There are 7 - 4 inch rigid metal conduits underground for a 2500 amp service with bonding bushings on 1 end of each pipe. can i run a 4/0 ground wire to each of them and end up on the ground bus with it, there is a 5000 kcmil equipment ground in each pipe? there is no way to get a larger size conductor on these bushings. any ideas would be greatly appretiated. also code articles..