On Feb 11, 7:31*pm, " wrote:
Can somone post a link to a description of how 3 phaze power works. My
brother is looking at buying a Felder combination woodworking machine
with 3 4kw motors in 3 phaze and while we both worked for an
electrician as kids we never worked with 3 phaze. If he buys it he's
planing on buying a converter as he can't get 3 phaze power at his
place. He worked in a shop with converter while in college but has
never had to set one up.
Thanks
Karl

The easiest way to produce 3 phase is to get a 3 phase motor of
about double the capacity that you will need. This motor can then be
"spun up" to the point that single phase (220 in the US) will drive
it. This static motor will create a third phase that is connected to
the 3phase or 'rotary' machine in question.
In the system I use, there are some buck/boost transformers and
'run' type capacitors, as I need very 'clean' 3 phase. This works
pretty well and the less demand/capacity equality you can build in the
better, a good case for overkill, as the larger 3phase motors are
relativly cheap. Things like large compressors need more of a 'fudge'
factor (I use the input from a 25hp to drive my 5hp 3 phase
compressor).
The older, bigger, 3 phase motors are better, as a lot of kinetic
energy in rotating mass is prone to smooth out the produced
electricty. I also advocate the use of pony motors to spin up the
initial 3 phase motor (any other motors in the system start off this-
do the big one first) instead of capacitors supplying the third leg...
especially in large systems!

Hope this helps
Dave G.