter than overnight (It has
only
been a few days).
I have had problems with the two new bulbs and with each of the new bulbs
paired with the old bulb.
It is a pain to get to the bulbs so I hate just moving bulbs around for
"fun".
I know the ballast could have suddenly had problems but it seemed so
coincidental.

Any suggestions?

Older ballasts are only for 40 watt bulbs unless marked for 34 watt
lamps. If the new bulbs are 34 watt lamps, they will draw too much
line current and the ballast may be tripping the thermal cutout which
must then cool. Ballasts may have to be replaced or 40 watt bulbs
used. Label on the ballast will be the source of an answer.
--
Mr.E

On Feb 5, 2:41 pm, Meat Plow wrote:
On Mon, 05 Feb 2007 15:32:30 -0500, John Pezzano Has Frothed:



I have permanent standard 40W 48" fluorescent fixtures in the bathroom (1)
and kitchen (3) installed by the builder 14 years ago (I have owned house
for 5 years). Recently, a bulb in the bathroom failed. Until I could
purchase a new bulb, I "borrowed" a bulb from the kitchen to use in the
bathroom. It works just fine.
Meanwhile I bought a two pack of GE kitchen and bath bulbs. I replaced the
missing bulb in the kitchen fixture. There was some flickering at first but
that went away. The next day, the fixture suddenly went out although the
other fluorescent fixtures on the switch stayed on. I replaced the new bulb
with the second new one and still had problems so I put both new ones in. It
worked fine for a few days, then suddenly went out again. When the switch is
turned off overnight, it comes back on again.

Some facts:
The fixture worked fine until I borrowed the bulb.
I have not tried shutting light off for shorter than overnight (It has only
been a few days).
I have had problems with the two new bulbs and with each of the new bulbs
paired with the old bulb.
It is a pain to get to the bulbs so I hate just moving bulbs around for
"fun".
I know the ballast could have suddenly had problems but it seemed so
coincidental.

Any suggestions?

John Pezzano

Change the ballast.


Hey troll, I just wanted to send you this message to make you give me
some lame replies and call me Jerkoff instead of Perkoff, cause I made
perkoff.com expecting no one to refer to it as Jerkoff. LOL you're
the typical idiot I was thinking of when the whole "Perkoff" concept
was thought up.

Anyway I'm not gonna reply to you any longer just watch you call me
Jerkoff instead of Perkoff and change around links I post from
perkoff.com to jerkoff.com.

LOL You the man.

No but seriously, your months of following me around doing the
same(lame) thing has gotten sorta lame. You're just not that
entertaining anymore.

Have fun obsessing over me, you jerkoff.

wrote in message
...
On Mon, 5 Feb 2007 15:32:30 -0500, "John Pezzano"
wrote:

I have permanent standard 40W 48" fluorescent fixtures in the bathroom (1)
and kitchen (3) installed by the builder 14 years ago (I have owned house
for 5 years). Recently, a bulb in the bathroom failed. Until I could
purchase a new bulb, I "borrowed" a bulb from the kitchen to use in the
bathroom. It works just fine.
Meanwhile I bought a two pack of GE kitchen and bath bulbs. I replaced the
missing bulb in the kitchen fixture. There was some flickering at first
but
that went away. The next day, the fixture suddenly went out although the
other fluorescent fixtures on the switch stayed on. I replaced the new
bulb
with the second new one and still had problems so I put both new ones in.
It
worked fine for a few days, then suddenly went out again. When the switch
is
turned off overnight, it comes back on again.

Some facts:
The fixture worked fine until I borrowed the bulb.
I have not tried shutting light off for shorter than overnight (It has
only
been a few days).
I have had problems with the two new bulbs and with each of the new bulbs
paired with the old bulb.
It is a pain to get to the bulbs so I hate just moving bulbs around for
"fun".
I know the ballast could have suddenly had problems but it seemed so
coincidental.

Any suggestions?

Older ballasts are only for 40 watt bulbs unless marked for 34 watt
lamps. If the new bulbs are 34 watt lamps, they will draw too much
line current and the ballast may be tripping the thermal cutout which
must then cool. Ballasts may have to be replaced or 40 watt bulbs
used. Label on the ballast will be the source of an answer.
--
Mr.E

Not my field, so I'll take your word for it, but are you able to explain
*why* a lower rated tube will pull more line current ? Just curious.

Arfa

On Tue, 06 Feb 2007 00:42:52 GMT, "Arfa Daily"
wrote:


wrote in message
.. .
On Mon, 5 Feb 2007 15:32:30 -0500, "John Pezzano"
wrote:

I have permanent standard 40W 48" fluorescent fixtures in the bathroom (1)
and kitchen (3) installed by the builder 14 years ago (I have owned house
for 5 years). Recently, a bulb in the bathroom failed. Until I could
purchase a new bulb, I "borrowed" a bulb from the kitchen to use in the
bathroom. It works just fine.
Meanwhile I bought a two pack of GE kitchen and bath bulbs. I replaced the
missing bulb in the kitchen fixture. There was some flickering at first
but
that went away. The next day, the fixture suddenly went out although the
other fluorescent fixtures on the switch stayed on. I replaced the new
bulb
with the second new one and still had problems so I put both new ones in.
It
worked fine for a few days, then suddenly went out again. When the switch
is
turned off overnight, it comes back on again.

Some facts:
The fixture worked fine until I borrowed the bulb.
I have not tried shutting light off for shorter than overnight (It has
only
been a few days).
I have had problems with the two new bulbs and with each of the new bulbs
paired with the old bulb.
It is a pain to get to the bulbs so I hate just moving bulbs around for
"fun".
I know the ballast could have suddenly had problems but it seemed so
coincidental.

Any suggestions?

Older ballasts are only for 40 watt bulbs unless marked for 34 watt
lamps. If the new bulbs are 34 watt lamps, they will draw too much
line current and the ballast may be tripping the thermal cutout which
must then cool. Ballasts may have to be replaced or 40 watt bulbs
used. Label on the ballast will be the source of an answer.
--
Mr.E

Not my field, so I'll take your word for it, but are you able to explain
*why* a lower rated tube will pull more line current ? Just curious.

Google "34 watt fluorescent fire hazard"
I think its the problem with older ballasts putting too much wattage
thru the tubes (as in voltage across each tube) rather than limiting
the power in watts to the tubes (as the voltages across the 34 and 40
watt tubes are different).
--
Mr.E

Check the new bulbs. Most new ones are energy efficient 36 watt type. I
have had problems in old inductance ballast fixtures with these. some times
they won't start unless I flip the switch on and off quickly. I have one
that cycles on the thermal which is what yours sounds like it is doing. Had
no problem until the replacement bulbs were used.
--
Bob L.
Lindenhurst, NY
"John Pezzano" wrote in message
...
But why suddenly would it have problems just when I put in new bulbs? It
worked fine with old ones.

Remember, replacing the bulbs is a pain - replacing the fixture (might as
well go the whole way and likely just as cheap) would be even more
difficult.

John

"Meat Plow" wrote in message
news
On Mon, 05 Feb 2007 15:32:30 -0500, John Pezzano Has Frothed:

I have permanent standard 40W 48" fluorescent fixtures in the bathroom
(1)
and kitchen (3) installed by the builder 14 years ago (I have owned
house
for 5 years). Recently, a bulb in the bathroom failed. Until I could
purchase a new bulb, I "borrowed" a bulb from the kitchen to use in the
bathroom. It works just fine.
Meanwhile I bought a two pack of GE kitchen and bath bulbs. I replaced
the
missing bulb in the kitchen fixture. There was some flickering at first
but
that went away. The next day, the fixture suddenly went out although the
other fluorescent fixtures on the switch stayed on. I replaced the new
bulb
with the second new one and still had problems so I put both new ones
in. It
worked fine for a few days, then suddenly went out again. When the
switch is
turned off overnight, it comes back on again.

Some facts:
The fixture worked fine until I borrowed the bulb.
I have not tried shutting light off for shorter than overnight (It has
only
been a few days).
I have had problems with the two new bulbs and with each of the new
bulbs
paired with the old bulb.
It is a pain to get to the bulbs so I hate just moving bulbs around for
"fun".
I know the ballast could have suddenly had problems but it seemed so
coincidental.

Any suggestions?

John Pezzano

Change the ballast.


--
Pierre Salinger Memorial Hook, Line & Sinker, June 2004

COOSN-266-06-25794

John Pezzano wrote:
I have permanent standard 40W 48" fluorescent fixtures in the bathroom (1)
and kitchen (3) installed by the builder 14 years ago (I have owned house
for 5 years). Recently, a bulb in the bathroom failed. Until I could
purchase a new bulb, I "borrowed" a bulb from the kitchen to use in the
bathroom. It works just fine.
Meanwhile I bought a two pack of GE kitchen and bath bulbs. I replaced the
missing bulb in the kitchen fixture. There was some flickering at first but
that went away. The next day, the fixture suddenly went out although the
other fluorescent fixtures on the switch stayed on. I replaced the new bulb
with the second new one and still had problems so I put both new ones in. It
worked fine for a few days, then suddenly went out again. When the switch is
turned off overnight, it comes back on again.

Some facts:
The fixture worked fine until I borrowed the bulb.
I have not tried shutting light off for shorter than overnight (It has only
been a few days).
I have had problems with the two new bulbs and with each of the new bulbs
paired with the old bulb.
It is a pain to get to the bulbs so I hate just moving bulbs around for
"fun".
I know the ballast could have suddenly had problems but it seemed so
coincidental.

Any suggestions?

John Pezzano




Are the new bulbs 40W or are they the crappy 25W tubes?

Sounds like the thermal protector in the ballast may be opening. Does it
come back on if you leave the switch on for a while?

Also check that the reflector is properly grounded, some tubes are more
sensitive to others and won't start without a grounded reflector.

Older ballasts are only for 40 watt bulbs unless marked for 34 watt
lamps. If the new bulbs are 34 watt lamps, they will draw too much
line current and the ballast may be tripping the thermal cutout which
must then cool. Ballasts may have to be replaced or 40 watt bulbs
used. Label on the ballast will be the source of an answer.

If it's only 14 years old then it'll be fine with the crappy 34W tubes.
Ballasts have been designed with those in mind for at least 30 years.

Not my field, so I'll take your word for it, but are you able to explain
*why* a lower rated tube will pull more line current ? Just curious.



Because to get the lower wattage they changed the gas fill, this causes
the arc voltage to be reduced, but at the same time the current is
increased. The net result is that wattage is reduced, but only because
the voltage is reduced further than it would be if the current stayed
the same.

If I recall right, you're in the UK which uses choke ballasts, reducing
lamp voltage on those increases current to a greater degree than doing
so with HX (leak) autotransformer ballasts so the wattage would stay the
same or even rise.

"James Sweet" wrote in message
news:YTTxh.4086$FM3.568@trndny06...



Older ballasts are only for 40 watt bulbs unless marked for 34 watt
lamps. If the new bulbs are 34 watt lamps, they will draw too much
line current and the ballast may be tripping the thermal cutout which
must then cool. Ballasts may have to be replaced or 40 watt bulbs
used. Label on the ballast will be the source of an answer.

If it's only 14 years old then it'll be fine with the crappy 34W tubes.
Ballasts have been designed with those in mind for at least 30 years.

Ok on that, both replies. Makes more sense now if I'm understanding it
right. Less volts, more current, so thermal series trip opens - right ? Yep,
I'm in the UK. Mostly choke ballasts with PFC cap on the older fittings, but
some newer ones are starter-less, with no PFC cap. I'd never really taken
that much notice. I have a mixture of both between the house and two lots of
business premises, and I just replace the tubes with whatever comes to hand
at the time from the supermarket or wherever, and have not had a problem so
far - fingers crossed ;~}On the PFC cap, I seem to remember years ago that
it was a big thing to disconnect it. Stopped the fittings registering on the
electricity consumption meter due to the big phase angle between volts and
amps caused by the choke ??

Just as an aside on the subject, I was looking for some shatter-proof types
( which I've since found out that they all are now, apparently ?? ) to go in
a food prep area, and I found out where the " T12 " or " T8 " thing comes
from. It would seem that for some archaic reason, the diameter of the tubes
is quoted in eighths of an inch, so a T8 is one inch diam, a T12 is one and
a half inches, a T2 is a quarter inch and so on. Just goes to show, you're
never too old to learn ... !

Arfa

Ok on that, both replies. Makes more sense now if I'm understanding it
right. Less volts, more current, so thermal series trip opens - right ? Yep,
I'm in the UK. Mostly choke ballasts with PFC cap on the older fittings, but
some newer ones are starter-less, with no PFC cap. I'd never really taken
that much notice. I have a mixture of both between the house and two lots of
business premises, and I just replace the tubes with whatever comes to hand
at the time from the supermarket or wherever, and have not had a problem so
far - fingers crossed ;~}On the PFC cap, I seem to remember years ago that
it was a big thing to disconnect it. Stopped the fittings registering on the
electricity consumption meter due to the big phase angle between volts and
amps caused by the choke ??



Yep, our autotransformer fluorescent ballasts are thermally protected,
it's an automatic resetting thing wired in series with the primary
winding. The problem with this is once the ballast starts to fail and
overheats, it will start cycling and most people have no clue what's
going on and ignore it. Sooner or later the protector contacts weld
together and then if you're lucky, the ballast heats the fixture body
enough that the supply wiring melts, shorts out and trips the circuit
breaker. Not everyone is lucky, as it's not unheard of for houses or
commercial buildings to burn down due to faulty ballasts. Usually it's a
fluorescent light that gets left on all the time. It's not very common
but it has happened.

Disconnecting the PFC cap should make the fixture read higher on a UK
electric meter. I just found out fairly recently that they measure
apparent power rather than true power. On a US style meter, the PFC
makes no difference on the reading, but low power factor equipment makes
the power company happy. Not sure what explains the difference in
meters, cultural perhaps? Either way, the only sensible reason I can
think of to remove the PFC cap, if it can be called sensible, is the
installation of older tech fluorescent dimming systems.


Just as an aside on the subject, I was looking for some shatter-proof types
( which I've since found out that they all are now, apparently ?? ) to go in
a food prep area, and I found out where the " T12 " or " T8 " thing comes
from. It would seem that for some archaic reason, the diameter of the tubes
is quoted in eighths of an inch, so a T8 is one inch diam, a T12 is one and
a half inches, a T2 is a quarter inch and so on. Just goes to show, you're
never too old to learn ... !



It's not just fluorescent tubes, other bulbs are in T, BT, PS, R and
other envelopes using the same measuring system. There's a page in an
old sales book I have at
http://sparcbox.hopto.org/files/GE%20HID%20Lamps.pdf which shows all the
different envelopes as well as has lots of other cool lighting
information. Do copy it down locally before you try to view it though or
you may see errors.

To make things more complex, our T8 tubes and your T8 tubes are not the
same. The T12s I believe are, at least the conventional type. 4' tube is
40 watts, rated 430mA, I have here a Thorn EMI ballast from the UK which
runs one of my tubes just fine using a 240V supply. The T8 tubes on the
other hand are 32W here, and are rated to run at 230mA from a high
frequency electronic ballast. The only magnetic ballast T8s we ever got
are either 18" or less in length and used with chokes, or the rare
single pin end instant start T8s, but most single pin lamps are T12.

"James Sweet" wrote in message
news:bhcyh.1762$177.111@trndny08...


Ok on that, both replies. Makes more sense now if I'm understanding it
right. Less volts, more current, so thermal series trip opens - right ?
Yep, I'm in the UK. Mostly choke ballasts with PFC cap on the older
fittings, but some newer ones are starter-less, with no PFC cap. I'd
never really taken that much notice. I have a mixture of both between the
house and two lots of business premises, and I just replace the tubes
with whatever comes to hand at the time from the supermarket or wherever,
and have not had a problem so far - fingers crossed ;~}On the PFC cap, I
seem to remember years ago that it was a big thing to disconnect it.
Stopped the fittings registering on the electricity consumption meter due
to the big phase angle between volts and amps caused by the choke ??



Yep, our autotransformer fluorescent ballasts are thermally protected,
it's an automatic resetting thing wired in series with the primary
winding. The problem with this is once the ballast starts to fail and
overheats, it will start cycling and most people have no clue what's going
on and ignore it. Sooner or later the protector contacts weld together and
then if you're lucky, the ballast heats the fixture body enough that the
supply wiring melts, shorts out and trips the circuit breaker. Not
everyone is lucky, as it's not unheard of for houses or commercial
buildings to burn down due to faulty ballasts. Usually it's a fluorescent
light that gets left on all the time. It's not very common but it has
happened.

Disconnecting the PFC cap should make the fixture read higher on a UK
electric meter. I just found out fairly recently that they measure
apparent power rather than true power. On a US style meter, the PFC makes
no difference on the reading, but low power factor equipment makes the
power company happy. Not sure what explains the difference in meters,
cultural perhaps? Either way, the only sensible reason I can think of to
remove the PFC cap, if it can be called sensible, is the installation of
older tech fluorescent dimming systems.


Just as an aside on the subject, I was looking for some shatter-proof
types ( which I've since found out that they all are now, apparently ?? )
to go in a food prep area, and I found out where the " T12 " or " T8 "
thing comes from. It would seem that for some archaic reason, the
diameter of the tubes is quoted in eighths of an inch, so a T8 is one
inch diam, a T12 is one and a half inches, a T2 is a quarter inch and so
on. Just goes to show, you're never too old to learn ... !



It's not just fluorescent tubes, other bulbs are in T, BT, PS, R and other
envelopes using the same measuring system. There's a page in an old sales
book I have at http://sparcbox.hopto.org/files/GE%20HID%20Lamps.pdf which
shows all the different envelopes as well as has lots of other cool
lighting information. Do copy it down locally before you try to view it
though or you may see errors.

To make things more complex, our T8 tubes and your T8 tubes are not the
same. The T12s I believe are, at least the conventional type. 4' tube is
40 watts, rated 430mA, I have here a Thorn EMI ballast from the UK which
runs one of my tubes just fine using a 240V supply. The T8 tubes on the
other hand are 32W here, and are rated to run at 230mA from a high
frequency electronic ballast. The only magnetic ballast T8s we ever got
are either 18" or less in length and used with chokes, or the rare single
pin end instant start T8s, but most single pin lamps are T12.

Thanks for that James. As I said, not really my field, but one I have an
interest in, so this is all fascinating stuff. I visit the U.S. a couple of
times a year, and have never even begun to suspect that there is any
difference between our flourescent fittings, and the ones I see over there.
Just goes to show ... ! As far as I know, here the " T " number just refers
to the physical diameter of the tube, and has no bearing on the power
rating. Although I have just been and looked at a few around the house, and
all my 5 foot T12's seem to be rated at 65 / 80 watts, and a 5 foot T8 that
I have, waiting to be disposed of, says 58 watts on it. The 6 foot T8's in
my garage say 70 watts on them !! So now I'm not so sure. I must admit that
I have never really taken any notice, and have had both T8's and 12's in all
of the fittings over the years, without any apparent problems. They seem to
be sold over here as either 'standard' or 'slimline' tubes, with no
indicated electrical preference for any particular age or type of fitting,
and no special reference to the power rating. If I went in an electrical
shop and just said " A 5 foot flourescent tube please mate ", the only
question I would then get asked is " Standard, or slimline ? " Personally, I
prefer the standard fat ones. It's probably just psychological, but I always
feel that the much larger surface area, gives out a stronger more 'even'
light.

Interesting also about PFC and the meter, and the differences between UK and
U.S. metering of supply. I thought a watt-hour meter was just a watt-hour
meter. I wonder watt ( !! ) the difference is in measuring technique between
a " true " one and an " apparent " one, and which overall, gives the more
accurate long-term consumption figure ? Could this be anything to do with
PFC caps and flourescent fixtures not reading on the meter? This
disconnecting of the cap was definitely a big thing years ago here, and I'm
pretty sure that it wasn't the stuff of urban myth. I know for sure that
when I was a teenager, and had a room that I used for all my radio gear, I
had the cap disconnected in the fitting in that room. I am sure that I had
shut everything in the house off ( it was a lot easier to do that back then
!! ) and proved that the light no longer caused the meter to go round. I
will have to look into this further.

Sorry everyone for taking this a bit OT.

Arfa

Thanks for that James. As I said, not really my field, but one I have an
interest in, so this is all fascinating stuff. I visit the U.S. a couple of
times a year, and have never even begun to suspect that there is any
difference between our flourescent fittings, and the ones I see over there.
Just goes to show ... ! As far as I know, here the " T " number just refers
to the physical diameter of the tube, and has no bearing on the power
rating. Although I have just been and looked at a few around the house, and
all my 5 foot T12's seem to be rated at 65 / 80 watts, and a 5 foot T8 that
I have, waiting to be disposed of, says 58 watts on it. The 6 foot T8's in
my garage say 70 watts on them !! So now I'm not so sure. I must admit that
I have never really taken any notice, and have had both T8's and 12's in all
of the fittings over the years, without any apparent problems. They seem to
be sold over here as either 'standard' or 'slimline' tubes, with no
indicated electrical preference for any particular age or type of fitting,
and no special reference to the power rating. If I went in an electrical
shop and just said " A 5 foot flourescent tube please mate ", the only
question I would then get asked is " Standard, or slimline ? " Personally, I
prefer the standard fat ones. It's probably just psychological, but I always
feel that the much larger surface area, gives out a stronger more 'even'
light.


There's a dizzying variety of fluorescent lamps with various guidelines
to the designations however there's exceptions to the rule. Residential
sizes up to the standard 4' tube are traditionally rated as follows.

F40T12/CW would be Fluorescent, 40 watts, Tubular, 12 8ths of an inch in
diameter with a cool white halophosphate phosphor.

F15T8/WW would be Fluorescent, 15W, 8 8ths (1 inch) diameter, warm white
halphosphate phosphor.

Now when the 34W lamps came out that threw a wrench in the works, those
are still referred to as F40.

T8 lamps in sizes greater than 18" appeared along with the corresponding
electronic ballasts they use. By far the most common is the F32T8 which
is 4' long, 32 watts, and 1" diameter. These are for electronic ballasts
only and will not work correctly on the magnetic type. Along with those
came the trichromatic phosphors which are designated by a 3 digit number
on the end. For example F32T8/735 is 70+ CRI with a color temperature of
3500K. F32T8/850 is 80+ CRI with a color temperature of 5000K.

To make things more complex, lamps intended for commercial/industrial
use have a different numbering system. F96T12/CW is a 96" long tube,
originally rated at I believe 75W but now you mostly see 60W energy
savers. F48T12HO is a 4' 60W High Output tube, which runs at 800mA and
is rated for cold weather use. F96T12VHO is a 96" Very High Output, a
220W tube running at 1500mA. Standard, HO, and VHO are available in the
common sizes of 18", 36", 48", 72" and 96", but you can get HO tubes for
signs all the way up to 120". 5' is a size we never got here, that and
the European 96" tube were designed to run from standard 80W and 125W
mercury lamp chokes which were already in production. Very old ones even
had BC caps on them, I don't think you see those much anymore though.


Interesting also about PFC and the meter, and the differences between UK and
U.S. metering of supply. I thought a watt-hour meter was just a watt-hour
meter. I wonder watt ( !! ) the difference is in measuring technique between
a " true " one and an " apparent " one, and which overall, gives the more
accurate long-term consumption figure ? Could this be anything to do with
PFC caps and flourescent fixtures not reading on the meter? This
disconnecting of the cap was definitely a big thing years ago here, and I'm
pretty sure that it wasn't the stuff of urban myth. I know for sure that
when I was a teenager, and had a room that I used for all my radio gear, I
had the cap disconnected in the fitting in that room. I am sure that I had
shut everything in the house off ( it was a lot easier to do that back then
!! ) and proved that the light no longer caused the meter to go round. I
will have to look into this further.



Well true power is more accurate, it's what determines the amount of
mechanical energy that must go into the generator. Apparent power comes
into play when dealing with conductor size and heating which includes
the windings in transformers and generators. You'll notice transformers
are rated in VA rather than watts, because they're good for a given
amount of amperage before the windings overheat. The Volt-Amps are equal
to Watts at a unity power factor, but as the PF is reduced, VA will
increase while Watts stay the same. Having the meter register apparent
power serves to provide incentive for increasing the power factor of
loads, which reduces strain in the distribution system. Inductive loads
such as fluorescent ballasts will have a lagging power factor, where the
current lags behind the voltage in the sine wave. Capacitive loads have
a leading PF, one can cancel out the other, hence the reason for
connecting a capacitor in parallel with an inductive load to bring the
power factor closer to unity. Normally disconnecting the PFC capacitor
would make a meter measuring apparent power read approximately double
what it would with a unity PF, I'm not familiar enough with the actual
design of the meters there to say what the actual real world effect
would be though.

"James Sweet" wrote in message
newspzyh.2717$da1.1199@trndny03...


Thanks for that James. As I said, not really my field, but one I have an
interest in, so this is all fascinating stuff. I visit the U.S. a couple
of times a year, and have never even begun to suspect that there is any
difference between our flourescent fittings, and the ones I see over
there. Just goes to show ... ! As far as I know, here the " T " number
just refers to the physical diameter of the tube, and has no bearing on
the power rating. Although I have just been and looked at a few around
the house, and
all my 5 foot T12's seem to be rated at 65 / 80 watts, and a 5 foot T8
that I have, waiting to be disposed of, says 58 watts on it. The 6 foot
T8's in my garage say 70 watts on them !! So now I'm not so sure. I must
admit that I have never really taken any notice, and have had both T8's
and 12's in all of the fittings over the years, without any apparent
problems. They seem to be sold over here as either 'standard' or
'slimline' tubes, with no indicated electrical preference for any
particular age or type of fitting, and no special reference to the power
rating. If I went in an electrical shop and just said " A 5 foot
flourescent tube please mate ", the only question I would then get asked
is " Standard, or slimline ? " Personally, I prefer the standard fat
ones. It's probably just psychological, but I always feel that the much
larger surface area, gives out a stronger more 'even' light.


There's a dizzying variety of fluorescent lamps with various guidelines to
the designations however there's exceptions to the rule. Residential sizes
up to the standard 4' tube are traditionally rated as follows.

F40T12/CW would be Fluorescent, 40 watts, Tubular, 12 8ths of an inch in
diameter with a cool white halophosphate phosphor.

F15T8/WW would be Fluorescent, 15W, 8 8ths (1 inch) diameter, warm white
halphosphate phosphor.

Now when the 34W lamps came out that threw a wrench in the works, those
are still referred to as F40.

T8 lamps in sizes greater than 18" appeared along with the corresponding
electronic ballasts they use. By far the most common is the F32T8 which is
4' long, 32 watts, and 1" diameter. These are for electronic ballasts only
and will not work correctly on the magnetic type. Along with those came
the trichromatic phosphors which are designated by a 3 digit number on the
end. For example F32T8/735 is 70+ CRI with a color temperature of 3500K.
F32T8/850 is 80+ CRI with a color temperature of 5000K.

To make things more complex, lamps intended for commercial/industrial use
have a different numbering system. F96T12/CW is a 96" long tube,
originally rated at I believe 75W but now you mostly see 60W energy
savers. F48T12HO is a 4' 60W High Output tube, which runs at 800mA and is
rated for cold weather use. F96T12VHO is a 96" Very High Output, a 220W
tube running at 1500mA. Standard, HO, and VHO are available in the common
sizes of 18", 36", 48", 72" and 96", but you can get HO tubes for signs
all the way up to 120". 5' is a size we never got here, that and the
European 96" tube were designed to run from standard 80W and 125W mercury
lamp chokes which were already in production. Very old ones even had BC
caps on them, I don't think you see those much anymore though.


Interesting also about PFC and the meter, and the differences between UK
and U.S. metering of supply. I thought a watt-hour meter was just a
watt-hour meter. I wonder watt ( !! ) the difference is in measuring
technique between a " true " one and an " apparent " one, and which
overall, gives the more accurate long-term consumption figure ? Could
this be anything to do with PFC caps and flourescent fixtures not reading
on the meter? This disconnecting of the cap was definitely a big thing
years ago here, and I'm pretty sure that it wasn't the stuff of urban
myth. I know for sure that when I was a teenager, and had a room that I
used for all my radio gear, I had the cap disconnected in the fitting in
that room. I am sure that I had shut everything in the house off ( it was
a lot easier to do that back then !! ) and proved that the light no
longer caused the meter to go round. I will have to look into this
further.



Well true power is more accurate, it's what determines the amount of
mechanical energy that must go into the generator. Apparent power comes
into play when dealing with conductor size and heating which includes the
windings in transformers and generators. You'll notice transformers are
rated in VA rather than watts, because they're good for a given amount of
amperage before the windings overheat. The Volt-Amps are equal to Watts at
a unity power factor, but as the PF is reduced, VA will increase while
Watts stay the same. Having the meter register apparent power serves to
provide incentive for increasing the power factor of loads, which reduces
strain in the distribution system. Inductive loads such as fluorescent
ballasts will have a lagging power factor, where the current lags behind
the voltage in the sine wave. Capacitive loads have a leading PF, one can
cancel out the other, hence the reason for connecting a capacitor in
parallel with an inductive load to bring the power factor closer to unity.
Normally disconnecting the PFC capacitor would make a meter measuring
apparent power read approximately double what it would with a unity PF,
I'm not familiar enough with the actual design of the meters there to say
what the actual real world effect would be though.

Thanks again James. You clearly know your flourescents and I have learnt
much from this ! So, who have we got out there from the UK, who knows power
distribution and metering ... ?

Arfa