Wednesday, May 31, 2023


RV Electricity – No~Shock~Zone by Mike Sokol – Issue 10

Issue 10 • August 26, 2018
MIKE SOKOL, editor
Brought to you as a public service by Support comes from our sponsors, advertisers and the contributions of readers, who believe that an educated RVer is a safe, happy RVer.

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Welcome to RV Electricity Issue #10 (or should I say 10,000?)!

That’s right – Thanks to you this newsletter now has more than 10,000 opted-in subscribers (10,176 as of last evening), which is fantastic! So Happy Anniversary, or Birthday, or X-day, or whatever to the RV Electricity newsletter. If only my hero Nikola Tesla could be here for the celebration. Yes, I would even power up my musical Tesla coil for him. Of course I have a Tesla coil that plays music through the electrical arcs themselves … really I do!  

Here’s a comment from my post on “RV Electricity – Pedestal power has changed in recent years”
Mike, thanks for this article and procedure for testing a pedestal. I have joined the Stray Voltage Patrol because the owner of a trusted RV campground shared how a camper pulled into one of their sites and discovered a hot pedestal. While the owner immediately fixed it, he reminded me that even with normal maintenance procedures things break. When I mentioned the SVP he was very supportive and said he likes the idea of people working together to solve problems rather than just having people complain. —Joe W. 

Joe, thanks very much for your comment, which leads us into my next announcement… 
The Stray Voltage Patrol now has 140+ members signed up, and we’re ready to start taking reports. We’re beginning this all manually until the integrated database is installed shortly. But for the next week or so all of your reports will go into a basic spreadsheet which I’ll post a link to the following week. Once we get our sea legs under us, we’ll then post a database search page so you can begin to find campground reports on how their electricity is working.

Please bear with us as we get this up and running. Our IT experts, Jess and Kim, are hot on it and know how important this topic is to all of you. We want to do this correctly without any big mistakes. You can make your report at  SVP-Report if you’ve previously signed up to be an SVP  member. If you still haven’t signed up to be a member of the Stray Voltage Patrol, go to SVP Sign-Up first before making a report. 

I’ll be assigning each of you a badge number based on your emails by the time you read this newsletter on Sunday, so please use that badge number with each report so we can begin tracking. In a few weeks we should have an automated login/password system installed and the database integration completed. 

If you have any questions or comments on the Stray Voltage Patrol, or if you’re a campground that would like to participate, please email and use SVP in the subject line. Thanks for your interest and support with this important safety project. 

Let’s play safe out there… 


P.S. And just a quick note that this newsletter is made possible by the voluntary pledges of the readers of We could not bring this to you without their support. If you deem what we provide to you here and at to be of special value and would like to be a part of our effort, please consider pledging a voluntary subscription. See the many options here. We will include you in special emails, articles and videos exclusively for our supporters.

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Pedestal Power Issues

I’ve just presented several of my No~Shock~Zone electrical safety seminars in Goshen, IN, and Winston-Salem, NC, and saw what I consider to be a number of poorly maintained campsite pedestals and RV shore power cords. All I can say is, WOW!

Some of the pedestals looked very old and didn’t have any identified circuit breaker in the vicinity, plus there were signs of visible arcing and wear on the outlets. I also found a number of RV cordsets with the jacket insulation pulled out of the strain relief clamp of the plug. I can’t believe the RV owners weren’t aware of the beat-up condition of their RV cordset plugs and the campground pedestal outlets. I know that new outlets and plugs cost money, but I believe that safety should be our primary concern.

I really don’t think you can trust shore power pedestals, especially after I saw one knocked over by a big coach backing up into the campsite. The next day they had propped it back up into position but not powered it up yet, so I couldn’t test before I had to leave.  This is one more very good reason to get an advanced/EMS surge protector for your RV. See my previous article on how basic and advanced surge protectors work HERE

Email me at mike (at) with your questions.

Your RV is generally your second largest physical asset. Protect it!
Home Electrical Box: 50-30-20 amp surface mount box • Breakers & receptacles included • Outdoor rated • UL listed • Pedestals also available. 30 & 50 Amp Surge Protector & Reverse Polarity: Continuously monitors & displays voltage & amp draw (RMS). Tests for & indicates: Reverse polarity • Exclusive open neutral inside the RV • Miswired pedestal • High neutral currents • Surge protector. Contact us at 800-500-2320 or

Industry Updates

SmartPlug has released the names of several new RV up-fitters and builders who are offering SmartPlug shore power inlets as an upgrade to the standard 30-amp RV twist-lock shore power plug and inlet. This RV power connector fits in a standard shore power inlet opening on your RV, doesn’t require a twisting action or locking ring to secure it, and is manufactured with marine grade components. See it in action at my next No~Shock~Zone seminar in Hershey, PA, this Sept. 12-16, where it will be available for purchase at the TechnoRV booth. Read more at SmartPlug. Following are some RV up-fitters and builders offering SmartPlug shore power inlets:

  • ARI Legacy Sleepers
  • SVO Group Inc.
  • Florida Coach Inc.
  • Nomad Vanz / Canada
  • Standard Design Van / Canada
  • XPCamper, LLC
  • Advanced RV
  • Coach House Motor Home
  • Lazy Daze Motorhomes
  • Renegade RV / REV Group

Survey Question
What kind of batteries are you using for your RV house power? 

Feel free to leave your battery amp-hour capacity in the comments.

Click image to enlarge.

Last month’s survey results:
Have you ever encountered a campsite pedestal outlet without a way to disconnect power before plugging in?

As you can see from the survey, 1 out of 8 of you (12%) have found multiple instances of shore power pedestals that don’t have a disconnect breaker so you don’t have to “hot plug” into live power. That’s not only a violation of the latest electrical code, it’s a bad idea because plugging a shore power cordset in under load will cause arcing and pitting of your power plugs, and it also does the same thing inside of the pedestal outlet. So campground power outlets WITHOUT a disconnect will be more worn than their properly switched counterparts, simply due to circumstance.

While you can’t fix the previous damage the pedestals have sustained, you can help prevent arc damage to your own shore power plugs and extension cords by turning off the main circuit breakers inside of your RV before plugging in, and before disconnecting. However, be aware that a pedestal outlet with a lot of arc damage has reduced contact area and increased oxidation, both of which can contribute to overheating.

It’s always best to watch for signs of shore power plug overheating, especially if you’re using an air conditioner or any type of electric heater. If you lay your hand on the shore power plug and it feels too hot to hold your hand on it for at least a 3-count, it’s probably getting too hot to be safe. You need to find another place to plug into shore power or reduce your load (turn off the air conditioner). 

This is a great application for an infrared thermometer such as the Southwire 30010S, which you can find in Lowe’s or from

I’m just giving you a SWAG (Scientific Wild A** Guess) here, but I’m estimating that any shore power plug (or extension cord) with a temp over 135 degrees F is highly suspicious and needs to be evaluated further. I’ll confirm the max temp readings you should see under load with a few of my engineering colleagues, but that’s a reasonable starting point. Infrared thermometers are great for other things like looking for dragging brakes on your RV, worn wheel bearings, overheating tires, and other things I haven’t even thought about yet. I’ll do a full article on Infrared thermometers in a future article since it’s such a useful tool.

Tools and Other Devices

If you need to crawl inside and underneath dark places, it would be great to keep both of your hands free. So instead of using a flashlight consider getting a headlight. Yes, these look a little funny, but once you use one you’ll never go back to a hand torch (that’s what the Brits call them). I like this one from Klein since it’s rechargeable and can be set to turn off automatically after 3 minutes. Find it at many big box stores or on

Last Month’s Posts

RV Electricity seminars in 2018.
(Printable) Pedestal Power Checklist.
Best grease for lubricating trailer plug? (with short video)
Is advanced pedestal testing feasible?

Avoid RVing snafus!
Prepare for your next big adventure with Road & Home’s Ready for the Road checklist. This simple, easy-to-use guide of must-have repair or replace products will keep you moving while on the road! Equip yourself with peace of mind and ensure safety and convenience when you head out. Shop the entire collection here.

Q&A’s from Forums

I spend a lot of time on dozens of other RV forums answering questions about electricity. Here are two of them: 

From the No~Shock~Zone
Q: Mike, we have a 50-amp RV and purchased a 50-amp surge protector (yup, we are listening to you). We frequently stay at 30-amp-only campgrounds and want to keep electrically safe. Right now we connect a 30/50 dog-bone adapter to the pedestal, then the 50-amp surge protector, and finally our RV’s 50-amp power cord. Is this the best way to hook everything up to protect our RV from electrical problems? Thanks. —Joni and Roger Weed

A. Joni and Roger,
Yes, I’ve discussed this with Surge Guard engineering, and the consensus is that the surge protector should match the shore power cord (and amperage) of the RV itself. So if you have a 50-amp shore power cord on your RV, you should get a 50-amp surge protector. If you have a 30-amp shore power cord on your RV, you should get a 30-amp surge protector. If you need to hook into a pedestal or house power that doesn’t match your surge protector plug, use whatever adapter is needed to connect your surge protector to the power outlet.

From the Forest River Forum:
Q: Mike,
My wife and I loved your Stray-Voltage presentation at the FROG Rally in Goshen last week, and wonder when you’ll be back in the area? —Willie P. 

A: Willie,
Thanks very much. As a matter of fact, I’ll be back in Goshen this October 3 and 4 for the Thor Diesel Pusher Club Rally, but you have to be a member of the Thor Diesel Club to attend. However, I will also be at the Hershey RV Show for all five days in a few weeks, and that’s open to everyone. See below for my seminar dates and times. 

Sept. 12-16, 2018, Hershey RV Show in Harrisburg, PA
Wed.-Sun., 9:30 a.m. to 10:30 a.m. in the Champions Club. Combined seminars every day presenting Surge Protectors and Hot-Skin/Stray-Voltage testing. See the full show seminar list HERE

Oct. 1-4, 2018, Thor Diesel Club Rally in Goshen, IN
Wed., Oct. 3, 2:15-3:15 – Surge Protectors, and Thurs., Oct, 4, 11:15-12:15 – Hot-Skin/Stray-Voltage. Open only to TDC members. Go HERE for more information or to join the Thor Diesel Club. 

Email mike (at) with your questions.

The best book on RV electricity, hands down!
RV Travel contributor Mike Sokol is America’s leading expert on RV electricity. Mike has taken his 40+ years of experience to write this book about RV electricity that nearly anyone can understand. Covers the basics of Voltage, Amperage, Wattage and Grounding, with additional chapters on RV Hot-Skin testing, GFCI operation, portable generator hookups and troubleshooting RV electrical systems. This should be essential reading for all RVers. Learn more or order 

Videos by Mike about RV Electricity

    • Testing for extension cord overheating with an infrared thermometer HERE.
    • How to check a campground pedestal for proper power with a digital meter HERE.
    • Using Silicon spray to lubricate a trailer plug HERE.

New & interesting finds on Amazon!
See what really cool stuff Amazon is featuring today. It’s a whole lot of fun just browsing through all these great items. The selection changes every day, so check back often. You never know what you will find, which is part of the fun of visiting here. Check it out.

Road Signs

Embracing imperfections
By Mike Sokol 
Once again, school is starting where I’m an adjunct professor teaching live-sound mixing one day a week. My task is to take a bunch of highly talented musicians and singers, and teach them how to mix music that will make lots of listeners happy. The only problem is, their playing is so perfect from years of regimented practice that their music often sounds boring. It really does. Read more

Copyright 2018 by Mike Sokol 

Sponsors editor Chuck Woodbury and I are looking for additional RV manufacturers to support this RV Electricity newsletter as well as my No~Shock~Zone seminars and videos. Please contact or to discuss sponsorship opportunities.

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Editor: Mike Sokol. publisher: Chuck Woodbury. Managing editor: Diane McGovern.

Everything in this newsletter is true to the best of our knowledge. But we may occasionally get something wrong.  So always double check with your own technician, electrician or other professional first before undertaking projects that could involve danger if not done properly. Tips and/or comments in this newsletter are those of the authors and may not reflect the views of

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Mike Wagner
4 years ago

Maybe it would be nice to talk about the pitfalls of leaving your entry cord or extension cord curled up. The voltage drop created by the transformer effect, under heavy current can be substantial.
Mike Wagner

Daniel Carioggia
4 years ago

Solar powered refrigerator. I have a 2018 Newmar King Aire that came with 4 solar panels on top already hooked up with a Schneider Electric C40 DVM display running from their controls under. I spoke with the solar panel mfg and Newmar. According to the solar panel mfg the combined power of the 4 panels is 30amps. This should be enough to keep my batteries charged while in storage in SC. They do not. The auto generator kicks in all the time to keep the batteries up to snuff while in storage. So if the panels cannot keep my batteries charged, how in the world would they be able to power a fridge while boon docking? I would be happy to participate in your study on solar panels.

4 years ago

Mike, when camping with 30amp service only in a 50amp rv there are power Y adapters that allow you to plug into the 30amp plug and a 15amp plug at the same time giving you a total of 45amp service to the rv. If you then plug into the ems surge protector would this provide protection? I have seen that these Y adapters do not work with gfci, don’t understand that but it makes me wonder if the Y adapter would be worth using? What are your thoughts on using these adapters?
Thanks, really appreciate your comments.

Don Chiles
4 years ago

Mike, I don’t understand your comment about “a wire on each sides of the camper”.
That’s a completely bogus explanation that makes no sense at all. What you had was an open ground connection (formally known as the EGC or Equipment Grounding Conductor). There is no “wire for each side of the camper,” as he stated. This is just one more example of why basic electrical training is so important for anyone running a campground. Much to do…

Solar Steve
4 years ago

A few years back we stopped in “Sun & Fun RV park” off Hwy 5 in Tulare, CA. Plugging into 30 amp I saw and smelled arcing within the pedestal. Tapping on the pedestal would produce an arc. It didn’t seem to be a short, rather a loose wire on back of the 30 amp breaker. I unplugged and reported it to the office. They called their electrician immediately and let me change to the next space. When I later inquired they said the electricial would not be available for a dayor two. Worse, they sent a later arrival into that same space, so I informed the new campers of the problem. They switched to use an adapter from the 20 amp outlet which got them by for the night.

4 years ago

When using an infrared thermometer be aware that it is giving you an average of the surface temperature within an area surrounding the red dot that shows on the surface. The farther away you get from the surface, the larger the area. An example would be 10 inches away is a 4 inch area. This ratio changes depending on the infrared thermometer brand.
So when you have a wire that is at 200 degrees and a surrounding area that is 70 degrees, you may read anywhere from 100 to 200 degrees depending on how far away from the wire you are.
Be careful to read the specs on your tester so you understand exactly what you’re seeing when you are checking temperatures. –Larry McGaugh, CheapHeat

4 years ago

We had a really interesting situation last month at a high mountain campground. Lightning struck a tree near a campsite. The bolt moved through the tree root (you could see the soil blown away along the path of the root) and apparently hit the wiring on a campsite panel. The panel was disabled from the strike. Oddly the trailer hooked to the panel was ok, but the truck was still attached to the trailer via the hitch and wiring. Apparently the onboard computer was fried. The owner had to have it towed and repaired. The camper next to me (retired electrician) surmised that the trailer wiring created a direct path to the truck electrical system which created the havoc. I did not see any kind of external surge suppressor though there could have been an internal one in the trailer.

4 years ago

I realize you’re still in progress, but the SVP report page lacks several conditions you’d still want reported. Bad wiring (hopefully before a shock?), chronically bad voltage (over/under), missing breakers as mentioned in this letter, etc.

Thanks for all the work!

Mike Sokol
4 years ago
Reply to  Wolfe

Yes, this is just a basic reporting page to get things working. I’ll include more drop-down selections just as you suggested next week. Thanks for your support.

4 years ago
Reply to  Wolfe

Is this Brett Wolfe?

4 years ago

Lead Acid 240Ah @ C/20
(2 @ Trojan T-125)

4 years ago

Everyone should always confirm that the shore power pedestal breakers are in the off position, before plugging in.

On 2 of my last camping trips, I came across power pedestals that the breakers were still on. I can’t understand how people can just yank the cord out of a HOT receptacle ? {bleeped} unsafe!

I have asked Mike to once again remind everyone to check that the breakers are off before plugging in.

4 years ago
Reply to  Jeff

Good reminder… I “love” watching the arccing when newbies plug in with the air and water heaters already on…

A side note about the main breaker method when the site breaker is MIA: since i usually turn off the pedestal, I only discovered my Jayco was miswired internally when I still got a small arc at a no-breaker site with my main breaker off. Wired the same as a house (shore hot to distribution bar instead of through the 30A), my main breaker was doing nothing.

Gene Bennington
4 years ago
Reply to  Jeff

For the last two years I have been a campground host for a state park in Ohio. After the camper/RV has left, I clean ashes from the fire ring, pick up litter/trash and make sure the 20A, 30A and 50A breakers are turned off for the next occupant. I can honestly tell you that at least 80% of the time the breaker associated with the receptable that was being used is still in the ON position. Hard to believe people just yank out their power cord without breaking power.

4 years ago

Hi Mike,
When I bought my trailer the slide out had no electric. So I installed a couple of outlets and a light on a 15 amp circuit .
Installed a female hook-up on the slide and use a #12 extension cord to the post. This essentially gives me 45 amps to the trailer instead of 30. It’s great when I heat with electric, I just plug a 1200 watt heater in and the rest for the trailer is on it’s own 30 amp. Do they make a Surge protector for the 15-20 amp outlets?

Mike Sokol
4 years ago
Reply to  Rob

Rob, no there’s no 20-amp surge protector on the market that I know of. You would need to purchase a second 30-amp surge protector and use the appropriate TT-30 to NEMA 5-15 (Edison) plug adapters. However, be aware that some older campgroud pedestals are powered by a single 30-amp feeder and may not have proper upstream over-current protection. So if you try to draw 45 amperes from an older pedestal (30 plus 15) it’s possible to overload the campground wiring on that leg. If you’re using one of these “cheater cords” you’ll want to monitor the pedestal closely for any signs of overheating. If the pedestal box is getting thermally hot, then time to go back to a single 30-amp outlet.

Terence Hennessy
4 years ago
Reply to  Rob

WHICH MEANS you have an ILLEGAL, UNSAFE, JURY-RIGGED DOUBLE MALE EXTENSIONS CORD? Risk to you or an child who runs thru, trips and contacts the exposed MALE PLUG prongs of the HOT extension cord end? SHOULD HAVE A MALE PLUG ON THE SLIDE CIRCUIT .

AL Simons
4 years ago

Answered the survey as LiFePo, which will be installed in a few weeks. RV is new, we’re still upfitting. 600AH of Battle Born.

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