Outdoor transformer Customer owned 13.8 Pri.
480/277 Secondary. Bond at Transformer as Required 250.30 (C)
sized by 250.66. 3 phases from Transformer Plus Ground to ist OCP. Can it be Bare Conductors (Parallel) & Must be sized by 250.66 as it's before OCP.
250.30 (B) 3.
Phase Conductors 6 sets of 750's .
750 x6 = 4500 x 12.5 % =5625.
Grounding conductor must be 600 mcm each conduit.
Your imput ?