RV EMS vs. Surge Protector: What You Need To Protect Your RV

Display for hard wired Surge Guard RV Power Monitor EMS system

Does trying to understand your RV’s electrical system and the RV EMS vs. surge protector debacle leave you scratching your head? Or does worrying about putting your RV at risk of serious damage keep you up at night?

We’ve been there. 

From RV newbies to full-time RVers who have been around the block a time or two, we have learned a lot about how to protect our precious adventure mobile. Even when pulling into . . . questionable . . . campgrounds that look as if their wiring and pedestals had not been updated in many many years. 

Modern RVs are capital F-U-N! They can take you almost anywhere and provide you with all of the comforts of home and all of the latest and greatest amenities and features, but that also comes with the added risk of having more things that can break or go wrong. 

We are helping you avoid the headache (and heartache) of RV electrical problems so that you can invest in high-quality “insurance” for your RV through the best RV EMS or RV Surge protector. 

Intro to RV electrical systems & electrical components

RVs typically come in either a 30 amp or a 50 amp configuration, which is used when the travel trailer, fifth wheel, motorhome, etc. is plugged into shore power (like at a power pedestal at an RV park or campground).

Hint: A quick way to know whether your RV is 30 amp or 50 amp is by the number of prongs. 30 amp usually has 3 and 50amp usually has 4 prongs

RV 30 amp and 50 amp plug side by side
50 amp plug on left, 30 amp plug on right

Whenever you are dealing with electricity there are risks, and it is important to understand how your RV’s electrical system works to protect it from damage, and more importantly to protect you from harm! 

Basics Terms for RV Electrical Systems

  • Volts: The electrical potential or force. The standard is 120 V for RVs in North America
  • Watts: The total power consumed or generated. Watts = Volts X Amps
  • Amps: The rate of electrical flow and how much electrical charge flows through a circuit per second. 30 amp or 50 amp is most typical for RVs, which determines how much electrical current the RV can handle. This is a measure of the rate of electric current flow or the intensity.
  • Joules: A measure of energy. For surge protectors or electrical management systems, joules indicate how much energy they can absorb before failing. Higher joules = more protection for your RV against power surges and spikes
  • Hertz & Frequency: Hertz (Hz) is a measure of frequency, representing the number of changes per second. This is the frequency of alternating current (AC) which in North America has a standard of reversing 60 times per second. AC is a type of electric current where the flow of electrons changes directions, creating a “wave” pattern. Hertz is a measure of how quickly the current alternates direction.

How does the current impact your system? What do you do if there are surges or spikes in voltage? How do you prevent the headaches of consistently popped breakers or blown fuses? How do you stay safe in inclement weather?

Let’s dive into the safest ways to weather the storm and the best tools for the job of protecting your RV’s (very expensive) electrical systems:

RV EMS vs. Surge Protector

What is a surge protector

An RV surge protector is a compact device designed to help keep your RV’s electrical systems safe from voltage spikes and surges. They can be a first line of defense, preventing sudden increases in voltage from damaging or frying your RV’s wiring, appliances, and electronics by quickly turning off power from the pedestal when a potentially harmful electrical event occurs (such as a surge in voltage) and then restore power once the issue has been resolved.


  • Affordable and budget-friendly
  • Basic protection against voltage spikes
  • Easy to use in any campground or RV park pedestal, simply plug and play!


  • Limited protection, leaving you at risk for other issues and complications outside of voltage spikes (such as low voltage or reverse polarity, which can both be costly)
  • There is no live monitoring, making it hard to build awareness of potential issues before they occur or in real-time
RV Fifth Wheel Camper with tall pine trees overhead on a sunny day at Laura S Walker State Park

What is an electrical management system (EMS)

An EMS is like the stronger older cousin of the surge protector. These systems not only protect against surges but also provide comprehensive monitoring of your RV’s electrical systems. This way you are not only protected from the danger but can also learn insight about what exactly happened that was putting your RV at risk.

With its enhanced capabilities, it can detect issues like low voltage, reverse polarity, and open neutral connections.

Brain starting to panic? Don’t worry! 

If these words feel foreign, we will help bring you up to speed in our brief overview of the most common electrical issues and mishaps.


  • A more comprehensive and wider range of protection including surge protection, voltage management, and monitoring for a variety of electrical issues
  • They are preventative, helping prevent tripped breakers and ensuring consistent power supply
  • They can alert you to problems proactively, in real-time


  • Higher cost
  • More complex installation and pricier fixes if it fails or breaks

Friends don’t let friends RV with the anxiety of the unknown! We want you to feel prepared and confident!

Common power issues and electrical problems in RVs

What they are and how they put your RV at risk…

  • Power or Electrical surges: sudden increases in voltage that can fry your RV electronics and appliances
  • Low voltage and high voltages: both high and low voltage and voltage fluctuations in voltage can damage sensitive equipment. For example, a high-voltage power surge from a lightning strike could fry the electrical components in your RV. Low voltage can also do damage and can be more likely to happen when everyone in the campground is trying to cool down from the sweltering summer heat, leading to a more significant draw from the RV park’s power grid. Unfortunately, most RV parks and campgrounds weren’t built to handle today’s modern RVs that demand a lot of power to run their fancy bells and whistles. Low voltage can lead to decreased airflow and motor failure due to overheating, while also putting the RV at risk of fire.
  • Reverse polarity: Incorrect wiring (hot and neutral wires connected to the wrong terminals at the campground or miswired pedestal can lead to dangerous situations where current can flow through the hot wire from the power source into your RV appliances and electronics. This can lead to dangerous situations such as short-circuiting, overheating, and electrical shocks.

Your RV may complete you, but you certainly don’t want to complete your RV’s electrical circuit. The results would be, well, shocking!

  • Open ground: If the power source or shore power is not properly grounded, this can in some cases cause your RV to become electrified. This typically will happen if you have problems with the electrical or appliances in your RV as well and can lead to a condition called “hot skin” as your RV is not properly grounded. This is where the RV itself can become electrified and can then pass into you if you were to touch various parts of your RV. This can lead to you getting an electric shock! This might be as small as tingling or a small muscle contraction, or can be severe and in some cases lead to severe injury or even death. Open grounds also increase the risk of electrical fire
  • Open neutral: The neutral wire has the job of returning the power load from any 120V draw back to the power source. If this is broken or “open” this can lead to drops or spikes in voltage and damage
  • Accidental 240v: Plugging your RV into the wrong power source can lead to a lot of damage. 240V is common for dryers and RV plugs can look similar, which can make it easier to make this mistake. RVs are 120V systems and should never be plugged into larger 240V outlets.
  • AC Frequency Deviation: Sometimes issues with the power supply or power grid can lead to changes in the frequency of the alternating current coming into the RV. These deviations from the standard (60 Hz in the U.S. and Canada) can damage electronic devices.
  • Faulty wiring and wiring issues: RVs are made by humans and in many cases are made rather quickly. It is not completely uncommon for RVs to have faulty wiring or wiring issues and these can be dangerous and lead to error codes displayed in an electrical management system.

This might seem like an uncomfortably LONG list of things that could go wrong with your RV’s electrical system and appliances.

The good news is that there are products that have been carefully designed to protect you and your RV!

As a quick general reference – From the list of potential power issues and electrical problems above, basic surge protectors will most commonly protect your RV from only voltage surges while more advanced electrical management systems will be better equipped to alert you to and protect you from a wider variety of concerns.

Types of devices: Portable vs. Hard-Wired units

Portable Units

Portable units can be easily plugged into the power pedestal, making it an easy, convenient, and more budget-friendly option than hard-wired units. 

Just keep in mind that if you are one who tends to leave things behind at campgrounds often… this is just one more “thing” to remember! 

We have driven off without our water pressure regulator several times, so we know how important it is to try to keep that “to do” or “to remember” list as short and sweet as possible.

Hard-Wired Units

If you would prefer a more hands-off approach, a hard-wired option may be best for you. It will be a bit more of an investment and honestly, this is in many cases completely worth it to have more comprehensive protection against issues that can be VERY costly.

Like thousands and thousands of dollars and multiple missed travel/trip opportunities, for example.

Hard-wired units will be permanently installed in your RV’s electrical system. Depending on the unit and your RV, this may take more advanced knowledge, so it is always worth seeking a professional if you are unsure or have questions.

In addition, some brands may not honor warranties if systems are not installed by a certified RV technician so it is always worth asking or taking the time to read the fine print rather than learning the hard way if you have a problem down the road!

Many higher-end RV’s or luxury units may also come with electrical management systems and hard wired surge protectors already installed. (Our DRV fifth wheel did) Just make sure that they are providing sufficient protection!

READ MORE: Best Luxury Fifth Wheels For Full-Time Living

Features to look for

When window shopping for your next surge protector or EMS device, it is important to note that not all devices are created equal.

A few features that can set these components apart include:

  • Surge Protection Rating (voltage protection): How much voltage is it rated to handle? Make sure it matches your RV’s needs. In North America, the standard voltage for an RV is 120V, so this would be what you are looking for protection around (overvoltage and under voltage protection above and below 120V or 3,600 Watts for a 30 amp RV and 5,000 Watts for a 50 amp RV
    • AMP compatibility: Ensure it matches your RV’s amp rating  (30 amp or 50 amp)
    • Joules rating: A higher rating is better for protecting your RV’s electronics from power surges. A good rule of thumb is a rating of at least 1,000 joules for your RV
  • AC frequency protection: Monitors and safeguards against changes in the frequency of the AC (alternating current). If a change or deviation is detected, it can disconnect from the power supply and provide an alert to avoid damage.
    • Normal AC Frequency: In the U.S. & Canada the normal standard of frequency is 60 Hertz (Hz), which means the current alternates direction 60 times per second.
  • LCD display & Indicator Lights: Provide feedback and insight about any issues or problems that might be impacting your RV’s electric input and systems. The best products will have diagnostic features and capabilities that can be displayed on a screen for you as the RV owner
  • Operating Temperature Range: Check the range of temperatures the product is rated to work in. The larger the range, the better! Larger ranges can be seen between -40F to up to over 200F.
  • Third-party tested for safety, reliability, and durability: One of the biggest companies that you will see certifying these products is UL (Underwriter Laboratories). This further ensures the products have been rigorously tested for safety.
  • Weather protection: If you opt for a portable unit, look for a weather-resistant design that will perform well in inclement weather and be okay for outdoor use.

Best RV surge protector and EMS models

Now that you have a solid understanding of why a surge protector or EMS is an important part of your RV setup, let’s look at a few of the most popular and well-liked products and brands. We will break down the costs, different models, and various features to help you find the best fit and best protection!

*Note: Each product below will be 50amp examples, but they all come in 30amp versions as well!

Hughes Autoformers

This is a well-known and trusted brand in the RV community that specializes in voltage regulators, voltage boosters, and surge protectors to protect your RV from a range of electrical concerns while also keeping it running if/when there is a voltage drop at the pedestal.

We have experienced voltage drops at campgrounds before, watching our voltage go down from 120 to 110 to 107 to 104…

Our EMS system shut our power off to protect our RV, but it would have been nice to get a voltage boost and keep our A/C running and our dinner cooking! (more on our RV’s exact system below)

RVer's Pick
Power Watchdog PWD50EPO, Bluetooth Surge Protector with Auto Shutoff, 50 Amp, Portable

50 amp (also comes in 30) portable surge protector with an auto-shutoff feature. Comes with a companion app to monitor things via Bluetooth and has a replaceable spike module should a large surge happen, saving you money as you will not have to replace the whole unit. 

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RVer's Pick
Hughes Autoformers PWD50-EPO-H, 50 Amp Spike Power Watchdog with Shut Off, Hardwired

6,1000-joule protection hard-wired system with auto-shutoff feature. Also comes with a companion app and a replaceable spike module. It has great reviews that also state installation was seamless and fairly quick (about 30 minutes). 

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02/18/2024 03:17 pm GMT

A pricier option with a few more perks:

RVer's Pick
Hughes Autoformers RV220-50-SP, Voltage Booster with Surge Protection, 50 Amp

Voltage boosting, park circuit monitoring, and surge protection all in one! This product keeps you safe from harmful electrical issues, while also boosting voltage 10% during drops to keep your RV and its appliances running smoothly. 12,000 Watts Capacity, 4,800 Joules of advanced surge protection with built-in indicator light

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02/18/2024 03:22 pm GMT

Progressive Industries

Progressive Industries is another highly reputable brand that has been providing surge protection and EMS for RVs since 1998.

Progressive Industries Portable RV Surge Protector, 30 Amp EMS with Integrated Display, Fault Detection, and All Weather Shield Assembly - EMS-PT30X

Protects your RV from dangerous high and low voltage levels as well as power surges. Built for RVs with 30 amp systems

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02/18/2024 05:27 am GMT
RVer's Pick
Progressive Industries Hardwired RV Surge Protector, 50 Amp EMS with Remote Display and Fault Detection - EMS-HW50C

Hard-wired units offer the highest level of electrical and surge protection. UL Certified and Canadian Approved, Lifetime Warranty. 3,580 joule and 88,000A rating. Operating Temperatures: -40F to +105F. 

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02/18/2024 03:27 pm GMT

Southwire Surge Guard

Family-owned since 1950, this is another great and reputable brand and also happens to be the brand installed in our luxury DRV Mobile Suites fifth wheel. They specialize in power protection, portable power solutions, transfer switches, cords, adapters, reels, and accessories.

RVer's Pick
Surge Guard 35550 Hardwire Model - 50 Amp

Analyzes the pedestal to ensure proper electrical conditions before allowing power to the RV. Provides protection against open ground, open neutral, reverse polarity, miswired pedestal, low and high frequency, plus low and high voltage as well as continued protection against low and high voltage and low and high frequency. Bluetooth capable with connection to their new and improved Surge Guard app. Lifetime Warranty with Connected Equipment Coverage

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02/18/2024 03:32 pm GMT

Southwire also has great hard-wired EMS options. You can see the newer version of what our RV has, listed below under “our EMS setup”!

Budget Friendly Pick

A budget-friendly option, coming in around $30-$50 for the 30-amp and 50-amp versions. Not a well-known brand like the brands above and has limited warranties including a 30-day return period and 36-month exchange. It does have thousands of high-quality ratings and reviews.

Budget Pick
POWSAF rv Surge Protector 50 amp with Waterproof Cover, rv Voltage Protector/Monitor with Surge Protection(4100 Joules), Designed with Easy to Use Handle Black

Identifies faulty park power plus offers 4100 Joules of surge protector. Protects your RV from dangerous high and low voltage levels as well as power surges. Designed for outdoor use, Weather resistant, All-weather shield assembly. Diagnostic LED, provides fault indication when you connect the wire to the power,

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02/18/2024 03:37 pm GMT

Do you really need a surge protector or EMS?

Put simply, if you care about protecting your RV from dangerous electrical situations, YES!

At the very least consider one of the budget-friendly surge protectors to protect your RV from voltage spikes that can fry your RV’s electrical and appliances.

If you have wiggle room in your budget, invest in the more sophisticated and comprehensive protection of an electrical management system. This will protect you against more potential issues and give you insight into exactly what errors or problems might be happening if they do arise.

It’s like a vaccine and an on-call doctor for your RV, all in one!

As full-time RVers, having a hard-wired electrical management system is one of those things that has simply made life easier. No matter the weather or the campground we can sleep well knowing our little home on wheels is protected and it is one less thing we have to set up or break down.

Your time is valuable and let’s be honest…life is busy! Having one less item on the RVing checklist to worry about with each and every trip is a luxury in itself.

Our EMS setup:

  • While it is no longer available in the market from what we can see, our 2015 DRV came installed with a SurgeGuard Plus Power Monitor EMS. This continually monitors shore power and shuts power off when it detects electrical conditions that could cause damage. It protects our RV from:
    • Over/under voltage protection, brown and blackout protection, miswired pedestal, reversed polarity, open ground, open neutral, high/low frequency, and multimode surge protection
    • It also has a backlit LCD remote display that indicates the source voltage, load current, and has a bypass switch
    • 3,350 Joules and an energy capacity of 130,000 Amps peak (max spike current)

This is the newer version of our RV’s model:

Surge Guard 34951 (50 AMP) - Full Protection Portable with LCD Display

Protects your RV from dangerous high and low voltage levels as well as power surges. Built for RVs with 50 amp systems. 3850 Joules of power surge protection and easy installation. Has a remote display for diagnostics and offers multi-mode surge protection and advanced features like a delay upon restart to protect the A/C compressor.

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Pro Tip: We recommend having an insurance policy that protects your RV completely if you were to experience any type of electrical incident. Take special care if you are a full-time RVer and your RV or trailer is your home. Not all policies are created equal and not all companies will cover your RV for full-time use. We have had great coverage as full-time RVers through Progressive, with similar coverage to what you would expect from a homeowner’s policy

How do you know which product is right for you and your RV?

The decision you make about any product for your RV is a personal one.

We want you to feel empowered to make the decision that is right for you. Here are a few points to keep in mind to help you:

  • How often will you be using your RV? If you are a part-time, fair-weather camper and your RV will spend most of its life unplugged in storage, you might be okay with a more budget surge protector option. This said, if you plan to have it plugged in most of its life (whether with frequent use or while in your driveway) you might want to consider a more comprehensive EMS option.
  • How many amps is your RV’s system? Narrowing it down to 30-amp or 50-amp products will eliminate half of the products, bringing you 50% closer to a purchase decision. Woohoo!
  • Check the joules rating: As a general rule of thumb, opt for a product that is rated for at least 1,000 joules. More = better protection in this case!
  • Do you want to know what errors are happening? Select a product with an array of indicator lights for common problems or a built-in or remote display screen
  • Are you willing to seek professional assistance to install a hard-wired unit? Installing a hard-wired EMS can require a bit more knowledge and some units will require a certified RV technician to install it in order to maintain any warranties. Something to consider when deciding between a portable or hard-wired unit

Proper steps for plugging your RV into a power pedestal

  • Check the power pedestal for reverse polarity using a multimeter if your surge protector does not have a built-in pedestal testing feature
  • Turn the circuit breaker off
  • Attach/plug in your surge protector or EMS system to the pedestal or power source
  • Plug in your RV’s 30 amp or 50 amp power cord to the surge protector
  • Flip the circuit breaker back on to get power
  • Check for any error codes or abnormalities

This is similar to the multimeter we carry with us everywhere we go (which comes in handy for many things):

Our Pick
Klein Tools MM325 Multimeter, Digital Manual-Ranging 600V AC/DC Voltage Tester, Tests Batteries, Current, Resistance, Diodes, and Continuity Black

Klein is a reputable brand for electricians and DIYers. This multimeter will last you for decades. It is a tool we couldn't live without.

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02/18/2024 03:52 pm GMT


We are just 2 everyday people who decided to take the leap, buy an RV, and go out in search of a life that was fulfilling and filled with experiences in nature. We are not electricians, electrical engineers, or certified RV technicians. This being said, we do pride ourselves on the amount of research we do and the thought we put into the products we choose to purchase to protect and use daily as full-time RVers.

We hope this article provides a helpful baseline of knowledge on your RV’s electrical system and how to protect it, as well as an idea of the different products on the market to help you bring one additional layer of protection to your RV so that you can have more peace of mind.

We highly recommend consulting a certified RV technician if you have additional questions or are looking for professional guidance or support with the installation. (Check out this Technician Locator through the RVTAA)

Additional Video Resources

The National RV Training Academy has some great video content about some other common surge protector and EMS questions:

Do you need a surge protector with an RV generator?

How to test RV pedestals before plugging in

What is RV hot skin and how to avoid it

Looking for more resources to keep your RV safe and learn the fundamentals? Check out our other RV Tips:

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