OK......retired "novice" here........stop confusing me !!!

I was under the impression that a normal household 240 volt power feed - connecting to two bus-bars in the AC Panel, are 180 ° apart, which in theory/practice could be called 2-phase for a 240 volt motor.

I like my old 1 1/2 Hp 220 v. monster running the air comp. Repulsion start, w/ brushes and commutator instead of a switch. Thing starts like 3-phase.

yes, the 2 bus bars are 180° apart. being 180°, they add to make 240. they are part of the same circuit. in the 2phase system, there are 2 seperate circuits. imagine a generator with 2 single phase windings, which are totally isolated from eachother. or even better, imagine 2 single phase generators, mechanically coupled together, to produce 2 seperate single phase outputs which are 90° set apart from eachother. and then imagine 2 single phase motors mechanically coupled 90° apart. This would negate the need for starting capacitor, starting winding, etc.. this is what 2phase is, except instead of 2 generators coupled together, its 2 isolated windings in one generator, and 2 isolated windings in one motor. the 2 circuits are completely isolated from eachother, both in the generator, in the power transmission lines, and in the motor. they never meet. very different from both single and 3phase systems we use today.

 

Hello, I also have Bridgeport mill with the same 2 phase motor. I saw this mill run before I bought it in Bristol PA.. It won't run run at my home connected on a 3 phase converter. It just barely tries to turn and won't spin up. It has 3 wires coming out from the windings to the switch. I also have never heard of 2 phase. Since I saw this thing run, how can I tell if it has been converted to a 3 phase winding, although I would think it would run on the converter. I am trying to find another 3 phase motor to test the converter, and possibly will take the motor to work and try to run it on 3 phase. Any input appreciated. Thanks

 

You may be better off to pick up a suitable 3 phase motor, if you already have the VFD?
Max.