Given: 120/240 volt, 3 ph., 4 wire, open delta electrical service, consisting of one 10 KVA transformer and one 15 KVA transformer with a center tap. Lets say that phase A and B are at each end of the 15 KVA center-tapped transformer and phase C is at the other end of the 10 KVA transformer. That makes phase C the high leg (208 volts to ground).

I know you can supply 240 volt 3-phase loads and you can supply 120 volt loads from A-N and B-N, but not C-N (since its 208 volts to ground).

My question: Is it OK to supply 240 volt single-phase loads from A-B, B-C and C-A? or can you only supply these loads from A-B and B-C?