As others have pointed out, the DC converter depending on what unit you have can draw enough power to trip a 2000 watt generator when the batteries are low. You can turn it off by tripping the circuit breaker, or pulling the plug etc. The water heater as mentioned can be a large draw as well. I'm missed the water heater switch setting and tripped my generator when trying to run AC more than once.
As already mentioned, without a good starting capacitor, even a 13.5k ac can trip a 3000 watt generator. I too have installed the Supco hard start caps in my last couple rigs. They are reasonably priced and seem to hold up well.
Finally, are you taking your Handi out of ECO mode prior to turning on the AC? Most of the friends I camp with that have the Handi find it won't run the AC in ECO at the altitudes we camp at. Not sure how they work at sea level.
Hope you get it sorted out