By Mike Sokol
Welcome to my J.A.M. (Just Ask Mike) Session, a weekly column where I answer your basic electrical questions. If you’re a newbie who’s never plugged in a shore power cord (or ask – what’s a shore power cord?), or wonder why your daughter’s hair dryer keeps tripping the circuit breaker, this column is for you. Send your questions to Mike Sokol at mike (at) noshockzone.org with the subject line – JAM.
Dear Mike,
I am about to go boondocking with my new pop-up for the first time and I have a new inverter generator to try out. Its manual says to be sure to ground it (the generator) to a ground electrode buried in the ground. What? I need an electrode and another cable? There is a “ground terminal” on the control surface. Please advise, as I’m new to this and not so savvy with the electrical side of things. Thanks. —Feral
Dear Feral,
The topic of RV generator grounding is something I’ve covered many times before, but don’t feel bad about your question because even electricians and some generator manufacturers don’t seem to understand how it works. So here’s the quick answer followed by a few links to deeper articles.
First off, the big answer is NO. You do not need to drive in any kind of ground rod for any single RV powered from either a portable or onboard generator. While it’s true that you would need a ground rod if you had a large generator that could power several RVs connected to it at the same time, you simply don’t need one for your situation. What you have created with a single RV running from a generator is something called a local ground plane, which means your entire RV and tow vehicle is its own ground, and doesn’t need to be connected to the earth.
But what about when you plug your EMS/TEP (Total Electrical Protection) surge protector into an inverter generator and it shows a “ground” code or error. Well, what that really means is that you have no Neutral/Ground Bond, which doesn’t have anything to do with being “grounded” to the earth at all. It’s an electrical condition where the generator (or pedestal) needs to provide power with the neutral and ground wires at nearly the same voltage (not floating).
If you get that no-ground error, all you need to do is get a simple Neutral/Ground Bonding plug I invented about 10 years ago. Looks like a plug without a wire, and it provides an internal jumper between the neutral and ground screws to create a local neutral bonding point. Just plug it into any unused 15- or 20-amp outlet on the generator (NOT in the RV) and you’re good to go.
Finally, NEVER drive any grounding rod in the earth without getting a proper inspection from your local Miss Utility (call before you dig – 811). Remember, there are all kinds of buried water pipes and electrical wires at any campground, and many homes also have buried natural gas pipes. You don’t want to punch through any of those pipes with an 8-ft. grounding rod. The results can be a deadly shock or explosion. So you don’t need a ground rod, and you’re not allowed to drive one anyway. Make sense?
For more information on this please watch the Webcast Video I did last year on it HERE.
And here’s an article where I cover this topic in great detail, just in case your local inspector tries to require you to drive a ground rod. Read it HERE.
This is where you can purchase an approved Neutral/Ground bonding plug from Amazon. Yes, it’s the one I designed.
OK, everyone. Remember that electricity is a useful and powerful force, so we all need to pay attention to safety precautions while using it.
Let’s play safe out there….
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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Thank you for your review.
I just want to make sure that I understand the info your shared….correctly.
SO….if I have the RV or my Living Quarters Horse Trailer plugged directly into the generator with the large black cord that came with the RV or my Living Quarters Horse Trailer, I do NOT need to use these plug. Right??
BUT….if I have extension cords plugged into the generator and use those cords for the RV or anything else….I should USE this plug to ground the narrator? THANKS!
Mike,
I just purchased two Yamaha EF2200is generators for my 2019 VanLeigh 5th wheel. Both started up at the dealer just fine. Dealer did not have a manual, nor does Yamaha have the manual online. A week later, I wanted to ensure everything worked. One generator is not producing power from either AC outlet. I foolishly did not plug in a power tool at the dealer; just ensured it started. The second gen supplies power, but I’m getting a “reverse polarity” warning off my Southwire 34950 surge protector. One of your Southwire neutral-ground bonding plugs is inserted into the outlet marked “floating neutral” on the gen. An outlet tester on both AC outlets shows two orange lights indicating “correct”. I have a 50 amp trailer; the Yamaha 2200 has a 30 amp receptacle for RV use, so I’m using a dogbone.
In summary; two brand new Yamaha EF2200is gens. One produces no power; the second indicates reverse polarity on the surge protector but “correct” circuit on the receptacle tester.
Any ideas are greatly appreciated. Hope you and yours are remaining safe and healthy.
A couple of quick thoughts. IIRC that generator has a resettable circuit breaker. Have you tried that? As far as reverse polarity reading on your surge protector, I wonder if your dogbone adapter is correctly wired? I’ve seen some imported junk lately that was miswired internally. And how are you combining your generators in parallel? Do you have an outboard parallel kit, or some sort of built-in companion connector on one of the generators with banana plug connections from the secondary generator? Let me know and I’ll try to write about this in my Sunday RVelectricity newsletter.
Thanks for getting back to me Mike. There is a resettable C/B and its been reset. Yamaha makes a wire kit to hook up the gens. While that’s my intent – to run them as a combo to get 4400W – today I was simply trying to ensure both gens worked independently. No luck trying to determine why one gen is not providing AC or DC power. Good thought on the dogbone; I’ll see if I can find a 30 amp outlet here to see if I can the same reading off pedestal power. Thanks again for responding Mike!! Rich
Reverse polarity is not an issue. Not producing any power is.
I made one of your grounding inventions once and instantly regretted it. The generator had the hot and neutral backwards. Not a problem for most appliances. But I had a TV that was buzzing. So I tracked down a floating ground. Ironically, my inverter is also wired backwards. I had to make special plugs for the generator and inverter that reversed the polarity and grounded properly.
The grounding invention showed you there was a problem. Rather than jury rigging the special plugs, possibly creating a more dangerous problem, it would be better to correct the wiring on the generator and inverter. Two wrongs don’t make a right.
My Honda 2000 only has 2, 3 prong outlets I use an adapter that plugs into both then plug my 30amp rv cord into that.
I currently use a surge protector that is not EMS/TEP so have not had this issue.
I would appreciate your thoughts about how to hook up if I upgrade to this type of protector?
What exactly is that adapter? Can you email me a picture? I can’t imagine why you would need it, so please let me know how and why you’re doing this. Seems like a very dangerous code violation at first blush. Send the picture to mike (@) noshockzone.org
My guess is the adaptor seeks to distribute the 30 amp load over two plugs in the same receptacle. Quite dangerous if the plug is split into two separate phases. Plus standard plugs areax 20 amps so the breaker on the other end couldn’t handle the full 30 amps.
I don’t see the need for a SP on a generator.