SEMCO 1000 Retrofit with AC servos and Mach3. . . . MONSTER BLU . . Her Name.!!

[Neale]

I had a similar but smaller-scale problem recently, which is why I asked! I have a lathe with a 3HP/2.2KW motor, 415V/3ph, of course. Without major dismantling and rebuilding the motor, I couldn't do the old delta-star conversion trick. I ended up buying a 240V-415V VF inverter, which is fine up to a point, and that point comes when there is heavy load on the inverter. I run it at 50Hz as the lathe has its own variable-speed drive but although the lathe should go up to 2500RPM, above 2000 the load (not cutting, just idling so to speak) is sufficient to trip the inverter. The problem isn't load as such, but the fact that the input is single-phase rather than the three-phase that it was originally designed to use, compounded by the fact that there is a rather crude voltage doubler to go from 240 to a nominal 480 in front of the inverter. If I could find a big 240-415 transformer that would help. That lot runs off a dedicated 16A supply which is fine. I suspect that if you look into it, the cheapest option might be to go for a three-phase supply to the workshop. It might be cheaper than a massive inverter. Still, you've got plenty of time to save up the pennies! Like everyone else, I'll be watching this one with interest.
[EDIT] Just had a look at those Digi-Phase converters. Haven't come across those before. Unfortunately there isn't quite enough information to see what they can do, although they do sound a step up from the simple rotary converter.