Can I use my house ground instead of a separate grounding rod for my off-grid stuff?

[ArtieKendall]

The manual for the EG4 battery rack says to connect it to a grounding rod. I would rather not do that, for two reasons: I don't want to drill a hole in my wall to run a grounding wire outside to a rod, and I don't want to set up a potential ground loop when I plug my charger/inverter into the wall. If either of those reasons sounds stupid, it's because I am brand new to this stuff, so please let me know if the above makes no sense.

My question (assuming the above isn't dumb) is, can I just connect all my equipment grounding screws to my house ground? I would like to just turn off a breaker for an unused outlet, pull the outlet out of the wall, disconnect its ground wire, and connect that ground wire to the ground screws on my batteries, inverter, etc. And of course, do something with the other wires to the outlet so they won't shock anybody if somebody accidentally turns the breaker back on.

Would that work?

 

[time2roll]

If truly off-grid with no connection I don't think a ground is even needed.

Anything like a portable generator or RV does not need a ground unless connected to a grid system.

 

[ArtieKendall]

If truly off-grid with no connection I don't think a ground is even needed.

Anything like a portable generator or RV does not need a ground unless connected to a grid system.

The only connection to the grid will be when I plug the AIO into the wall to charge the batteries when there's no sun, but that will be a regular three-prong 120V AC cord that has a ground wire connected to the house ground.

 

[LowerCarbonFootprint]

If truly off-grid with no connection I don't think a ground is even needed.

Anything like a portable generator or RV does not need a ground unless connected to a grid syst

If truly off-grid with no connection I don't think a ground is even needed.

Anything like a portable generator or RV does not need a ground unless connected to a grid system.

When you say it isn't needed....does this assume a NG bond screw in place on the inverter? That this would trip a breaker to protect the circuit?

 

[time2roll]

When you say it isn't needed....does this assume a NG bond screw in place on the inverter? That this would trip a breaker to protect the circuit?

A permanently mounted power source connected to distribution panel should have a N-G bond. I don't think it needs an earth ground unless tied to utility power. If plugging an appliance direct to the inverter the N-G bond is optional.

A breaker will trip from over current regardless of grounding. A GFCI will trip with 5 mA imbalance between N & H regardless of ground.

The safety ground acts as a return path when there is a fault so there is less likelihood of a person becoming part of the return path during a fault. Think of the neutral as the drain and the ground as an overflow or emergency drain.

Probably a bit oversimplified. But then no details of the actual set up was given.

 

[LowerCarbonFootprint]

A permanently mounted power source connected to distribution panel should have a N-G bond. I don't think it needs an earth ground unless tied to utility power. If plugging an appliance direct to the inverter the N-G bond is optional.

A breaker will trip from over current regardless of grounding. A GFCI will trip with 5 mA imbalance between N & H regardless of ground.

The safety ground acts as a return path when there is a fault so there is less likelihood of a person becoming part of the return path during a fault. Think of the neutral as the drain and the ground as an overflow or emergency drain.

Probably a bit oversimplified. But then no details of the actual set up was given.

Thanks for the reply. When connected to grid via AC in, and in battery/inverter mode, the outlets off the sub panel show open ground. When in one of the utility modes the outlets would show correct because the relay was appropriate for that use. This setup was with no NG bond in inverter and subpanel had N and G separate. The grid was providing the NG bond and the EG4 3000 EHV relay used the utility neutral on the AC input.

When using inverter and battery mode, I hear the relay flip and it shows open ground on the outlets. It's almost as if my off grid set up needs the NG bond screw in so that when the relay opens for Inverter/Battery use it still has a bond at first location.

 

[time2roll]

Yes. I repeat... A permanently mounted power source connected to a distribution panel should have a N-G bond.

Best to select equipment that has this feature as an option. Verify in the installation manual how to use the feature. Some inverters will not like it and are designed for isolated portable use to power an appliance direct. The transfer switch will isolate the bond while the alternate (grid/gen) power source is used. Can't use the grid N-G bond in conjunction with the inverter.

 

[DIYFi]

Been looking for this for a week. Thanks, that explains it.