Is it safe to connect my house ground to my AIO and batteries ground screws?

[ArtieKendall]

The EG4 manuals say to ground their batteries, racks, and inverters to a grounding rod, which would make me drill a hole through my wall, and I don't want to do that, nor have I seen anyone else do it in any of videos I've watched.

The system I'm planning will not be connected to the grid, except to plug the AIO unit into the wall to charge the batteries. Just a rack of batteries, an AIO charger/converter, and solar panels. (I will have a grounding rod outside for the panels.)

Would it be safe to connect the grounding screws on my batteries and AIO unit to my house ground, i.e. the ground wire from an unused electrical outlet?

Thanks for any advice.

 

[Ampster]

I would not go to a ground wire in an outlet, because someone could inadvertantly eliminate that circuit and you would lose the ground.Also ther gound wire on that circuit is too small. I did not haeve to drill a hole, I found the ground wire from my main panel to the ground rod and attached my other grounds to that at a convenient spot. I think it is better to use #6 wire to connect to the ground. . Anywhere between the ground rod and your main panel will work. You want the shortest path from your equipment to ground to protect your equipment.

 

[Crowz]

When I installed my hybrid system and ran the wires to feed it I bought 4 conductor wire so I had a real ground run to it from the mains.

 

[ArtieKendall]

I would not go to a ground wire in an outlet, because someone could inadvertantly eliminate that circuit and you would lose the ground.Also ther gound wire on that circuit is too small. I did not haeve to drill a hole, I found the ground wire from my main panel to the ground rod and attached my other grounds to that at a convenient spot. I think it is better to use #6 wire to connect to the ground. . Anywhere between the ground rod and your main panel will work. You want the shortest path from your equipment to ground to protect your equipment.

Please bear with me; I'm new to this. My main panel wiring is all underneath a cover. Should I remove the cover, drill a hole in it, and then run a wire through that hole to connect the main panel ground with my AIO and battery grounding screw? Thanks.

 

[ArtieKendall]

When I installed my hybrid system and ran the wires to feed it I bought 4 conductor wire so I had a real ground run to it from the mains.

Are you talking about connecting the ground wire in the Romex to the ground terminal in the AC-in of the hybrid inverter?

 

[Crowz]

I have it L1 L2 N and a ground wire aka 4 conductor. The ground wire has green insulation on it and yep its connected to the ground spot in the hybrid inverter.

 

[ArtieKendall]

I have it L1 L2 N and a ground wire aka 4 conductor. The ground wire has green insulation on it and yep its connected to the ground spot in the hybrid inverter.

Thanks for the help.

 

[Ampster]

Should I remove the cover, drill a hole in it, and then run a wire through that hole to connect the main panel ground with my AIO and battery grounding screw.

Yes, if that is the easiest. There are usually available prepunched spots that you can knock out the slug to run your ground wire to the ground wire in the main panel.

 

[Tulex]

I don't understand grounding the batteries/racks to a ground. There is no AC there. Heck, people make battery boxes out of wood, or no box at all.

 

[Ampster]

I don't understand grounding the batteries/racks to a ground.

I am guessing that maybe with UL listed rack batteries, grounding may be a UL requirment. That may be why there is a grounding screw or lug. Grounding is not only for AC, it also protects from lightning strikes which could go through any metal enclosure on its way to ground.

 

[Tulex]

I am guessing that maybe with UL listed rack batteries, grounding may be a UL requirment. That may be why there is a grounding screw or lug. Grounding is not only for AC, it also protects from lightning strikes which could go through any metal enclosure on its way to ground.

I can accept that. Though, I would think that it would have to go through the inverter first to get to the battery, which is grounded already.

 

[Ampster]

I would think that it would have to go through the inverter first

I don't have much experience with lightning but what little I know is that it does not alway follow the logical path.

 

[ArtieKendall]

I don't understand grounding the batteries/racks to a ground. There is no AC there. Heck, people make battery boxes out of wood, or no box at all.

Grounding is more confusing to me than everything else combined, but here is what it says in the EG4 LL battery manual:

"EG4-LL and EG4 Battery Rack Interface
1. Grounding - One end of the grounding conductor is connected to the grounding screw on each battery chassis and the other end is connected to a grounding lug (or screw) on the rack/cabinet. Attach a grounding wire from the door of the rack/cabinet to the same grounding lug (or screw). Finally, connect a grounding conductor to the grounding lug (or screw) on the rack/cabinet, then connect the grounding conductor to a grounding rod.
(Warning - DO NOT ground rack/cabinet or door to negative or positive
bus bars)"

No joke: they don't want you to connect the positive bus bar to ground. Even I knew not to do that.

But then just when I was thinking I was starting to understand it, I read this in the LV6548 manual:

"14. WARNING: Because this inverter is non-isolated, only three types of PV modules are acceptable: single crystalline, poly crystalline with class A-rated and CIGS modules. To avoid any malfunction, do not connect any PV modules with possible current leakage to the inverter. For example, grounded PV modules will cause current leakage to the inverter. When using CIGS modules, please be sure NO grounding."

The one thing I was sure of before today was that you are supposed to ground your panels, and now the LV6548 manual says not to.

I was planning to spend nearly $10K this week for an off-grid system. Now I'm thinking I would be an idiot to buy anything when I don't even know what to ground, let alone how.

 

[Pilot Bob]

You don’t ground PV modules back to the panel unless it was designed that way. You do want to ground modules and the racking for shorts and lightning strikes. This should be to a separate ground rod or to the systems ground rod located outside near the meter base.

 

[Mark-]

You might check out this thread: https://diysolarforum.com/threads/array-grounding-and-components-grounding.64787/#post-838667

 

[CorkyL]

As explained to me - Think of grounding the DC casing/ equipment(PV and rack system) to an earth ground not connected to electrical ground. AC grounds all should go back to the Load panel or where the ground rod is located for your house. The inverter goes back to there.