Smaller EGC on 30A circuit

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The reason the NEC wants the correct size EGC if one is provided with a conduit is if a fault ever happen some where inside of the raceway between a ungrounded and the EGC it will still open the OCPD, as Don has said, even the #14 will most likely fault enough current to open the OCPD but conductors smaller then a #10 can build up heat much faster and if the run is long can cause the failure of the insulation before the OCPD opens, so it's not that the pipe can be used as a legal EGC, but that since you have installed a wire EGC it must meet the same requirements as if it was the only EGC because it can fault inside of the conduit to a ungrounded conductor.

Kind of the same idea behind why we must run EGC's sized for the full circuit size in each conduit of a parallel run.
 
SceneryDriver said:
Just go replace it with a #10. How much wire are we talking about? Do it right, even when no one's looking.


SceneryDriver
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Ideally right. Theres about 75' of conductors. The 1/2 emt run has numerous bends, I don't think it will be feasible to just pull in a lone 10with 3 other wires already in there. Which means it all would have to go. And I would need a helper to do it. Are you free this afternoon Scenery Driver?


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I worked midnights last night and was able to take a look at the installation again. The #14 was actually a #12. I pigtailed it to the box and to the outlet with #10. I hope that is the path to least resistance in both fault current and with my employer for spending the extra time on this when I was told to leave it be.


Thanks for your thorough explanations though, very informative. I hope this was an acceptable fix.
 
mwr said:
Ideally right. Theres about 75' of conductors. The 1/2 emt run has numerous bends, I don't think it will be feasible to just pull in a lone 10with 3 other wires already in there. Which means it all would have to go. And I would need a helper to do it. Are you free this afternoon Scenery Driver?


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I worked midnights last night and was able to take a look at the installation again. The #14 was actually a #12. I pigtailed it to the box and to the outlet with #10. I hope that is the path to least resistance in both fault current and with my employer for spending the extra time on this when I was told to leave it be.


Thanks for your thorough explanations though, very informative. I hope this was an acceptable fix.
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What you should hope for is :
(1) Nothing ever goes wrong withe the job. Even though it is somewhat agreed there is not hazard, the fact that you installed a non-Code compliant job bodes badly if any investigation or legal action should arise for ANY reason. (say someone gets injured the the install comes under scrutiny)
(2) No inspection authority spots the violation, especially the "fix". It would most likely put all your future work under the inspectors microscope. I'm confident that a vast number of the electricians I work with make every attempt to install a Code compliant job and I provide a second set of eyes and a bit of "insurance". When you don't strive for compliance yourself you do yourself a disservice.


I might add that post #19 is very relevant IMO.
 
augie47 said:
What you should hope for is :
(1) Nothing ever goes wrong withe the job. Even though it is somewhat agreed there is not hazard, the fact that you installed a non-Code compliant job bodes badly if any investigation or legal action should arise for ANY reason. (say someone gets injured the the install comes under scrutiny)
(2) No inspection authority spots the violation, especially the "fix". It would most likely put all your future work under the inspectors microscope. I'm confident that a vast number of the electricians I work with make every attempt to install a Code compliant job and I provide a second set of eyes and a bit of "insurance". When you don't strive for compliance yourself you do yourself a disservice.


I might add that post #19 is very relevant IMO.
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I guess since Auggie is questioning my integrity I should point out. The EGC is achieved from the mechanical ground of the emt. The extra #12 is an additional bond. From the responses I got here I gathered that was not an issue.

I would have no problem explaining the error to my AHJ and showing him the installation.

Of course Auggie would fail it.... how about any other inspectors here?

BTW Auggie, you don't know my work ethics nor the respect I have for electricity so you have no right to question them in your alluding post.
 
mwr said:
I guess since Auggie is questioning my integrity I should point out. The EGC is achieved from the mechanical ground of the emt. The extra #12 is an additional bond. From the responses I got here I gathered that was not an issue.

I would have no problem explaining the error to my AHJ and showing him the installation.

Of course Auggie would fail it.... how about any other inspectors here?

BTW Auggie, you don't know my work ethics nor the respect I have for electricity so you have no right to question them in your alluding post.
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I would have failed it as a violation of table 250.122.
 
qcroanoke said:
I would have failed it as a violation of table 250.122.
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OK, but its apparent the egc is the conduit which is acceptable. 250.122 no longer applies. The additional #12 goes beyond the minimum. (would that excuse fly with an inspector?)

Surely you will respond with something to back your red ticket, but say I disconnected the #12 totally. Does that fail too?
 
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mwr said:
I guess since Auggie is questioning my integrity I should point out. The EGC is achieved from the mechanical ground of the emt. The extra #12 is an additional bond. From the responses I got here I gathered that was not an issue.

I would have no problem explaining the error to my AHJ and showing him the installation.

Of course Auggie would fail it.... how about any other inspectors here?

BTW Auggie, you don't know my work ethics nor the respect I have for electricity so you have no right to question them in your alluding post.
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He is not judging you, at least not for the purpose of putting down on a public forum, he is telling you if he saw this from your work that he is making a judgement based on what he sees in an installation. If he should see something that shows what he feels may be some incompetence that is going to raise his suspicions at least a little and he is likely to look a little harder at things. You probably do the same thing when you come onto a site where you didn't do the installation, find something you don't feel is right and then you wonder "what else did they do". That is just human nature to do that.

mwr said:
OK, but its apparent the egc is the conduit which is acceptable. 250.122 no longer applies. The additional #12 goes beyond the minimum. (would that excuse fly with an inspector?)

Surely you will respond with something to back your red ticket, but say I disconnected the #12 totally. Does that fail too?
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I am quite confident he will respond with something to back the red ticket. Spare conductors are allowed in raceways, but a green conductor can only be used for one purpose so how can we have a spare green conductor may be one approach. I believe all EGC need to be bonded together as well as to the enclosure if it is metallic in most any enclosure that contains splices or connections to devices only exception would be an "isolated grounding conductor".

I'm not saying that conductor doesn't likely improve the resistance of the raceway portion of the EGC some, but NEC doesn't recognize it as any kind of supplement if it is not sized to 250.122.
 
kwired said:
I'm not saying that conductor doesn't likely improve the resistance of the raceway portion of the EGC some, but NEC doesn't recognize it as any kind of supplement if it is not sized to 250.122.
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Please excuse my ignorance. You'll probably think I have gathered my grounding knowledge from piece meal reading. I remember reading something about "Choke effect" when it comes to bonding gec's..... can you think of any circumstance where a "choke effect" would occur in an installation where both a conductor raceway both serve as the egc?
 
mwr said:
Please excuse my ignorance. You'll probably think I have gathered my grounding knowledge from piece meal reading. I remember reading something about "Choke effect" when it comes to bonding gec's..... can you think of any circumstance where a "choke effect" would occur in an installation where both a conductor raceway both serve as the egc?
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A choke effect only happens where there is single AC conductor in a ferrous raceway.

The EGC is required to be installed with the ungrounded and grounded conductors of the circuit. There is no ferrous metal between the conductors of the circuit so there would be no choke effect.

About the only time we ever run a single AC conductor in a ferrous raceway is for the grounding electrode conductor.
 
mwr said:
OK, but its apparent the egc is the conduit which is acceptable. 250.122 no longer applies. The additional #12 goes beyond the minimum. (would that excuse fly with an inspector?)

Surely you will respond with something to back your red ticket, but say I disconnected the #12 totally. Does that fail too?
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I backed up the red ticket with 250.122.
Minimum size equipment grounding conductors for grounding raceways and equipment.
30 amp overcurrent device requires a #10 copper equipment ground (minimum)
You yourself said The #14 was actually a #12. [I pigtailed it to the box and to the outlet with #10. in post#22.]
that is wrong.
If you took it loose on both ends it is as Kwired pointed out:. Spare conductors are allowed in raceways, but a green conductor can only be used for one purpose. Your inspector may or may not let it go.
 
qcroanoke said:
I backed up the red ticket with 250.122.
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The conduit is the primary EGC and meets the minimum requirment. The #12 left in place is supplemental. I am guessing that 250.122 no longer applies.


p.s.- What code cycle did 250.122 come into effect? Was a #12 ever allowed as a EGC on a 30A circuit?
 
don_resqcapt19 said:
A choke effect only happens where there is single AC conductor in a ferrous raceway.

The EGC is required to be installed with the ungrounded and grounded conductors of the circuit. There is no ferrous metal between the conductors of the circuit so there would be no choke effect.

About the only time we ever run a single AC conductor in a ferrous raceway is for the grounding electrode conductor.
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Strictly speaking, the choke effect could also happen if the source of the current in the EGC was some other circuit not in that raceway. Or, of course, lightning surge. :)




Tapatalk!
 
mwr said:
The conduit is the primary EGC and meets the minimum requirment. The #12 left in place is supplemental. I am guessing that 250.122 no longer applies.


p.s.- What code cycle did 250.122 come into effect? Was a #12 ever allowed as a EGC on a 30A circuit?
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What code section says that an installed EGC of the wire type does not have to meet the rules found in 250.122?
 
I feel you are arguing for the sake of arguing.
Many knowledgeable folks here have informed you that, being it an actual safety issue or not, the Code requires a wire type equipment grounding conductor be sized per 250.122. There is no provision for a smaller conductor, supplemental or not.
If you elect to install something that does not meet Code you can expect to be called on it.
In my earlier post I was expressing my opinion that if you elect to upsize the conductor at termination it might well be construed as an attempt to deceive the inspector which can result in very interesting circumstances.
You know what the Code states. You can agree, disagree, comply or not. If you choose not to comply, as noted you put your reputation in peril as well as open yourself and your employer up to liability.
 
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Im not arguing for the sake of it Auggie. But since you questioned my integrity for the second time, let me ask you.... (question is for anyone else for that matter, I would love to see the response)

If you were on a service call and found this installation would you inform the homeowner you must pull new wire to bring it to compliance, would you pigtail it as I described or would you do absolutely nothing and not think twice about it?

I think I already know the answer.....
 
Disregard my last post. Re-reading makes me realize it comes off very confrontational and that is not my intent here Auggie. I would be interested to hear what another service guy would do if he encountered this installation but I don't want to inquire at the expense of you thinking I am alienating you.

Have a nice evening.
 
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mwr said:
Disregard my last post. Re-reading makes me realize it comes off very confrontational and that is not my intent here Auggie. I would be interested to hear what another service guy would do if he encountered this installation but I don't want to inquire at the expense of you thinking I am alienating you.

Have a nice evening.
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I would tell the homeowner it was a violation of the NEC and ask them what they would have me do about it. If they asked me if it dangerous I would answer no, but it is a code violation. Note it on the invoice if they said leave it be have them sign it and leave.
 
qcroanoke said:
I would tell the homeowner it was a violation of the NEC and ask them what they would have me do about it. If they asked me if it dangerous I would answer no, but it is a code violation. Note it on the invoice if they said leave it be have them sign it and leave.
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You would note on your own invoice that your own work in not code compliant?
 
iwire said:
You would note on your own invoice that your own work in not code compliant?
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No, The question was what would I do if I encountered such an install.

"I would be interested to hear what another service guy would do if he encountered this installation."

See posts 35 & 36.
 
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