For a 400A service with all service entrance conductors paralled and in the same stick of RMC, and taking into account derating according to Table 310.15(B)(2)(a), Table 310.16 shows using at least 350 kcmil cables. With 6 total cables in the the RMC, it should be 3 to 3.5" based on Table C9.
So, why do I see so many paralleled 4/0 conductors in 3" RMC for a 400A service?
So, why do I see so many paralleled 4/0 conductors in 3" RMC for a 400A service?