Ok, this title is super clickbate, but I needed to make a point. If you ask in a dreaded Facebook group about surge protectors for your RV, you’re guaranteed to get some serious EMS mansplain. “Don’t get a surge protector, you must get an EMS!” And yes, I’m totally content in using that word to describe this situation.

EMS refers to “Electrical Management System,” and it’s a product line from Progressive Industries. “Surge protector” is a more generic term for a range of devices from different companies that protect your RV’s electronics form large spikes in power. Progressive’s EMS is a surge protector. In fact, it’s sold as one:

Progressive did a fantastic job of marketing their EMS line several years ago, and for that reason, people highly recommend them. But there are many products sold by other companies that do the same thing, perhaps with features you might prefer or at a better price. They just aren’t sold under the (probably trademarked) moniker “EMS.” Even Progressive’s varied EMS products do different things.

So what the heck are we talking about here?

Surge protectors are essential for protecting your RV’s electronics from spikes, but most of these devices have additional features that protect your rig from other electrical bugaboos. Reversed polarity (probably the most common issue), high or low voltage, and open grounds, for instance.

I suspect what many folks mean when they say “you need an EMS,” what they really mean is “you need something that protects you against high or low voltage and has auto-shut-off.” That’s really the class of surge protectors that gets you into the $250+ price range. Most of the devices in this class offer similar features, including miswired receptacles, spikes, and the aforementioned voltage.

Voltage is the thing most likely to change, so you can’t just rely on the fact that the campground is offering decent voltage when you plug in. As hundreds of RVs turn their air conditioners on in the heat of the day, voltage can drop quickly. Prolonged use of electronic circuits and motors at improper voltage can overheat and destroy them. And auto-shut-off means your rig is protected in real time as these changes happen.

No doubt Progressive Industries offers great products in their EMS line, but we highly recommend the Power Watchdog with EPO from Hughes Autoformers (read our review here). Why? In addition to the normal range of electrical protection, it also offers a field-replaceable surge module that keeps you from having to throw the thing away after a surge, and it has a Bluetooth app that allows you to check your usage and restart your device from inside while in your underwear when you accidentally turn too many things on at once.

You do “need” a surge protector. But surge protectors have a wide range of features that you should compare before pulling the trigger on a purchase. EMS is just a marketing term.