Rotary Phase Convertors, UK vs USA type

Nov 22, 2007 1 Replies

Hello, I've recently bought a 5Hp Graziano SAG 180 lathe about 54 years old (1953 date on the motor) which being ex-government was lightly used and maintained.



Being in Australia I have 240V mains and would like to build a 240V rotary phase convertor to power the lathe. The USA circuits all run off 230V single phase which is supplied by a center tapped pole transformer giving 230V across two active wires with neutral from the center tap.



These two actives are each connected to a phase on the convertor's idler motor, if I built this circuit I would have to connect one phase of the idler and the lathe motor to neutral. My question is this: are UK rotary phase convertors wired this way with one phase to neutral or is there a different method with say neutral hooked up to the middle of the "Star" and 240 across one phase of the idler motor?.



Thanks, Mark


Hi Mark

I built a rotary phase converter from US plans found on the web a fe years ago, it showed two lives to the idler motor, being in the UK, used live and neutral and it worked fine. Hope this helps. ATB Alan.

=Mark Harriss]Hello, I've recently bought a 5Hp Graziano SAG 180 lathe about 54 years old (1953 date on the motor) which being ex-government was lightly used and maintained.

Being in Australia I have 240V mains and would like to build a 240V rotary phase convertor to power the lathe. The USA circuits all run off 230V single phase which is supplied by a center tapped pole transformer giving 230V across two active wires with neutral from the center tap.

These two actives are each connected to a phase on the convertor's idler motor, if I built this circuit I would have to connect one phase of the idler and the lathe motor to neutral. My question is this: are UK rotary phase convertors wired this way with one phase to neutral or is there a different method with say neutral hooked up to the middle of the "Star" and 240 across one phase of the idler motor?.

Thanks, Mar

-- alspee

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