Grounding electrode conductor

[mathew stouffer]

The Grounding electrode conductor is contacting the aluminum grounded conductor. Other than the dissimilar metals, is this an issue. The GEC runs through the utility room wall, exposed.

[Brandon Whitmore]

It looks like the neutrals and grounds are secured under the same terminal bar which makes that panel the service equipment, non- sub panel, main panel thingy:D

If that's the case, everything is inter- connected anyways, so I don't see it as a problem.

[mathew stouffer]

Thanks

[mathew stouffer]

There is a meter on the exterior wall.

[Jerry Peck]

Is the GEC exposed to potential damage where a protective raceway is required?{250.64(B)]

Same thing I was wondering, does the grounding electrode conductor "follow the surface"?

From the 2008 NEC. (underlining and bold are mine)
- 250.64 Grounding Electrode Conductor Installation.
- - Grounding electrode conductors at the service, at each building or structure where supplied by a feeder(s) or branch circuit(s), or at a separately derived system shall be installed as specified in 250.64(A) through (F).
- - - (B) Securing and Protection Against Physical Damage. Where exposed, a grounding electrode conductor or its enclosure shall be securely fastened to the surface on which it is carried. A 4 AWG or larger copper or aluminum grounding electrode conductor shall be protected where exposed to physical damage. A 6 AWG grounding electrode conductor that is free from exposure to physical damage shall be permitted to be run along the surface of the building construction without metal covering or protection where it is securely fastened to the construction; otherwise, it shall be in rigid metal conduit, intermediate metal conduit, rigid nonmetallic conduit, electrical metallic tubing, or cable armor. Grounding electrode conductors smaller than 6 AWG shall be in rigid metal conduit, intermediate metal conduit, rigid nonmetallic conduit, electrical metallic tubing, or cable armor.


Interesting that 4-wire SER is being used.

I found that interesting as well, and why was it done? Not that it is a 'bad thing' as it is not, and, in fact, it is a 'good thing', provides redundancy for the ground (although, that could pose a problem if the neutral connection became poor or lost, then all neutral current would also be going through the ground conductor too).

[Jerry Peck]

There is a meter on the exterior wall.

In most cases, that would not be a problem, see the code section posted above.

[mathew stouffer]

No it is run through the studs. You can see it in this photo.

[Jerry Peck]

No it is run through the studs. You can see it in this photo.

Mat,

I would recommend they either close that wall in for those stud spaces where that grounding electrode conductor is run (making them into enclosed stud cavities) or nail a protective runner board along the wall protecting it. Those two choices would be much easier than trying to put conduit around it at this point.

[Michael Schirmer]

No problem. I would have more of a problem with the circuit grounds and neutrals sharing taps.

[ken horak]

is that conductor a #6 or a #4 ? Need to know that before passing judgement. Just because it goes to a ground rod does not mean it a # 6.
I know of contractors that only carry #4 and use it for water and rods.

[Fred Warner]

The Grounding electrode conductor is contacting the aluminum grounded conductor. Other than the dissimilar metals, is this an issue. The GEC runs through the utility room wall, exposed.

Dissimilar metals in contact can oxidize which in turn could create a problem. I would have an electrician form the conductors away from each other so as to remedy that issue.


Another issue might be the 4-conductor SER feeding the panel. If this panel includes the service overcurrent protective device, then it should have been fed with 3-wire SEC, not 4-wire SER. The 4th wire which was intended at time of manufacture to serve as an equipment grounding conductor, is now in parallel with the grounded conductor, which is a violation of code.If, in fact, the panel does not contain the service disconnect, then the equipment grounding conductors must be placed on an equipment grounding bar, the bonding screw removed from the neutral bus, and the grounding electrode conductor relocated to originate in the service equipment.
My guess is that the "electrician" used 4-wire cable in place of 3-wire for the service conductors, and figured "what the heck, might as well tie this 4th wire in, too". Common mistake. But a mistake/violation, none-the-less. :)

[Jerry Peck]

Another issue might be the 4-conductor SER feeding the panel. If this panel includes the service overcurrent protective device, then it should have been fed with 3-wire SEC, not 4-wire SER. The 4th wire which was intended at time of manufacture to serve as an equipment grounding conductor, is now in parallel with the grounded conductor, which is a violation of code.

My guess is that the "electrician" used 4-wire cable in place of 3-wire for the service conductors, and figured "what the heck, might as well tie this 4th wire in, too". Common mistake. But a mistake/violation, none-the-less. :)

Fred,

I am apparently missing something here. I know that the service entrances conductors are typically run as 3 conductors, 2-ungrounded conductors and 1-grounded conductor, but I don't recall a prohibition against running a ground wire with it - do you have the code on that? I know that "could" cause a problem (as I stated in my post a few days ago above) if the neutral were to have a bad or open connection - put is it prohibited?


If, in fact, the panel does not contain the service disconnect, then the equipment grounding conductors must be placed on an equipment grounding bar, the bonding screw removed from the neutral bus, and the grounding electrode conductor relocated to originate in the service equipment.

You are referring to if the panel main is just that, a panel main, and not the main service disconnect, making this a non-service equipment panel, in which case ALL the grounds would need to be relocated from the neutral terminal bar to a ground bar, provided that the panel is not labeled "Suitable for only for use as service equipment." (which would mean there is no way to isolate the neutral from the enclosure).

The other question which arises is the service cable is runs in what looks to be a conduit and not clamped to the enclosure.

[Fred Warner]

Fred,

I am apparently missing something here. I know that the service entrance conductors are typically run as 3 conductors, 2-ungrounded conductors and 1-grounded conductor, but I don't recall a prohibition against running a ground wire with it - do you have the code on that? I know that "could" cause a problem (as I stated in my post a few days ago above) if the neutral were to have a bad or open connection - but is it prohibited?

Hi Jerry: Since all of the conductors in the SER must be considered conductors contained in the same cable and of the same circuit as per 300.4, then the EGC is not being used as a Grounded Conductor, therefore it isn't governed by parallel conductor rules,(not a parallel neutral) but rather by EGC rules found at 250.130. This section states (250.130(A)) that this connection shall be made by bonding the EGC to the Grounded Service Conductor AND the Grounding Electrode Conductor. It would seem unusual to have this identical condition in both the metering enclosure and the service disconnecting means if they are in separate enclosures. (Not saying it hasn't been done countless times over the years):) but certainly redundant. So, I guess each condition where this appears would best be evaluated on its own individual merits.

[Jerry Peck]

Since all of the conductors in the SER must be considered conductors contained in the same cable and of the same circuit as per 300.4,[/quite]

300.4 addresses "300.4 Protection Against Physical Damage."

Not sure what you are referring to about 300.4 in relation to what you said?

[quote]then the EGC is not being used as a Grounded Conductor, therefore it isn't governed by parallel conductor rules,(not a parallel neutral) but rather by EGC rules found at 250.130.

This section states (250.130(A)) that this connection shall be made by bonding the EGC to the Grounded Service Conductor AND the Grounding Electrode Conductor.

- 250.130 Equipment Grounding Conductor Connections.
- - Equipment grounding conductor connections at the source of separately derived systems shall be made in accordance with 250.30(A)(1). Equipment grounding conductor connections at service equipment shall be made as indicated in 250.130(A) or (B). For replacement of non–grounding-type receptacles with grounding-type receptacles and for branch-circuit extensions only in existing installations that do not have an equipment grounding conductor in the branch circuit, connections shall be permitted as indicated in 250.130(C).
- - - (A) For Grounded Systems. The connection shall be made by bonding the equipment grounding conductor to the grounded service conductor and the grounding electrode conductor.
- - - (B) For Ungrounded Systems. The connection shall be made by bonding the equipment grounding conductor to the grounding electrode conductor.
- - - (C) Nongrounding Receptacle Replacement or Branch Circuit Extensions. The equipment grounding conductor of a grounding-type receptacle or a branch-circuit extension shall be permitted to be connected to any of the following:
- - - - (1) Any accessible point on the grounding electrode system as described in 250.50
- - - - (2) Any accessible point on the grounding electrode conductor
- - - - (3) The equipment grounding terminal bar within the enclosure where the branch circuit for the receptacle or branch circuit originates
- - - - (4) For grounded systems, the grounded service conductor within the service equipment enclosure
- - - - (5) For ungrounded systems, the grounding terminal bar within the service equipment enclosure
- - - - - FPN: See 406.3(D) for the use of a ground-fault circuit-interrupting type of receptacle.

That what is shown in that photo:
- - - (A) For Grounded Systems. The connection shall be made by bonding the equipment grounding conductor to the grounded service conductor and the grounding electrode conductor.


It would seem unusual to have this identical condition in both the metering enclosure and the service disconnecting means if they are in separate enclosures. (Not saying it hasn't been done countless times over the years):) but certainly redundant. So, I guess each condition where this appears would best be evaluated on its own individual merits.

Unusual, yes. Redundant, yes. One *could* even say 'required' by the above wording in (4) ;) , albeit *not required* as the same connection is also made via the grounded conductor, which simply makes it redundant, unusual, wasteful even, but ... against code?

So, does that mean you are agreeing that it is not prohibited?

As I said, and you agreed, it would be redundant, but ... it is also therefore allowed, not against code, right?

http://www.cable.alcan.com/NR/rdonlyres/0D7E3254-803E-4F52-912F-669A2DD4A66C/0/serw.pdf

http://www.cable.alcan.com/alcancable/en-US/Products/United+States/Stabiloy+Building+Wire+Products/STABILOY+Service+Entrance+Cable+Type+SE+Style+R.ht m

(bold and underlining are mine)
"Alcan Type SE Style R three conductor insulated, round-type Service Entrance Cable is designed for above-ground service entrance use, as well as interior wiring."

http://www.acewireco.com/pdfs/2670.pdf

"APPLICATION: Primarily used for interior “service - runs” from the main service to distribution panels and individual load centers; maximum conductor temperature of 75°C; maximum potential of 600 volts. Also used as branch circuit or feeders for wiring of ranges, wall - mounted ovens, counter - mounted cooking units, and clothes drying circuits where the a - c supply is not over 150 volts to ground. May be used in overhead service for attachment to the side of a building from the weatherhead to the meter equipment."

[Fred Warner]

Jerry: I intended to cite 300.3(1) which in turn cites 310.4. Sorry. My bad.
As far as the redundancy, I don't think this 4th conductor acting as an equipment grounding conductor and bolted to the grounded conductor on each end termination could be called a parallel neutral, because it doesn't qualify under the definition of parallel conductor.
Do I believe it's code compliant.....not yet (keep working on me:D )........but something is telling me "no".

IMHO, and only MHO, It's a slippery slope when neutral return current may divide along 2 paths. In this particular scenario there would be a minimal amount of resistance which would in turn allow the opening of the OCPD.

It's just that there are two conductors originating in the metering enclosure and terminating in the service equipment in an identical method. This type of redundancy raises a red flag with me. :)

[Jerry Peck]

Jerry: I intended to cite 300.3(1)


Fred,

You mean 300.3(B)(1), right? :)

By the way, 300.3(B)(1) references 310.4, not 300.4. ;)

Those dang numbers git all confusing all da time. :D


As far as the redundancy, I don't think this 4th conductor acting as an equipment grounding conductor and bolted to the grounded conductor on each end termination could be called a parallel neutral, because it doesn't qualify under the definition of parallel conductor.

We are in agreement there.


Do I believe it's code compliant.....not yet (keep working on me:D )........but something is telling me "no".

It is code compliant, in fact the cable is marked SER (actually SE Type R) for a reason ... Service Entrance Type R ... i.e., "service entrance" cable, which is ... allowed to be used as "service entrance" cable. :D


IMHO, and only MHO, It's a slippery slope when neutral return current may divide along 2 paths. In this particular scenario there would be a minimal amount of resistance which would in turn allow the opening of the OCPD.

It's just that there are two conductors originating in the metering enclosure and terminating in the service equipment in an identical method. This type of redundancy raises a red flag with me.

We are in agreement there too.

It really raises some dire warnings, however ... the SER cable has the groundING conductor sized the same as the groundED conductor (at least the ones I've seen do), so ... if the neural groundED conductor was lost, the groundING conductor would serve the same purpose, and, being as they are connected to the same thing a both ends, there should not be a problem, especially as the neutral groundED service entrance conductor is not even required to be insulated.

In that sense, they "act like" and "serve the purpose of" "parallel conductors" as addressed in 310.4 (depending on their size).

[Mike Schulz]

Are you sure that is not the Bond wire to the gas meter ?
They run those like that all the time here. Most of the time on the exterior wall or under the crawl space.
I'm ready for my beating...........:D

[Fred Warner]

I think that the metering enclosure located outside also has a service disconnecting means in it and the 4-wire cable is just improperly terminated. This would make the most sense to me. :)

[Fred Warner]

I think you are on the right track Fred, I have asked that same question twice in this thread. I wonder if anyone has noticed. rbj

If that's the case, it's an easy fix. Simply have to install an equipment grounding bar and relocate the EGC's including the 4th conductor of the SER cable to it; then remove the bonding bolt from the neutral bar which will effectively "float" the neutral bus away from the enclosure and stop all that return current from traveling on the EQC's. But, it's still going to have to have the grounding electrode conductor removed from the neutral bar and brought out to the service equipment (located in the meter/disconnect enclosure) and terminated there. :)

[Jerry Peck]

I think that the metering enclosure located outside also has a service disconnecting means in it and the 4-wire cable is just improperly terminated. This would make the most sense to me. :)


I think you are on the right track Fred, I have asked that same question twice in this thread. I wonder if anyone has noticed. rbj


We (at least some of us) have noticed but think otherwise.

There is a main in that panel, and ALL the equipment grounding wires are on that same terminal bar, which suggests to me that the only thing different is that they ran SER instead of SE, and that there is no disconnect outside (otherwise, why have one inside?).

If the scenario Fred and Ben are proposing is correct, then the correction is a lot more than simply relocating the 4th (equipment ground) wire to another terminal bar ... ALL the equipment grounding conductor would need to be relocated as well .. AND the neutral terminal bar would need to be verified that it is indeed not connected to the enclosure.

Mat is the only one who can clear those questions up for us.

[Fred Warner]

Jerry: I intended to cite 300.3(1) which in turn cites 310.4. Sorry. My bad.
As far as the redundancy, I don't think this 4th conductor acting as an equipment grounding conductor and bolted to the grounded conductor on each end termination could be called a parallel neutral, because it doesn't qualify under the definition of parallel conductor.
Do I believe it's code compliant.....not yet (keep working on me:D )........but something is telling me "no".

IMHO, and only MHO, It's a slippery slope when neutral return current may divide along 2 paths. In this particular scenario there would be a minimal amount of resistance which would in turn allow the opening of the OCPD.

It's just that there are two conductors originating in the metering enclosure and terminating in the service equipment in an identical method. This type of redundancy raises a red flag with me. :)

Jerry, I am now convinced beyond a reasonable doubt that parallel paths on the line side of the service disconnect are permitted by NEC rules. The grounded conductor is used for all bonding and grounding purposes on the line side of the service disconnect. Thanks for your help. :)

[Fred Warner]

..................
If the scenario Fred and Ben are proposing is correct, then the correction is a lot more than simply relocating the 4th (equipment ground) wire to another terminal bar ... ALL the equipment grounding conductor would need to be relocated as well .. AND the neutral terminal bar would need to be verified that it is indeed not connected to the enclosure.

Mat is the only one who can clear those questions up for us.

See my post above where I already mentioned relocating all the EGC's.
The neutral bar shown in the photo at the beginning of this thread has a removable bonding bolt.

[Jerry Peck]

See my post above where I already mentioned relocating all the EGC's.

That you did, apologies for missing it.


The neutral bar shown in the photo at the beginning of this thread has a removable bonding bolt.

I still don't see that, not even on zooming in???

But I did see a stranded neutral with what looks to be cut off and missing strands.