Re: 600 amp 480v/277 service 3 phase 4 wire
Assuming you actually need 600-ampere of supply, and no adjustment or correction factors need to be considered, use Table 310.16, 75? coulmn to find the conductor that has an ampacity of at least 300-amperes. Remember to follow the rules of 310.4. The egc will be sized per Table 250.122. Each raceway will have to have a full sized egc.
The raceways should be sized per Chapter 9 of the NEC. Start at the notes, and the calculate conduit fill using Table 5 for the conductor type and size you use, and then refer to Table 4 to determine raceway size, again depending on the type you use.