RVelectricity: Pros and cons of the big three brands of EMS surge protectors

Dear Mike,
Do you know anyone who has tried out the EMS surge protectors from the big three manufacturers? —Fabian

Dear Fabian,
Indeed I do, and that would be me. I have sample Advanced/EMS surge protectors from Hughes, Progressive Industries, and Surge Guard in my shop and I’ve experimented with all of them.

Now, I didn’t get the opportunity last year to try to blow them up with a high-energy pulse test that can simulate a lightning strike, and that was because COVID got in the way. But I did do bench testing to see how each brand performs for Over/Under Voltage, Open Ground, Reversed Polarity, and Generator 60 Hz Frequency.

Overview

An Advanced/EMS Surge Protector is a lot more than just a bigger version of the surge strip on your office computer. The Advanced/EMS units from all three manufacturers do indeed have MOV voltage spike protection that will help keep nearby lightning strikes from getting into your RV’s electrical system.

They also continuously watch for voltage above 128 and below 104 volts, check to make sure the Ground connection is intact, and report Hot-Neutral Reverse Polarity on a receptacle. And when they find something dangerous, they shut down a big relay which removes your RV from the pedestal power, thereby saving your RV electrical system from damage.

Don’t get a basic surge protector if you can afford to spend more…

Yes, I know that you can buy a basic surge protector (without the EMS function) for less than $100. But that’s just a bigger version of your office surge strip. The Advanced/EMS versions do cost more money (maybe $275 to $400, depending on 30- or 50-amp versions), but I consider them to be well worth the investment. Even a few seconds of pedestal electricity over 140 volts can be very dangerous, and I’ve seen it go over 200 volts on occasion, which is a sure way to fry a lot of things in your RV. That’s a big dollar fix that could take months to repair.

Here they are in alphabetical order with my basic pros and cons of each.

Hughes Power Watchdog with EPO (Emergency Power Off)

Hughes is the new kid on the block. They originally started with their Autoformer voltage booster product. The Power Watchdog is not that, since it doesn’t actually boost the campground voltage by 10% like their Autoformer. But it does monitor for high or low voltage, reverse polarity, open ground and high amperage. Plus, it checks for downstream open neutral problems in your RV, a great feature for a 50-amp service. Watch Mike’s interview with Tony Barthel about the Hughes Power Watchdog HERE.

Pros: Hughes Power Watchdog

• Their Bluetooth phone app is great and allows you to not only monitor instantaneous voltage and current draw from your RV, you can also see your total Kilowatt Hour Usage. 
• Comes in both 30- and 50-amp versions with portable or hardwired options. 
• You can replace the MOV module yourself in the field if it wears out from too many surges

Cons: Hughes Power Watchdog

• That big angry dog on the outside of the case is BRIGHT when it goes red to warn you of a problem. A few of my readers also say that even the normal light is bright enough to attract attention from thieves, and have bagged it to hide the light.
• No waterproof plug cover option available

Progressive Industries EMS (Electrical Management System)

These are the guys who started it all and coined the phrase “EMS” (Electrical Management System). Their EMS surge protectors come in both hardwired and portable versions in 30- and 50-amp sizes. While they do have a remote panel, you can mount in your RV. There’s no Bluetooth app just yet.

Pros: Progressive EMS

• Most popular brand
• Solid performance
• Great replacement warranty if the MOVs wear out
• Waterproof plug cover available as an option

Cons: Progressive EMS

• No downstream open-neutral protection 
• No Bluetooth interface at this time
• Simple number warning codes you need to look up error codes on a chart

Southwire/Surge Guard Total Electrical Protection

I’ve done a lot of testing with this product line, so I understand their testing algorithms intimately. That’s also why I think their ability to shut down power in the case of a voltage problem may be the best of them. They invented the downstream open-neutral sensing, which can save your bacon on a 50-amp service if the campground or your RV neutral opens up. If that occurs, it will shut off power to your RV before the voltage can reach dangerous levels.

They do have a Bluetooth version, but their smartphone app is still in development. So if you want a remote monitor you’ll need to buy their $50 unit and stick it on the wall. Also, their MOV devices are not field replaceable when they wear out, but they do offer a replacement warranty similar to Progressive.

Pros: Surge Guard

• EMS function also available in their Southwire ATS (Automatic Transfer Switch)
• Full replacement warranty in the event the MOV devices wear out
• Great voltage protection algorithms
• Upstream and downstream open-neutral protection
• Bluetooth remote panel available 
• High-Joule MOV devices

Cons: Surge Guard

• No smartphone Bluetooth app at this time
• Non-replaceable MOV devices
• No waterproof plug cover option available

There you have it – my take on the pros and cons of the big three brands of EMS surge protectors. I’m hoping to do some destructive testing on all three product lines this fall, so let’s keep our fingers crossed. Mikey likes big booms...

Let’s play safe out there….

Shop for EMS surge protectors:
• Find EMS surge protectors on TechnoRV
• Hughes Power Watchdog on Amazon
• Progressive Industries EMS on Amazon
• Southwire/Surge Guard Total Electrical Protection on Amazon

Mike Sokol is an electrical and professional sound expert with 50+ years in the industry. His excellent book RV Electrical Safety is available at Amazon.com. For more info on Mike’s qualifications as an electrical expert, click here.

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