Generator Open Ground & Floating Neutral Fix
Your RV surge protector with generator setup might not work like you expect. These protectors are great for keeping your RV safe from bad power. But when you plug one into a generator, especially an inverter generator, you’ll often see an error light and get no power at all.
Why does this happen? Most of the time, it’s because of a floating neutral generator design. This makes your RV EMS surge protector generator combo think something’s wrong, even when it’s not.
The good news? There’s an easy RV generator open ground fix. A simple neutral ground bonding plug (some people call it a generator neutral plug for RV use) solves the problem fast.
This guide will show you exactly how to use generator with RV surge protector systems, what tools you need to test your setup, and when you really need this fix for your RV camping power setup.
Tip
Some EMS surge protectors display low voltage or overload warnings when your generator is under heavy load (like running an AC). If you see this, try turning off other devices or using a soft start.
Why Your RV Surge Protector Shows an Open Ground or Reverse Polarity
When you connect your RV surge protector with generator power, the EMS (electrical management system) checks if everything’s safe first. If it finds a problem, your RV EMS surge protector generator system stops the power and shows a warning.
You might see messages like RV surge protector open ground, open neutral warning, or surge protector reverse polarity. Don’t worry, your generator probably isn’t broken! The real problem is how your surge protector looks at the generator’s wiring.
What is a Floating Neutral?
A floating neutral generator has its neutral wire separated from the ground wire inside. This is how most inverter generator RV models and smaller portable generators are built. It’s perfectly safe for running most things, but RV EMS surge protector generator systems don’t like it.
Why? Your surge protector expects to see a bonded neutral generator RV setup , just like your house has. In your home, the neutral and ground wires connect together at the main panel. When your surge protector doesn’t find this connection in the generator, it thinks something’s wrong with your RV generator safety setup.
That’s why you get an RV surge protector open ground or open neutral warning even though your generator works fine. The surge protector is just being extra careful. It won’t let power through until you tie neutral to ground generator connections using the right method.
Which Generators Have This Problem?
You’ll see this problem mostly with inverter generator RV setups and small portable units. These generators save fuel and run quietly. They do this partly by using a floating neutral generator design, it’s just how they’re built.
Here are common generators with floating neutrals that need a generator neutral plug for RV use:
- Honda EU2200i / EU3200i – Super popular inverters with floating neutrals.
- Champion Dual Fuel 2500W / 4500W Inverter
- Westinghouse iGen Series – includes iGen2200, iGen4500, and others.
- Predator 2000 / 3500 (Harbor Freight) – Good budget inverters.
- Yamaha EF2200iS
- Generac GP2200i
What About Built-in RV Generators?
Good news if you have an onboard generator, like a Cummins Onan. These usually come as a bonded neutral generator RV setup from the factory.
They’re made just for RVs, so they work great with 30 amp RV surge protectors or 50 amp RV surge protectors without any need for adjustments.
Bigger Generators Often Work Fine
Generators over 5000 watts usually don’t need a neutral ground bonding plug. These bigger units include construction-style generators, RV-ready models that come with 30A or 50A plugs already built in, and dual-fuel generators that have transfer switches.
But don’t guess about your RV camping power setup, always test it or check the manual to be sure. Even some of these bigger generators might still need a grounding plug for RV generator use to work right with your surge protector.
How to Test If Your Generator Has a Floating Neutral
Before you buy or build a bonding plug, it’s a good idea to test your generator to see if it actually needs one. Not all generators have a floating neutral, some are already bonded internally, especially larger or RV-specific models.
The easiest way to find out is by using a basic outlet/receptacle tester like this one by Sperry Instruments (click to view on Amazon). These pocket-sized tools are inexpensive, easy to use, and available at most hardware stores or online.
How to Use
- Start your generator and let it run for a minute or two so it’s operating normally.
- Plug the tester into one of the generator’s standard 15A (Edison-style) outlets.
- Read the light pattern on the tester. Each one comes with a diagram printed on it to help you decode what the lights mean.
What Is a Neutral Ground Bonding Plug?
A neutral ground bonding plug (also called a generator neutral plug for RV use) is a simple tool that fixes the floating neutral problem.
This small device creates a safe connection between the neutral and ground wires inside a regular plug. Just stick it into any standard outlet (15A) on your generator, and your RV surge protector with generator setup should start working right away.
How It Works
When you use this grounding plug for RV generator connections, it completes the circuit your surge protector needs to see. The plug doesn’t change how your floating neutral generator works, it just gives your RV EMS surge protector generator system what it’s looking for.
Think of it like this: the bonding plug makes your generator look like a regular campground power pedestal to your surge protector. Your surge protector not working with generator problems go away because now it sees the bonded neutral generator RV connection it expects.
The rest of your RV runs exactly the same. The plug just tells your surge protector that your RV generator safety setup is good to go.
Plug Recommendation
Southwire Company LLC Neutral-Ground Bonding Plug
Key Features
- Designed to fix “open ground” or “floating neutral” errors from generators.
- Works with standard 15A (Edison-style) outlets on portable generators.
- Safe, sealed internal connection between neutral and ground.
- No tools needed.
- Durable build from Southwire, a trusted RV electrical brand.
- Small size makes it easy to store or keep plugged in.
My Review
I’ve tested a few generator bonding plugs, and this one from Southwire is the most reliable. It fixes the floating neutral issue immediately when plugged into a standard outlet on your generator.
I like that it’s a true “plug-and-play” solution. No wiring, no risk, and no guesswork. You just insert it into an unused outlet, and your surge protector will stop blocking power.
It’s also compact enough to leave plugged in or toss in your generator case without taking up space. If you use a surge protector with an inverter generator, this is one of the easiest fixes around.
Pros
- Instantly solves open ground and floating neutral issues.
- No wiring or electrical knowledge needed.
- Safer and more convenient than making a DIY plug.
- Small and easy to keep plugged in or store.
- Made by a reliable, RV-focused brand.
Cons
- Only works with 15A (household-style) generator outlets.
- Not needed if your generator already has a bonded neutral.
- Slightly less budget friendly than a homemade option.
DIY: How to Make Your Own Generator Neutral Plug (Bonding Plug)
If you don’t want to buy a ready-made neutral ground bonding plug, you can make a DIY bonding plug for generator use with a few parts from the hardware store. This quick fix solves your RV surge protector open ground problems when using portable generators.
The generator neutral plug for RV setups works by connecting the neutral and ground wires inside a regular 3-prong plug. This makes your floating neutral generator look like a bonded neutral generator RV system. Your RV EMS surge protector generator sees this connection and stops showing the open neutral warning and power flows like it should.
Making one is pretty easy, but RV generator safety matters here. Build it right, and you’ll fix your surge protector not working with generator issue safely. Build it wrong, and you could hurt your RV’s electrical system or get shocked.
Only try this RV generator open ground fix if you’re comfortable with basic electrical work. If you’re not sure, just buy a pre-made grounding plug for RV generator use instead.
What You’ll Need
- 3-Prong Male Plug
- 12 or 14 AWG Bare Copper Wire
- Small Flathead Screwdriver
- Wire strippers (optional but helpful)
How to
- Open the plug housing – Unscrew the plug and open it to expose the terminals inside. You’ll see three screw terminals: Silver screw = Neutral | Green screw = Ground | Brass screw = Hot
- Prepare your wire – Cut a 1–2 inch piece of copper wire and strip both ends if needed. This wire will connect the neutral and ground.
- Connect neutral to ground – Attach one end of the wire to the silver (neutral) screw and the other end to the green (ground) screw. Tighten both screws to secure the wire in place.
- Do not connect the hot leg – Leave the brass (hot) screw empty. Do not touch it or attach anything to it.
- Reassemble the plug – Carefully close the plug housing and screw it back together. Make sure the wire is secured and nothing is loose inside.
- Plug it into your generator – Insert your new bonding plug into a standard 15A outlet on your generator (Edison-style). It does not need to be connected to your RV, just into any unused outlet on the generator.
- Check your surge protector – With the bonding plug in place, plug in your surge protector. It should now allow power to pass through without any “open ground” or “open neutral” warnings.
Safety Note
This method is widely used, but it only works if wired correctly. Never connect the hot terminal to anything. If you’re unsure about any part of this, it’s better (and safer) to buy a professionally-made bonding plug like the one from Southwire.
Do You Really Need a Surge Protector With a Generator?
Lots of RVers wonder if they really need a surge protector when using their own generator. After all, generator power is usually cleaner than what you get at some campgrounds, right?
While that’s often true, surge protectors with EMS do more than just stop power surges. They protect against low voltage drops when you run your AC, reverse polarity from wiring mistakes, and frequency problems that can fry your electronics.
Even good generators can have issues, especially when you’re running big appliances, sharing power with another RV, or using long extension cords that cause voltage drops.
So when should you use one? If you have a hardwired EMS system, you’ll need to make it work with a neutral ground bonding plug anyway. It also makes sense if you switch between shore power and generator power often, let other campers plug into your generator, or just want to protect all those expensive electronics in your RV.
You might skip it for quick stops or if you only run small stuff like phone chargers. But for most RVers, using an RV surge protector with generator setups adds peace of mind, and with a simple generator neutral plug for RV use, your surge protector will work perfectly with any floating neutral generator you have.
To Wrap it Up
Using an RV surge protector with generator power might not seem needed at first. But if you have an EMS system or just want to keep your RV safe, it’s worth doing.
The RV surge protector open ground error is super common when people try to use surge protectors with portable or inverter generator RV setups. The good news? It’s really easy to fix with a neutral ground bonding plug.
You can buy a ready-made generator neutral plug for RV use or make a DIY bonding plug for generator connections yourself.
Keep one in your RV toolbox and you’ll be ready for anything, whether you’re camping off-grid or switching between campground power and your floating neutral generator.
Taking a few minutes to set up your RV camping power setup right can save you from expensive repairs later.
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With a larger inverter generator capable of 240v, do you need ground/neutral plug for both circuit s (aka legs, or phases)?
Hi David,
If your generator is capable of 240V it should already be grounded internally and not require a neutral ground bonding plug to work with a surge guard.
Is there a problem using a neutral ground bonding plug on an inverter generator? I fear that there might be some design of the inverter that might be damaged by shorting these points.
No, neutral ground bonding plugs are ok to use on inverter generators.
Why do people “not feel the need” to use surge protection with generator?
I would like to run my two YAMAHA generators in parallel. (EF2000iSv2, 1600 Running Watts/2000 Starting Watts). A knowledgeable friend advised that I will only need one neutral ground bonding plug. I’m a bit skeptical. Is my friend correct of should I purchase a second neutral ground bonding plug?
Hi Pat,
I’m not an expert on parallel connecting generators. I’ve only done it myself a few times. I do know that when in parallel generators are connected with ground wires as well. I think your friend is correct but like I said I’m not super knowledgeable when it comes to parallel connected generators.
I have a new champion 4650 inverter generator and a Southwire 34931 surge protector. When I plug my 30 amp Keystone Passport 2019 RV into the suppressor I get the open ground light and no power to the RV. Read your blog and purchased a Southwire generator neutral-ground bonding plug (model 44400). Plugged it into the generator and still had the same results (open ground). What do I do now? Just not use the surge protector when using the generator? I do have the generator grounded to a grounding rod while doing all of this. Thanks for your help!
Hi Dick,
I honestly don’t understand why the neutral ground bonding plug isn’t working. Champion recommends using one on their own website to fix the open ground problem.
I would try using the grounding plug in different outlets while the generator is on and the surge protector is plugged in to see if that works. Or try having the plug in before connecting the surge protector.
The problem could be that the 20 amp plug is only fixing the problem for the 20 amp outlets and not the 30 amp one. To test this you could try plugging the surge protector into the free 20 amp outlet instead with an adapter to see if the open ground is fixed there.
If it still isn’t working there could possibly be a problem with the plug, the surge protector, or even the generator.
Unfortunately using the grounding rod won’t fix the grounding issue for the surge protector but it would make using the generator without the surge protector a little safer.
You could try contacting Champion directly to see what they recommend as well.
Hello, I was wondering if its safe to run my 30 amp jayco jayflight 2022 to my new champion 4450 starting watts 3550 running watts without a bonding plug. Thanks in advance.
Hi Chris,
It’s fine, you won’t need the bonding plug if you aren’t trying to bypass a surge protector. And it’s not a requirement to use a surge protector with a generator.
I have 2 Champion units (2000 w) to pair together with the pairing wiring. I can run one unit with using the 20 amp plug on one, but the 30 amp plug when paired together won’t work. Is there a solution to that? Have a hardwired Surge Guard 35550 unit
Hi Al,
Are you using the Champion parallel kit (click to view on Amazon) with the 30 amp RV outlet?
Even with the parallel kit installed it will still have a floating neutral. Putting a neutral ground bonding plug in one of the 20 amp outlets should make it so the 30 amp outlet works with the surge guard.
If the plug doesn’t work you can also ground one of the generators using the ground terminal, grounding rods, and grounding wires.
Thank you for the response. Yes, I am using the Champion parallel kit. Tried it with grounding plugs in one and both 20 amp outlets and it still won’t work on the 30 amp. Will need to try the grounding rod.
Guess if that doesn’t work I’ll need to look at bypassing the Surge Guard
You can check out this forum thread where they talk about an issue like yours.
One of the RVers has a 73500i parallel kit and talks about swapping the AC wires to get the grounding plug to work. Maybe it’s a long shot but it’s worth looking into.
Thanks Jenni. I got it figured out. The 2 black plugs that go from the parallel adapter to the generator both look the same and there are no markings indicating whether they get plugged into the right hole. Well it does matter. by plugging it in and checking the voltage on the 30 amp plug I got it figured out and working.
Thanks for you help
Thanks for the update, I’m happy to hear that you figured it out!
I have a Watch dog 50 a.m. surge protector hardwired into my RV when I plug in my generator ( Predator 3500). I am getting the open ground warning that won’t let electricity pass. On my generator I have put an internal jumper (12 gauge ) from the neutral to the ground. The inside wiring all the neutrals and grounds run and series. Also when I plug in a tester into the 20 amp plug on the side of the generator I am getting a correct circuit 2 yellow lights. So it looks like the plugs on my generator are all showing properly bonded grounds. But my search protector still isn’t satisfied. Do you have any ideas or suggestions?
Hi Mike,
It sounds like what you’re doing should be working.
I would check the adapters you are using to plug your RV into the generator. I’ve heard that they can sometimes cause issues.
If you’re using a short adapter you might want to try switching to a dog bone one like this (click to view on Amazon).
I have a Kawasaki GE5000AS portable generator that I have used with my RV for several years.
This Winter I had the twist lock 30amp adapter overheat and I made a new plug and when I used a tester with the three lights on it I am getting an open ground light on all plugs 30amp and 15 amp.
Is this generator an open ground – floating neutural unit?
Hi Earl,
Your generator does have an open ground. To ground it you need to use a generator grounding rod like this (click to view on Amazon).
Or you could try using a ground bonding plug to stop the open ground light from showing.
I have this same problem of a open ground. A friend suggested that I get an adapter that plugs into the 30 Amp outlet and the 20 amp outlet on the generator and and connects to the 50 amp plug on my surge protector. That didn’t work but does it do anything
Hi Michael,
I think that method is for drawing more power from the generator, not for fixing the open ground.
I have a 3650 W generator which stops electricity flow when the fridge compressor kicks in. It was the only appliance connected to the generator and the wattage on the fridge is 1800. A friend suggested using a surge protector but I’m not sure this will correct the problem of the tripping on the ground fault circuit.
What do you think?
Hi Terry,
I don’t think a surge protector would stop that from happening, it sounds like a problem with the generator keeping up with the sudden increase in load.
If your generator is in ECO mode that could be the issue. Or your generator might need servicing, there could be something clogging the carburetor or in the fuel system, causing it to not reach full power.
I am trying to charge my Lithium batteries using a 3200i generator with the 30 amp rv plug. The charger is through a Mastervolt PowerCombi 12V/2000W 100A 120V. The charger state indicator light switches from Inverter Mode (off) to Bulk Mode charge and back about every 5 seconds. All other lights on the Mastervolt are green. Makes it hard to boondock without a charging device. Thanks