Wes wrote:


I don't know but would adding some load side capacitance mellow out how your motor reacts?
I'm hoping our EE's on the list have comments on that one.
No, you do NOT want to put capacitors on the
output side of a VFD. The VFD
produces 400 V square waves of varying duty cycle,
to create the right currents
in the motor windings. Capacitors will draw huge
currents on the edges of those
square waves, and either fry themselves or the
transistors in the VFD. You can
cobble up an L-C filter if you really feel the
need, but it shouldn't be nexessary
in most cases. Old motors run in a moist
environment might be more susceptible
to insulation breakdown, so if you are running
machines in an unheated garage, that
might be more of a concern.

Jon