we are installing a 5kv S&C sw. that is feeding a 4160 - 480v transformer. my question is, does the equip. ground con. from transformer back to s&c sw. have to be rated for 5000v, or would 600v wire be ok?
I agree with Nick. It’s routine for equipment-grounding/bonding conductors in medium-voltage systems to be relatively large compared to phase conductors, like in the 2/0-4/0 AWG size.