Electrical System Protection

When RV owners think about electrical system protection, the first thing that comes to mind is a "surge protector." However, not all surge protectors are equal and basic models offer less than you think and do not protect your RV or its electrical components.

This article looks at the various electrical problems you will encounter while RVing and provides solutions to protect you and your RV.

Electrical Concerns

Since surges are the first thing that comes to most people's minds, let's look at them first.

Here are five causes of electrical surges:

  1. Circuit/Outlet overload. If too much load is placed on an electrical circuit overload may occur and spark an electrical fire.

  2. Lightning strikes. If lightning strikes close by or hits electrical utility equipment, a spike of thousands or even millions of volts can surge through your RV's circuits, frying electrical devices.

  3. Electrical line damage. Tree limbs, ice and heavy winds can damage electrical lines and cause them to short. These shorts can result in surges of power coming into your RV.

  4. Faulty or damaged wiring. Mice and other rodents like to chew on the wiring inside of walls and ceilings of your RV. This can result in electrical shorts and power surges as well as fires.

  5. High-demand appliances. Appliances such as air conditioners, microwave and residential refrigerators use a lot of electricity. When they cycle on/off, you may notice a slight flicker in the lights caused by the sudden change in power consumption.

If you study these you'll note that only "Lightning strikes" and "Electrical line damage" affect power coming into your RV so, a surge protector on your electrical supply would only help with these two specific conditions. The other three are all internal and inject the surge condition downstream from an RV surge protector.

Other dangerous and damaging electrical faults include, but are not limited to:

  • Over/under voltage

  • Open ground and open neutral

  • Reversed polarity

  • Miswired pedestals

  • Hot-skin condition

Some of these conditions, such as over/under voltage are quite common and encountered in many campgrounds, especially during hot or cold weather when multiple rigs are running air conditioners or heaters. Your RV may have already suffered hidden damage from this as it does not usually cause immediate failure but accumulates damage over time until total failure occurs.

EMS vs Surge Protector

An EMS or Electrical Management System is somewhat like a surge protector on steroids. It offers surge protection as well as protection against these other conditions.

EMS devices are available with a range of protection, in portable and hardwired versions and models for both 30 and 50-amp RVs

When shopping for an EMS, take careful note of the faults it detects as some models offer a greater range of protection than others.

Portable models are popular as they simply plug into your power source and your RV's electrical cable plugs into the EMS. The downside of this format is that it may be subject to theft if not secured. Some models include a tether point to affix the device with a steel security cable or chain.

Hardwired models are wired into your RV, before its junction box. With these, you simply connect your power cable to a pedestal as before.

Some models provide indicator lights to identify faults, some include a fault indicator that can be mounted remotely and still others provide fault information through a smartphone connection.

If you have a 30-amp RV, you will need a 30-amp model and if your RV has a 50-amp electrical system, you'll need a 50-amp model. They are compatible with power adapters so if you connect a 50-amp RV to a 30-amp power outlet, using an adapter cable, you still have full protection.

Different makes and models may function differently but most interrupt the power when a fault is detected. When the fault has been corrected, the connection is re-enabled.


There are several brands of EMS devices available and most have 30-amp and 50-amp models available in portable and hardwired version. I am unable to recommend any specific make or model as each have a different feature set. Check the manufacturer’s website for specifications and features then choose the one you fell is best suited to your needs.

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