Earth ground connection help

[Ennis437]

Thanks for the help yesterday guys!. I now know that I need to Earth ground my solar panels and it seems to be that the majority agree that the earth grounding conductor needs to be connected at one location. Which raises a few specific questions that maybe you guys could help with? Should I run my solid copper conductor from my panel frames underground and connect directly to my house grounding electrode? Or should I run the copper wire back to the main service panel and connect it to my ground neutral bar? Or should I have a separate ground rod and then connect that to the house grounding electrode? My set up is as follows. Two SP6548 set up in split phase. My AC in is coming from the grid from my MAIN panel where the ground and neutrals are bonded. I assume this same bus bar also includes my house main earthing connection to my electrode? Then MY AC out goes to a SUBPANEL where I have separated the grounds and neutrals. The sub panel IS NOT earth grounded to the main panel. I wasn’t sure if this was neccesary??? With my set up? Sorry for the long post thanks in advance for the help!!

 

[BentleyJ]

The subpanel should have a ground wire that runs back to the source (main panel) and connects to that ground bus.

The PV ground should run to the same panel as the other wires where the inverter breaker is located.

 

[Ennis437]

The subpanel should have a ground wire that runs back to the source (main panel) and connects to that ground bus.

The PV ground should run to the same panel as the other wires where the inverter breaker is located.

So the PV EGC would go to my sub panel and not my main panel that has the neutral ground bond?

 

[BentleyJ]

Your entire electrical system main panel, subpanel(s), receptacles, switches, appliances, generators are required to be grounded to at least ONE continuous (continuous in this case does not prohibit splices or connections) grounding loop or daisy chain that is connected to a driven ground rod or UFER ground in some dry, desert situations.
Can you install a second ground rod or a separate, stand alone lightening strike protection system on a building? Yes, but that is beyond the scope of your question and can introduce ground loops. This becomes an engineering project.

You should run a ground wire from the subpanel ground bus back to the main panel and attach it to the main ground bus. As is your system does not meet electrical code.

Then your inverter can be treated just like any other appliance that would be added to the subpanel. That being the appliance equipment ground connects to the same panel the breaker and neutral originate from.

EDIT: keep in mind an equipment ground conductor can be downsized according the NEC. For example, a 100Amp subpanel would only require an 8AWG ground and a 200Amp subpanel would require a 6AWG.

 

[zanydroid]

I saw another thread that said the PV EGC has an exception (probably in 690) that allows it to take a separate path to the N-G bond from the circuit conductors. I don’t have a code reference.

Which is theoretically slightly better for lightning protection.

 

[Rednecktek]

at least ONE continuous (continuous in this case does not prohibit splices or connections)

????? You mean I fished that long ass wire through two plates, a wall, a well casing, two more walls, and the panel for nothing?!?!?!

 

[zanydroid]

????? You mean I fished that long ass wire through two plates, a wall, a well casing, two more walls, and the panel for nothing?!?!?!

? Well you can usually splice except it adds pain in other places… like needing a splice box or (for GEC) special splices.

Ground though in general is easier to splice than other conductors. Smaller and fewer of them

 

[Balrog006]

? Well you can usually splice except it adds pain in other places… like needing a splice box or (for GEC) special splices.

Ground though in general is easier to splice than other conductors. Smaller and fewer of them

Grounding strips or case mounted lugs in enclosures are the easiest way to splice or daisy chain your grounds.

If you’re using a bare solid #6 as a panel/mount ground you can mount an enclosure on the array with a ground strip/lug inside and (if you don’t already have one to transition from PV wire to THWN) and transition from that solid ground to a stranded TWHN #10 or so as required by your other home run wiring and take it back to your panel with your other grounding connections.