Seeking advice if this wiring is correct for LV6548 off-grid w/generator and sub-panel from main panel

[Hammbonius Dr. K]

@FilterGuy, I’m brand new here, so I hope I’m asking the right guy, but I want to hook up my LV6548’s pretty much exactly like the attached screenshot and I’m just wondering why only one and not both N-G screws should be removed if the critical loads panel ground is attached to the main breaker panel and both AC in’s are grounded in the main panel as well. And, in this picture, I see the AC out’s are not attached, so I don’t need to include AC out ground wires?

 

[FilterGuy]

There are a couple of things going on here.

1) the reason I show the grounds from the inverters NOT being connected is that the NEC requires the Equipment grounding conductor be run along with the non-grounded conductor. This meets that requirement without creating ground loops.

2) There is no NG-Bond in the critical loads panel.
Note: The highlighted part below is my attempt to show that the case of the load panel is tied to the equipment grounding conductor (assuming the case is metal).



3) When the inverters are generating power from the battery, the disconnect input neutral from output neutral. That means the low impeadance path through the main panel N-G ground no longer exists. Consequently one (and only) one needs to be created. Therefor, one of the inverters need to create the N-G bond.

 

[Hammbonius Dr. K]

I’ve been trying to figure all of that out for three days. Now, I can finish wiring that stuff up With peace of mind!

 

[Biigtiitan]

Thank for all with this input as the N-G bonding gets a bit confusing, this all helps, thanks again to all especially FilterGuy.

 

[FilterGuy]

keep in mind that the new firmware for the EG4 6500EX changes the situation. You may want to review this resource if you are useing the 6500:

Grounding and bonding for EG4 6500 EX inverters.

In February 2023, EG4 announced a significant change to how their inverters do grounding and bonding. Overall, these changes allow for much greater flexibility in installing the inverter in ways that are both supported and meet the NEC...

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