Can a rotary single to three phase converter fault to too high an output voltage

[Chris Wilson]

I have used a commercial single phase to three phase rotary converter here for some 18 to 20 years without issues. It runs, one at a time, a Harrison 11 inch swing lathe, a Bridgeport universal milling machine, a hydraulic surface grinder, or a two post two ton vehicle lift.

Today I ran the Bridgeport to accurately drill some holes and it seemed to turning bloody fast and i think I smelt a hot electrics odour. I turned it off pronto and tried the lathe. That too seemed to be over speeding. Having had a plethora of bad luck issues in the workshop I locked the doors and called it a night, and opened a beer.

Before I actually measure the output voltage can any of the gurus here say if a rotary phase converter can suddenly start playing up outputting too high a three phase voltage? If so what might cause this? There's a gizmo on one of the house power sockets that reads mains voltage, current, Wattage and phase. The mains, as expected, is still in spec

Thanks.

[themadhippy]

As well as the voltage double check the frequency is correct

[jpanhalt]

I don't think too high a voltage has much effect on 3-phase induction motor speed.  It could cause overheating.  How did the converter sound?  Perhaps you lost a phase, which can cause overheating, but not increased speed

[Chris Wilson]

It did, in hindsight, perhaps sound a bit "growly". I will check voltage and frequency tomorrow, thanks for the info chaps!