My company had a hotel project in Saipan, but less knowledge of NEC codes and NEMA codes.
The original drawings designed by a local consultant. The wiring method is showed in the following pictures.
But the construction drawings designed by a Hong Kong consultant. The wiring method changed, showed in the following pictures.
Now, the questions come such as the following:
1. Which wiring method can be accepted or/and permitted in America and why? Which code or clause can provide the proof?
2. Why 2 main incoming buss-bars at least in a panel? I can't find any description in NEMA PB-1.