Line Side Tap Neutral count as GEC to main panel?

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Digiacog

Member
Location
Boulder, CO USA
Hi Folks, Colorado solar guy here.

First time posting here, and my apologies if this is a dead horse type question: Does the Line Side Tap Neutral (Bonded in the Fused disconnect) count as GEC to main panel, or do I need to run a GEC to my fused disco even though my Neutral is accomplishing the same bond? Both my egc/GEC and Neutral are #6 AWG THWN-2

I've had an Estes Park inspector call me out on "paralleled conductors" and made me remove the additional EGC/GEC wire between fused disco and the Main Service Panel. (He also said I could leave the paralleled conductors if I upgraded them to 1/0 (hah!))

I've had a Boulder inspector ask me to add a #6 GEC from the fused disconnect's ground bar and crimp it to the GEC, a foot away from where it is landed next to the Neutral in the main panel!

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? or are they functionally the same, and I should just suck it up and do what each AHJ wants instead of trying to get them on the same page?
 

ggunn

PE (Electrical), NABCEP certified
Location
Austin, TX, USA
Occupation
Electrical Engineer - Photovoltaic Systems
Hi Folks, Colorado solar guy here.

First time posting here, and my apologies if this is a dead horse type question: Does the Line Side Tap Neutral (Bonded in the Fused disconnect) count as GEC to main panel, or do I need to run a GEC to my fused disco even though my Neutral is accomplishing the same bond? Both my egc/GEC and Neutral are #6 AWG THWN-2

I've had an Estes Park inspector call me out on "paralleled conductors" and made me remove the additional EGC/GEC wire between fused disco and the Main Service Panel. (He also said I could leave the paralleled conductors if I upgraded them to 1/0 (hah!))

I've had a Boulder inspector ask me to add a #6 GEC from the fused disconnect's ground bar and crimp it to the GEC, a foot away from where it is landed next to the Neutral in the main panel!

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? or are they functionally the same, and I should just suck it up and do what each AHJ wants instead of trying to get them on the same page?
My vote is with Inspector #2, but sometimes (usually? always?) it is easier to give the inspector what he wants than to go to the mat over a small point.
 

jaggedben

Senior Member
Location
Northern California
Occupation
Solar and Energy Storage Installer
Code wise you are supposed to have both. Functionally, assuming the neutral is installed correctly and properly bonded at both ends, it probably adds little benefit to have the GEC run between the same two points. But also note that the GEC may go directly to the electrode and, depending on the details of the installation, does not have to 'parallel' the neutral back to the main panel.
Just wait until another inspector tells you that your not allowed to bond the neutral at the fused disconnect because "it's not a service". :slaphead: That's a more dangerous misconception, although if you provide a proper EGC instead the safety issues should be overcome.
 

ggunn

PE (Electrical), NABCEP certified
Location
Austin, TX, USA
Occupation
Electrical Engineer - Photovoltaic Systems
Just wait until another inspector tells you that your not allowed to bond the neutral at the fused disconnect because "it's not a service". :slaphead: That's a more dangerous misconception, although if you provide a proper EGC instead the safety issues should be overcome.

We debated that issue to death in here a while back and I do not wish to reignite it, but I really wish the NEC would unequivocally and unambiguously declare it one way or the other.
 

Digiacog

Member
Location
Boulder, CO USA
Code wise you are supposed to have both. Functionally, assuming the neutral is installed correctly and properly bonded at both ends, it probably adds little benefit to have the GEC run between the same two points. But also note that the GEC may go directly to the electrode and, depending on the details of the installation, does not have to 'parallel' the neutral back to the main panel.
Just wait until another inspector tells you that your not allowed to bond the neutral at the fused disconnect because "it's not a service". :slaphead: That's a more dangerous misconception, although if you provide a proper EGC instead the safety issues should be overcome.

The Lakewood inspector IS of that opinion that it is not a 2nd service, since the inverter shuts off at the same time as the grid. He makes us unbond the neutral in the fused disco!!! Drives me nuts, but I gotta do it his way.;)
 

ggunn

PE (Electrical), NABCEP certified
Location
Austin, TX, USA
Occupation
Electrical Engineer - Photovoltaic Systems
The Lakewood inspector IS of that opinion that it is not a 2nd service, since the inverter shuts off at the same time as the grid. He makes us unbond the neutral in the fused disco!!! Drives me nuts, but I gotta do it his way.;)
A lot of folks agree with him and a lot of folks don't. I wish the Code would take a stand.
 

iwire

Moderator
Staff member
Location
Massachusetts
The Lakewood inspector IS of that opinion that it is not a 2nd service, since the inverter shuts off at the same time as the grid. He makes us unbond the neutral in the fused disco!!! Drives me nuts, but I gotta do it his way.;)

A lot of folks agree with him and a lot of folks don't. I wish the Code would take a stand.

IMO the NEC has a stand.

Service. The conductors and equipment for delivering electric energy from the serving utility to the wiring system of the premises served.

Only energy from the utility can be a service.

As far as the bonding question ........... good luck. :)
 

ggunn

PE (Electrical), NABCEP certified
Location
Austin, TX, USA
Occupation
Electrical Engineer - Photovoltaic Systems
IMO the NEC has a stand.



Only energy from the utility can be a service.

As far as the bonding question ........... good luck. :)
I still wish the NEC would say that in a disco feeding a line side tap from a utility interactive inverter the neutral shall be (or shall not be) bonded to the GEC. It's a common enough scenario and there is plenty of disagreement about it. The section you quoted could have been (probably was) written into the Code before there was a 690. Even though it makes very little if any difference electrically either way, there should be a correct way to do it.
 
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jaggedben

Senior Member
Location
Northern California
Occupation
Solar and Energy Storage Installer
IMO the NEC has a stand.
Only energy from the utility can be a service.

1st) A service is made of energy?

2nd) you have a problem with 230.2(A)(5).

3rd) It's clearly nonsensical to argue that the physical elements of a service temporarily cease to be a service as an interconnected power production source intermittently sends energy out to a utility.

The definition of a service should be changed to reflect reality. I'm going to propose that for the next cycle just so we can stop having these discussions.:cool:
 

iwire

Moderator
Staff member
Location
Massachusetts
1st) A service is made of energy?

2nd) you have a problem with 230.2(A)(5).

3rd) It's clearly nonsensical to argue that the physical elements of a service temporarily cease to be a service as an interconnected power production source intermittently sends energy out to a utility.

The definition of a service should be changed to reflect reality. I'm going to propose that for the next cycle just so we can stop having these discussions.:cool:

Do you understand that what I posted is directly from article 100 of the NEC?
 

Digiacog

Member
Location
Boulder, CO USA
Line Side Tap grounding / bonding requirements are still ... complex

Line Side Tap grounding / bonding requirements are still ... complex

... if you provide a proper EGC instead the safety issues should be overcome.

The inspectors usually make me take out an EGC between Fused Disconnect and Main Panel, if I've installed it. Seems they want the EGC from the inverter to stop at the fused disco, and only the Neutral to Bond the Fused disco Neutral bar to the Main Panel Neutral Bar. I guess they want that EGC on the equipment side of the Main Bonding Jumper (green screw). But I thought I'm supposed to be able to land my GEC/EGC from my inverter on the same busbar that's connected to the existing GEC.!?

I was under the impression that the Neutral was accomplishing the Grounding of the Fused Service Disconnect.

So let me make sure I have this right, with the appropriate code references:

1. There is supposed to be a GEC at the Fused disco. 250.24(D) Grounding Electrode Conductor for service-supplied AC systems and
250.64(D) "For a service or feeder with two or more disconnecting means in separate enclosure supplying a building or structure, the grounding electrode connection shall be be made in accordance with (1), (2), or (3):
(1): Common Grounding Electrode and Taps. (... Essentially a GEC tap enters each enclosure), Sized according to 250.66. *This is what I usually will do from now on

(2): Individual Grounding Electrode Conductors. A grounding electrode conductor shall be connected between the Grounding Electrode System and one or more of the following, as applicable:
1: Grounded conductor in each service equipment disconnecting means enclosure. 2: Equipment grounding conductor installed with the feeder. 3: Supply-side bonding jumper.

(3): Common Location. A grounding electrode conductor shall be connected in a wireway or other accessible enclosure on the supply side of the disconnecting means to one or more of the following as applicable:
1: Grounded service conductor(s) *Does this mean my Neutral, being already connected to the GEC in the Main Panel, makes a separate GEC at the Fused Disconnect not necessary? I'm trying to figure out what that Estes Park Inspector was thinking, making me remove the GEC wire since it paralleled the Neutral Is my Neutral a Supply Side Bonding Jumper? 2: Equipment grounding conductor installed with the feeder 3: Supply-side bonding jumper

In this Before / After, I thought I had it right Before, and I am baffled why the inspector didn't like it. Before (Left Picture) I had The Neutral Bonded in the Fused Disconnect (Just out of sight but to the right of the Main Panel), and I ran My GEC / EGC into my Main panel, not on the Neutral Bar. Inspector Man made me take out the Green from FD to MSP. (right picture) I felt this made my GEC connection less good, but figured I had that #6 White anyway, to essentially the same place.
panelbeforeandafter.jpg

2. I am bonding the neutral in the fused disco with a Main Bonding Jumper (the green screw) per 250.24(C)

3. Any metal pipe should have at least 1 bonding bushing or hub, etc, grounding that chase to the enclosure, or bonding bushings on both ends if you're running a GEC through it. (Do Ya'll view bond bushings are cheap insurance against inspectors that don't trust lock rings or do you try to use the minimum you can get away with?) I don't really understand if System Bonding Jumpers are required, or what exactly they entail. The Code is making me go cross-eyed. I should be Bonding for Services as in 250.92, right?

4. I am not bringing a EGC from my Fused disco to my Main Panel. The Neutral is the grounding conductor for the line side of a service... for some reason inspectors prefer a additional GEC (the #6 crimped outside the Main Panel onto the existing GEC.)

Thanks for reading my (poorly) collected thoughts. I guess I still don't fully understand Why the GEC connection to my Fused Disco can't take place in the Main panel, on the Bus Bar. Why would you want a GEC but not an EGC? Am i being confused simply by reading code for 12 hours?
 

jaggedben

Senior Member
Location
Northern California
Occupation
Solar and Energy Storage Installer
So let me make sure I have this right, with the appropriate code references:


I'll give you my opinion, but there are a few different code sections that can be used to argue either way. See iwire's postings.

1. There is supposed to be a GEC at the Fused disco. ...


If you believe that the disconnect is a service disconnecting means, then yes. If you don't, then no.

Also 690 requires a GEC so you've got one coming from the inverter. That's really a second GEC. It can go straight to the electrode if you want, but the question might be whether it is allowed to connect to the existing AC GEC in the main panel, and in my opinion there's nothing in the code that prohibits that. You just have to bond enclosures and raceways it passes through.


2. I am bonding the neutral in the fused disco with a Main Bonding Jumper (the green screw) per 250.24(C)


Again, if it is being treated as service disconnecting means, then yes. Otherwise you don't boned the neutral, and you send a EGC back to the existing service disconnecting means.


3. Any metal pipe should have at least 1 bonding bushing or hub, etc, grounding that chase to the enclosure, or bonding bushings on both ends if you're running a GEC through it. (Do Ya'll view bond bushings are cheap insurance against inspectors that don't trust lock rings or do you try to use the minimum you can get away with?) I don't really understand if System Bonding Jumpers are required, or what exactly they entail. The Code is making me go cross-eyed. I should be Bonding for Services as in 250.92, right?


In my opinion, yes, and if you have bonded the neutral at the disco then definitely yes.


4. I am not bringing a EGC from my Fused disco to my Main Panel. ...

Not to sound like a broken record, but ...
If you (or the inspector) is not treating the fused disco as a service disconnecting means, then yes, you bring an EGC back to the main panel. If the disco is being treated as the service disconnecting means, then you only need a (bonded) neutral.

Why the GEC connection to my Fused Disco can't take place in the Main panel, on the Bus Bar.


In my opinion it can. The NEC is really really vague about where GECs can be routed, in my opinion, but doesn't prohibit going through the main panel. In fact I've had one AHJ tell me that the solar GEC couldn't go anywhere else.


Why would you want a GEC but not an EGC?

The purpose of the GEC is to reference the system to the earth at a location. That's kind of independent of the need for a ground fault return path, which is provided either by the neutral (on the line side) or the EGC (on the load side), depending on which side of the service disconnecting means you are on.

Put another way, you need either a bonded neutral or an EGC, but not both. You may or may not also need a GEC, which you may or may not want to put through the same raceway, but that is all fairly independent of the previous statement.

Am i being confused simply by reading code for 12 hours?

Yes but you're not alone.
 
Someone get me up to speed. What exactly is the debated question? If the PV "line side tap disconnect" is a service, a service disconnect, or neither? I think it is very clear that it is an additional service disconnect enclosure (230.40 ex #5 calls them service entrance conductors then definitions). What is the counter argument (or is that not what is debated)?
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
1st) A service is made of energy?

2nd) you have a problem with 230.2(A)(5).

3rd) It's clearly nonsensical to argue that the physical elements of a service temporarily cease to be a service as an interconnected power production source intermittently sends energy out to a utility.

The definition of a service should be changed to reflect reality. I'm going to propose that for the next cycle just so we can stop having these discussions.:cool:
There is no good reason to change the definition of a service. All we need to do is to make clear that the line side disconnect for an power source such as wind or solar is a service disconnect.
 

ggunn

PE (Electrical), NABCEP certified
Location
Austin, TX, USA
Occupation
Electrical Engineer - Photovoltaic Systems
I just want to say that the last few posts have reinforced my point quite well. The NEC should (IMNSHO) unambiguously direct which way this should be done. Having to make this decision based on second and third order interpretations of the Code (a lot of which was written long before PV was a consideration and left unchanged) is bound to result in disagreements.

One more thing I will say: Either a system is safe or it isn't. The way it is built should not hinge upon what you call it.
 
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iwire

Moderator
Staff member
Location
Massachusetts
1st) A service is made of energy?

2nd) you have a problem with 230.2(A)(5).

3rd) It's clearly nonsensical to argue that the physical elements of a service temporarily cease to be a service as an interconnected power production source intermittently sends energy out to a utility.

The definition of a service should be changed to reflect reality. I'm going to propose that for the next cycle just so we can stop having these discussions.:cool:

Do you understand that what I posted is directly from article 100 of the NEC?

My apologies jaggedben, I was reading your post on mobile while out with my wife and stopped reading it too soon. You obviously know it was the NEC definition

That said ... I see no reason to change a definition that has worked fine just because article 690 has problems.

PV is the new kid on the block and its rules / requirements are changing every code cycle. I don't see this stopping anytime soon.
 

Digiacog

Member
Location
Boulder, CO USA


...connect to the existing AC GEC in the main panel, and in my opinion there's nothing in the code that prohibits that. You just have to bond enclosures and raceways it passes through.



Thanks for taking the time to reply, I think the Estes Park inspector was just mistaken, thinking my green was an EGC and not a GEC. I think the Boulder Inspector would have passed my first picture.

I think the "not a service" thing is a non-issue, its obviously a service disconnect, those taps are from service conductors! That's why we buy a 60A suitable for service equipment disconnect. Disconnect means not considered a service disconnecting means are listed in

230.71 Maximum Number of Disconnects
(A) General. The service disconnecting means for each service permitted by 230.2 or for each set of service entrance conductors permitted by 230.40 Ex 1, 3, 4, or 5, shall not consist of more than six switches (not 230.82(6)! ... For the purpose of this section, disconnecting means installed as part of listed equipment and used solely for the following shall not be considered a service disconnecting means: Power monitoring equipment, Surge-protective devices, Control Circuit of GFP systems, and Power-operable disconnects.

So, my Solar Line Side Tap disconnect doesn't count toward the max 6 normal service disconnects, but it is a service disconnect, and I believe I could have up to 6 Solar Service disconnects in addition to the 6 regular service disconnects allowed.

Sorry if I'm fanning the flames of a long-dead debate, but this is really good practice for me, to try to back up my thoughts with code references.
 

jaggedben

Senior Member
Location
Northern California
Occupation
Solar and Energy Storage Installer
There is no good reason to change the definition of a service. All we need to do is to make clear that the line side disconnect for an power source such as wind or solar is a service disconnect.

My apologies jaggedben, I was reading your post on mobile while out with my wife and stopped reading it too soon. You obviously know it was the NEC definition

That said ... I see no reason to change a definition that has worked fine just because article 690 has problems.

PV is the new kid on the block and its rules / requirements are changing every code cycle. I don't see this stopping anytime soon.


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.

I'd like to know what solutions you guys would propose to keep AHJs from telling us that 'a PV disconnect is not a service disconnect' that would be less confusing. (You can't come up with any that would be more concise! :cool:)

The rest of the code is written pretty much in a way that implies and assumes that everybody understands what when a disconnect is a service disconnect. In fact the CMP has rejected proposals to make it clearer as being 'not necessary.' And yet our OP has shown once again that it is necessary, and he's not the first to do so.

And BTW, there are no issues with 690. The fixes would be in 230 and/or 705. Or just article 100.

One final point: As energy storage (both grid and customer) starts becoming a big thing, we are only going to get more and more services that aren't primarily for delivering energy to the premises. We might as well change the definition now.
 
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