Monday, March 20, 2023


RV Electricity – Surge Protector Evaluation


Hi Mike,
Your articles in the No~Shock~Zone are outstanding. Thank you for caring enough to share and help people like me stay safe as we head out on our first travel trailer/4000-mile/27-stop retirement trip. Boy, we really could be in trouble without the electrical know-how you have shared.

We purchased a TRC Surge Guard RV Power Protection Model 34730 120-Volt / 30-Amp unit online for our R•pod 177. My question is: Is this going to take care of “surge” and electrical management or should we return and get something else? Thank you for your reply. —Linda Moon

Dear Linda,
Thanks for your kind words. It really does make me feel good that I’m helping people, so keep those questions and comments coming. To answer your question I’m going to show you how I deconstruct the spec sheet on a piece of gear to determine if it will do the job. So let’s look at a Surge Guard 34730 and see what it’s about.

First of all, I try to go directly to the manufacturer’s website for the most accurate and relevant information. While Amazon and eBay can give you a good overview, and the comments can be helpful, many times there’s inaccurate information that could bias me in the wrong direction. So I always go to the source. Here’s what I found out about your Surge Guard 34730:

  • Protects RV from faulty park power
  • Built-in intelligence
  • Automatic reset on power restoration
  • Shuts off power when the following is present:
    • Open neutral
    • Low (<102V) and High (>132V) Voltage
  • LCD display (English)
  • Multi-mode surge suppression
  • 128 second reset delay protects A/C compressor
  • Continuously monitors for:
    • Voltage and amp draw (RMS)
    • Reverse polarity (miswired pedestal, elevated ground voltage)
  • 2450 Joules of power surge protection
  • Convenient plug disconnect handles
  • Weather resistant

So a quick glance tells me it has the ability to disconnect your RV if the incoming voltage gets too high or too low. This qualifies it as a “Smart” Surge Protector. Secondly, it has an LCD display rather than just a few blinking lights. Again, that’s a good thing for troubleshooting the power from the pedestal. And finally, it does include an actual “surge protector” with 2450 Joules of surge protection. That’s actually a measure of how much “surge” energy it can absorb so as not to pass it into your RV’s electrical system. However, I really don’t like the word “surge” as it’s actually more of a “spike” on an oscilloscope, but that’s what the industry has chosen to call it. Still, 2450 Joules of energy absorption should be sufficient for anything except for a direct hit with lightning, and in that case NOTHING will protect your electrical system. That’s why I say it’s always best to unplug from shore power if you’re in an electrical storm.

Now to your question at hand. Is this a good choice that will take care of your surge and electrical management needs? I would say yes, but maybe it’s not the best choice. That’s because on the Surge Guard website I found that it’s a discontinued model. The replacement is the Surge Guard 34830, which appears identical on the outside, but includes more complex electronics on the inside plus a few additional features, specifically the following:

  • NEW! Surge Failure
  • Voltage and amp draw (RMS)
  • Reverse polarity (miswired pedestal, elevated ground voltage)

I do like the ability to monitor RMS amperage draw in addition to voltage. And apparently it will indicate if there was a surge failure while you’re away. That could be a great warning to check your refrigerator for spoilage if there was an extended outage. Also, while I was discussing this with tech support I found out that the 34830 also includes an over-temp monitor in the plugs themselves. So if there’s a poor connection that causes the plug to overheat to above 200 degrees, it will also shut down. And finally the 34830 includes a limited lifetime warranty, while the 34730 has a 1 year limited warranty. So I would consider the Surge Guard 34830 to be a better choice if you’re purchasing one right now. However, your 34730 is still a great choice and won’t let you down.

What you should take away from this is to always go to the manufacturer’s website for the most up-to-date information. Sometimes products on Amazon and eBay may not be the latest offered, and thus you may be missing an important feature or upgrade.

So, have a great trip. And let’s play safe out there….

Mike Sokol

Mike Sokol is an electrical and professional sound expert with 40 years in the industry. Visit for more electrical safety tips. His excellent book RV Electrical Safety is available at For more info on Mike’s qualifications as an electrical expert, click here.




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Michael Fisher
5 years ago

Hi Mike,
I’m glad that Linda asked the surge question as I’m of one that would ask such a question…like asking directions…a guy thing.
So sir because of Linda asking and your easy down to earth no special language need to understand answere, I can now go and purchase what we need to help keep us safe in our journey and travels ! We thank you and Linda < Fish <

5 years ago

I have a 30 Amp camper and connect to the 50 Amp service via a 50 to 30 reducer. What is the wisest electrical connection for me to use?

Robert G
5 years ago

I also have the PRogressive one and get me save at few campground. My friend fry is and yes they replace it without any question. I see the Suregard come with lifetime warranty but we have no history how this will work. I will go with PROGRESSIVE anytime soon. Also the green and yellow color really attract attention from somepeoples that could be interested in getting a cheap one????

5 years ago

I didn’t see anything about phase protection, I realize on a 30 amp service its not an issue. But people should know on a 50 amp service its a big deal. Because without it a miss wired shore power pedestal can cause a serious overload on the neutral leg.
How do you know when you have an incorrectly wired Shore Power Pedestal?
There are two simple ways, one is to install a surge protector that identifies incorrect phasing and locks out the power to the RV. The second way is to use a simple voltmeter that is rated to test AC voltage up to 300 volts. If the pedestal is wired correctly when you test from Leg-1 to Leg-2 (not Neutral) and the two legs are 180 degrees out of phase as they should be, the meter will read 240 VAC (see figure 7). When the Shore Power Pedestal is wired incorrectly, the two legs are at the same phase. Then the test from Leg-1 to Leg-2 (not Neutral) will read 0 volts on the meter (see figure 8). As stated previously, this is an unsafe condition because you can have a 100 Amp load on a wire that is only rated for 50-amps. All of that being said this means that using a 30-amp to 50-amp pigtail adapter will NOT allow you to see 240 VAC in your breaker panel. Because in that scenario your just splitting the same single black hot leg on the 30 amp plug to feed both the red and black on the 50 amp plug.

5 years ago

Surge Guard does NOT have a Lifetime replacement, whereas Progressive Surge Protectors do. Something to consider down the road. I highly recommend Progressive Surge Protectors.

5 years ago
Reply to  Jeff

Yes, and I can also say that Progressive Industries makes using the lifetime warranty very easy. They are truly customer oriented.

Jim Guld
5 years ago
Reply to  Jeff

SurgeGuard now has a lifetime warranty and slightly better surge protection, Jeff. Progressive is still a good choice.

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