Difference between various grounding toplogies?

[LionKing]

As per NEC, there are three options to ground the DC side, earlier it seemed that the Option 1 (separate electrode for DC side) was the only way to go later NEC clarified the statements and now we have three ways - two of which involve common electrode for DC and AC.

I'm in Pakistan and the govt here probably decided to just copied NEC's initial rules, so the only acceptable way to legally do DC grounding here is by having a separate electrode. Getting a new grounding electrode is quite expensive and we already have one electrode installed, I was wondering if there is any downside to to option 2? If the inspector shows up, he will still see two grounding wires coming out of the ground (although they are bonded together). Any suggestions? Btw, the required resistance is <= 5 ohms for each GEC.

 

Another question: I'm using Voltronic Infini Solar 10KW plus inverter. It has a equipment grounding screw on the body, that connects with AC grounding side, right?

[Jaco De Jongh]

16 minutes ago, LionKing said:

I'm using Voltronic Infini Solar 10KW plus inverter. It has a equipment grounding screw on the body, that connects with AC grounding side, right?

Yes that is correct. 

[bluwater]

Ideally, everything should be bonded together and there should only be only one path to ground. If you have two ground rods, you are essentially creating a path for current to flow from one ground rod, through your equipment to the other. This can be a problem in case of a lightning strike.

For a good understanding about grounding I would suggest that you watch this video by Mike Holt. He is an absolute legend when it comes you NEC codes and electrical theory.

 

 

Edited September 11, 2018 by bluwater

[Chris Hobson]

All his videos are good and easy to follow.