Ground fault using generators

[pjmoser]

I have a digital circuit tester that I keep plugged into an ac receptacle in my trailer. When I use my Honda 2000 generators (either in both in tandem or a single solo) I get a ground fault alarm on the tester. I have tried connecting the ground terminals of each generator together and to the body of the trailer. The alarm sounds even when the trailer is insulated from earth - stabilizers raised, hitch jack raised, truck and trailer on rubber tires.

[AirsDream]

Do you ground your generators, using their ground terminal (don't know about Hondas, but my Yamahas have a separate ground point on their frame) and a good, deeply planted ground rod?

[Buttercup]

In most Honda portable gas generators the neutral circuit is not bonded to the frame of the generator or to the earth ground lead; and are commonly called Floating Neutral generators. The floating neutral configuration is common for applications such as connection to a recreational vehicle and connection to home power where the transfer switch does not switch out the neutral to ground connection.

Even if you bond the trailer to the ground connection on the generator, you still do not have a Neutral Bonded setup. So, the fault detector is likely seeing that.



In a Floating Neutral system, trailer occupants are not endangered by electrocution from current going to ground since the ground wire and the neutral wire are not bonded at the generator bus, the equipment grounding wire does not offer a path for the fault current to complete the circuit back to the generator windings. In effect an open circuit, current will not travel it and so the fault current does not even go to ground. The figure above, illustrates why that is the case.

At my house, I have a 240-120 volt, 7kva step down transformer powering the trailer when it is parked. I set this up so that I could run the AC at home when I need and doing that through an extension cord on 120 volt outlet causes too much voltage drop...blah, blah, blah. My point is that this transformer is an isolation transformer and as such I do not have a neutral bonded to earth ground even though the ground wire of the trailer is bonded to the ground of my electrical system of my house. The nature if the electrical isolation of my primary and secondary windings of my transformer prevent a path for current to flow through the ground of my trailer. It also is a floating neutral in this case.

[ROBERT CROSS]

Originally Posted by pjmoser

I have a digital circuit tester that I keep plugged into an ac receptacle in my trailer. When I use my Honda 2000 generators (either in both in tandem or a single solo) I get a ground fault alarm on the tester. I have tried connecting the ground terminals of each generator together and to the body of the trailer. The alarm sounds even when the trailer is insulated from earth - stabilizers raised, hitch jack raised, truck and trailer on rubber tires.

I use a "dog bone" adaptor when using our 2000i...


You need to put a short jumper wire between the ground and neutral in the end that plugs into the generator.

The fault your seeing isn't a safety concern, it's done just so the circuit won't show a fault when a tester is applied.

Bob

[pattonsr]

Bob has it right. Built-in Surge Guard or Progressive EMS will also show an error code. The remote on the Progressive has a bypass switch but the better way is make up a plug with the jumper wire between ground and neutral. Plug into one of the two 20 amp receptacles on the Honda or Yamaha and the error goes away. You only need one plug even if you are using 2 generators in parallel.

[Phoenix]

Quote below is from Honda EU2000i Generator Owners Manual. There is no need to worry about a ground fault indication using regular AC circuit testers.

==========

Ground System

Honda portable generators have a system ground that connects generator frame components to the ground terminals in the AC output receptacles. The system ground is not connected to the AC neutral wire. If the generator is tested by a receptacle tester, it will not show the same ground circuit condition as for a home receptacle.

[mwilliamsmd]

I hope you guys understand all this???? My take away is... it's safe to use the generators despite the error indicator, right?

[aftermath]

Yes

[Al and Missy]

Another way of stating all this is in your home, neutral is bonded to safety ground and also connected to a ground rod at the meter. Thus the power system is referenced to earth ground and a shock hazard to earth ground exists. The generator system, as explained by buttercup, is a floating neutral, not referenced to ground either safety ground or earth ground and thus there is no shock hazard as long as the isolation is maintained. But also as pointed out by several, some analyzers will detect the lack of a bond between the neutral and ground.

Al

[chasgail]

Thanks for the info - great forum, bunch of brainiacs willing to share good data so we all sleep a little better. Much appreciated.

[A W Warn]

Originally Posted by pjmoser

I have a digital circuit tester that I keep plugged into an ac receptacle in my trailer. When I use my Honda 2000 generators (either in both in tandem or a single solo) I get a ground fault alarm on the tester. I have tried connecting the ground terminals of each generator together and to the body of the trailer. The alarm sounds even when the trailer is insulated from earth - stabilizers raised, hitch jack raised, truck and trailer on rubber tires.

When the trailer electrical cord is plugged into the generator, the ground wire from the trailer is connected to the ground terminal on the generator through the receptacle and plug. Connecting the ground terminal to the trailer in another way does not ground anything. Possibly, contact to earth, otherwise known as ground, can be accomplished through the jack or stabilizers, but this is not reliable. Possibly, in an older trailer with a copper plumbing a ground could be accomplished through the water system, though it would not be reliable.

If you want the whole system to be grounded while the generator is connected to the trailer, you must connect the ground terminal of the generator to an earth ground. A wire connected from the generators ground terminal and mechanically fastened (clamped) either to a ground rod driven into the earth or to a metal water pipe partially buried in the earth will do this. I think (not sure) grounding using this method will correct the issue with your tester and also the ground fault breakers and GFCI receptacles will function properly.

[J. Morgan]

An earth ground will not correct the fault reading on the fault detector.

Only bonding the ground and neutral will do this, but this "fix" is neither desirable or necessary.

The best fix is to ignore the fault reading while on generator.


Brevi tempore!

[A W Warn]

Originally Posted by J. Morgan

An earth ground will not correct the fault reading on the fault detector.

Only bonding the ground and neutral will do this, but this "fix" is neither desirable or necessary.

The best fix is to ignore the fault reading while on generator.


Brevi tempore!

Will the ground fault breakers and GFCI receptacles function if your advice is taken?

[ROBERT CROSS]

Originally Posted by J. Morgan

The best fix is to ignore the fault reading while on generator.
Brevi tempore!

Really....how would you know if you actually had a ground fault?....



I'll use my genetically modified doggie bone...TYVM.



Bob

[J. Morgan]

http://www.noshockzone.org/generator...utral-bonding/


Brevi tempore!

[cmipilot]

Am I missing something obvious here or isn't modifying the "dog bone" going to require cutting off the factory end and replacing it to provide access for the jumper wire you're proposing?

[J. Morgan]

No, you plug it into the spare generator receptacle.

However, IMHO, it is a total waste of effort, but I reserve the right to be wrong.


Brevi tempore!

[Msmoto]

Every time I fire up my Northern Tool 4000w electric start generator which is sitting on the ground, it triggers the ground fault breaker to trip on my Serenity.

My plan is to have the generator connected to a good ground, possibly a five foot heavy chain, or even a copper pole in the ground to see if this can be eliminated. It is frustrating to have to reset this each time I use the generator.