On 11/08/2016 11:08 AM, Guy Sotomayor Jr wrote:
  I?m looking to have to do something to get 3-phase for
the
 IBM 4331 gear. I haven?t quite added up the power
 requirements yet but I?m guessing its going to be in the
 10-15kVA range. Since the power to all of the gear is
 really split between 3 loads (string of 4 3340 drives,
 3803 control unit + 2 3420 tape drives and 2821 control
 uint + 1403 printer + 2540 card reader/punch) I need to
 figure out if it?s best to have one big converter or 3
 smaller ones. It?s unlikely that I?d be running all of the
 peripherals at once. The 4331 itself runs off of single
 phase 220v. TTFN - Guy  
This is tricky stuff.  Motor VFDs produce 400 V square
waves
of varying duty cycle, so unless you built a very good
filter, you couldn't feed that to a a lot of these devices.
Possibly you could rewire all that stuff to run the
electronics off single-phase power, and use VFDs for the
3-phase motors.  I know the tape drive vacuum blowers and
1403 printer had 3-phase motors in them.  Likely the 3340's
do, too.  I'm guessing some of those control units may have
run off single-phase, with the supplies balanced across
different phases.  That was fairly common for stuff that
didn't draw massive amounts of power.  Sounds like QUITE a
project!
Jon