26 Aug
2015
26 Aug
'15
1:48 p.m.
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.
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