Hello
Location-industrial bldg
I need to feed a 400a 3 phase panel from an existing 400a 208v 3phase main breaker panel. I'm going to conect directly to the bus and use a mlo panel because the existing panel is full but only draws 50a each phase during peak houres. My question is abuot the size conductors to use. If i parallel the conductors what size do i need?
3/0 thhn =200a *2=400a?
or
500kcmil thhn= 430a 500/2=250kcmil
Do you go by the circular mil area?
This is in a small electrical rm and the panels will be about 4 ft apart conected with EMT or Trough i'm not sure yet.
