325 watts fridge
1200 13500 btu air conditioner (but may draw up to 1900 watts)
1200 water heater on electric
2725 total You will be fine on a 30 amp and will have enough power to operate the converter, too.
Duty cycle on an absorption fridge is 2:3 so it is on 40 minutes of each hour.
Cycling on a ten gallon electric water heater is 15 minutes every four hours if no water is drawn off. Time to first cycle is about 90 minutes on electric.
In the time before I had a hybrid inverter/charger I would flip the water heater off before I cooked or used the coffee maker.