"Paul Drahn" wrote in message
...
On 11/1/2011 4:14 PM, PrecisionmachinisT wrote:
"Paul wrote in message
...
On 10/31/2011 8:27 PM, Ignoramus23114 wrote:
I have bought a 3 phase 45 kvs transformer 480 - 240.

Since I buy and sell industrial equipment, I will be sure to come
across 460v only machines. So, I thought, I could use this transformer
to make 460v from 230v, which is what my building has.

So, realistically, can it be used in reverse? to make 460v.


i
Sure. We have been using such a configuration for 5-6 years to power a
large convection oven that melts the solder paste on circuit boards. The
KVA rating is reduced about 10-15%.

We learned the hard way to never switch on an unloaded transformer.
Blows
a fuse in the metering panel almost every time. So, the transformer is
never shut off using the circuit breakers.


I switch power into an unloaded 30kva transformer via a 20 amp triplex
breaker every single day withouy any problems whatsoever.



Ours is a 75kva. A 100 amp circuit breaker is between it and the meter
base with quick blow 200 amp fuses. Replaced one or more fuses in a two
week period. That cost more than running continuously for several years.


Just sayin...

--people all around the world routinely switch unloades transformers on and
off without any problem whatsoever--and so it's definitely something else
that's wrong with whatever situation you have going on causing the problem
there.