This has been coming up alot lately!
To answer the original poster's questions:
1Ø is nothing at all like 2Ø.
First off, Single Phase is just thst - Single Phase!
Two Phase is a Polyphase System - like 3 Phase is.
2Ø has Two individual Phases, which are 90° offset - like 3Ø has Three individual Phases, which are 120° offset.
There are 2Ø 3 Wire, 4 Wire and 5 Wire systems (more like "were"...). It's an older, antiquated polyphase Power System, which has been made obsolete by 3Ø systems.
It's still in use on Stepper / Servo Motors, along with the control + clock circuitry for them.
The closest comparison to 1Ø would be on Motors.
A Single Phase Split Phase Induction Motor resembles a Two Phase Induction Motor, being that the 1Ø Motor has both a "Run" winding and an "Aux./Start" winding, which in the starting sequence will have a Phase offset between 30° and 75° - maybe coming close to 90°.
Of course, the Two Phase Motor will have no start switch, no start Capacitor, and will have at least one additional Phase Line connecting to the windings. Both windings will always be active, and both will have 90° offset (± may come into effect).
Check out the Technical Reference area for Transformer and Motor Schematics for 2Ø Systems.
They may be accessed from the Menu For Technical Reference Area
p.s. direct url is: https://www.electrical-contractor.net/ubb/Forum15/HTML/000064.html
edited some silly cornfusion!
[This message has been edited by Scott35 (edited 09-27-2003).]