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To ground or not to ground

MartyByrde

Off-Grid Innovator
Joined
May 16, 2022
Messages
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Location
USA
Hi all,

I am building an off grid solar trailer. All of the components will be inside of the enclosed trailer including the combiner boxes. My plan is to ground the main panel box and frame of the trailer to an 8ft copper rod directly outside the trailer.

My question is around whether or not the solar panel arrays should have their own grounding rod? They will be at varying distances, some will be within 5 feet of the trailer, some will be up to 30 feet away. Should I just run the copper wire from the arrays to the grounding rod outside the trailer?

Maybe I don’t need to ground the panels at all?

Appreciate any help and insight!2B4C1D68-86CE-4B26-8939-87C2021B2FF7.jpeg
 
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plan is to ground the main panel box and frame of the trailer to an 8ft copper rod directly outside the trailer.
Explain why you think that is required…

The first thread in the link provided says, “For simplicity's sake, I will not discuss corner grounding, impedance grounding, or ungrounded systems in this post.”

A mobile system is an “ungrounded system” of sorts; it is grounded to the frame but it has no circuit to dirt so it is a “separately derived system. “
 
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Explain why you think that is required…
Grounding is something that’s confusing for me. I watched a video on YouTube of a guy building a solar trailer and he did this.

Grounding a solar trailer
The first boost in the link provided says, “For simplicity's sake, I will not discuss corner grounding, impedance grounding, or ungrounded systems in this post.”
What do you mean first boost in the link?
A mobile system is an “ungrounded system” of sorts; it is grounded to the frame but it has no circuit to dirt so it is a “separately derived system. “
So it doesn’t need to be grounded?
 
What do you mean first boost in the link?
Spell check I guess. I meant ‘thread’ or ‘post.”
So it doesn’t need to be grounded?
to answer that ‘need’ must be defined. Right after one defines “EGC” and the AC system ground being different requirements in NEC.

1) it is required by some jurisdictions
2) it is not required ‘functionally’ as the dirt is not part of a mobile electrical system’s circuit. (Manufactured housing electrical systems do not have an earth/dirt ground; they are grounded at the meter through their 4-wire connection) But a system where grid does not exist? Not required but could be wise.
3) there is language in NEC that talks about lightning dissipation
4) I’m not an EE or an electrician. My offgrid solar camper has never had a rod into dirt and it is safe; RVs don’t have ground rods.

A solar trailer shouldn’t either imho
 
Spell check I guess. I meant ‘thread’ or ‘post.”

to answer that ‘need’ must be defined. Right after one defines “EGC” and the AC system ground being different requirements in NEC.

1) it is required by some jurisdictions
2) it is not required ‘functionally’ as the dirt is not part of a mobile electrical system’s circuit. (Manufactured housing electrical systems do not have an earth/dirt ground; they are grounded at the meter through their 4-wire connection) But a system where grid does not exist? Not required but could be wise.
3) there is language in NEC that talks about lightning dissipation
4) I’m not an EE or an electrician. My offgrid solar camper has never had a rod into dirt and it is safe; RVs don’t have ground rods.
What about the panel box inside the trailer?
A solar trailer shouldn’t either imho
 
The trailer should be grounded back to the one and only one bonded ‘ground’ and if shorepower/grid is provided for/ then that N/G bond has to be physically disconnected when grid power is switched on.

There are several very good grounding/bonding instructions in the resources folder of this site. I would go there now
 
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