Yoopersup,
The 3/0 does not apply here as you have have service entrance conductors that total more than 1100kcmil. It has to be 12.5% of the total if the phase conductors are in a single raceway or cable tray. When the grounded conductor is run in parallel conduits it is sized by Table 250.66 based on the phase conductor in each raceway. In this case you need a 1/0 in each raceway unless the Article 220 load calculation requires a larger grounded conductor.
250.24(C)(1) Routing and Sizing This conductor shall be routed with the phase conductors and shall not be smaller than the required grounding electrode conductor specified in Table 250.66 but shall not be required to be larger than the largest ungrounded service-entrance phase conductor. In addition, for service-entrance phase conductors larger than 1100 kcmil copper or 1750 kcmil aluminum, the grounded conductor shall not be smaller than 12 1/ 2 percent of the area of the largest service-entrance phase conductor. The grounded conductor of a 3-phase, 3-wire delta service shall have an ampacity not less than that of the ungrounded conductors.
(2) Parallel Conductors Where the service-entrance phase conductors are installed in parallel, the size of the grounded conductor shall be based on the total circular mil area of the parallel conductors as indicated in this section. Where installed in two or more raceways, the size of the grounded conductor in each raceway shall be based on the size of the ungrounded service-entrance conductor in the raceway but not smaller than 1/0 AWG.
Don
