In this case A, B and C are the three phases. Their value vary from an area to another. In mine 14 400V is used for each phase. Between two phases it's 25 000V.
Just on a side note... Standard AC, single phase calculations are actually fairly easy. The fun starts with 3-phase power and non-sinus AC (square wave, sawtooth, etc.)
I love seeing older transformers in service...those cool fins really give it character....I notice a lot of newer ones even in the larger size don't really have fins like this anymore.
In this case A, B and C are the three phases. Their value vary from an area to another. In mine 14 400V is used for each phase. Between two phases it's 25 000V.
Just on a side note... Standard AC, single phase calculations are actually fairly easy. The fun starts with 3-phase power and non-sinus AC (square wave, sawtooth, etc.)