On Dec 27, 12:27*am, "
wrote:
I have a 460v 3 ph. 3 hp. Allen Bradley VFD. I would like to apply DC
to the buss from a single phase power supply instead of a rotary
converter. Any problems with this?

Maybe you can run the DC bus from an external source, but the control
electronics do not run from the DC bus, they need the AC input to some
transformer for (possibly?) 5 volts, and whatever other voltages are
used to for the logic, and transistor drives.

IOW, I think you ~might~ be able to give it the high voltage 680 volts
DC power, but you might also have to give it the 480 volts AC to drive
the computer and transistor drive/control circuitry.