From: Scott
Quinn
I have seen some roads where the utility has 2 of
the phases plus
neutral going down them, not true 2-phase power, but 2 phases 120/240
degrees apart with the third phase just not present.
My house has something like that; the previous owner wanted '3-phase service'
for machine tools (I think - could have been a compressor, or something) in
his basement workshop, so they sold him a pseudo-3-phase service. I forget
the exact details of how it works, but the 3rd phase is at 170V to neutral,
It
should be 208V - see center grounded delta online.? 240 *
sin 60 degrees = 207.8 V.
Jon