3 phase Delta, phase B high leg with A & C center tapped. Grouped service disconnects, 1. 400a two pole breaker on phase A & B serving a 400a single phase lighting and appliance board.
2. 100a 3 phase breaker serving the HVAC panel.
Service conductors are (2) parallel 250 Kcmil on A & C and a #3 on the high leg B
