30 amp power cord overheating

Yard camping usually implies your hooked into 15 amp house connection - if so that is likely at max capacity running just the AC and might not even be able to do that depending on type/length of extension cord. When I do that I usually switch the fridge and hot water heater to propane and use a kill-a-watt to monitor the voltage in the rig to make sure it doesn't drop too low and damage the air conditioner. If your batteries are low the converter can also be a major electric draw.