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How to Ground All-In-One Inverter System?

Thersom1948

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I'll start by saying: I think I have read every thread on grounding on this forum, and most of the links to outside sources that have been posted.

I am more confused than ever.

Ground is almost never addressed for any system builds here, including Will's videos. When it is, you get a dozen conflicting opinions from "experts" and then several physics/electricity theory lessons that belong in an EE 400 level course. and at the end you still don't have an answer.

So I'll try to ask a simple question and hope I can get a simple answer.

System:
-My system is NOT grid-tied. It is portable. Inspired by Will's "hand truck" build.
-BUT it will use grid-charging via a regular 120v AC outlet
-Growatt SPF 3000TL LVM
-EVE cells
-Ground mounted panels

GROUND:
1. Ground PV panels from lightning via frame to real earth ground. Ground rod in earth. Check.
2. During grid charge, AC will be grounded through the house system. Check.

3. Simple question: How is the AC Output from the Growatt grounded when NOT on shore power?

i.e., the Solar Generator is in a box, isolated all on it's own, Just Battery and Inverter and PV input - but the Inverter is powering AC loads.

EDIT: To make it even more simple: Why do none of the "Solar Generator" builds anywhere address grounding? Not jackery / goal zero etc or DIY. Does a fully self contained solar generator system not need to be grounded?

Thanks! sorry if I sound grumpy - trying to find answers on this topic is infuriating.
 
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No grid tie. No earth ground reference. On the inverter, the output is referenced to the inverter. So the inverter case is the "ground". Good practice has the inverter case connected to the battery negative.
 
#3 You do not have to earth ground any inverter. You do earth ground a converter, (charger/inverter). But that is done through the third wire in the cord back to the utility entry point. You do not need an earth ground as there is not a reference from the inverter to the earth. The inverter's case acts as the "ground" side of the 120vac.
 
This is an off grid system, without a utility entry point with an inverter/charger correct?
 
It would be useful to determine whether the all-in-one is UL 458 listed (or built to that standard even if not UL listed). If so, the AIO will automatically switch the neutral-ground bond based on whether the AIO is acting as an inverter (bonded to inverter chassis which in turn is connected to the negative busbar) or a charger (bonded externally at the source). I think I'm muddling my words a bit, see the attached image (from Samlex) for a fuller and better explanation.
 

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I wonder if a house's AC mains socket can be used as the ground connection for an inverter/portable solar generator ?



The above are sold on sites that sell EMF/grounding bed sheets/pillows/earth bands ....
 
This is an off grid system, without a utility entry point with an inverter/charger correct?

Well...both.

It is not permanently grid tied.

But I will use a wall outlet to charge the battery when shore power is available.
 
#3 You do not have to earth ground any inverter. You do earth ground a converter, (charger/inverter). But that is done through the third wire in the cord back to the utility entry point. You do not need an earth ground as there is not a reference from the inverter to the earth. The inverter's case acts as the "ground" side of the 120vac.

@Zil can you specify if that is for circuit safety/completion or Lightning safety/protection?

This is what nobody ever talks about when the discuss grounding, why we always talk past each other.

For example if I have the unit:
-Disconnected from shore power
-Being charged via solar power by a line coming in to the house
-Have the solar panels grounded outside

Still the Generator inside needs a lightning ground path somewhere right?
 
When did you add a generator to the question? Ok ok I went back to post#1. You refer to the panels as "ground mounted" That is not portable. If the inverter/charger is not plugged into the grid power outlet the inverter ac is likely referenced to the inverter case. That will be explained in the manual that is with your inverter. My inverter could be different than yours. Only the grid needs an "earth ground". If you do not have a portable system you could tie the case to your existing earth ground at your main panel. But it is not needed.
 
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