Simple way for me to tell is... BEFORE I turn on power or turn off power, I make sure all major appliances are turned off inside the coach. Then, I start the genset, go inside and wait for the microwave clock to start flashing. Then I turn on the A/C units one at a time. I've had the electric water heater, both A/Cs (13.5 and a 15) and a hair dryer running OR the microwave running....but not both. So far, everything seems to run just fine off the genset. And it DOES take about 2-3 minutes for the power to switch on after starting the genset.