Agree on trial and error. Seems not all 30 amp breakers are created equal (some have been abused more than others). We've been hitting a bunch of Samborees and if you're lucky you get 30 amp, so it's keep the water heater on propane and watch the AC/Microwave use. We've converted all lighting over to LEDs so that's one less rather big power draw from the converter. It can get warm while only running one AC, but we get by.