3 phase to single phase wiring

Hope someone can help me with a little problem I'm having.

I've purchased a 3 phase boxford lathe that I need to run off single phase, all the wiring to the inverter and control pendent is in place and I just need to wire up the motor.

The problem I'm having is that the layout of the wiring is different from the usual layout of six terminals this only has five marked A B C and N with N having the three wires that would normally be connected to three separate terminals and bridged together.

So is it a simple case of disconnecting the three cables from the N terminal and connect one to each of the A B and C terminals.

The motor is a Brook Crompton Parkinson motor VMA544CMD 550w.

Hope this makes sense and thanks in advance for any help.

Regards

Joe

Provided the cables are labelled, this is not a problem. I assume you want to connect the motor in Delta, if the cables are marked you will have A1 B1 and C1, and A2 B2 and C2 will be connected together on the N terminal? if this is the case, you will need to use seperate connectors, and connect A1 to B2, B1 to C2 and C1 to A2. the motor is now connected in delta for 240v three phase running. put one phase from the vfd to each connection. If the cables are not marked, start by assuming that the A B and C are the "ones" and the three connected together are the "twos" test from A1 with a multimeter till you get continuity, that is A2, and so forth.

Hope this helps.

Phil

The motor is wired Star (Wye). Is your inverter configured for Star or Delta? If it's Star just leave the motor as is and leave the neutral unconnected. If you want Delta you will have to re-arrange the windings as Phil described above.

If you are unsure, leave it Star for now. the downside is slightly lower power and top speed but less stress on the inverter.

Robert G8RPI.

Wot Phil and Robert said with a diagram:

You probably want the motor wired in delta to match the inverter. As the other ends of each coil are accessible on the N terminal, it should be straightforward.

One thing I learned on the forum was to make sure the start of each coil (marked with a dot) is connected in the sense shown - apparently the motor runs rough if one of the coils is wired backwards.

Dave