On Sun, 09 Sep 2012 15:58:38 -0700, Gunner
wrote:

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.

I wouldn't screw around with any fuses in the Buck-Boost transformer
at all - just feed it from a 2-pole 240V 20A breaker if you're using
all 12-gauge wiring, 15A breaker if some is 14 or16-ga cords.

If you want to save yourself some heartache, get panel-mount
fuseholders and 3A or 5A fast-blow fuses, put one on the side of each
fixture connected to the Hot lead to each ballast.

With a dozen fixtures in a Carport mounted at 8' - 9' it's not a huge
problem to track down a shorted ballast...

BUT it's a good habit to fuse 277V lights, because when you can put 30
to 50 High-Bay fixtures on the same 277V leg in a Warehouse, tracking
down a single shorted fixture will take you all day (or more) and
drive you nuts as they yell "What's taking you so long? We can't work
with the lights off!"

Whereas the one fixture with the burned ballast will pop it's fuse and
isolate itself - You find that fuse blown, check the ballast before
you replace the fuse.

-- Bruce --