no neutral on the m/c, the voltages across the 3 phases are 440,440,380, i am sure that the problem exists when the rotary phase converter is turned off without isolating the m/c first as it has done this twice now as soon as the motor shuts down the ammeter shows a current draw of +40 amps which lunches the control, normal running the ammeter shows 2-3 amps with the m/c on, i don't understand why there should be a large current draw when the phase converter is turned off and the m/c isolator is closed, i have no experience of rotary phase converters so i do not know if this behaviour is normal or not