An RV is loaded with electrical components. To keep your air conditioners, battery chargers, and entertainment systems operating in perfect order, clean electrical power needs to be supplied to the RV. Yet, campgrounds are not always the best at providing surge-free protection.

Surges, spikes, low voltage, and incorrectly wired pedestals can cause serious (expensive) damage to your RV’s electrical system. Fortunately, a number of aftermarket devices are available to combat the dreaded surge and spike.

A surge protector will prevent these spikes and surges from passing through the system. It does this by utilizing metal oxide varistors, commonly knows as MOVs. A MOV does nothing at normal voltage levels, but when the voltage rises to an unsafe level, it shorts that power to ground. Energy surges are rated in units of joule. Try to find the highest rating possible when shopping for a surge protector.

Most products referred to as surge protectors also contain some sort of low- and high-voltage protection. This is important because many RV electrical problems stem from low-voltage power from a campground pedestal. When the voltage drops, the amperage increases and this creates extra heat, which causes items such as motors and electronics to fail. A good surge protector will disconnect power to the RV whenever the incoming voltage falls out of the acceptable operating parameters, typically 106 volts on the low side and 132 volts on the high side.

AC places a heavy load on an RV’s electrical system. Electrical motors in general require three times the current to start them as it does to run them. AC compressors have high head pressures on startup that create additional demands that can trip a circuit breaker. Modern units have a built-in delay that will not allow you to start an air conditioner until a certain time has passed since it was shut down, so that the head pressure can bleed off to lower the starting amperage. Fortunately, should you have older units, most surge protectors can be set to add a 2-minute delay so that your ACs can bleed down after a power failure restart.

You can wait it out to see if the voltage comes back up to a useable level. Generally, campgrounds with low voltage have added sites beyond what the electrical service was originally designed for. Later in the afternoon when other campers switch on their AC, the load on the grid can be too much, so the voltage drops to an unsafe level. Those campers without surge protectors run the risk of causing serious damage to their AC compressor motors, capacitors, and other electric components.

If you don’t want to wait it out, you can run your generator to provide clean power. If running your generator is not an option, most surge protectors do offer a bypass mode that will allow you to supply power to the RV during low-voltage conditions. Be aware that you should only do this when power is absolutely needed. In that situation, switching off your AC and entertainment system is advised. Use this mode only to power your basic electrical needs.

Types of Protectors
Surge protectors can be hardwired into your RV or they can be portable. For portable units, you plug your power cord into the surge protector, which connects to the campground pedestal. However, your surge protector is now out in the open and subject to rain as well as theft. It’s also one more thing to have to connect when you set up camp.

Hardwired units are mounted inside the RV and are wired directly into the electrical system. They should be connected between the power cord and the transfer switch. Some owners simply cut a few feet off of the cord and splice the unit in, while others just add a short whip between the surge protector and transfer switch. Hardwired units are theft proof and are not exposed to the elements, so they are a better choice. However, smaller RVs with limited compartment space and no transfer switch may be best served with a portable unit.

Our choice for a motorhome was the Progressive EMS HW50C with remote display. The remote display shows incoming voltage, as well as frequency and amperage draws. It’s a bright red LED rather than a dim LCD, so it’s easy to read in bright lighting.

Every RVer should consider some sort of surge protection. With the value of the electrical components in your RV and the potential for some expensive damage from electrical anomalies, RVing without surge protection is similar to driving without insurance. Fortunately, the wide variety of offerings in this area provides some great solutions to this common problem.