Question Generator Neutral/Ground Bonding plug

[Joe Hogan]

This is an interesting article regarding using a generator to power a RV. There are specific RV rules issued by NRIV regarding separate neutral and grounding circuits with good reason. However this sometimes "floating" ground generator power will not power a RV. The common solution is to plug in a Ground Bonding device sold at camping stores and Amazon.

Here is a brief article. RV Electricity – Generator neutral bonding basics - RV Travel

Has anyone had this issue and used a Bonding Plug?

 

[Kevin D Pem]

No problems on an old RV!

WHY!!!

Because in the NEC there is new art and existing art. You may remember the 2 prong plugs in the house you grew up in. Well you can build on an old system without replacing the old with new. That is why you can still buy 2 prong plugs at the better hardware stores.

What do you do if you add an addition to an old house? You do what this plug does or you do it right. I would say if inspected the plug approach would not pass. To extend a circuit you feed a GFIC plug with the old. (in this case the generator) Then have the system running with a protected ground. We are talking about shock protected, not separately grounded. The grounded plug on the web page is not the legal fix, but rather the illegal work around.

All generators I have had in, well, forever have a ground lug on the panel. to ground properly for shock protection go to the store(hardware store) and buy a ground rod. Buy an acorn nut, and piece of wire one size smaller than the house wire.

Attach the ground lug on the generator to the wire.

cut the ground rod in 1ft pieces with an angle on the end like some of the more serious tent stakes.

Use the acorn nut to attach the wire to the 1ft piece of ground rod. berry the rod in the dirt/planter/earth and water and keep watered as though you wanted it to grow. You have just made a good earth ground that will keep you shock free and not interfere with other GFIC devices on your rig.

I suggest keeping the other pieces of ground rod in the basement ready to replace rods you can't retrieve, because the lazy way is to lay it flat and covered up. The best way is drive it like a tent stake and then water. I will also admit that I don't ground my system. But if your system fails because you don't have a ground that is my suggestion.

 

[Gronk]

OK,please explain to me how grounding the generator to the earth works when the RV is not grounded to the earth? What you are explaining works great for a house or other structure with a ground rod.

 

[Kevin D Pem]

The ground lug on the generator creates a ground for the un insulated ground that most people see as the ground pin on an outlet. And though the two hot legs of the generator float, the ground is in fact a ground.

The plug you found actually just lies about being a ground.

A GFIC has no ground when used in old work but it protects the user from the power by shutting the power down when the power makes a complete circuit on the wrong location. You can look at a GFIC as a comparitor circuit that makes sure the power on the two hot legs stays equal.

an Example of grounding the generator would be like using an extention cord on the roof of a house. Just because you are not on the ground does not mean the cord is not grounded.

 

[Gronk]

I fully understand the ground system for what you say, but again, the RV is not grounded to the earth. For a structure, grounding the generator to the earth is good, but not the RV.

 

[Kevin D Pem]

Its about occupants coming in contact with the ground. Just like a house if the danger exists GFIC protected outlets are required, Lets say all outside outlets in both house and your RV must have this protection. As well as kitchen and bath outlets. The rest of the outlets the ground lug is all that is required, mostly for appliances that are not double insulated.

Your house wiring is grounded at the box and no where else. This is the same in your RV. I don't understand the question I guess.

 

[Kevin D Pem]

We are not talking about lightning protection grounding here, just house wiring

 

[Gronk]

OK, I will try to explain myself again. The RV is ONLY grounded through the power cord. Nowhere else. Therefore, when you plug into the pedestal the RV is grounded through the electrical system which will have a ground rod driven into the earth. If I plug my trailer into the generator that is sitting in the back of my truck there is no ground rod driven into the earth. Grounding the generator in that fashion will serve no purpose since the source of the power is in the back of my truck. Also, my generator is mounted on rubber feet and not electrically connected to my truck and the truck is not electrically connected to the earth. The only ground an RV has is through the power cord and there is no seperate wire going from the frame to the earth. In a "hot skin" situation the reason you feel the shock is because the pedestal has no proper ground and you are a conductor for the electrons to travel back to the source. Since the generator is not (under normal circumstances) grounded to the earth you would not complete the circuit and feel a shock. If you are trying to power a structure that normally gets its power from the grid then, yes, you will have a ground rod driven into the earth with a wire going back to the panel. A GFCI works by monitoring the power going trough the line and neutral. An imbalance of more power going through the line than returning on the neutral (doesn't matter why or how) the GFCI disconnects the line side.

 

[Kevin D Pem]

If I plug my trailer into the generator that is sitting in the back of my truck there is no ground rod driven into the earth. Grounding the generator in that fashion will serve no purpose since the source of the power is in the back of my truck.

Take the front plate off the generator and look at what the ground lug is wired to. Then consider what happens if you run a wire from that lug to a ground rod(no matter what size). Take the time to draw the circuit and compare to a pedestal. In effect you will be doing the same by running the lug to the earth. The zip file has two generator pics. Notice that all grounds in the generator I have pictured for you go to the front plate that in fact like all generators have a ground bolt on the front panel as pictured in the second pic. I have not seen any generator without a grounding point in the years I have been RVing unless you consider my Poorboy generators that don't produce house voltages. I discribed in above posts how to accomplish a temporary ground as you seem to make references to in this quote.

"All generators I have had in, well, forever have a ground lug on the panel. to ground properly for shock protection go to the store(hardware store) and buy a ground rod. Buy an acorn nut, and piece of wire one size smaller than the house wire.

Attach the ground lug on the generator to the wire.

cut the ground rod in 1ft pieces with an angle on the end like some of the more serious tent stakes.

Use the acorn nut to attach the wire to the 1ft piece of ground rod. berry the rod in the dirt/planter/earth and water and keep watered as though you wanted it to grow. You have just made a good earth ground that will keep you shock free and not interfere with other GFIC devices on your rig."
Myself

 

[Gronk]

Again, unless you put a ground rod on the RV, a ground rod on the generator does not protect the RV. You have an open circuit with only a ground on the generator. The RV is grounded to the generator through the power cord. By the way, as per the NEC the ground rod is to be a minimum four feet long and expected to be eight feet long (driven straight down). You can go ahead and ground your generator any way you please, but I personally will not drive a rod especially in a campground. That being said, I am done trying to explain myself.

 

[RandyB]

@Gronk Mike Sokol is considered THEE source for RV electric. Here is a link to one article and from there you should be able to find other articles and a link to Mike. Good luck

RV Electricity – Generator grounding and bonding - RV Travel

By Mike Sokol Dear Mike, I purchased a generator for the RV. It is a 3500-watt unit and came with an RV 30-amp outlet. I thought that it would tie the ground and neutral together but upon doing a continuity check on it all three poles are open. The generator does have an earth ground […]

www.rvtravel.com

 

[Kevin D Pem]

@Gronk Mike Sokol is considered THEE source for RV electric. Here is a link to one article and from there you should be able to find other articles and a link to Mike. Good luck

RV Electricity – Generator grounding and bonding - RV Travel

By Mike Sokol Dear Mike, I purchased a generator for the RV. It is a 3500-watt unit and came with an RV 30-amp outlet. I thought that it would tie the ground and neutral together but upon doing a continuity check on it all three poles are open. The generator does have an earth ground […]

www.rvtravel.com

Hey @RandyB It is not that @Gronk and I have different view points. we just have wires crossed in communication. For this reason I spent some time looking things up, including looking at Gronks history, per website listed.
Where our wires are crossed is the grounding vs. bonding issue. To keep this thread useful I have looked up and referenced a couple more websites.

OSHA Fact Sheet: Grounding Requirements for Portable Generators | Occupational Safety and Health Administration

and

Differences Between Bonded and Floating Neutral Generators

What are the differences between floating neutral and bonded neutral? Is it important? Is there a way to check the type of neutral of a portable generator?

generatorbible.com

For the reference of the NEC I agree to drive a 8 even 4 foot grounding rod in a campsite is unacceptable. Portable generators don't exclude grounding requirements according to 250 in the NEC. In my book any method of obtaining a ground is better than none. My suggestion of 1 foot rod watered and kept wet is in fact a compromise. It does not meet code so to speak but reduces shock hazard just the same. I suggest laying the rod in the dirt rather than driving but a 1 or 2 foot rod can be removed like a tent stake can be removed, and if watered will produce a good ground. Because permenent ground rods are not kept wet one needs more rod to maintain a good ground.

When I say NEC does not exclude grounding requirements because we are connecting our house rather than connecting our devices directly to the generator as the only exclusion in the requirement for grounding I say does not exclude grounding.

I don't question @Gronk 's qualifications after knowing who I was talking to, I would have pulled up some sources for what I was saying earlier. For the record I was ready to quit this conversation at much the same time as we weren't getting anywhere.