Ernie- 3 phase from the generator for that voltage does not have to be grounded but it will have to have an equipment ground. look at 250.20(B). If the neutral conductor of the utility and the equipment grounding conductor are terminated in the transfer switch I think it would be best if the equipment grounding conductor from an ungrounded 480v. supply (generator) is tied to the enclousure of the transfer switch. I further think that the neutral of the utility supply should be tied to a bar in the transfer switch with a Main Bonding Jumper that is removable.
