Bypass bus bar in simple DC ground setup

[Netsua]

I don't have a metal battery enclosure, so the only thing I have to ground on the DC side is the inverter itself. The designated AC ground is properly connected to the sub panel -> main panel (where neutral is bonded to ground).

I will bond the two earth points as the instructions require, but do I really need to run a ground bus bar from my negative bus bar (creating the DC ground/neutral bond) if the only thing I have to ground on the DC side is the inverter itself? Seems like I could run straight from the designated DC ground on the inverter to the negative bus bar itself - which in turn would go to the GE/earth. I would still only have a ground/neutral bond in one place - because there's nothing else to ground - right?

My setup has been running fine for years, but I'm learning I should not have a 48V system floating. I'm more confused on this grounding issue than anything I ever ran into on the system otherwise.

 

[eabyrd]

I am not an electrician, but In my opinion, based on all that I have read in the resources here and on other forums, and on a classic Mike Holt rant you should not have a second earthing stake in the circuit. Doing so is an invitation to have a lightning surge run roughshod through your system. There are exceptions if your systems are totally separate, but it reads as if yours connects to the main panel. If so let all the EGC earthing connections, and your battery negative connection ride that earthing connection. Do not create a second one

 

[Netsua]

I am not an electrician, but In my opinion, based on all that I have read in the resources here and on other forums, and on a classic Mike Holt rant you should not have a second earthing stake in the circuit. Doing so is an invitation to have a lightning surge run roughshod through your system. There are exceptions if your systems are totally separate, but it reads as if yours connects to the main panel. If so let all the EGC earthing connections, and your battery negative connection ride that earthing connection. Do not create a second one

I assumed your comment was silly, because the second grounding electrode is NEC compliant. But upon further research, it does seem to be valid after all! I'm just trying to get away from needing 30ft of 4/0...

 

[eabyrd]

I assumed your comment was silly, because the second grounding electrode is NEC compliant. But upon further research, it does seem to be valid after all! I'm just trying to get away from needing 30ft of 4/0...

Your earthing conductor shouldn’t need to be that large. There is a table in the NEC that applies. Don’t confuse a grounded conductor (neutral) with an Equipment Grounding Conductor ( what ROW calls earthing and I wish we did too). Two totally different things

BTW if I or anyone here say something that seems silly, call them on it. Be polite, but silly can mean they’re ( or I am) wrong, which can be damaging to others

i learn more by being corrected than by being right

 

[Netsua]

Your earthing conductor shouldn’t need to be that large. There is a table in the NEC that applies. Don’t confuse a grounded conductor (neutral) with an Equipment Grounding Conductor ( what ROW calls earthing and I wish we did too). Two totally different things

BTW if I or anyone here say something that seems silly, call them on it. Be polite, but silly can mean they’re ( or I am) wrong, which can be damaging to others

i learn more by being corrected than by being right

Well thankfully, before I called you out on it, I did my research. And apparently it’s like the only instance ever where professionals say the NEC is wrong haha.

What I don’t understand, is why I here comments like yours but the magnum manual says the GEC has to be the same size as the largest DC conductor...

 

[sunshine]

My setup has been running fine for years, but I'm learning I should not have a 48V system floating.

My 12v system ran into a number of unexplained issues when I grounded the negative and not since after the ground was disconnected.
Certainly earth the inverter but reconsider the necessity to ground the DC side.
Those with a 48v system, specially within a marine environment (galvanic corrosion), may disagree.

 

[eabyrd]

My 12v system ran into a number of unexplained issues when I grounded the negative and not since after the ground was disconnected.
Certainly earth the inverter but reconsider the necessity to ground the DC side.
Those with a 48v system, specially within a marine environment (galvanic corrosion), may disagree.

At 12 volts there is absolutely no need to do so. 48 plus code says yes, but … I have read many differing opinions on the value

i do, but hey I am not an electrician

 

[eabyrd]

Well thankfully, before I called you out on it, I did my research. And apparently it’s like the only instance ever where professionals say the NEC is wrong haha.

What I don’t understand, is why I here comments like yours but the magnum manual says the GEC has to be the same size as the largest DC conductor...

Out of curiosity what NEC version are you using. My MIke Holt source says they’ve removed references to multiple grounding electrodes beginning in 2017. I haven’t looked myself

Auxiliary grounding electrode for an array

I know nothing of PV systems. But was wondering if you do decide to have an auxiliary grounding electrode. Do you have to have a bonding jumper to terminate in the intersystem bonding connection device like cable/comms/satillite does Or does it being connected the the EGC suffice for bonding...

forums.mikeholt.com

and yes, I put a lot of stock in this group

 

[GeeGee]

deleted post