surge protectors

Why You Really Need an EMS and Not Just an RV Surge Protector

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Starting out as a new RVer is expensive! You likely just dropped several thousand dollars on a down payment for your rig. Now you have to spend hundreds (or even thousands) more on getting all the gear?! No one warned you how expensive being an RV owner can be, did they…

You might be tempted to skip the RV surge protector. But in the long run, this is an enormous gamble. A surge protector is the only thing protecting your RV from electrical damage. Damage that leads to costly repairs or even fires.

There is a common misconception that all RV surge protectors are created equal. So why would you pay a few hundred dollars when you could get “the same thing” for less than a hundred bucks? I’ll tell you why if you keep reading. 

What is an RV Surge Protector?

In the simplest terms, an RV surge protector protects your rig from power surges. Power surges can occur for various reasons from lightning strikes to faulty campground power poles. 

When using a surge protector you will always plug your surge protector into the power pole first. After that, your RV extension cord connects directly to the surge protector. That way, if a power surge occurs, your surge protector responds in real-time to disconnect from the power source, saving your rig’s electrical system. 

The RV surge protectors you see that cost around $100 typically only protect against increases in power. However, there are many more things that can go wrong with electricity.

That’s where an electrical management system (EMS) comes in.

electric meters

What is an EMS?

EMS stands for “electrical management system”. It is technically still an RV surge protector, but it has many additional protective features. High voltage (power surges) is just one issue you can run into with electricity. 

Other problems you might encounter include low voltage, faulty shore power wiring, open grounds, reverse polarity, or damaged power poles. An EMS will protect against all these things. 

You might wonder how big of a deal are all those “other electrical problems” anyway. When you arrive at a new campsite, you have no idea the status of the electrical system. Who knows, the camper before you could have clipped the power pole while pulling in or out. 

Or the electrical system could falter under the stress of hundreds of air conditioners running at the same time on a hot summer day. Low voltage might not seem like a big deal, but it causes increased resistance in your electrical system. This increased resistance means your electrical system is working harder, which can lead to electrical fires. It also causes things like air conditioners to run hot, which puts a tremendous strain on AC compressors causing an expensive repair when they finally go out much sooner than they should. 

House fires can be traumatic, but RV fires are often even worse. A small space combined with highly flammable materials can quickly ignite. 

Using an EMS is a relatively affordable way to have peace of mind and save yourself thousands of dollars in damage. Typically, when searching for an EMS it will be called an EMS instead of a surge protector. 

However, some companies market them as surge protectors. If you look at the description, you should see the added protections an EMS offers. If nothing else, the price will usually give it away. To get the most protection for your RV, you need to buy an EMS which typically costs at least $200-$300.

What are the Best EMS Options on the Market?

There are many brands that offer surge protectors and EMS. While this list doesn’t name them all and some other brands (like Southwire) are also well respected, there are three brands that stand above the crowd. If you go with any of these options, you’ll be purchasing a solid product. 

Choosing the Right RV Surge Protector for Your Rig

Before I jump into specific models, it is important to know if your RV uses 30 or 50 amp power. If you have a 50 amp RV, you’ll need to purchase a 50 amp surge protector or EMS. If your rig uses 30 amp power, you’ll need a 30 amp surge protector or EMS. 

Once you plug your EMS or surge protector in, wait about a minute for the all-clear reading and you’re ready to plug in the rest of your electrical. 

If you have a 50 amp rig but only 30 amp hookups available, you’ll need to use a dog bone adaptor to “step down” from 50 amps to 30 amps. You’ll connect your 30-to-50-amp adaptor to the power pole directly then plug the surge protector into the adaptor.

Also Read:  RV Electricity So Anyone Can Understand

You can even add another dog bone to step down from 30 amps to 15 amps which will let you get electricity from a regular house outlet. It is very useful for moochdocking (aka mooching off your friends and family by living in their driveway now and then). We may or may not be doing this as I write. 

When purchasing a dog bone adaptor, ensure you get the right male and female ends to match your system.


Hughes Autoformers RV Surge Protector

Many RVers love the Hughes Autoformers EMS options. The Power Watchdog 30+EPO or 50+EPO offers the best protection. The biggest selling point compared to other electrical management systems or RV surge protector options is the replaceable surge modules. 

This feature means if there is a huge power surge that damages the unit, you can replace just the surge protection module rather than the entire surge protector. 

The Power Watchdog has an auto-shutoff feature, but even more convenient is the auto-on. Once the power stabilizes for 90 seconds, the surge protector automatically restores power to your rig. This feature means you don’t have to go outside to the power pole to turn things back on.

You can even monitor and control the unit via Bluetooth from your smartphone. Again, very convenient if you’re in the middle of something and don’t want to run outside. 

The 50 amp model provides up to 4800 joules of protection. This means your rig will be protected even from very large power surges. 

 Autoformers RV surge protector

Progressive Industries

Another popular and solid brand for an RV surge protector is Progressive Industries. They have many surge protector-only units as well as EMS options

Compared to other EMS units, one of the best features is user-friendliness. Most RV surge protectors use different colored lights to indicate problems. Progressive Industries surge protectors, on the other hand, have a digital display. It tells you exactly what you need to know whenever a problem arises. 

The 50 amp model protects against power surges of up to 3,580 Joules which is the lowest among the top three brands. 

Progressive Industries RV surge protector


Finally, you also can’t go wrong with a Camco RV surge protector. The Camco Power Defender is what Joel and I have for our rig. When we were first getting started, buying all the supplies was indeed painful. Despite this, we decided to spend the extra money to get an EMS for the added protection. 

The Power Defender from Camco protects against surges up to 4,200 joules with their 50 amp EMS. This is slightly less than the Hughes Autoformers Watchdog but more than Progressive Industries.  

It is easy to use and we’ve been satisfied with our purchase for the past several years. Despite near-constant use, we haven’t had any problems with it. 

Portable Vs. Hard-Wired Surge Protectors 

Most people, especially when starting out, opt for a portable surge protector. These units are plugged into the power pole and then you plug your rig into the surge protector. For beginners, portable surge protectors are the simplest way to get started. There is no setup besides plugging it in.

However, there are also hard-wired RV surge protectors you can get and install inside your rig. If you’re reading this article, you probably don’t know much about surge protectors or electricity. If you decide to purchase a hard-wired unit, please pay a professional to install it for you.

Messing with electricity can be dangerous or even fatal if you don’t know what you’re doing. 

Protect Your RV Surge Protector Against Theft 

While it doesn’t happen often, people have been known to walk off with an EMS or RV surge protector. After all, it’s a pricy piece of equipment. The best practice is to lock your unit up using a chain or a bike lock. 

Most models will have a security ring you can run your lock through to stop people from taking it. Typically, RV park crimes are crimes of opportunity. So while a lock doesn’t eliminate the possibility of theft, it makes it quite a bit harder.

Which RV Surge Protector Do You Think is Best?

  • If you already have an RV surge protector, which one did you get an why?

  • Do you think it is worth the extra money to get an EMS?

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