In most cases, yes. Whatever the service conductors hit first must be service rated, and everything downstream must be wired like you would a sub-panel. That's one reason we like seeing even main-breaker panels wired with the neutrals and grounds on separate buses.When you putting in an automatic transfer switch, are you suppose to separate the neutrals and grounds in the panel that it is feeding. Does the transfer switch become the first disconnect?
I concur!I swear there needs to be a generator forum. I see so many generator posts come through.