I'm trying to understand how the power in my home works, and the part I'm having trouble with specifically is why in the step-down service transformer, the resulting out-of-phase 120V "hot" lines are out of phase by exactly 180*.
I understand in a step-down transformer a center tap halfway in the middle would result in half the voltage because there are fewer coils, but why would each of these circuits be out of phase by 180*?
What about if there is more than one "center tap?" Perhaps 3 instead of one? Would the resulting circuits be out of phase by 90*?