ECN Forum Forums General Topics of the Trade General Discussion Area 350 mcm for 300 amps?

If part of the run is underground, wouldn't the 75°C {THWN} rating likely apply?

Aside from that, 350-kcmil seems like part of the bid-process "level playing field." As being on the side of the specifier and his client, presupposing different calculations and ratings not specified could be viewed as shortchanging the building owner.