Can you Ground both Solar Panel and Off-Grid inverter to 1 Ground rod?

I have 3 x 400 watts panel in series and a 3000 watts off-grid toroidal inverter. Not sure if these 2 needs to have its own ground rod. Solar panel has its own DC SPD and Inverter its AC SPD.

Ground rod is 5/8". 10 feet, copper

Thanks!

The NEC *requires* the panel's frames and racking to be tied back to the main structure's grounding system.
Additional grounding electrodes are optional. I always avoid 2nd earth grounding points when I am able to.

BTW: This is from my set of papers on grounding:




The series of 4 papers can be found starting here:

FilterGuy said:

BTW: This is from my set of papers on grounding:

View attachment 123121


The series of 4 papers can be found starting here:

Grounding Made simpler - Part 1: AC/houshold grounding

To get the paper, click on the orange button at the top of the screen. The subject of grounding is a complex, multifaceted subject, that is often treated as an after-thought but needs to be considered from the beginning of the design and build...

diysolarforum.com

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Ground mounted solar systems are already grounded via the structure. Sinking an extra ground rod for a ground mounted system can be nothing but beneficial.

I don't think the same thing could be said for a roof mount. While my first inclination is to agree with your article, I'd have to sit and think on that for a while.

MurphyGuy said:

Ground mounted solar systems are already grounded via the structure.

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That is why I said "I always avoid 2nd earth earthing points when I am able to." When multiple earthing points are unavoidable (such as ground mount arrays) I advise routing the Equipment Grounding conductor from the array directly to the common earthing point of the main structure and NOT routing it through the inverter.

MurphyGuy said:

Sinking an extra ground rod for a ground mounted system can be nothing but beneficial.

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If the ground mount system is already grounded via the structure, then an extra ground rod won't make much difference either way. However, I still would not add a grounding electrode at the array because 1) that guarantees the dual grounding electrode problems will be enabled and 2) it is extra work and cost that is not needed.

BTW: Having multiple earthing points in a system has been shown to be problematic in multiple studies. All the generator manufacturers used to insist on auxiliary ground rods at the generators. However, Mike Holt went on a campaign to show them the problems with multiple earthing points. Since they made the change, they have found that their warranty costs have dropped dramatically.

If you search for MIKE HOLT Grounding on Youtube, you will find a lot of great videos about grounding. He is careful to use NEC terminology so the videos are sometimes hard to follow, but he makes a lot of great points.

This is a good one that has content related to this subject.

FilterGuy said:

This is a good one that has content related to this subject.

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Have that one in my sig linked to the meaty bit.

sunshine_eggo said:

Have that one in my sig linked to the meaty bit.

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As part of my prep for writing the grounding papers, I watched around 12 hours of Mike's videos. You can see the similarities between my drawings and some of the drawings he shows.