Grounding Parallel

[DasMrDomo]

Hi Folks,

I've ran into a situation with my local building official, and I would love some input on the subject matter.

Scenario:
400Amp service being fed by (2) Sets of (4-wire) 3/0 Cu.

Based off NEC 250.66 and the cross sectional area, should the ground be based on number of sets, thus (2) 3/0 Cu.

OR

Should it be based on total wires, thus (8) 3/0 Cu.

Any and all input would be appreciated.

 

[don_resqcapt19]

If you are asking about the grounding electrode conductor, it is based on the sum of the circular mil area of two 3/0 conductors. 167,800 x 2 = 335.6 kcmil requiring a 2 AWG copper grounding electrode conductor.
See Note 1 in Table 250.66.

 

[Little Bill]

If you are asking about the grounding electrode conductor, it is based on the sum of the circular mil area of two 3/0 conductors. 167,800 x 2 = 335.6 kcmil requiring a 2 AWG copper grounding electrode conductor.
See Note 1 in Table 250.66.

What if the electrodes are ground rods?

 

[LarryFine]

What if the electrodes are ground rods?

The portion that connects only rods still needs not exceed #6 cu.