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Complete Off Grid Grounding??? some Questions

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Merlin

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Feb 25, 2021
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Hi friends,

time for some more questions to you.

I want Grounding my whole Solar System. I am completely Off Grid.
Have 1x SC120A Growatt for 12 Panels
1x Epever for 3 Panels - goes directly to the Charger not in the combiner Box
1x Combiner Box
2x Inverters


I have a ground metal 12 ft behind the Panels and have on every single aluminum rail a ground conductor and the wire goes through.
So all Panels are grounded about the Solar Railing directly in the ground.

My Question is.....

Need I connect this wire to the combiner Box as well?
Need I connect my Charge Controllers and Inverters as well to the same wire?

Thank you in advance for reply I don´t find somewhere else correct answers.
 
Oh, my Home just run all with 120V and is NOT Grounded.
Should I Ground just my Home and the Panels or just the Panels or just the Whole System?
 
The solar panel frames are grounded to provide some lightning protection. In your 120Vac, the green/ground must refer back to the source. That is the inverter. There is likely a 'case lug' and that is the point to use to establish "earth" "ground" or whatever you wish to call the bare/green wire.
 
There are 4 parts to this grounding resource material. Look thru all of them to start. Then proceed with the part hat matches your system/needs. Grounding is important.
diysolarforum.com

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 diysolarforum.com
 
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My off grid system is intentionally left ungrounded, and has been 9 years and running. I'll tell you this, for what it might matter to you... I've seen grounded systems fried by nearby lightning strikes which traveled through the ground and found their way into the system via the ground rod. Last year, a friend of mine lost his inverter and dsl modem exactly due to that. Conversely, I've had a nearby strike travel into my house via my black iron propane manifold and arced right off my stove, while I was standing literally 6 feet away. Scared the living shit right outta me too. System was untouched however. My panels are not grounded either, but the entire rack and posts are all pressure treat lumber on concrete footings, no metal except for screws and the carriage bolts that turn the pivots for changing the angle.
 
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Thank you all guys to support me again. I text back more on the weekend.
Appreciate that.
 
BlackWaterPark said:
My off grid system is intentionally left ungrounded, and has been 9 years and running. I'll tell you this, for what it might matter to you... I've seen grounded systems fried by nearby lightning strikes which traveled through the ground and found their way into the system via the ground rod. Last year, a friend of mine lost his inverter and dsl modem exactly due to that. Conversely, I've had a nearby strike travel into my house via my black iron propane manifold and arced right off my stove, while I was standing literally 6 feet away. Scared the living shit right outta me too. System was untouched however. My panels are not grounded either, but the entire rack and posts are all pressure treat lumber on concrete footings, no metal except for screws and the carriage bolts that turn the pivots for changing the angle.
Click to expand...
Wow, thats hard stuff BWP...
But I running my System still ungrounded until now.
I build a big Rack out of pressure thread lumber as well but i have ground spikes out of metal they goes in the ground.
Sorry I don´t have a look on the recommended 4 parts till yet, but something tells me I should ground just my Solar Panels and the combiner box and thats it. the Panels and CB are 100 ft away from my home. anyways text later....
 
Solar Frames & rails are grounded for Lightning Protection, not electrical, there is no "electrical" connection to the aluminum framing.
Pressure Treated wood and Aluminium do NOT mix well ! Use only Stainless Screws / Bolts and isolate the aluminum contact entirely. I used strips of rubber from a Tractor Tire Tube.
The AC Distribution panel in the house/cabin should be properly grounded to a Long Grounding Rod or Grounding Plate and connected to the grounding strip within the AC Distribution panel and then all AC Wiring grounded there accordingly.

Wiring a building with VAC and not following the Grounding Requirements... Might as well play Russian Roulette but put 3 rounds in the cylinder.
 
MSO. In a total off-grid system. The ac distribution within the structure doesn't need any rod driven into the earth. That rod does nothing in a off-grid system. The only ac "ground" reference is back to the inverter.
Using earth rod connections to solar frames will provide some lightning protection. There can be a case made for connecting the solar panel negative to the lightning ground rods.
 
Merlin said:
Hi friends,
I want Grounding my whole Solar System. I am completely Off Grid.

My Question is.....
Need I connect this wire to the combiner Box as well?
Need I connect my Charge Controllers and Inverters as well to the same wire?
Click to expand...
Merlin are you in the USA or some other country?

I am not smart enough to know if we are or are not leading Merlin in the direction of a "GROUND LOOP".
I have a similar issue with my own build and hope to see the perfect solution reached in this thread.

What voltage, AC or DC, is traveling 100 feet to the house? I found this in another thread and I believe you are running 196 volts DC:
"I am fine because I need to go just 80 ft with 4S - 3P, 196V, 34 Amp and have just a lost of 1.55%"

Merlin says there are "ground spikes out of metal" near the panels BUT the house is not grounded.

I am assuming there are 2 wires, PV +/-, between the array and the house.

Would adding a ground rod or connection to ground (which I don't believe exists at this time) 100 feet away, at the house,
create a "GROUND LOOP"?

I am assuming the charge controller, inverters and AC distribution panel are in the house.
 
There are 4 parts to this grounding resource material. Look thru all of them to start. Then proceed with the part hat matches your system/needs. Grounding is important.
diysolarforum.com

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 diysolarforum.com
 
RandyP said:
There are 4 parts to this grounding resource material. Look thru all of them to start. Then proceed with the part hat matches your system/needs. Grounding is important.
diysolarforum.com

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 diysolarforum.com
Click to expand...
If that is for me, thanks. I'm on my second read of all of them and others as well.
For whatever reason it's not sinking in. :confused: I'll get it figured out before adding power.
 
WYtreasure said:
If that is for me, thanks. I'm on my second read of all of them and others as well.
For whatever reason it's not sinking in. :confused: I'll get it figured out before adding power.
Click to expand...
Check out Mike Holt's videos on youtube. He has some good general grounding specific videos, and I believe even some that are specific to ground loops, and to PV array grounding. He is a good explainer, and it may be that your learning style connects more with his presentation than the written resources.
 
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