Re: Explain 3 Phase

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "G by way of Terry Fritz <twftesla-at-uswest-dot-net>" <nieporgo-at-email.uc.edu>

>
>One more time.....  The electrical service supplied to 99.9% of American
>homes is single phase, 120/240 volt, 3 wire service.  Single phase means ONE
>phase...period....not 2 phases 180 degrees apart.  The service enters the
>house via a cable comprising two insulated (hot or line) conductors wrapped
>around an uninsulated, grounded, neutral conductor.  The neutral conductor
>is connected to the midpoint of the secondary winding on the distribution
>transformer on the pole or the pad and connected solidly to ground.  The
>voltage between the two line conductors is 240 and between either line and
>neutral is 120.  The function of the neutral conductor is to carry the
>unbalanced portion of the load.  If you had only identical 100 watt, 120
>volt light bulbs as the only loads in your house, and they were evenly
>distributed so the same number of bulbs ran on each line conductor, the
>neutral conductor would carry no current.  The two line conductors are of
>opposite POLARITY compared to the neutral conductors.  The same situation
>exists on a Y connected 3-phase bank.  The neutral is grounded for safety
>reasons.  One of which is that the maximum voltage from line to ground in
>your home is 120 volts.  So, even if you stuck your finger in a 240 volt
>dryer outlet, you would feel a 120 volt shock, provided you had good contact
>with the ground.  To experience 240 volts you have to stick both fingers in
>the outlet.  DON'T TRY THIS!  Hope this helps.  Coil safe!
>
>Eric
>edavidson-at-icva.gov

This seems to be getting academic, but the intuitive response is that 
opposite polarity and 180 degree phase difference are one and the 
same (for AC signals). This is the same principle on which bi-polar 
coils operate.
Greg
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ICQ 95403614