Short circuit current of 3-phase open delta transformer

For a 3 phase open delta transformers:

When you are computing the short circuit current between the 208v high leg (point B) and neutral. Do you only use one 75kVA or do you add the other transformer to produce 75kVAx1.5 (or other value) = 112.5kVA?

Im thinking if you need to add because between point B and neutral, there are more than 1 winding (or 1 transformer) involved. What do you think?

The following is the nameplate of the transformers and the lever was set to 2nd: