What's the difference between a single phase and a three phase 208V wiring? Does the first has 2 wire only? Can you also identify the wires as to hot, neutral, and ground? This wiring applies to installing an Air conditioning unit.
Thanks.

If a building has 208, it will very likely be a 3 phase system.

I'm going to define the legs as L1, L2 and L3 for a 3 phase system.

For BOTH systems, neutral is an OPTIONAL wire to the device.

For 208 three phase, to get a 3 phase motor to run in the opposite direction, reverse any connection. (L1,L2); (L2,L3), (L1,L3)

To operate a SINGLE phase motor on a 208 V system, pick any two wires and there will be 208 between them. If neutral is used there will be 125 V between neutral and any L.

Does that answer your question?

Where feeder is used and why