How are the transformers connected?
In order to get 208/120 secondary system, it has to be connected for 3 phase configuration.
Six single phase units connected in 3 phase formation will provide Two banks of 750kVA, 3 phase system, each with 2.7% Z.
In that case the SCC will be 2*(750/1.732*0.208)/.027=154,000A
jbartos:
There is a decimal error in your post. It will be 55555 kVAsc or 154,000A on the secondary of the transformers.