Neutral bond

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Jonrmay

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When you have a line side solar P.V. tap that ends in a disconnect,
Are you allowed to bond the neutral in that disconnect.
I was under the impression that by definition of solar system, service equipment and by article 250-142 that you are only allowed to double bond a neutral, generally, in service equipment only.
Any clarity would be appreciated.
 
I b
Jonrmay said:
When you have a line side solar P.V. tap that ends in a disconnect,
Are you allowed to bond the neutral in that disconnect.
I was under the impression that by definition of solar system, service equipment and by article 250-142 that you are only allowed to double bond a neutral, generally, in service equipment only.
Any clarity would be appreciated.
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I believe that was ambiguous for many code cycles and only in the 2020 code was it clarified that you bond it like a service.
 
Jonrmay said:
When you have a line side solar P.V. tap that ends in a disconnect,
Are you allowed to bond the neutral in that disconnect.
I was under the impression that by definition of solar system, service equipment and by article 250-142 that you are only allowed to double bond a neutral, generally, in service equipment only.
Any clarity would be appreciated.
Click to expand...
The short answer is "ask the AHJ". Here in Texas we have many jurisdictions where the 2020 NEC has been adopted but for a line side PV interconnection we are required to keep N and G isolated in the PV AC disconnect and run an EGC through it from the service. I disagree with jaggedben; I have read the sections of code he references and I don't think it's at all clear. If it's what the code writers intended, IMO they should have stated it clearly in 705.11.
 
ggunn said:
The short answer is "ask the AHJ". Here in Texas we have many jurisdictions where the 2020 NEC has been adopted but for a line side PV interconnection we are required to keep N and G isolated in the PV AC disconnect and run an EGC through it from the service. I disagree with jaggedben; I have read the sections of code he references and I don't think it's at all clear. If it's what the code writers intended, IMO they should have stated it clearly in 705.11.
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Sorry, I can't resist seizing the opportunity to state my disdain for the NFPA/NEC, but this is yet another example of the incompetence of the NFPA. The neutral Bond thing has been an ambiguous nagging issue for many code cycles, and here they try to clarify it and STILL botch it and make it clear as mud.
 
electrofelon said:
Sorry, I can't resist seizing the opportunity to state my disdain for the NFPA/NEC, but this is yet another example of the incompetence of the NFPA. The neutral Bond thing has been an ambiguous nagging issue for many code cycles, and here they try to clarify it and STILL botch it and make it clear as mud.
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On that we are agreed.
 
This issue is one that is being caused by infighting between two code making panels.

Two panels with totally different ideas of how these installations should be made.

Panel 10 has the expertise on services and Panel 4 on alternate energy systems.

This is being resolved in the 2023 code, but only because CMP 10, added a new Article 231 in the first draft that would have taken all of the line side stuff out of 705. The correlating committee stepped in and forced an agreement between the two panels for the 2023, with the end result that the line side disconnect is a service disconnect and subject to the rules in 230 for services, and 250 for grounding and bonding.
 
don_resqcapt19 said:
This issue is one that is being caused by infighting between two code making panels.

Two panels with totally different ideas of how these installations should be made.

Panel 10 has the expertise on services and Panel 4 on alternate energy systems.

This is being resolved in the 2023 code, but only because CMP 10, added a new Article 231 in the first draft that would have taken all of the line side stuff out of 705. The correlating committee stepped in and forced an agreement between the two panels for the 2023, with the end result that the line side disconnect is a service disconnect and subject to the rules in 230 for services, and 250 for grounding and bonding.
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Wow I didn't know it was that complicated.... IMO they should have never introduced the concept of "supply side connection" and just had interconnections be done via 230.40 exception #2 (with possible modifications to the number and grouping).
 
electrofelon said:
Wow I didn't know it was that complicated.... IMO they should have never introduced the concept of "supply side connection" and just had interconnections be done via 230.40 exception #2 (with possible modifications to the number and grouping).
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Why couldn't they have just added one sentence to 705.11 and be done with it?
 
ggunn said:
Why couldn't they have just added one sentence to 705.11 and be done with it?
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Sure, but I still say it would be simpler to have not gotten into "normal" and "PV" disconnects and this supply side connection nonsense. Just stick with 230.40 exception 2, a well established practice which has been used for half a century. What they did seems like one of these "let's make as convoluted as possible" things.
 
ggunn said:
Here in Texas we have many jurisdictions where the 2020 NEC has been adopted but for a line side PV interconnection we are required to keep N and G isolated in the PV AC disconnect and run an EGC through it from the service.
Click to expand...
On that, I agree. There is no logical reason to bond anything to the neutral in the PV equipment.

It is not used to establish the beginning of the premises EGC system as is done in the service main.
 
LarryFine said:
On that, I agree. There is no logical reason to bond anything to the neutral in the PV equipment.

It is not used to establish the beginning of the premises EGC system as is done in the service main.
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It is, for all practical purposes, a service disconnect and needs to be installed exactly like any other service disconnect.
 
don_resqcapt19 said:
It is, for all practical purposes, a service disconnect and needs to be installed exactly like any other service disconnect.
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Larrry Fine said: ^
On that, I agree. There is no logical reason to bond anything to the neutral in the PV equipment.

It is not used to establish the beginning of the premises EGC system as is done in the service main.

And therein lies the ambiguity. Personally, I do not care. I do not see a safety or functionality difference either way.

EDIT: I do not know what all the business below is about; I do not know how it got in here and I can't find any way to delete it.
 

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LarryFine said:
On that, I agree. There is no logical reason to bond anything to the neutral in the PV equipment.

It is not used to establish the beginning of the premises EGC system as is done in the service main.
Click to expand...
But you could make the same argument about a 230.40 exception #2 install and say the neutral shouldnt be bonded in the discos and an ssbj should run back to the tap or split point of the sets. (I know code specifically does not allow that for service disconnects but just talking about the theory).
 
ggunn said:
Larrry Fine said: ^
On that, I agree. There is no logical reason to bond anything to the neutral in the PV equipment.

It is not used to establish the beginning of the premises EGC system as is done in the service main.

And therein lies the ambiguity. Personally, I do not care. I do not see a safety or functionality difference either way.

EDIT: I do not know what all the business below is about; I do not know how it got in here and I can't find any way to delete it.
Click to expand...
It does establish the connections for the EGCs on the load side of that disconnect and main bonding jumper is required at the PV line side disconnect for that purpose. Remember that any faults on the load side of that disconnect are fed from both the PV inverter, a minor contribution to the fault current, and by the utility, the major contribution to the fault current.
 
don_resqcapt19 said:
It does establish the connections for the EGCs on the load side of that disconnect and main bonding jumper is required at the PV line side disconnect for that purpose. Remember that any faults on the load side of that disconnect are fed from both the PV inverter, a minor contribution to the fault current, and by the utility, the major contribution to the fault current.
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Be that as it may, with either wiring method there is continuity between the EGC in the PV system, the service ground, and all the neutral conductors. The fault clearing either goes through the PV AC disco or around it, but it is still there; I don't see that it makes any difference to functionality or safety.

But be that as it may the NEC could get everyone on the same page with a simple unambiguous statement in 705.11 rather than by giving us a bunch of "if this then that" syntactically tortured language elsewhere in the code.
 
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