Off grid grounding.

[Ron Asbury]

I know there are many discussions on the topic but I am still confused.
This will be a 1st time install (DIY) in a totally off grid cabin. The system will be a SunGold Power 6548 inverter, 8x 415watt panels and 2x 48v 100ah server rack batteries.

Is this crude diagram of the grounding of the system safe? Grounding is the hardest part for me to understand.

 

[sunshine_eggo]

Assuming you're just grounding the PV frames, it looks good.

The only thing you're omitting is where the N-G bond is. The inverter should supply it when inverting, but it will open it when charging from generator.

Ideally, you would want to bond N-G in the AC panel, disable it at all times in the inverter, so that even when running on generator, the system will still have an N-G bond.

 

[Ron Asbury]

Thank you, that is the answer I was looking for. Yes, only PV frames grounded. Now to determine how to disable the N-G bond in the inverter. The user manual isn't clear or I cannot find it. Anyone who has disabled it in the SP6548 please let me know,

 

[sunshine_eggo]

Most voltronics type inverters have a bonding screw that you remove.

Try this:

 

[Ron Asbury]

Thank you, that helps a lot. I will contact Sun Gold Power to see if indeed the bonding screw has been removed.

 

[sunshine_eggo]

Thank you, that helps a lot. I will contact Sun Gold Power to see if indeed the bonding screw has been removed.

I think you need to open the unit and look for it. If it's there, you need to remove it if you want to provide the N-G bond in the AC panel.

 

[Ron Asbury]

Just a follow-up.
Reply from SunGoldPower.
https://signaturesolar.com/blog/dem...ng-in-solar-power-systems-with-eg4-inverters/Also found this at Signature Solar.

 

[Supervstech]

If this is the case, then all ya have to do is bond them on thw panel, and you are good.
The panel should come with a bonding screw, if not, just place a #4 solid copper wire between N bar and ground bar.

 

[Consumerbot3418]

Also, it's pretty easy to verify the N-G bond. With all power off, you should measure continuity from N to G, and after breaking the bond in the panel, there should no longer be continuity. Replace the bond, confirm continuity, and you'll know you've got it right.