On 7/31/2017 3:34 PM, Bob La Londe wrote:
"G Ross" wrote in message news
Keith Nuttle wrote:
I am posting this to the woodworking group because wood workers know a
lot about everything. ;-)

I am a volunteer at church and one of things that I do is change the
florescent lights when they die. Most of the fixtures are four tube
fixtures.

Is there a test to tell if a Florescent light tube is bad and needs to
be replaced, or the light is not working because its companion is dead?

I have struggled with this. Sometimes when one of the tubes is replaced
the other seems to start working. So it would be nice to test the tube
to see if even though working it should be replaced.


In the hospital where I used to work, if a bulb in a fixture went out
they replaced all 4 bulbs. Since they always did that, when one went
out all the others were the same age and likely to go before long.
Apparently this practice was cost effective for them. But then, their
maintenance crew was being paid.

I always replace just the bad one. In fact, did that today.

***************

I have a bunch of 8' cans hanging from chains in my shop. They hold two
tubes. When I notice one acting flakey I just replace both of them.
Some of my 8 footers are 10 years old, and I have yet to replace a
ballast. All of the cans are ten years old.

When I was a kid one of my chores was replacing the tubes in the 4' cans
above the drop ceiling in our family grocery store. I also had to
replace a number of ballasts over the years. One day I asked my dad if
he thought the bulbs being bad were affecting the ballasts. He made a
couple phone calls and said lets try just replacing all the bulbs on a
can the instant one starts acting up and see. I replaced one or two
ballasts over the next year, and then not another one until the day I
left home.

I don't know how many ballasts my dad replaced after I left home, but...

A few years ago my dad stated with authority that if a tube starts
acting you should just replace all the tubes on the can as your ballasts
will last longer if you do. I'm not sure if he remembers our
conversation from over 35 years ago, but I do.

I've never heard or read an "authority" state that to be the case, but I
pretty much believe it. Given what a ballast costs I think its cheaper
to just replace all the tubes the instant one tube starts to flicker or
act flakey. For somebody who might need to hire an electrician the cost
of a bad ballast is much more.



Don't use Phillips bulbs!!! POS.
I just replaced a sylvania that was years, old, and a phillips that was
months old. They were in troffers in the basement, 2 adjacent troffers.

I've got to find Sylvnia, or GE bulbs. I won't do another case of
Phillips. All the crappy Phillips died in months, I had 2 cases fail in
a relatively short time. A total waste of money.


--
Jeff