Strange 240V Motor Wiring

I would measure the resistance of each motor lead to the motor frame. If one of them is near zero, that would be the one to connect to neutral. If both are a few megohms, it probably doesn't matter, especially if you connect the motor frame to the previously cut earth conductor.

However, you should seek some local expertise on this.

I forgot to mention that there are two capacitors on the motor (start and run?). I'm not sure whether this makes any difference.

That's getting out of my bag of tricks; almost everything I do is 3-phase. Is there some switching device (like a centrifugal switch) in this motor that transfers from one capacitor to the other?

I've only worked with 3 phase myself. There is a small 'black box' in the junction box on the motor which I assume deals with the switching (I'm not sure how to post pictures here.) It is connected to the brown wires on the two capacitors and also the mystery '1' wire from the lead (there is a brown and a blue wire going to each capacitor.) Would this suggest that the '1' wire was positive?

Since this is an AC motor, the lead which is positive alternates at 50 Hz - No?

Note that compressors require a large starting torque so the start capacitor should be big - over 100µF. I assume that this is a capacitor start/capacitor run motor. That would be the appropriate design for driving a compressor.

Normally, a centrifugal switch would cut out the start capacitor when the rotor approaches synchronous speed. The motor would then run as a 2- phase motor. The second phase supplied by the run capacitor which also helps to correct power factor.

The mystery is the black box.

Please follow Tornado's advice.

The "Black Box" you describe is most likely the start relay and usually the start and run caps have a common connection to the "hot" or "phase" lead(mystery 1 wire).

Go for it!

Yes!! It works!

Many thanks to Tornado, Baffled and Unredundant. The positve goes to pin 1 and then to the 'black box' (relay,) then to the capacitors. Negative goes to pin 2 and then into the motor.

The motor seems to start and run the the compressor just fine.

Thanks again.