I measure zero ohms from neutral to the ground pin, indicating the neutral is bonded to the green safety ground

Hmm... That would indicate that it is bonded. The wiring diagram in the manual also shows that it is bonded neutral. It is apparently an error in the manual to say that it is floating.

but infinity ohms from the neutral to the generator support frame.

The frame may or may not be connected to the alternator casing. Your reading seems to indicate that it is not connected, but that is different from a floating or bonded neutral.

More importantly, do I have a safety problem here if I connect that generator to the house in case of a major power outage?

You need a floating neutral unless you are switching the neutral wire with your transfer switch (a 3-pole switch).

 

The wiring diagram in the manual also shows that it is bonded neutral.

I'm not seeing a Neutral-Ground bond in that diagram...

 

null

 

KevinR:
i agree with tabora
i think you are good to go!
at least from what i see in the posted diagram from gen knot.

with the generator off and not connected to any appliance or house generator inlet
verify by checking from the white neutral to the y/g ground.
it should be "OL" or open on a good digital ohm meter readout.

frame or chassis grounding to the outlet earth or green or in your case y/g ground is normal on an floating neutral gen set.
the generator will be grounded to your inlet system when you make the proper 4 wire inlet connection to the house.

quick note:
make sure you are using an main to generator breaker interlock
or dedicated switching panel for the generator inlet
or automatic transfer switch

iowagold said: "
with the generator off and not connected to any appliance or house generator inlet
verify by checking from the white neutral to the y/g ground.
it should be "OL" or open on a good digital ohm meter readout. "

As I said in my original post, I measured a zero ohm dead short between neutral and ground, not an open circuit.

 

oh yea
KevinR
the bond connection should be under the gen head bell cover on the end of the gen head

 

Just out of curiosity, does it indicate floating or bonded on the front panel?

 

GenKnot: Nowhere on the generator does it say anything about bonding. Here's all the front panel says:

Regarding the bonding inside the unit, here's what I saw:

 

Here is what the NEC says about objectionable current:

Chapter 2 Wiring and Protection: Minnesota Electrical Code 2023 | UpCodes

UpCodes offers a consolidated resource of construction and building code grouped by jurisdiction

up.codes

 

Remove the white wire as shown and then recheck the receptacles to make sure the gen has a floating neutral now.

 

GenKnot - and the rest of the great forum members: Many thanks to all. I could not do this without your help, so I'm immensely grateful.
It is 98 degrees right now (110 in the garage), so this is going to wait until tomorrow morning when the temps are a little cooler. Removing that white jumper should be easy. I wouldn't have known it was there, or that removing it would cure the fault without the forum help.
Cheers,
Kevin

 

BINGO! Beat me to the post.

 

I ran into this with my AI Power 7600 max inverter. The manual said it was a floating neutral. I then looked into a parallel kit that was two hots and a ground made for this generator. This made me think it was a bonded neutral. Elsewhere deeper in the manual it stated it was a bonded generator. I took the cover off and quickly located and disconnected the bond as my main use is home backup. I think double-checking the bond should be part of a new generator introduction because this is obviously a common issue.

Conor

 

Glad that you got it removed. Does sound like it was much more work than it should have been.

As for that statement by DuroMax...well, all I can say is that it was apparently written by a clueless individual.

 

My portable generator is floating and my surge protector confirms this as theres no ground LED lit up on the surge protector when using the generator, but this is ok apparently if your using extension cords.

 

A nice video from Champion that describes what is done above to convert the gen to floating neutral.

 

It turns out that Champion is not the only DuroMax competitor that disputes DuroMax's false claims about generator neutral bonding.

Here's what Cummins Power Generation, a major player in the generator market, says in this article:

"The problem with grounding the neutral both at the normal service and at the generator is shown in FIGURE 2. Multiple neutral grounds would not be recommended because ground fault current would split and (low in two parallel paths according to the impedance of each path. The NEC 250.24(A)(5) would prohibit a bonding jumper between the generator neutral and ground show in FIGURE 2. The ground fault current sensed by the GFP sensor will be the difference between the actual total of ground fault current and that part of the ground fault current returning through the sensor on the neutral. If the sensed ground fault current does not exceed the setting of the GFP, the GFP equipment will be rendered ineffective. The solutions are to not ground the neutral a second time at the generator, or ground the generator neutral and not connect the normal distribution and generator neutrals together, i.e., use 4-pole transfer switches."

Since the average portable to house generator hook-up is via an interlocked 30 or 50 amp breaker that only switches the two hot leads and not the neutral, DuroMax is giving false, and dangerous information to users, claiming their neutral is floating (when in truth it isn't), encouraging them to use this in violation of the National Electric Code prohibition from bonding neutral to ground at multiple points in non-Separately Derived Systems.

 

Nice Cummins info you found there.

And yes, as the FAQ posted in #19 says, "DuroMax open frame Generators are considered Floating Neutral Generators". And then that FAQ continues to state that the "ground and neutral are connected together in the stator housing". So, they are bonded (connected) neutral-ground generators.

The frames of portable generators may or may not be connected to the other physical parts of the generator, but that is another matter and has nothing to do with having a floating or bonded neutral.

Here is an example of a frame-to-ground bonding wire.

 

Nice Cummins info you found there.

And yes, as the FAQ posted in #19 says, "DuroMax open frame Generators are considered Floating Neutral Generators". And then that FAQ continues to state that the "ground and neutral are connected together in the stator housing". So, they are bonded (connected) neutral-ground generators.

The frames of portable generators may or may not be connected to the other physical parts of the generator, but that is another matter and has nothing to do with having a floating or bonded neutral.

Here is an example of a frame-to-ground bonding wire.

View attachment 18207

To clarify that for those who don't know the fine points of the subject, that was a picture showing the bonding of the generator frame to the green ground wire of the generator, but not to earth ground - which should only happen at the main panel for a non-Separately Derived System (like a portable generator connecting via an interlocked 30 or 50 amp two pole breaker - which should always have a floating neutral). It is only when using a true Separately Derived System (SDS) that the neutral and ground wires should be bonded. In an SDS, a ground rod should be used, and most importantly, a four-pole transfer switch must be used to totally separate the now SDS generator (and its neutral) from the house panel, and the house's ground bond.

It was interesting that the major players like Cumins Power Systems and Champion Power Equipment understand that and teach it to their customers, yet DuroMax keeps spouting false information on using their falsely labeled generators - in violation of the National Electric Code.

 

Kevin,

I may have missed it if this was mentioned, but you don’t want to use your generator as a free standing power source (tools or equipment plugged directly into the generator outlets) without having a bonded neutral in place. Maybe you will never need to do this, but just in case the need does come up, I’d recommend either making or buying a “Bonding Plug”. Super simple to make either using a regular 120 volt 3 prong plug or a a 240v 4 prong 30 amp twist lock plug. Just connect a piece of 10 or 12 AWG wire between the ground and neutral prongs. Once you plug it in to an open outlet, you have successfully and temporarily reverted your generator to a bonded neutral.

One last thing, there is a regulation that states that generators must be labeled as bonded or floating neutral. Maybe on that brand it is hidden somewhere in small print, but I’d look and if it shows it listed as bonded, make a label that says Floating Neutral and apply it over the original designation.

 

Larry,

You are absolutely correct on both points. When using a generator stand alone, not connected to a building, with tools plugged into the generator directly, one of two things are needed:

• Either the generator should have a bonded neutral, or
• If it is a floating neutral generator, a bonding plug is required, as you correctly pointed out, to make the required bond between neutral and ground.

Your second point, the requirement for a label, is also correct. NEC Article 445.11 requires:

“Each generator shall be provided with an accessible nameplate giving the
manufacturer’s name, the rated frequency, the number of phases if ac, the
rating in kilowatts or kilovolt-amperes, the power factor, the normal volts and
amperes corresponding to the rating, and the rated ambient temperature.”

On my first look for that label last week on my DuroMax generator after GenKnot asked about that, I didn’t find it. Now that I know that NEC 445.11 requires it, you can bet that I’m going back out to the hot garage to check that again more thoroughly check that when the hot temps go down. I hope this is not yet another NEC violation by DuroMax.

Thanks for your good on-target comments, and keep up your good inputs to the generator forum.

Another interesting YouTube video on this issue is here:

Kevin

 

A follow up on why it takes me some time to answer GenKont and Larry63’s questions about the generator having a label plate as required by NEC 445.11, is that my generator while in storage, is not easy to see.

Since I run it only twice a year, and don’t want humidity to cause rust, so in storage, I keep it in a BIG plastic bag, with four large silica gel desiccant containers inside the bag, to draw out any moisture in the bag, and keep the generator rust free. Here are pictures showing that:

Just to the right of the gas cap, you can see the bonding plug, ready to use if I need to use the generator stand-alone, not connected to the house's bonding system.

 

Moved post to proper location

 

I agree, it is not crystal clear and could be written more clearly. The thing that makes me think it applies to all generators is, if only for >15kW wouldn’t it be listed as #6? So I’m thinking the top applies to all. The next inset part is for larger generators, and then back to all generators. Wouldn’t bet my life on it, but that’s how I’m reading it. And if this is correct, I’d of listed everything that all generators needed and then had a section that only applied to larger ones….but that’s just me.