Paul and John,

The reason no one answers questions like this is that there are too many potential
problems from unanswered questions.

First, a 208:440 three phase transformer will deliver about
465 volts when powered by 220 3-phase, probably not what your
surface grinder wants. You didn’t mention whether it’s wired
wye or delta, that also matters.

Second, three phase inverters don’t really like inductive
loads (like transformers) beyond the motors they are designed to power.

Third, are you sure you have enough power capacity from
your inverter? Nameplate ratings of the inverter and the
440/3-phase motor should be compared.

David Josephson

The Rotary Engine free News Letter. 750 subscribers world wide.

ACRE NL web site. http://www.rotaryeng.net
YouTube  Key word "PaulLamar2". Keep clicking
this as Youtube will try to divert you to advertising.