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Off-Grid earth grounding to clear Open Ground

mini4mw

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Apr 25, 2021
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I've gone through hours of video, forum posts, docs and Giandel support, but I still can't find an outright answer which is what I think we all want when dealing with electricity so no one gets hurt.

Question: How to run ground for DC battery system and AC panel fed from Giandel 24v 4000W inverter to alleviate an open ground.

Base setup:
1600W panels on unistrut ground mount
2 batteries in series for 24v 300amp/hr
60 amp MPPT
Giandel 24v 4000W inverter, does not bond ground to neutral
AC panel old school breakers, no GCFI or Arc Fault breakers
AC panel fed direct wire from Giandel (hot/load, neutral, ground), not via inverter outlet and wires broken out
AC panel feeds AC outlets around a building rather than pulling extension cords.
AC panel has hot from inverter to dual breaker to feed both sides of the panel
AC panel currently has neutral to ground bond removed
Earth ground 8' deep
No external power, AC, Generator, etc. Only incoming power is solar feeding batteries and batteries feeding equipment

Unistruts/panels grounded 6AWG direct to earth ground
AC panel ground bus 6AWG direct to earth ground
Inverter chassis ground connects to AC panel ground bus bar
Inverter AC output direct wires: ground wire connects to AC panel ground bus. Hot goes to jumped dual breaker and neutral goes to neutral bus bar in AC panel

When I test an outlet supplied power through the inverter I show an open ground, but I was expecting a proper ground due to the earth ground connections. I thought perhaps I need to bond neutral to ground in the AC panel as show on page 5 of the "stationary systems" doc (https://diysolarforum.com/resources/grounding-made-simpler-part-2-stationary-systems.161/) but Giandel advised:

"Is your electrical panel a GFCI socket? Please do not connect the neutral and ground, it is dangerous, will cause electric shock, also can not pass HIPOT testing. Unless you use a GFCI socket to connect the inverter's Neutral and ground. If you want the tester show "GROUNDed", that is also possible, just connect the inverter's Neutral to Ground terminal, but please use GFCI socket to connect them."

Are saying I need all GCFI breakers instead of using the panel bar to bond ground and neutral or are they saying use the bar AND use GCFI breakers? GCFI breakers sure cause a cost increase. I believe its 2nd option as everything I've read says you can only have 1 connection between ground and neutral. If a GCFI bonded ground and neutral, there would be several. Course then it could trip the GCFI can clear the fault..

Any other grounds I should make?

Thanks-
 
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Obligatory not an Electrician or AHJ, but everything I know about electricity says that you need to bond your Neutral to Protective Earth at precisely one place. Usually, this is your main AC panel.

Victron Inverters actually include a relay internally that will bond PE to Neutral when they are not connected to grid power.

The reality is the only person who can say that your installation is kosher is your local electrical inspector.
 
Giandel's response was to use a GFCI outlet to bond neutral to ground, which doesn't seem right. Not sure how you would even do that unless you connected ground and neutral at the outlet which would be a no no. I don't think they understand the setup, which would be my fault for not explaining more clearly.

I'm going to run the hard/direct wires from the inverter to the panel (hot to dual breaker, neutral to bus and ground to separate bus), connect the neutral to ground crossbar in the panel (this will be the only neutral to ground connection), the panel has a 6 awg copper to an 8' earth ground, put GCFI outlets as the first connection from the panel breaker and daisy chain any other outlets off the GFCI.

Learning from welding, electricity always wants to take the easiest/shortest path back to connect a circuit. Giandel does not support/complete a neutral - ground bond. Leaving the bond at the AC panel (which has no other incoming power except the inverter) will provide the best path back to the inverter via neutral but also carry overload to the earth ground, I believe..

Going to see if I can find someone in the friend tree to check me out. Any thoughts are always appreciated.
 
I might be wrong (not an electrician) but I think Giandel is saying that if you want to connect neutral to ground at panel:

*AC panel has hot from inverter to dual breaker to feed both sides of the panel

Then that dual breaker should be a GFCI breaker... But that's just my interpretation and what sounds kosher to me.
 
For the system you describe, only. There is no need for a "hammered into mother-earth ground rod" unless you instal a Franklin Lightning Point.
On your ac current side, there is no real neutral or hot until the one side is connected to the inverter housing, or otherwise connecting the green to one of the hots that then becomes the neutral.. The inverter housing is usually the 'ground' (green) circuit, but many are 'floating' with no internal connections.
 
Giandel's response was to use a GFCI outlet to bond neutral to ground, which doesn't seem right. Not sure how you would even do that unless you connected ground and neutral at the outlet which would be a no no. I don't think they understand the setup, which would be my fault for not explaining more clearly.

I'm going to run the hard/direct wires from the inverter to the panel (hot to dual breaker, neutral to bus and ground to separate bus), connect the neutral to ground crossbar in the panel (this will be the only neutral to ground connection), the panel has a 6 awg copper to an 8' earth ground, put GCFI outlets as the first connection from the panel breaker and daisy chain any other outlets off the GFCI.

Learning from welding, electricity always wants to take the easiest/shortest path back to connect a circuit. Giandel does not support/complete a neutral - ground bond. Leaving the bond at the AC panel (which has no other incoming power except the inverter) will provide the best path back to the inverter via neutral but also carry overload to the earth ground, I believe..

Going to see if I can find someone in the friend tree to check me out. Any thoughts are always appreciated.
GFCIs are (the only) permissible way to provide a 3 prong outlet when you do not have an actual Protective Earth. They work by monitoring the current in the hot and neutral wires and, if they differ by more than 5mA, tripping the outlet. The site where I've done a lot of electrical work (under the supervision of a licensed journeyman) was built in 1937, so a frighteningly large number of circuits are still just 2 wire. Our general policy is to put GFCIs in these to protect the users. It is legal to do so under NEC.

GFCIs do not provide a bonding to earth, but what they do do is protect you from stray currents that do not return to the source via the neutral.
 
I called an called a guy I used to work with a few years ago that is an electrician. He confirmed that there needs to be a single neutral to ground bond as close to the source of the power, be it inverter, generator or street power. On the same ground bar the bonding occurs on should have a copper wire to the earth ground. I went ahead and put the bonding crossbar back in the panel connecting neutral to ground in the AC panel and now I have a grounded circuit instead of the open ground. Somewhat oddly, if I plug a tester directly in the inverter, it also shows a grounded circuit. I also added GFCIs as the first outlet and daisy chained remaining outlets. This is much cheaper than buying a GFCI breaker.

I may not need the grounding rod at this time, but I am trying to set everything up to possibly connect to street power which may or may not happen at some point in the future.

I'm still not 100% sure what Giandel was saying. In the last reply, when they said put in a GFCI to bond the ground they sent me an Amazon link for a GFCI outlet.. They did answer within 24hrs each time and did answer questions about their product clearly.

Thanks for the replies.
 

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If you are not connected to the grid you do not need a ground rod. The circuits refer back to the source. A ground rod refers back to the grid utility. You need to refer back to the inverter or generator. If you ever get grid power the question of ground will be answered by Code.
 
If you are not connected to the grid you do not need a ground rod. The circuits refer back to the source. A ground rod refers back to the grid utility. You need to refer back to the inverter or generator. If you ever get grid power the question of ground will be answered by Code.
Doesn't matter if you're on or off grid. If you're doing electrical in a permanent structure, you're still subject to code whether you like it or not. I work with an organization that is way off-grid in WA. You had better believe that we still need to pull county permits, and get inspections for any significant electrical work.

Either way, in a permanent structure, for the sake of safety, you should still have a proper protective earth, and the neutral should be bonded to that as close to the power source as possible.
 
If you are not connected to the grid you do not need a ground rod. The circuits refer back to the source. A ground rod refers back to the grid utility. You need to refer back to the inverter or generator. If you ever get grid power the question of ground will be answered by Code.


My AHJ checked that I had a properly connected ground rod for the panel as the first order of business.

Simple off grid setup, a few panels, one inverter and one panel with two circuits.

He also checked that the roof mounted solar panels (on a shed) were properly connected to the same ground rod.

Since my Sigineer inverter has a ground lug on it (not connected) he checked for continuity to the panel ground which was present via the ground on the 8 AWG wire from the inverter to the panel. Standard 8/2 wire with ground.
 
Those ground rods are for lightning protection. It will do no harm having the off grid inverter connected to a earth ground rod, it does nothing positive either. The inverter has no reference to the earth ground, it has reference to it's case. An off grid generator if used for more than one connection, like a small neighborhood of two or more campers, needs have a proper earth ground rod. Off grid generators, like a portable Honda, with one connection does not need the earth ground rod.
 
Perhaps, but the AHJ said he would fail me on the electric if there was not a ground rod for the electric panel. Again, it's just a two circuit panel in a shed.

Grounding the panels for lightning was not important to him.

Just one AHJ but he is the most important AHJ for me !
 
If you are not connected to the grid you do not need a ground rod. The circuits refer back to the source. A ground rod refers back to the grid utility. You need to refer back to the inverter or generator. If you ever get grid power the question of ground will be answered by Code.
So horribly wrong. This place scare me !!!!
 
I am thinking not having it all connected to ground would make an accidental shock less severe to a person who is.

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I was barefoot in the garage on the concrete and this crusty old box fan shocked the heck out of me when I went to move it. Would that have happened if ground was not part of the circut? I kind of think not.
 
I am thinking not having it all connected to ground would make an accidental shock less severe to a person who is.

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I was barefoot in the garage on the concrete and this crusty old box fan shocked the heck out of me when I went to move it. Would that have happened if ground was not part of the circut? I kind of think not.
Would not have shocked if there were not some incorrect wiring in the circuits. The problem is the problem not the symptom is the problem.
 
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