3-phase power

[Charles Dickman]

On Tue, Jan 4, 2022 at 12:00 PM Adrian Stoness via cctalk <
cctalk at classiccmp.org> wrote:

> you can use a vfd drives to get 3phase power from single u just gotta size
> them bigger then the load u would normally need
>
> Yes, in principle this is true. In the simplest case, the VFD input is
just a 6 diode full wave rectifier into a capacitor. BUT things like power
factor correction on modern drives means the input circuit is a lot more
complex. Usually the small VFD will be designed for single phase power or
3phase power and the derating is done for you. Using a 3phase drive on
single phase typically won't work because the drive will detect a phase
loss and shut down. I know for one Rockwell drive there was an internal
hack that allowed it to work on single phase so the sales people could plug
into a 120vac outlet.

Chuck D.