Bunk: I guess I am getting too old for this crap. The thermal aspect of the DPS unit never entered my mind. I will have to get more information on the DPS units as I seized on the low price and the fact I do not need to vary the freq just change 1P to 3P and get close to 5HP out, and the attractiveness of the small size.
Do you have a VFD manuf you would suggest.

I have to admit I am at eyeball level underwater on VFDs. I understand in general terms how they work, but have no useful application experience.


Sonny: For an old motor that would be a PITA to change out I'd stick with a static converter. I would suspect most newer motor would work with inverters with no problem. Film coatings for magnet wire have improved significantly in recent years. Older equipment was not made for crappy sine waves with strange garbage floating around on the supply voltage.

Thanks for your comments.
JLG

James Geraci