The last 2 times I have been out in modern campgrounds, my progressive EMS shut my power down briefly at night due to high voltage, >134 volts. This was a nuisance to me due to me using a CPAP machine. People without an EMS never knew there was a brief high voltage issue. But I have to figure that isn't too good for all the equipment in the RV. So, I plugged my CPAP into my inverter and used it like a UPS..... I guess this will become my standard practice.
I was very surprised that high voltage seems to be a common problem.....