Saturday, September 23, 2023


RVelectricity: DIY generator neutral-ground bonding plug

Dear Readers,
In response to several inquiries about how to make your own neutral/ground generator bonding plug, here’s the full DIY generator bonding plug article I wrote nearly 10 years ago.

When a portable generator won’t power your RV

See my video on testing for a floating neutral here.

I received this email from a reader who wants to power his RV from a Honda portable generator.

I have a 2011 Fleetwood 40-footer. I’m trying to get my Honda EU3000 generator to power up the motorhome for a few items. My display after plugging in will show NO LOAD. This generator will power anything else I try such as a 30-foot trailer with one air conditioner, compressor, etc. I also have a Coleman 5000 and that will power up the motorhome.

I have an adapter cord 50-amp female going to 30-amp (3 prong) male. The Honda worked with my 2002 Monaco hooking the same way. The reason I like to use the Honda is when I am at the track this time of year, there is no need to run the motorhome generator since there is no need for air conditioning. I have called Honda and they were no help. —John Z., Purcellville, VA

Basic Ground-Neutral bonding theory

John, all RV electrical systems are wired with their Ground and Neutral buses floated (unbonded from each other). There are lots of good reasons for this, most specifically that it’s an NEC and RVIA code requirement that the safety ground wire never carries any load current. Also, there can be only one Ground-to-Neutral bonding point in any distributed electrical system in the USA.

Now, when you’re plugging your RV into power from a building (your garage outlet) or campground (pedestal outlet), your RV has its Ground and Neutral buses “bonded” (connected) together externally as part of the service panel’s earthed safety ground system. Again, lots of reasons for this, but the fact is you can only have a single G-N bonding point according to the National Electrical Code and RVIA building codes.

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When a floating neutral generator won’t work…

So when your RV is powered by its on-board generator, this G-N bond connection is created by the transfer switch set to generator mode. But when the transfer switch is set to receive shore power, your RV expects the external power source to bond its Ground and Neutral wires together.

Now, if you have an inline voltage monitor system from a manufacturer such as Surge Guard or Progressive Industries, your voltage monitor is checking for the Neutral and Ground voltages to be very close to each other, probably within 3 volts or so.

This works well if you’re plugged into shore power that’s properly grounded and bonded, but this voltage protector can be tripped off by plugging your RV shore power plug into a portable generator without an internal Neutral-Ground bond. If you don’t have a voltage protection device on your RV, then you may never know that your generator has a floated neutral (unbonded G-N bus).

Generator types

Contractor-type generators such as your Coleman 5000 are generally N-G bonded internally, which is why it runs your RV just fine. However, many portable inverter generators from companies such as Yamaha and Honda (your EU3000, specifically) have floated Neutrals (no internal Neutral-Ground bond) since they expect an external N-G bond to happen somewhere else. And while RV-approved generators may have an internal N-G bond, it seems that many of the most popular portable inverter generators from Honda and Yamaha have floating neutrals.

Honda help desk couldn’t help

I discussed this very point with Honda engineering, and they confirmed that their inverter generators have floated Neutrals and they simply say that you should follow all local electrical codes for bonding-grounding. So your EU3000 isn’t providing the Ground-Neutral bond that your RV requires to think it’s getting properly grounded power, while your Coleman 5000 has a Neutral-Ground bond already so it operates your RV properly. Seems crazy, but that appears to be the scenario.

DIY your own…

It’s pretty simple to wire a special “Neutral-Ground bond” jumper plug for your Honda or Yamaha generator which will allow you to power your RV through its voltage protection device. You can obtain or make a dummy 15-amp “Edison” plug with the Neutral (white) and Ground (green) screws jumped together with a piece of 12- or 14-gauge wire (see photo below).

This G-N jumper plug can be plugged into one of the generator’s unused 15- or 20-amp outlets, and the entire generator’s electrical system will be N-G bonded. You can then use the other 20-amp Edison outlet or the 30-amp outlet to power the RV.

Just be sure to mark this plug specifically for its intended purpose. It won’t really hurt anything if it’s plugged into a correctly wired home outlet. But it will create a secondary G-N bonding point that could induce ground loop currents and create hum or buzz in a sound system. That doing that will also guarantee any GFCI outlet in the branch circuit to trip with even a few mA of load current.

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Buy one that’s factory made

If you’re not 100% comfortable wiring your own N-G bonding plug, then you can buy one from Southwire on Amazon for less than $17 delivered. I keep one in my gig-bag for when I have to power sound systems from a Honda generator, and it works great for that application as well. But if you don’t have any sort of EMS/Advanced surge protector, or you’re not powering sensitive electronics, you probably don’t need an N-G bonding plug at all. But when you need it, you’ll really need it. Buy one from Amazon HERE.

Note that this is a generator-only G-N bonding plug which should be only plugged into a portable generator while powering your RV. It should never be used to create a bootleg ground in a residential or RV outlet that was not properly wired with a ground conductor.

Let’s play safe out there….

Send your questions to me at my new RVelectricity forum here.

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



  1. Mike,
    I’m hoping you might be able to help with a problem I’m having. I have a Honda EU7000is, obviously has a floating neutral and will not power my trailer (with built in power monitor) without a Edison plug. With the Edison plug in power will come on and activate the transfer switch on the trailer immediately tripping the gfci on the generator and shutting down power from the generator.

    • Something seems wrong since the EU7000iS doesn’t have s GFCI on the 30-amp twist-lock outlet. How are you connecting your RV to the generator? Are you plugging into the twist-lock 30-amp or 20-amp Edison outlet on the generator?
      Do you have a 30-amp or 50-amp RV? What kind of dogbone adapter are you using to plug into the generator?
      Are you sure that your RV doesn’t have an internal Ground/Neutral bond in the load center. That would be a code violation which would cause any GFCI to trip. But you should not be plugging your RV into the 20-amp GFCI outlet on your Honda.

      • I’m using a twist lock 30 amp to and rv 30 amp. My rv is a 50 amp, I recently picked up an L14-30p to 14-50r but haven’t had my trailer near my generator to test it.
        I’m fairly certain the rv doesn’t have a ground/neutral bond, when I first tried connecting the trailer without an Edison plug the trailer wouldn’t power on and would turn on the fault light (trailer only has a blue light to communicate an issue with shore power).

          • And is this a manufactured generator bonding plug you bought from Amazon or Southwire, or did you wire it up yourself?

          • Yes it’s plugged into the 20 amp gfci that trips. Just to rule out a a specifics outlet I tried moving it around the 4 20 amp outlets with the same result each time.

            The plug was purchased online, I did pull it apart and confirmed correct wiring.

            I should mention this isn’t a new generator although it runs everything else I can plug into it could it just fine. Could it be the gfci outlets are worn and the combination of a bonding plug and plugging into the 30 amp twist lock is just a perfect storm?

          • I suspect you might need to build a kludge cable, which is a short 1 ft male to female 30-amp twist lock dogbone the a ground/neutral bond in one of the connectors. Let me think on it…

  2. Great article! Would you suggest also using a G-N bonding plug with a floated Neutral inverter generator for uses other than powering an RV – such as powering a refrigerator or freezer during a power outage?

    Thank you.

  3. My question is: If you are running 2 generators in parallel (In my case, a set of Honda eu3000is) do you need to put bonding plugs on both generators? Most parallel kits just hook the generators together and then you use the companion genny’s built in L5-30 plug, but my parallel cables come together in the middle with a L5-30r. Regardless, do I need to have bonding plugs on both generators or will one do the trick? If so, which generator should get the bonding plug? Does it matter?

  4. Mike, I have a pretty good understanding of household electricity but this article made the concept of bonded vs. unbonded so easy to understand.
    Thank you!


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