EqGrCond in meatllic conduit

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augie47

augie47

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Tennessee
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State Electrical Inspector (Retired)
You inspect a job with a 800 amp feeder. The feeder is parallel 250 kcmil Cu in 3 seperate conduits (600 amp calculatd load). In one conduit, a 1/0 Eq Ground is installed {viol 250.122(F) }. The conduits are metallic.

Would you:
accept as is ?
require the one EGC to be removed ?
other ?
 
iwire said:
IMO they either have to remove it or add others.

310.4(C) comes into this as well.
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This is one of those cases when I wear my inspector hat, I must agree, but, when I put on my common sense hat,it seems silly to remove a 2nd adequate grounding means.
 
Feeders in parallel require a full size EGC in each raceway. This has been a common mistake by designers and installers.
I believe the reason is a fault can be feed from each end.
 
augie47 said:
This is one of those cases when I wear my inspector hat, I must agree, but, when I put on my common sense hat,it seems silly to remove a 2nd adequate grounding means.
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Yeah I can see that side of it, :D but I also have to believe that 250.122(F) went into the code for a real reason. :smile:
 
Thanks, Tom, and I understand the reasoning. Were it PVC, I could definitely see the logic, but when the EGC is simply an adequatelty sized parallel path to metallic conduit... ?
i just hate saying (as an option) "remove this 'adequate' grounding path"

If the building has a ground ring and they bonded the panel to that (in addition to the metallic conduits) would that not be acceptable ? Difficult to see the difference.
 
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augie47 said:
i just hate saying (as an option) "remove this 'adequate' grounding path"
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Is it really adequate in this installation?

It sure seems like it should be using plain old common sense but I really do not know that it is.

250.122(F) did not just accidentally become a code section, at some point someone had to justify a reason to add it into the NEC. :smile:
 
Another thing to consider that has nothing to do with safety but fairness.

If other contractors bid on the job based on doing a code compliant installation why should this contractor get to cheat?
 
iwire said:
Another thing to consider that has nothing to do with safety but fairness.

If other contractors bid on the job based on doing a code compliant installation why should this contractor get to cheat?
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since his "added" wire is an "extra" "above and beyond NEC requirements" , is he cheating ? :)
 
augie47 said:
since his "added" wire is an "extra" "above and beyond NEC requirements" , is he cheating ? :)
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He is if the job specs require a wire EGC in addition to the conduits.

He is not above and beyond, he is in violation. It is not gray, it just goes against your mindset that it is enough. The NEC says it is not enough. :smile:

Your looking at a direct violation of at least two code sections. 250.122(F) and 310.4(C) which specifically mentions the equipment grounding conductors.
 
your're confusing me with logic and rules :D

I'm not in disagreement with you..just frustarted I guess ...at something that makes no sense to me, but probably just due to my lack of understanding as to "why". I guess I was in hopes I would see an answer other than "beause the Code says so". I hate having that as my reason when it defies commonsense.
 
C3PO said:
I am curious as to why they ran an EGC in one of the conduits and not the other two???
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I think they believe in EGC in metallic for added safety, but don;t fully understand the Code.



(You work in this county, the 2nd half of that sentence should not suprise you..you are one of the six that own a Code book)
 
augie47 said:
your're confusing me with logic and rules :D

I'm not in disagreement with you..just frustrated I guess ...at something that makes no sense to me, but probably just due to my lack of understanding as to "why". I guess I was in hopes I would see an answer other than "beause the Code says so". I hate having that as my reason when it defies commonsense.
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Not sure what your frustrated at? just give them their options. What frustrates me if you allowed the installation yet I have to play by the rules. No offense ment by that comment.
 
whatever you do, at the very least you should give them a warning and make sure they understand that they are using the pipe as the 3 required egc's, and that the egc they provided is inadequate for their intent so that they do not make this mistake in the future
 
augie47 said:
I think they believe in EGC in metallic for added safety, but don;t fully understand the Code.



(You work in this county, the 2nd half of that sentence should not suprise you..you are one of the six that own a Code book)
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No surprises there except for the fact that they used copper. It doesn't really make sense to me either, and I also pefer to give people better answers then "the code says so" but for the sake of following the code and CYA my vote would be either:

Option 1: add a 1/0 EGC to the other two runs

OPrion 2: pull the 1/0 out of the conduit
 
augie47 said:
I think they believe in EGC in metallic for added safety, but don;t fully understand the Code.



(You work in this county, the 2nd half of that sentence should not suprise you..you are one of the six that own a Code book)
Click to expand...
The best way to look at it augie47 is that the installation is not code complient per section 250.122(F) and 310.4(E). As far as explaining to the contractor why, explain that you do not write the code you just enforce it. If they can substantiate why it's ok have them submit a code proposal. If you inspect an installation that you know is not complient and anything happens it won't be fun. You might hear words like malfeasance, nonfeasance exc. The NEC is not perfect but it's what we hang our hat on.
 
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