On Sun, 09 Sep 2012 14:16:32 -0400, "Michael A. Terrell"
wrote:


ATP wrote:

"Gunner" wrote in message
...
On Sun, 9 Sep 2012 10:19:19 -0400, "ATP"
wrote:


"Gunner" wrote in message
. ..
Ive got a shop 14' wide by 55' long

For years Ive had a series of 4' double tube florescent fixtures
hanging and have had no issues with them.


Your best bet is to install T8 fixtures over your machines and switch them
individually. You can get decent Lithonia fixtures at Home Depot with real
ballasts for pretty cheap money, at least here in NY. Payback on using T8
instead of T12 is quick, and task lighting is also a good way to save
money.
Buy a fixture at a time as you can afford it.

But which voltage?


I would just buy new 120v fixtures. I actually have some nice indirect 277
T5 fixtures that I wanted to use but eventually decided installing a buck
boost transformer and having a different voltage in the shop just wasn't
worth it.


What's the big deal? A single 24 V transformer in boost
configuration will drive all the lights. 277V is 115% of 240, and 264 V
(240+24) is within 5%. Standard light switches are rated for 277 volts.
80 watt lamp at 277 draws 0.2888 amps. Round that up to .3A per tube
for easy calculations. 40 Watt would be about .15A. 55 feet only has
room for a little over six eight foot fixtures in a single row, so the
maximum load would be .6A * 6 or 3.6A if all six fixtures are on. If he
used the other four fixtures over machines, that would be another 2.4A
for a total of 6A at 277 Volts. You don't need, or even want isolation
on the fixtures. The housings should be grounded, so a fault will blow a
fuse, or trip a breaker. They used to put a fuse in some brands of
eight foot fixtures, so a failure wouldn't take out all of the light
fixtures. Not a bad idea, but the fuses need to be rated for 600V
circuits to prevent a plasma arc inside the fuse.

You can even wire the fixtures to turn on pairs of tubes instead of
all four, with some ballasts.

I just went out and pulled down the (3) transformers on a board (G)
that were hooked up for buckboost. They are Acme 1kvas and I just
downloaded the data sheet from Acme. Shows exactly how to do it..and I
was right in my last post.

Thank you!! A life saver!!!

Ill put a fuse on the single input hot leg (H1X4) and one on the
single output leg. ( That will unfortunately leave me the H4 hot
....hummm..no..if I put it on the input side of the H4 pass
through...and another on the X1 output..thats three...hummm unless I
have some doubled breakers..that will cover the input and output side
with two (double) breakers. Or do you think I need to put fuses on
the output side and just a double breaker on the two input lines?

What would YOU do?

According to the data..this thing in buckboost will handle 41 amps and
Im not going to have more than about 15 amps worst case sceanario with
every light in the shop on at the same time.

My apologies..but I appear to have just discovered another hole in my
memory left over from the stroke. I know Ive done these before..quite
a few of them. In fact..the 3 phase buckboost I originally installed
some 10 or so years ago to get a machine up to voltage...as I
recall..they had about 190 volts in the shop..and the VFD was kicking
out with an undervoltage alarm..so I put this together and ran their
lathe until they redid the entire shop and service..and I got to
"scrap" it. VBG

And now Im relearning how to do it!! Yippeee!...sigh.
Gunner

--
"Confronting Liberals with the facts of reality is very much akin to
clubbing baby seals. It gets boring after a while, but because Liberals are
so stupid it is easy work." Steven M. Barry