Reconnecting Lathe motor problem

[robgraham]

Bit of a failure of record keeping (or at least I cannot find the record!), so help is required please.

I disconnected the motor for my Myford lathe about 6 months ago so that it could be moved. I now find that the details in the Myford Handbook do not match the motor I have and I'm stuck. And it's not helped by there being two red wires and two black wires - the motor can be reversed.

The motor terminals on my motor are labelled AZ, A, Z and T whereas the Handbook says they should be A1, A2, Z1 and Z2, with the A terminals being the run coil. On mine, AZ and A have a 6 ohm resistance and there's 9 between Z and T. I could take the plunge and reckon on A and AZ being the run coil but some words of comfort would be appreciated.

Can anyone tell me which is the run coil and the starting coil as there is no capacitor so I'm assuming there's a centrifugal switch to disconnect the starting. coil.

Thanks Rob

[Bob Minchin]

Z & T = start according to my myford manual

[Andy Wade]

A - AZ is indeed the run winding and Z - T is the start winding, connected via the centrifugal switch. Whatever the markings, the lower-resistance winding is always the running one, IME.

Yes, that's pretty normal. Make sure the switch is opening OK, otherwise the motor will overheat.

[Rob G]

Thanks guys - that is what I was guessing but it's always good to get some reassurance. Interesting that another Myford Manual has that info.

Just to really make me annoyed at not marking and recording, my father had rewired the whole thing using a contactor to take the switching load off the Dewhurst switch contacts - and somewhere is the wiring diagram... somewhere.

Rob

[Rob G]

Information was 100% correct; motor running sweetly and urgent repair job completed. Many thanks guys Rob