Random CEE question

[Jackflash]

Sorry, if:

- There's an unspliced GEC from the meter base to a ground rod, so that the CEE only needs a bonding jumper, not a GEC.
- And given the service size #4 Cu is sufficient for the CEE.
- And there's a #4 Cu from the CEE to the ground bar in the interior panel
- And there's a #4 Cu or bigger EGC in the feeder from the service disconnect to the interior panel

Then what's the code violation?

Cheers, Wayne

This is kind of my question, and thanks for simplifying it. That would make sense to me but, 250.50 states 'All grounding electrodes as described that are present shall be bonded together to form the GES.'
THANK YOU

 

[Tulsa Electrician]

Surprised no one mentioned the offset nipple. I can not see the locknut in the panle. I would bet it's not a grounding/ bonding type.
What code you on. 2020 by chance?
It matters on what you have there and what to do with it.
However the offset nipple needs addressed no matter the code year your on.
I would address the question ask about the disconnect next to meter and is it service equipment or maybe an emergency disconnect.
Then determine the location of the MBJ.

 

[jaggedben]

I'll try to be comprehensive...

The CEE is sufficient to serve as the premises grounding electrode system by itself*, but currently it does not qualify for that because it is connected to a subpanel. Because of where it's currently connected, it currently qualifies only as an auxilliary electrode (250.54). It is not a code violation to have it connected there, but it's not advisable, and ...

The ground rod is insufficient to serve as the grounding electrode system by itself (250.53(A)(2)), so the grounding electrode system is not up to code.

Relocating/extending the GEC for the CEE to terminate anywhere between the outside service disconnect and the service point turns it into a premises electrode and fixes the code violation of insufficient grounding. Doing so makes the ground rod superfluous, but since it is there it must remain bonded to the rest of the system. (250.50) As far as the NEC is concerned, the ground rod GEC termination can stay where it is, or be moved to the service disconnect, or be bonded to the CEE GEC. From what I've gathered on this forum, the utility may either insist that it be moved from the meter socket or require that it stay there, depending on who the utility is and what part of the country you're in. Yup, utilities are that arbitrary.

*If there is an underground metal water pipe on the premises, it's also required to be bonded to the service neutral or one of the other electrodes.

 

[wwhitney]

Because of where it's currently connected, it currently qualifies only as an auxilliary electrode (250.54).

Why? Why can't the feeder EGC do double duty as a bonding jumper from the service disconnect to the CEE?

Cheers, Wayne

 

[Jackflash]

Surprised no one mentioned the offset nipple. I can not see the locknut in the panle. I would bet it's not a grounding/ bonding type.
What code you on. 2020 by chance?
It matters on what you have there and what to do with it.

Very good eye. That specific town is 2011.

 

[GoldDigger]

In recent versions of the Code, any available CEE must be used as a Ground Electrode. But there is no defined hierarchy as to which electrode must have an irreversible connection to the bond point and which ones can be added in by one or another form of bonding jumper.
It makes sense to consider the CEE is primary, but the Code does not require that.
If you want the EGC from outside disconnect to inside inside panel to do double duty as a bonding jumper for the CEE you must meet the sizeing requirements for a bonding jumper in that position.
The cleanest way to do it would be to extend the CEE connecton in an irreversible way to either the outside disconnect or to the meter if the utiliity allows it.
If the main GES to neutral bonding point is at the meter, it could be problematic to come up with the bonding jumper path to that point from the inside panel.

 

[wwhitney]

If the main GES to neutral bonding point is at the meter, it could be problematic to come up with the bonding jumper path to that point from the inside panel.

Is there any requirement that two different GEs be bonded to the grounded conductor at the same location? Vs one bonded at the meter and one bonded at the service disconnect.

Cheers, Wayne

 

[Dennis Alwon]

I don't see it as a bonding jumper because it doesn't directly connect to another electrode. IMO, we have 2 electrodes and both must be continuous since they don't jump between the electrodes.

 

[wwhitney]

I don't see it as a bonding jumper because it doesn't directly connect to another electrode. IMO, we have 2 electrodes and both must be continuous since they don't jump between the electrodes.

Good point, which motivated me to check the details in Article 250. 250.50 says all the grounding electrodes need to be bonded together, and 250.53(C) puts some requirements on the "bonding jumper(s) used to connect the grounding electrodes."

One of those is 250.66 on GEC sizing, which implies the bonding jumper has to be of the wire type. So if the feeder EGC isn't of the wire type, it can't be a bonding jumper. Another requirement from 250.53(C) is that the bonding jumper has to comply with 250.64(E) on bonding a GEC to any metallic conduit enclosing it. But as the EGC is bonded to the enclosures at both ends of the feeder, that shouldn't be an issue, unless there is a sleeve of metallic conduit--then the EGC would need to be bonded to the end of the conduit where the presumably cable-type feeder emerges from it.

But other than the above, I don't see any reason the feeder EGC can't serve as the bonding jumper. That still leaves the fact that the ground rod GEC is routed to the meter and the feeder EGC/bonding jumper goes to the service disconnect. As far as I can see, the above argument also applies to the service neutral conductor acting as a bonding jumper to bond the two electrodes together.

Cheers, Wayne

 

[Jackflash]

The power company wants the ground rod bonded at their meter, we will reroute the CEE #4 to the main disconnect & then pull another#4 as a bonding jumper

 

[LarryFine]

Is there any requirement that two different GEs be bonded to the grounded conductor at the same location? Vs one bonded at the meter and one bonded at the service disconnect.

Nope.

 

[wwhitney]

Nope.

What about 250.50 "All grounding electrodes . . . that are present at each building or structure served shall be bonded together to form the grounding electrode system"? You see the grounded service conductor as being sufficient to provide the required bonding? I think that's right, not sure.

Cheers, Wayne

 

[don_resqcapt19]

Sorry, if:

- There's an unspliced GEC from the meter base to a ground rod, so that the CEE only needs a bonding jumper, not a GEC.
- And given the service size #4 Cu is sufficient for the CEE.
- And there's a #4 Cu from the CEE to the ground bar in the interior panel
- And there's a #4 Cu or bigger EGC in the feeder from the service disconnect to the interior panel

Then what's the code violation?

Cheers, Wayne

The violation is that the conductor from the concrete encased electrode is connected to the neutral at a location that is on the load side of the service disconnect. It can only be connected to the neutral within the enclosure that contains the service disconnect. See 250.24(A)(5).

Also the main bonding jumper is not connected in the service disconnect as required by 250.24(B).

 

[jaggedben]

Why? Why can't the feeder EGC do double duty as a bonding jumper from the service disconnect to the CEE?

Cheers, Wayne

You may be right that this is a loophole that the CMP hasn't completely closed, but I'll explain the limits to pushing this idea.

First of all, the EGC would have to meet the size requirements. In the case of the OPs EGC between a service and a main distribution subpanel that's probably fine, but as a general rule you can't say it works. Also, what would be the point of the Auxiliary Grounding Electrode rule if any electrode connected to an EGC were considered part of the GES? That rule implies that the EGC isn't considered a bonding jumper.

Second, in some cases you'd get into objectionable current situations. For example, suppose the OP also has a metal underground water service that provides a continuous metal path to the neighbors' GECs. If you bond the water pipe to the CEE, leaving them both connected to the subpanel EGC, you'll likely have some amount of objectionable neutral current from the neighbor's services on the subpanel EGC. In this respect check out 250.121 and its exception. It only mentions GECs, not bonding jumpers, but that's probably only because they didn't anticipate you raising this question.

 

[jaggedben]

Sorry, if:

- There's an unspliced GEC from the meter base to a ground rod, so that the CEE only needs a bonding jumper, not a GEC.
- And given the service size #4 Cu is sufficient for the CEE.
- And there's a #4 Cu from the CEE to the ground bar in the interior panel
- And there's a #4 Cu or bigger EGC in the feeder from the service disconnect to the interior panel

Then what's the code violation?

Cheers, Wayne

See previous post. No slam dunk code violation yet, but in practice may lead to violating 250.6(A) if people think it's allowed to bond GES electrodes via EGCs.

 

[wwhitney]

The violation is that the conductor from the concrete encased electrode is connected to the neutral at a location that is on the load side of the service disconnect.

In my narrative, it's not. The #4 Cu from the CEE is going to the ground bar of the subpanel, not the neutral bar, and the neutral bar is isolated, as usual in a subpanel. Likewise, although I didn't mention it, the MBJ is still in the service disconnect.

So neither of your concerns are code violations. Any others?

Cheers, Wayne

 

[wwhitney]

First of all, the EGC would have to meet the size requirements.

Yes, I take that as a given.

Also, what would be the point of the Auxiliary Grounding Electrode rule if any electrode connected to an EGC were considered part of the GES? That rule implies that the EGC isn't considered a bonding jumper.

Not sure of the point of the rule, but it provides relief from "250.50 or 250.53(C)" and so, for example, you could still do that without checking that the EGC size is sufficient, or if the EGC is not of the wire type. So the idea of EGC as bonding jumper doesn't render that section superfluous.

Second, in some cases you'd get into objectionable current situations. For example, suppose the OP also has a metal underground water service that provides a continuous metal path to the neighbors' GECs. If you bond the water pipe to the CEE, leaving them both connected to the subpanel EGC, you'll likely have some amount of objectionable neutral current from the neighbor's services on the subpanel EGC.

Given that 250.121 explicitly allows an EGC to function as a GEC within the specified limits, the above concerns are not unique to EGC as bonding jumper. Certainly "EGC as bonding jumper if it meets all the requirements for both" seems a natural corollary to 250.121, if not an explicit one.

Cheers, Wayne

 

[Jackflash]

Anything against taking the CEE to the panel on a term block with the bonding jumper from main disconnect?

 

[don_resqcapt19]

In my narrative, it's not. The #4 Cu from the CEE is going to the ground bar of the subpanel, not the neutral bar, and the neutral bar is isolated, as usual in a subpanel. Likewise, although I didn't mention it, the MBJ is still in the service disconnect.

So neither of your concerns are code violations. Any others?

Cheers, Wayne

Sorry, I replied to what I see in the picture, however your narrative is a violation of 250.65(F) as the bonding jumper from the CEE is not connected by one of the 3 methods listed in that subdivision.

 

[wwhitney]

however your narrative is a violation of 250.65(F) as the bonding jumper from the CEE is not connected by one of the 3 methods listed in that subdivision.

How's that? The only requirement in (2017) 250.65(F) for bonding jumpers is the reference to 250.53(C), which I already discussed compliance with.

Cheers, Wayne