Got a “built in” RV generator? Don’t have to “plug and unplug” shore power cords when switching from shore power to the genset? Then you have an ATS (automatic transfer switch). They’re convenient, indeed, as the rest of us without them have to go outside, typically open a door, and plug the shore power cord into a special receptacle fed by the genset.
However, there are a couple of caveats you need to be aware of: An ATS is not a “perfect” device, and problems can occur. Here’s a good rule when firing up the generator when using an ATS. In fact, this is a good rule when firing up any RV generator, ATS or not: Reduce power consumption before firing up the generator. That means, make sure the air conditioner, the microwave oven, the portable electric space heater–any of those “big draw” devices are turned off.
A big surge in electrical current can actually damage an ATS, and in some cases, the genset itself. There have been cases, too, when the ATS somehow wasn’t fast enough to isolate the generator from the shore power system–with very nasty and sometimes expensive results. Take the extra moment to reduce your power consumption before you hit the start switch.