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Conflicting ideas re. adding VFD to a Schaublin 102?

Pretzel Logic

Aug 10, 2018
I have a 102 lathe with the original motor, ie. 1.5HP 3 phase 420V, 2 speed and with a double star connection, but my supply is only 240V single phase(Australia).
A while ago I connected up a cheap VFD(230V 1ph in and 380V 3phase out) directly to the motor, bypassing the contactors. The motor ran well up to top speed but I couldn't get any usable low speed torque. I could stop the motor with my boot on the pully wheel.
I decided recently to get a name brand VFD, Teco or Delta, but the catch now is that none of these, in Australia or UK, (haven't tried US suppliers)come as 230V single phase input and 3ph 420V output, only 230V 3phase output and apparently this is a problem for a double star connection motor?
I've been told a voltage doubler on the input will do the job, checked but I haven't
found one yet.
Others don't seem to have a problem using a VFD with this motor. Grrr...