BX as a ground.

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al hildenbrand

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Minnesota
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Electrical Contractor, Electrical Consultant, Electrical Engineer
Now if you had an amendment like Massachusetts's Rule 3, you could probably continue using your non-compliant "EGC". But that just shows that Massachusetts feels the same way I do, because they had to make an explicit rule to allow you to do that, since the NEC itself does not allow it.

As you can see, I'm in Minnesota. I don't have a comment, other than to respond to you points and analogies as you requested.
 

al hildenbrand

Senior Member
Location
Minnesota
Occupation
Electrical Contractor, Electrical Consultant, Electrical Engineer
Originally Posted by al hildenbrand Sorry, that is your opinion. I've given a Code sequence in 406.4(D)(1) that counters that. Please substantiate your opinion with a Code that 250.118 always applies to existing installations.
I'm not going to be able to do that directly, I am going to cite the idea that all relevant parts of the NEC apply to your work. You can't just go to one section, see where it leads, and then you are done.
I submit the reason you are not able to do that is because the Code is silent on the matter. A thunderous silence.
 

wwhitney

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Retired
Sure it does. You check the OCPD end of the Branch Circuit to verify the connection of the Branch Circuit.
The title of 250.130(C) limits it scope. 250.130(C) is out of bounds if you are not either (a) replacing a nongrounding receptacle or (b) extending a branch circuit. So you must go to 406.4(C).

Cheers, Wayne
 

iwire

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Location
Massachusetts
Al, this thread has over 240 replies, over 4,500 views and I don't see a single post sharing your interpretation.

When this happens to me I rethink my position.
 

romex jockey

Senior Member
Location
Vermont
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electrician
So let's up the ante' as i alluded to in post #32 Mr Iwire....

Imagine 250.4(A)(5) extending itself to validate existing installs egc

I don't think one needs reinvent the wheel here btw.....

~RJ~
 

iwire

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Staff member
Location
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So let's up the ante' as i alluded to in post #32 Mr Iwire....

Imagine 250.4(A)(5) extending itself to validate existing installs egc

I don't think one needs reinvent the wheel here btw.....

~RJ~

IMO there is no way we can really discuss a code section like that with any authority because it is vary vague. That code section is entirely up to the AHJ to discern.

250.4(A)(5) Effective Ground-Fault Current Path.
Electrical equipment and wiring and other electrically conductive material likely to become energized shall be installed in a manner that creates a low-impedance circuit facilitating the operation of the overcurrent device or ground detector for high-impedance grounded systems. It shall be capable of safely carrying the maximum ground-fault current likely to be imposed on it from any point on the wiring system where a ground fault may occur to the electrical supply source. The earth shall not be considered as an effective ground-fault current path.
 

romex jockey

Senior Member
Location
Vermont
Occupation
electrician
Yes i know Mr Iwire , i'm asking you to imagine a '17 change....



250.4(A)(5) Effective Ground-Fault Current Path.
Electrical equipment and wiring and other electrically conductive material likely to become energized shall be installed in a manner that creates a low-impedance circuit facilitating the operation of the overcurrent device or ground detector for high-impedance grounded systems. It shall be proven as a test result to be capable of safely carrying the maximum ground-fault current likely to be imposed on it from any point on the wiring system where a ground fault may occur to the electrical supply source. The earth shall not be considered as an effective ground-fault current path.

~RJ~
 

mivey

Senior Member
Al, this thread has over 240 replies, over 4,500 views and I don't see a single post sharing your interpretation.

When this happens to me I rethink my position.
All that is well and good but evidently the folks in his work area have not posted as his regional ECs and AHJs seem to agree with him. If the real world Al works in has the same interpretation, why would he rethink his position because of a few forum opinions that contradict his real world experience?

Our forum is just a small subset and perhaps Al is giving us a view into an area that has a unique set of circumstances.

That said, I happen to agree with Al that if the existing circuit was ever recognized and allowed as an approved grounding means then we can't later say "my bad" and force an upgrade if it is not being modified. I happen to like his argument that points out the slippery over-reach slope of what that would mean with other code changes.

I am not clear about if BX without strap was ever recognized nationally as a grounding means but Al's area evidently recognized it. I have also seen BX used as a grounding means but unfortunately did not have the awareness at the time to note if all of it was with or without the strap as I have seen both and did not know enough to know if it was a compliant install or not. By the time I started paying attention it was a limited distance on flex.

I will say I do not remember wholesale replacement of old BX unless we were doing a rewire. Never thought about Al's points much till now but I do see where he is coming from.
 

iwire

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Location
Massachusetts
Mivey, who said anything about having to rip out existing?

As far as why he might rethink his position is that his area is just a small part of the whole much more so than this forum.
 

al hildenbrand

Senior Member
Location
Minnesota
Occupation
Electrical Contractor, Electrical Consultant, Electrical Engineer
Al, this thread has over 240 replies, over 4,500 views and I don't see a single post sharing your interpretation.

These are from this thread.

You are trying to apply current code to old wiring methods it can't be done.

First, does the AC cable have a bonding strip? If so then the jacket is a listed EGC can can be used as such. If not the jacket was still approved for grounding when it was installed so the question arises can it still be used for that purpose. IMO this is like NM cable with the reduced EGC that was installed years ago.

If you are only talking about a home inspector or a bank inspector (or even an electrical inspector) I would be comfortable putting in grounded outlets that were grounded through the bx.

As Al stated although a 90 year old AC cable may be a lousy EGC it was permitted to be used for grounding when it was installed so what section of the NEC would require it to be removed or not used as such?

I think too that in order for the retroactive/grandfather argument to hold any weight the bx armor would only qualify as an egc if it was approved for such by the NEC/ul during the time period in which the dwelling was wired. A 1956 house then yeah, sure but a 1929 house, I don't think so, unless of course there is an old code passage that states otherwise.
 

al hildenbrand

Senior Member
Location
Minnesota
Occupation
Electrical Contractor, Electrical Consultant, Electrical Engineer
At this point, Wayne, you and I are going in circles. You wish to trap me into applying 2014 NEC 250.118 into retroactively altering the legal-as-installed-status of an EXISTING Branch Circuit wiring method. You seem to have said you can't show a Code passage that tells you to retroactively reverse the status of inspected and approved existing wiring.

I'm going to pull back a bit from the tail-chasing with you Wayne.

I'm going to slow down and let this thread ripen. I've stated a clear case that is consistent with the Real World I work in.
 

wwhitney

Senior Member
Location
Berkeley, CA
Occupation
Retired
:? Reconnecting the existing branch circuit conductors in no way modifies them if they aren't cut or extended
The branch circuit conductors are not modified. But you are making a new connection. That's new work covered by the NEC. It is incumbent upon you to ensure that both sides of that connection meet the current NEC. You can't put in a receptacle that is non-compliant (e.g. lacking in TR for locations that require it) or connect to an "EGC" that is non-compliant.

Cheers, Wayne
 

wwhitney

Senior Member
Location
Berkeley, CA
Occupation
Retired
A new receptacle is two "conductor's in volume" because it is "new". The box is not new. The Branch Circuit is not new. If the existing conductors plus the device two conductor count results in a cubic inch requirement exceeding the existing volume, then the volume HAS to be increased in some manner.
You are missing my point. I'm interested in the parallel example to the issue at hand. I.e. at the time the box and receptacle were installed, the box volume was sufficient. Then the NEC rules changed, and under the new rules, the box is too small. You go to replace the receptacle. Do you have to fix the box volume problem?

By your logic with respect to 250.118, you don't, because 406.4(D)(1) doesn't lead you to 314.16. Yet you suggest that you do. Isn't that a contradiction? Why do you "jump" to 314.16, but you don't 'jump' to 250.118? It's inconsistent.

Cheers, Wayne
 

al hildenbrand

Senior Member
Location
Minnesota
Occupation
Electrical Contractor, Electrical Consultant, Electrical Engineer
The branch circuit conductors are not modified. But you are making a new connection. That's new work covered by the NEC.
There was a connection there before my work and there is a connection there after my work, the same number of connections.

But, you said it here, yourself: "The branch circuit conductors are not modified."
 

wwhitney

Senior Member
Location
Berkeley, CA
Occupation
Retired
But I have shown you the Code that establishes the armor of armored cable as (in the 1918 NEC) a ground conductor and that is passed on through time as the language of the Code evolves. The 406.4(D)(1) required grounding-type receptacle is connected to the grounding means as an EGC.

BTW, let's keep it simple and stay with receptacle replacement, the question as the OP asked.

The point of my question was to explore the consequences of your idea that the language in 406.4(D)(1) makes the old "grounding means" into an EGC. To quote you, "in for a penny, in for a pound." How far are you willing to take that idea? Can I extend the branch circuit and rely on that "EGC"? If not, what's the difference?

I maintain the difference is that you know the "grounding means" isn't really a good (low impedance) EGC, and for just replacing a receptacle you may find that an acceptable risk, but extending the circuit would be too much risk. And I don't see any difference between connecting a new conductor to that "grounding means" and connecting a new (replacement) receptacle to that "grounding means."

Cheers, Wayne
 

al hildenbrand

Senior Member
Location
Minnesota
Occupation
Electrical Contractor, Electrical Consultant, Electrical Engineer
You are missing my point. I'm interested in the parallel example to the issue at hand. I.e. at the time the box and receptacle were installed, the box volume was sufficient. Then the NEC rules changed, and under the new rules, the box is too small. You go to replace the receptacle. Do you have to fix the box volume problem?
I'm not missing your point. A new devices has a two conductor count, the old existing device before removal, was one conductor. The new device is "the new work". The box and branch circuit are existing.

To keep this (MY) point consistent with the OP scenario, Please, Wayne, let's agree that there is enough volume in the box.

Your allusion to "in for a penny-in for a pound" thinking just doesn't play, without the actual Code language instruction to reverse the inspected and approved status of existing Branch Circuit method.

Tail chasing.
 

al hildenbrand

Senior Member
Location
Minnesota
Occupation
Electrical Contractor, Electrical Consultant, Electrical Engineer
The point of my question was to explore the consequences of your idea that the language in 406.4(D)(1) makes the old "grounding means" into an EGC. To quote you, "in for a penny, in for a pound." How far are you willing to take that idea? Can I extend the branch circuit and rely on that "EGC"? If not, what's the difference?
406.4(D)(1) instructs me to connect the EGC contacts of the grounding-type device to the grounding means. . . It does not make any statement about 250.118. Tail Chasing.

I maintain the difference is that you know the "grounding means" isn't really a good (low impedance) EGC, and for just replacing a receptacle you may find that an acceptable risk, but extending the circuit would be too much risk. And I don't see any difference between connecting a new conductor to that "grounding means" and connecting a new (replacement) receptacle to that "grounding means."
Wayne, that is a safety argument, based on knowledge from OUTSIDE the text of the NEC. I am making a Code based argument. Tail Chasing.
 
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