Upgrading a standard 200A overhead residential service to 320A, what size conductors from the new weatherhead to new 320A meter line-side?
Might seem strange but if a single service disconnecting means is what is supplied you must have ampacity corresponding to the overcurrent protection, with multiple service disconnecting means conductors in question only need to be sized to the calculated load. So a single 400 amp disconnecting means needs 400 amp conductor (allowed to be smaller conductor for dwelling if 310.15(B)(7) can apply), but two 200 amp disconnecting means with a total load calculation of only 250 amps could legally use 250 amp conductor here. The single 400 amp disconnect needs 400 amp conductor even if load calculation was only 100 amps.will be 2x 200A panels. Demand load under 80% on each.