We have been using the Surge Guard Portable 30 Amp protector for several years (model:18277). Last summer we were camping in the Poconos and my power shut off. I looked at my Surge Guard and it showed 134 volts trying to pass thru the system. The Surge Guard will automatically disconnect your trailer system from the pedestal on either a high voltage or low voltage problem at the pedestal. As I watched it for several minutes, as the voltage went down to 124 volts, my trailer power came back on. Later, as I was doing some stuff outside the trailer, my kids came up saying there was no power in the trailer again. I looked at the Surge Guard and saw 97 volts. When it came up to 108 volts, the power came back on in the trailer. We notified the camp ground manager that there were issues. He didn't know anything about it. Maintenance came and looked at it and claimed they couldn't find any issues. Later that day, power went out to the trailer again and I saw 139 volts on the display.
5 trailers around me that had no protection had melted power prongs. The cost of the Surge Guard more than paid for itself that day.
2012 Ford Expedition EL
2012 26BH (Traded)
2002 Prowler Lynx (totaled due to tire blowout)