Bond Bushing Grounding Wire Size

[LuanDo]

If someone can direct me to where in NEC 70 to look up bond bushing wiring size to bond to 4" rigid metal conduits that carry 4/0 3-phase wires for 35Kv feeder to a large transformer and then to a switchboard, it would be much appreciated. I was thinking of Table 250.66 or Table 250.102(C)(1) but not sure which is the right table to use. The contractor was using #3 and #6 AWG wires for bond bushing but owner insisted 1/0. Thank you.

 

[don_resqcapt19]

I don't see a specific requirement in Part X of Article 250, so since this appears to be the conductors between a transformer secondary and the first OCPD, they would be supply side bonding jumpers and sized per Table 250.102(C)(1).