"BEAR" wrote in message
...


Wondering if you are using/used a VFD if you might share your experiences
in terms of the details of setting it up, your experiences with a given
motor(s) and any other insights into selecting a VFD & motor combo??

I've not much to add to the other replies, except to say that I'm using 3
VFDs - a couple of 3 HP Mitsubishi FR-220E models to power a Clausing 5914
lathe and a Clausing 8540 horizontal mill, both with 2 HP motors and an
Hitachi L100 that powers a 1 HP motor on a KO Lee surface grinder. All are
powering the original motors and the Clausings are nearly 40 years old and
almost certainly *not* inverter-rated.

My usual approach to wiring is to run 220 VAC from a sub-panel to a fused
disconnect box and from there to the VFD. Rigid conduit up to the
disconnect box and LiquiTite between the disconnect and VFD and VFD and
motor. So far I've been able to wire the on-tool power switches to control
terminals on the VFD (in a separate run) of LiquiTite to provide motor
for/off/rev on the lathe & mill and for/off on the grinder. The disconnect
lets me shut off power to the VFD when it is not being used, though others
accomblish the same thing with a cord and plug.

The only minor problem was with the Hitachi because the original were
momentary push buttons for start and stop. The Hitachi L-100 lacks the
built-in logic to use this setup directly as it expects a sustained "on"
contact closure. A tech note from Hitachi provided wiring for a small
control relay and diode, which fixed that problem for around $15 at Radio
Shack. I think that this is referred to as "3-wire control" and has the
benfit that a power outage will shut down the motor until power is back up
*and* the start button is depressed again. The drum switches on the lathe
and mill will power either back up when power comes back on unless I
manually turn the switches to off.

Mike