A/C on shore power trips breaker after 30 minustes

OK, I started the A/C and it did the same thing. I am going on a month-long trip to Montana so I will see if a dedicated 30 amp in a RV park will work. I also ordered a backup portable A/C unit to keep me from frying. Worst case I can run the generator but that seems too disruptive for other RVers. I am thinking that I may not have ever run the A/C at home except to put a load on the generator to maintain the generator each month.