Okay Ernie- Now that I understand what you have ie: 480/277v. for both the generator and the utility, you will need a 4-pole transfer switch to disconnect the SDS grounded conductor from the utility grounded conductor. Each will need a gorunding electrode and without the grounded conductor running through a pole of the transfer switch you'd be grounding your two systems in two places which is a code violation. Your first post only mentioned 480v generator which would lead me to think that the generator was running ungrounded single voltage.
