Hi Gonehuntinrfishin,
Welcome to the Heartland Owners Forum.
Some of the Onan generators come with two 30 amp breakers and others with a 20 and a 30. Regardless, the generators are spec'd at 48.5 amps total. So depending on what's pulling power and how much, you could simply be asking too much of the generator, causing one of the breakers to trip.
If in addition to the center air conditioner, you're also running other loads, it's not hard to get close to 30 amps on one leg or the other of your power system. If you have a residential refrigerator, when the compressor starts, it can pull extra amperage - perhaps more than 8 amps. And the Power Converter is running in the background pulling 2-12 amps as it changes modes. And I think sometimes it can peak above 15 amps.
So, is there any possibility you just have to many amps being drawn?