On Sun, 01 Jan 2006 18:36:14 GMT, "Peter Grey"
wrote:



"Don Foreman" wrote in message
.. .
A threephase motor run from a Phase a matic willl not run as smoothly
as it does on true 3-phase power. Whether that matters or not depends
on the application.

Does that hold true for a RPC as well?

No or much less so, depending on how well (or if) l the RPC is
"tuned". If perfectly tuned for a given load then there will be no
vibration or torque ripple, but even untuned it will be smoother
than single-phase -- which is what a Phase a matic supplies once the
motor is started.

Don't make too much of this. I have a 9" beltdrive Logan lathe
with a singlephase motor and never noticed any problem. Levin
jeweller's lathes use singlephase motors and can do exquisitely fine
work. I'd say don't worry about 3phase vs singlephase, use
whatever induction motor you find that fits your application.

If you want to go with VFD or think you might want to later, then
definitely go with a 3phase motor, even if you run it on single phase
(Phase a matic) for a while.