Line Side Tap Neutral count as GEC to main panel?

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don_resqcapt19

Moderator
Staff member
Location
Illinois
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retired electrician
There's no good reason not to change the definition of a service. I'll propose to simply change "to" and "from" to "between" and "and". There should be no practical consequences except to remove this silly notion that service conductors aren't service conductors if connected to a power source.
You have plenty of time to work up a public input for the 2020 code. They are due the first Friday in November of 2017.
 

Smart $

Esteemed Member
Location
Ohio
Sorry for being late to the discussion. I've been reading most of the posts as it progressed but too busy to post myself...
...So, which inspector is right?:? Is 1 wire Sufficient or do I need to run both the Neutral and a separate GEC? What are the benefits of each way?
Neither.

First, there are no paralleling rules for GECs. To be in parallel with neutral, it has to be a neutral, and thus, white insulation or equivalent as permitted. Other requirements kick in as well.

The remainder of the issue centers around what has already been made obvious: Service Disconnecting Means or not. I side with 'not'. Still do. It is quite simply a Service-PV System disconnect.

As such, there is no need to bond the GES via a GEC or GEC tap to the grounded conductor (neutral). The GES is already bonded to the service neutral at another point or points, and the GEC(s) are sized based on the ungrounded conductors size(s). The service is sized to deliver the calculated load without the additional energy provided by the PV System, so it stands to reason the GES is already sufficient. However, the disconnect must have neutral-to-enclosure bond (albeit a jumper, which is not to be confused as a Main or System Bonding Jumper) to ground the enclosure and establish an EGC for the PV side.
 

jaggedben

Senior Member
Location
Northern California
Occupation
Solar and Energy Storage Installer
As such, there is no need to bond the GES via a GEC or GEC tap to the grounded conductor (neutral). The GES is already bonded to the service neutral at another point or points, and the GEC(s) are sized based on the ungrounded conductors size(s). The service is sized to deliver the calculated load without the additional energy provided by the PV System, so it stands to reason the GES is already sufficient. However, the disconnect must have neutral-to-enclosure bond (albeit a jumper, which is not to be confused as a Main or System Bonding Jumper) to ground the enclosure and establish an EGC for the PV side.

And what about the solar GEC? If it's a 690.47(C)(3) combined EGC/GEC, where does it need to terminate? Can it run through the same enclosure and raceways as the service conductors?
 

ggunn

PE (Electrical), NABCEP certified
Location
Austin, TX, USA
Occupation
Electrical Engineer - Photovoltaic Systems
However, the disconnect must have neutral-to-enclosure bond (albeit a jumper, which is not to be confused as a Main or System Bonding Jumper) to ground the enclosure and establish an EGC for the PV side.
Neutral to enclosure?
 

Smart $

Esteemed Member
Location
Ohio
And what about the solar GEC? If it's a 690.47(C)(3) combined EGC/GEC, where does it need to terminate? Can it run through the same enclosure and raceways as the service conductors?
It don't have to go anywhere beyond the disconnect...
...to the grounding busbar in the associated ac equipment. ...


Neutral to enclosure?
Yep. You're not on the load side of a service disconnecting means, so you ground/bond to the service grounded conductor.
 

ggunn

PE (Electrical), NABCEP certified
Location
Austin, TX, USA
Occupation
Electrical Engineer - Photovoltaic Systems
Yep. You're not on the load side of a service disconnecting means, so you ground/bond to the service grounded conductor.

You said:
As such, there is no need to bond the GES via a GEC or GEC tap to the grounded conductor (neutral). The GES is already bonded to the service neutral at another point or points, and the GEC(s) are sized based on the ungrounded conductors size(s).

And then you said:
...the disconnect must have neutral-to-enclosure bond (albeit a jumper, which is not to be confused as a Main or System Bonding Jumper) to ground the enclosure and establish an EGC for the PV side.

This is confusing to me. It seems as though you are saying that you believe that the neutral should not be bonded to the EGC/GEC in the switch but the neutral instead of the grounding conductor should be tied to the enclosure of the switch. That makes no sense to me.

I know this is redundant on my part, but this discussion continues to make it apparent to me that the NEC should address this point directly rather than leaving it up to the interpretation of what is at best ambiguous and at worst contradictory articles in the Code.
 

Smart $

Esteemed Member
Location
Ohio
[What you said I said :p]

This is confusing to me. It seems as though you are saying that you believe that the neutral should not be bonded to the EGC/GEC in the switch but the neutral instead of the grounding conductor should be tied to the enclosure of the switch. That makes no sense to me.
The GES is [typically] already bonded to the service neutral elsewhere [but a GEC can be terminated at any point on the service neutral].

All that is required [when GES is terminated elsewhere] is the non-current carrying metal parts be bonded to the neutral at the Service-PV System disconnect... and this in turn establishes the termination point for the PV System combo EGC/GEC.
 

jaggedben

Senior Member
Location
Northern California
Occupation
Solar and Energy Storage Installer
It is not a Service Disconnecting Means under Code. Terminology is a key factor in this discussion.

The distinction between Service Equipment and Service Disconnecting Means is clearly lost on the AHJs who are telling participants in this forum not to bond the neutral. That's why I think it will be clearer if we just change definition of a service so that there is no difference.
 

Smart $

Esteemed Member
Location
Ohio
The distinction between Service Equipment and Service Disconnecting Means is clearly lost on the AHJs who are telling participants in this forum not to bond the neutral. That's why I think it will be clearer if we just change definition of a service so that there is no difference.
If we change "definitions" to the point the disconnect is undoubtedly a Service Disconnecting Means, it would not only make it more apparent the neutral must be bonded to the enclosure and PV side grounding conductor, you'd also kick in the requirement to run a GEC to the disconnect.

The rules are already in place which require the neutral bond. What is needed is to 'educate' these inspectors... but I do agree we have to start somewhere, and until the experienced and knowledgeable agree, it will be hard to 'educate' anyone. :slaphead:
 

ggunn

PE (Electrical), NABCEP certified
Location
Austin, TX, USA
Occupation
Electrical Engineer - Photovoltaic Systems
The GES is [typically] already bonded to the service neutral elsewhere [but a GEC can be terminated at any point on the service neutral].

All that is required [when GES is terminated elsewhere] is the non-current carrying metal parts be bonded to the neutral at the Service-PV System disconnect... and this in turn establishes the termination point for the PV System combo EGC/GEC.
I'm sorry if this has been covered already and I am not just trying to be argumentative, but can you direct me to language in the NEC which directs that the neutral shall be tied to the enclosure. I do not recall ever seeing this anywhere.
 

jaggedben

Senior Member
Location
Northern California
Occupation
Solar and Energy Storage Installer
I'm sorry if this has been covered already and I am not just trying to be argumentative, but can you direct me to language in the NEC which directs that the neutral shall be tied to the enclosure. I do not recall ever seeing this anywhere.

250.24(C) and 250.92(A)(1)

The problem with Smart$ argument is that neither of these sections unambiguously applies to a supply side PV disconnect if such a disco is not already considered a 'Service Disconnecting means' or 'at the service' (respectively).

Again, if we simply change the definition of the service so that applies to any conductors and equipment connecting a utility to a premise, regardless of the direction of energy flow, then most of the ambiguity goes away.

The only remaining problem sections would be those that refer to the 'supply-side of the service disconnecting means' in a way that could be taken to imply, grammatically, that any such thing on the 'supply side' is not the service disconnecting means. This interpretation is contradicted by some other sections, such as 230.82(5) and 230.71(A), which imply that certain (not all?) of such connections are service disconnecting means or service equipment. Perhaps regular use of the word 'normal', as in 'supply side of the normal service disconnecting means' is all that is necessary to nix this interpretation. Currently the word 'normal' appears in only one such spot that I'm aware of (230.40 Exception 5), but at least that means there's a precedent for it.

In all, these proposals would substantially fix the problem, in my opinion, without adding more than one word to any section of the code.:D I think shortcircuit's proposal in this thread is also in the same spirit.
 

Smart $

Esteemed Member
Location
Ohio
250.24(C) and 250.92(A)(1)

...
Ummm... For the disconnect enclosure, 250.92(A)(2), likely utilizing (B)(1), but not the only means [i.e. could be bonded using raceway(s) and/or jumper(s)].

Not 250.24(C). That's for Service Disconnecting Means. :angel:

Technically, if you don't require a neutral for the PV System, you do not have to bring one to its disconnect. But then you'd be required to bond through other means as noted in my first sentence.
 
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