Let's assume the primary circuit is 12,470Y/7,200. That means the xfmr primary windings are arranged as a 7.2 kV, corner-grounded, open delta.
Ok.. If I look at it that way, it starts to make sense.. I don't deal with the primary side at all, but it's good to know how that side is configured.
I don't normally deal with delta either.. in my world, everything is WYE, or single-phase.
