I have seen 800 amp services using two 500 kcmil conductors for each phase. I'm assuming that the ampacity is figured as 430 amps(THHN) X 2 = 860 amps, rather than as being equivalent to one 1000 kcmil conductor at 615 amps. Would three 250 kcmil parallel conductors be 290 amps X 3 = 870 amps?
Dave
