Depends on assumptions...
(150A?2)?(120V?3?)=108kVA
112.5kVA?(480V?sqrt3)=135.3... x250%=338.3A.... round down to 300A primary OCPD.
400AF/300AT disconnect, 300kcmil primary conductors.
112.5kVA?(120V?3?)=312.5A.... ?125%=390.6A.... round up to 400A secondary OCPD.
400AF/400AT disconnect, 600kcmil secondary conductors (also post-fuse because already using it, but could be downsized to 500kcmil, economics factor into decision).
(2) 200A MCB panels, 3/0 feeder taps
All ratings, sizes based on 75?C terminations, 75?C or better Cu conductors , no adjustment and correction required.
I leave grounding conductors as an exercise for the OP'er....