I use a Progressive EMS unit. Won't plug in without it. Here's why.
In our second season, we were in an old campground at the far end from the entrance. It was stupid hot and humid. Entered the coach a couple of times to find the AC off, and its breaker tripped. I reset it a couple of times. Eventually noticed the lights "browning out" occasionally. Turns out the circuit we were on was the oldest in the park, and hadn't yet been replaced. With the hot weather and everyone running their AC, there were frequent and severe voltage drops.
Next trip out, yup, no AC. Blowing warm. The low voltage fried the compressor. Thankfully, we were still inside the Coleman warrantee, and they replaced it.
Ever since, I only plug in with the EMS connected. We've been in similar circumstances a number of times since then, and the unit has disconnected us every time. When power returns to spec, it delays reconnecting a bit over two minutes, to give the AC compressor time to cool off and lose pressure.
Trust me, it's three-hundred-something bucks well spent.