i phase -> 3 phase ?

A variable frequency drive rectifies the single (or 3 phase) line power into DC, then constructs 3 phases of AC from the DC supply, usually with a PWM modulation method. But this produces an AC output voltage about as high as the AC input voltage, so if you cannot reconnect the motor for lower voltage operation, you would need a 3 phase step up transformer between the drive an the motor, also.

Here is an example of this kind of drive:

A variable frequency drive (VFD) such as

-Lasse

Real "old school" way to do this would be to use a transformer to step up to 415 volts, and then a good sized "starting" capacitor to do a fairly bad job of synthesizing phase lag to power 3rd phase lead on motor. Efficiency isn't nearly so good as with modern solid state drives, but, it's cheap, and you see lots of old machine tools and other gear with 3 phase induction motors run that way, hooked to single or two phase mains....

W Letendre

drive:

assuming it is "normal" european 3-phase the 415V is between phases, each phase to neutral is still only 240, so not step up should be needed

-Lasse

I know you asked for solid state but rotary is cheap:

The good thing about rotary converters is that they are *much* more tolerant of short term overload.

Michael Kellett

Bit overkill for 1/8 hp though ! I've just found this on eBay:-

Thanks to all for your information and interest.

Jim Hawkins