My manual has a blurb about 50 amp service too. It also says that there is a bypass valve in the utility compartment so I can fill the fresh water tank from the city water inlet....but it doesn't have that valve. It's an error.
I think that a lot of the stuff in the manual is just generic stuff that applies to more that then Fiesta/Terra models. I have noticed other discrepancies and generalities as well, which lead me to believe this is the case.
Back to the issue. I only have one breaker labelled AC, so unless there is one hidden somewhere or mislabeled, I can't just turn on AC off.