When you add up all of the on-board 120VAC appliances wattage numbers you will find it does indeed exceed the 30AMP MAIN BREAKER capacity.
You may have been running too many things at the same time or perhaps the incoming 120VAC from the pedestal is somewhat on the low side. This will also make your appliances draw more current...
If the camp ground pedestal 30AMP Service connection is worn and not making good contact with your shore power plug will also cause this same thing...
I keep a good watch on the 120VAC status by using an inexpensive RV 120VAC PLUG-IN AC VOLTMETER. This model has the SAFE ZONE painted in GREEN and we can do a quick glance at the meter before we turn on something that is high wattage like the Microwave when the Air Conditioner was already running...