Glossary
Surge protector (EMS)
A device between the pedestal and RV that blocks voltage spikes and, on EMS models, low voltage and wiring faults.
A surge protector installs between the campground pedestal and the RV's power cord, and its basic job is absorbing voltage spikes before they reach the coach's electrical system and appliances. Campground wiring varies widely in age and condition, and spikes from lightning or grid switching are common enough that most experienced owners treat this as required gear, not optional.
An Energy Management System, or EMS, goes further than basic surge protection. It continuously monitors incoming voltage and will cut power automatically if it detects conditions like low voltage, high voltage, open ground, or reversed polarity, all of which can damage air conditioners, electronics, or create a shock hazard if left uncorrected.
The mistake worth avoiding is buying a basic surge-only unit and assuming it also protects against wiring faults, which it does not. If a campground has a history of bad pedestals, or you camp at a wide range of parks, the added monitoring in an EMS model is generally worth the extra cost over surge protection alone.
Where this comes up
- Best RV Surge ProtectorsBuying guide
- Best RV Power CordsBuying guide