RV glossary · Electrical & power
Surge protector
Also called: EMS, Electrical management system
A device between the pedestal and the RV that protects against power surges. An EMS also shuts off power for dangerous problems like high or low voltage, reversed polarity or open grounds.
Campground power isn’t always reliable. Low voltage during busy summer weekends, miswired pedestals and surges from storms can damage an RV’s air conditioners, refrigerators and electronics.
A basic surge protector absorbs voltage spikes. An electrical management system (EMS) adds continuous monitoring and automatically cuts power for low or high voltage, reversed polarity, open ground or open neutral, then restores it when conditions are safe. Units come in 30-amp and 50-amp versions, portable or hardwired.