I have installed 400 amp service underground in 3" pvc with four 4/0 for the lines (parallel) and two 3/0 for the neutral (single phase). The POCO has turned down the connect because they say the wire 4/0 was one size too large.

I''ve been told that the meter can will not handle the amperage of the wire, the meter can is rated for 600 amps. They want me to pull the 4/0 out and replace with a total of five 3/0 conductors, four for the load and one for the neutral. This does not make sense to me? Any suggestions?