I have a three phase 480v primary step down to 120/240v secondary transformer. I have XO at secondary for my neutral if needed. In my application I don't need a neutral for the three phase machine I am feeding. I have an EGC coming in and out to secondary of course they come together in the transformer and bond metal casing along with a ground rod. Do I bring XO down and bond with all my EGC even if I don't need it on the secondary side? it doesn't feed anything else other than the machine.