On 8/26/15 12:33, Paul Koning wrote: > 90? Three phase power is 120 degrees apart, center-tapped "two > phase" home power is 180 degrees, but I don't know of any power > company service that produces 90 degree shifts.
There's a bunch of 90-degree two-phase stuff in Philadelphia; in particular the city center has a lot of buildings that are fed 90-degree two-phase from PECO. I suspect (but do not actually know) that PECO derives two-phase from three-phase using Scott-T transformers. -- Christian Kennedy, Ph.D. ch...@mainecoon.com AF6AP | DB00000692 | PG00029419 http://www.mainecoon.com PGP KeyID 108DAB97 PGP fingerprint: 4E99 10B6 7253 B048 6685 6CBC 55E1 20A3 108D AB97 "Mr. McKittrick, after careful consideration…"
