Grounding a portable generator

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Toddlaroche

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Location
New York State
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Marketing
I’m using a DuroMaxSP12000EH generator. DuroMax calls it a floating neutral generator, but I think that’s misleading. It probably would be better described as an “isolated ground” configuration. The neutral coming out of the generator windings is bonded to the generator casing at the anchor point of the outgoing ground wire.

A continuity test between the neutral and ground pins of the generator receptacles confirms they are bonded. The generator housing is mounted on insulated mounts, so the generator’s exterior frame is not carrying any ground circuit, but there is a grounding nut on the generator control panel to which a grounding rod can be connected.

With me so far?

I’d like to power my house with this generator when the grid goes down. My current hook-up goes from the generator’s 240volt receptacle with a 4-line cord: the 2 hots feed directly into a bipole 50amp breaker at the main service panel, the neutral and ground wires feed directly into the respective busses at the panel. Of course, the neutral and ground busses are connected together at the main panel. An approved interlock device is installed on the panel, and I am not using a transfer switch.

So now my question(s):

DuroMax suggests that the proper way to go about grounding the generator is to use an appropriate grounding rod wired to the grounding nut on the generator, while “removing” or disconnecting my ground wire that runs in the cord from the generator receptacle to the breaker panel, thereby avoiding a “double ground” situation that could cause a loop. I think this make sense... seems correct and safe enough to you?

I suppose that’s all fine as long as it’s safe — I just have to find a place close to the generator where I can get an 8’ rod installed!

But if I do this, do you think I should remove the jumper between the neutral and the ground at the generator casing? This way, (because the neutral and ground busses are connected at the house main panel) there would be no chance at all of having a ground loop between the generator ground rod and the main panel grounding rods... or would it not matter??

Now, the “easier way out” for me is to not go through the process of driving in a new grounding rod and just use my current set-up (i.e. grounding the generator through the ground wire running from the receptacle to the main ground bus). If this is acceptable, however, I suppose it would be prudent (or mandatory??) to remove the neutral-ground jumper in the generator, correct? This would prevent the ground wire running between the generator and the panel from being energized, since it’s bonded to the neutral at the generator and the main panel, yes?

So overall, those are my two options as far as I understand it - 1) use a grounding rod at the generator and remove the generator to main panel ground wire, or 2) use the main panel ground bus to ground the generator and disconnect the generator’s neutral-ground bond (jumper). Are both acceptable options?

If you were wiring this scenario, which way would you do it??
 
I am closing this thread, in accordance with the Forum rules. This Forum is intended to assist professional electricians, inspectors, engineers, and other members of the electrical industry in the performance of their job-related tasks. However, if you are not an electrician or an electrical contractor, then we are not permitted to help you perform your own electrical installation work.
 
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