Phase converter

[3405jimmy]

I have a 5.5hp rotary phase converter which provides 3ph for a Bridgeport mill and a Colchester bantam 2000 lathe. Just lately when I start the lathe all that happens is I get a loud buzzing from the phase converter but no rotation of the lathe. If I disengage the start lever on the lath and fire up the mill it works perfectly. Anyone come across this problem before?

Jim

[Malcolm]

Have you lost a phase on the lathe motor? If the converter runs the mill it is presumably OK. Try checking continuity on all three phase leads from the converter, through the starter to the motor terminals, then continuity on the three phases of the motor itself.

[3405jimmy]

Malcolm,

Thanks for the advice I think you were correct in your diagnosis although I didn’t have anything to test things with. I pulled the all the wiring out to check it and found a couple of suspect connections which I tightened up since then it’s been trouble free.