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One thing that you absolutely need for your RV is an EMS (electrical management system). An EMS protects your RV wiring and appliances from damage that can be caused by poor power. It monitors all shore power coming into your rig and cuts the power if it senses a problem.
In our 9 years of full time RVing, we have encountered power problems ranging from low voltage to open grounds. There is no doubt in my mind that our EMS has prevented damage to our RV on numerous occasions.
As the old saying goes – It is not if but when.
You can prevent potentially catastrophic damage to your RV with a device that costs a few hundred dollars. So get an EMS. Consider it part of the purchase price of your RV or an insurance cost but do it. It only takes one mis-wired or malfunctioning post to cause hundreds or thousands of dollars of damage to your rig.
An EMS can be portable or hardwired. Portable EMSs are convenient because they are easy to replace, if they fail. On the other hand you’ll want to lock it to the power post when in use so that it can not be stolen. Hardwired EMSs are permanently wired into your RV electrical so they are not likely to be stolen but will be harder to replace if required.
It should be noted that you need more than a simple surge protector. A surge protector protects against surges, that’s it.
Now for the EMS-PT30X review
We have the Progressive Industries EMS-PT30X. We have been using this model and it’s predecessor since we started RVing back in 2012. In all of those years, we have never, not once connected our RV to shore power without our EMS. That is how important we think it is to use an EMS.
Details & Specs

The EMS-PT30X is a portable EMS (electrical management system) that protects your RV from electrical damage.
It gets plugged in to a shore power post. Then RV plugs into the EMS.
Once the power is switched on, the EMS performs a series of checks before allowing any power through to your RV. If a problem that could cause damage is detected, power is not passed to the RV.
The entire time you are connected to shore power through the EMS, it continuously scans the power. If there is a problem, it cuts the power off before it can cause damage to your RV.
A scrolling display that shows you real-time amp usage, voltage, hertz and any error that has been encountered.
Protects against:
Power Surge – 1,790J, 44,000A surge current, Response time <1 Nano second
High/Low Voltage
Open Ground
Open Neutral
Reverse Polarity
AC Frequency Deviation
Accidental connection to 240 volt power
Additional features:
Time delay for AC compressor – if the EMS cuts power to the RV due to an electrical problem, it delays restarting for 136 seconds in order to protect your AC compressor.
Lock bracket.
Well built and sturdy.
I’m not an electrician so if you want more detailed electrical information the user manual can be found here.
Progressive Industries EMS-PT30X

The EMS-PT30X is well built, sturdy and does exactly what it is supposed to do, protect your RV from electrical hazards.
Highly recommended.
Pros
- Peace of mind – I know my RV is protected – the EMS will cut off the power before anything can be damaged by an electrical issue.
- More than just a surge protector.
- Protects against Reverse Polarity, Open Neutral, Open Ground, High & Low Voltage, AC frequency deviation & accidentally plugging into 240 volt power.
- Portable and easy to use. No configuration or wiring required; just plug it in, plug your shore power cord into it and turn on the breaker.
- Display is easy to read both day and night.
- Display shows real time power usage so you can easily see how many amps you are using, the voltage, hertz and and error that has occurred.
- Weather shield covers the plug socket in case of rain.
- Limited lifetime warranty. When we had an issue, after encountering poor power at an RV park, Progressive Industries was easy to work with and replaced the unit. (The EMS cut all power to our RV before any damage could be done! Yay!)
- Lock bracket makes it easy to lock to the power post. We use this adjustable cable lock.
- List of error codes and their meanings is printed on the side of the EMS so you do not have to go looking for the manual when you get an error code.
Cons
- Display scrolling can seem very bright at night in a dark location, of course this also means you can see it. (We resolved this by wrapping a velcro stip around the EMS and we simply slide it up over the display if we do not want it to draw attention at night.)
- Can be difficult to keep upright or off the ground if the power post at the RV park is very short – this is likely to be an issue with all portable EMS units or surge protectors. (We keep a few wooden shims on hand just in case.)
Progressive Industries also makes a 50 amp version of this EMS.
EMS-PT50X
Conclusion
We have been using the Progressive Industries EMS-PT30X since 2012. As I said earlier, there is absolutely no doubt in my mind that it has prevented damage to our RV. In weather ranging from 120 degree heat to pouring rain and even snow, it has kept our RV safe from electrical harm.
It is easy to use, well built and sturdy. It was definitely money well spent and I can happily recommend it.
Over the years, our EMS has warned us about low voltage, open grounds and open neutrals on RV park power posts. Without the EMS-PT30X we would have had no idea there was a problem and would certainly have damaged our RV.
This is one of the select few items that we feel you absolutely need to have to protect your RV.
There are alternative RV EMS systems out there, the other one that I have heard highly recommended is the Southwire 34930 Surge Guard 30A-Full Protection or 50A-Full Protection. I have never personally used it so I can’t tell you much more about it.
It bears repeating; you can prevent potentially catastrophic damage to your RV with a device that costs a few hundred dollars.
More detail – exactly how we use it.
Every single time we set up at a new site, the first thing we do is check the power. The last thing we want to do is set everything up only to find out that the power does not work properly!
How to check the power at a campsite
- Verify that the breakers are off. Then visually inspect the power post to make sure that it isn’t melted, burnt or just plain broken.
- Plug in the EMS (only the EMS not the RV shore power cord) and flip the breaker on.
- The EMS will run through a series of power tests to ensure that it is safe to plug in your RV. If it does not find any issues, it allows power through to the outlet on the EMS and displays E0 on the scrolling display screen.
- If there is a problem with the power the EMS flashes an error code on the display. For example, E2 indicates that there is an open neutral. (The list of error codes is printed directly on the side of the EMS for easy reference.)
- If an error is detected, go back to the office. Let them know that the power check indicated a power problem and ask to switch sites or to have the post repaired.
- If the power looks good, flip off the shore power breaker and lock the EMS unit to the power post.
- The final step is to plug the RV power cord into the EMS and flip the power back on.
Once the power to our rig is on, the EMS-PT30X continuously monitors the electricity coming into our rig. We know that if the EMS encounters an issue, it will cut all power to our RV before any damage can be done.
The display scrolls through the voltage, hertz, amp usage so that we can easily see the status any time. If we are parked at the right angle I can even read the display by looking out the window.
Neat tips:
- If you are using an electric hot water heater, you can tell when the water is hot by looking at the amps you are using. The amp reading will drop as soon as the water gets to temperature and the heating element turns off.
- You can get an idea of how many amps an appliance is using by watching the amp display too! Check the amp usage reading on the EMS. Turn on the appliance and check the amp usage again. If the first reading was 3 amps, and after turning on your hot water heater the amp usage jumps to 15 amps, then you know the hot water heater is drawing 12 amps.
OK, that’s it for now. Hope you enjoyed reading.
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THANKS FOR READING!
We’ve been full-time RVers since 2012. Over 127,000 miles and 47 states later, we are still towing our home around the United States.
On TowingHome we share what we have learned along the way; what we love (and what we don’t) about the RV lifestyle, tips and tricks, our favorite campgrounds, places and gear.
We hope that it makes your journey a little bit easier.