250.122(B) Increase in size - were did the change come from.

[don_resqcapt19]

Charlie I see your point. I'll give another. So now you have a #10 because of conductor heating derating. How long a run can you make with the #10's on a 20 amp breaker before you run into fault issues because you have only a #12 EGC.

Again, how do you write a code rule to cover that. Show me the words.

...
Anyway, I see that as long as the CMP feels warm and cozy with a ROP then it's a done deal.

The often make changes based on the comments.

 

[Sierrasparky]

No, I did not say write a rule to make a EC hire a PE to deal with every day EGC sizing.
The PE is for Validating my CODE. I just don't think that a EC from Kalifornia is going to have enough weight to make it happen .
The change would need to PE and peer review for it to work in my opinion. :thumbsup:

 

[don_resqcapt19]

...I just don't think that a EC from Kalifornia is going to have enough weight to make it happen .
...

All it takes is a well written proposal with a solid technical substantiation.

 

[Sierrasparky]

All it takes is a well written proposal with a solid technical substantiation.

I respectfully disagree. There is a appearance of political and authoritative preference in these things.
I believe that if this is going to change it will need the proper vetting.
Right now I don't even know what language to use that we here can have consensus on.

 

[don_resqcapt19]

I respectfully disagree. There is a appearance of political and authoritative preference in these things.
I believe that if this is going to change it will need the proper vetting.
Right now I don't even know what language to use that we here can have consensus on.

Have you ever submitted a proposal or comment? How many ROPs (TCRs) and ROCs (TCDs) have you read?

 

[Cow]

You must of failed an inspection, huh?

 

[Sierrasparky]

Nope, No failed inspection.
Just was not aware of the interpetation here on this forum. Have a NEC handbook and it states " for voltage drop upsizing.
I see the complete stupidity of the current interpetation.

As far as the ROP's read I feel since the many failures thus far to correct the wrong it will take some vetting that I do not posses by myself.

 

[don_resqcapt19]

...
Just was not aware of the interpetation here on this forum. Have a NEC handbook and it states " for voltage drop upsizing.
I see the complete stupidity of the current interpetation.

There is no interpretation involved...the voltage drop wording was removed. The only interpretation is what is the "normal" size of the ungrounded conductor.
The handbook is not the code...the code is the code and it says what it say.

 

[Sierrasparky]

There is no interpretation involved...the voltage drop wording was removed. The only interpretation is what is the "normal" size of the ungrounded conductor.
The handbook is not the code...the code is the code and it says what it say.

If most were ok with the current interpetation then there would be no reason to change it then.


Also the NEC should not allow a book of interpetations to be published with thier name all over it. I don't give a crap that there is a clause in the inside cover. Tell me what the purpose of the book is for then. Oh it is for humor , coffee table reading, exersising your eyes.
get real.

 

[charlie b]

So now you have a #10 because of conductor heating derating. How long a run can you make with the #10's on a 20 amp breaker before you run into fault issues because you have only a #12 EGC?

I calculate that at about 210 feet (one way circuit length), but it might be OK even for a 420 foot (one way) circuit. By contrast, if you used #10 for both the ungrounded and the EGC, you might not have trouble clearing a fault unless the circuit length exceeded 540 feet. But of course, you might be dealing with equipment performance issues with a circuit that long anyway, if you only used #10 for the ungrounded conductor.

So in light of this one, limited example, there is no technical reason that we would need to upsize the EGC from #12 to #10, in that any circuit that is not so long that it causes VD issues at the end of the line would be able to clear a fault in a reasonable time, even with a #12 EGC. Did I mention already that I didn't like this rule? :happyyes:

 

[don_resqcapt19]

If most were ok with the current interpetation then there would be no reason to change it then.

The proposed change is only about trying to make clear what wire size is to be used as the base wire size so the amount of upsizing can be calculated.

Also the NEC should not allow a book of interpetations to be published with thier name all over it. I don't give a crap that there is a clause in the inside cover. Tell me what the purpose of the book is for then. Oh it is for humor , coffee table reading, exersising your eyes.
get real.

It is a book of comments, not interpertations. As far as its pupose, it has none for me.

 

[Rick Christopherson]

Did I mention already that I didn't like this rule? :happyyes:

Hey, if they didn't at least make some changes from one cycle to the next, municipalities wouldn't need to adopt the new version and electricians wouldn't need to shell out the money for a new copy. I think some code changes are in fact driven for the sake of change, and this appears to be one of them. The most telltale sign of this is how poorly the substantiation was, yet the code panel apparently bought into it.

 

[Sierrasparky]

The proposed change is only about trying to make clear what wire size is to be used as the base wire size so the amount of upsizing can be calculated.



It is a book of comments, not interpertations. As far as its pupose, it has none for me.

A book of comments not interpetations , It is called a handbook , some consider such a item a manual, what a crock it's nothing more than glossy toilet paper.

 

[iwire]

I respectfully disagree. There is a appearance of political and authoritative preference in these things.
I believe that if this is going to change it will need the proper vetting.
Right now I don't even know what language to use that we here can have consensus on.

Anyone can get a code change accepted, for instance George Stolz, Don and Charlie have all had proposals accepted.

 

[don_resqcapt19]

A book of comments not interpetations , It is called a handbook , some consider such a item a manual, what a crock it's nothing more than glossy toilet paper.

I don't buy the handbook because I have no use for it. I don't need someone to tell me what they think the rule means. That being said a lot of people use that book and assume that it is an offical document. Most of the time it is correct, but not aways.

As far as not being an interpertation, the NEC is an ANSI standard and I believe there are specific procedures required for an "official" interpertation. In the case of the NEC, that requires the submission of a request for "formal interpertation". The questions must be phrased so that they can be answered "yes" or "no". The request is sent to the members of the code making panel and they vote on it just like they do on a change proposal.

 

[don_resqcapt19]

Hey, if they didn't at least make some changes from one cycle to the next, municipalities wouldn't need to adopt the new version and electricians wouldn't need to shell out the money for a new copy. I think some code changes are in fact driven for the sake of change, and this appears to be one of them. The most telltale sign of this is how poorly the substantiation was, yet the code panel apparently bought into it.

I don't really like the rule either because it is telling me that when I reduce the size of the OCPD and use the same size conductor as on the larger OCPD, that I some how increase the available fault current.

As I said before, Table 250.122 needs to be changed so it works like Table 250.66. The EGC should be based on the size of the ungrounded conductor and not on the size of the OCPD. That would eliminate the issue with sizing the EGC when the ungrounded condutor is upsized.

 

[Sierrasparky]

I don't buy the handbook because I have no use for it. I don't need someone to tell me what they think the rule means. That being said a lot of people use that book and assume that it is an offical document. Most of the time it is correct, but not aways.

As far as not being an interpertation, the NEC is an ANSI standard and I believe there are specific procedures required for an "official" interpertation. In the case of the NEC, that requires the submission of a request for "formal interpertation". The questions must be phrased so that they can be answered "yes" or "no". The request is sent to the members of the code making panel and they vote on it just like they do on a change proposal.

Look I don't rely on the Handbook , some do. I got mine free with the purchase of the NEC. That is why I have one. As far as the only place to rely on an interpetation is to get an official ruleing by writing in. That is unbeliveable that someone would actually put in print.

Just so you know some AHJ actually use the handbook to understand the code and enforce it.
I think this thread should be closed as I intended to get a consensus on a goal to get this code re-written properly and done once and for all.
As I see this crowd will not let it happen.

Good Luck
I will try with the CA EC and the Ca buildings and standards.

 

[don_resqcapt19]

Look I don't rely on the Handbook , some do. I got mine free with the purchase of the NEC. That is why I have one. As far as the only place to rely on an interpetation is to get an official ruleing by writing in. That is unbeliveable that someone would actually put in print.

Just so you know some AHJ actually use the handbook to understand the code and enforce it.

If they enforce something that is in the handbook and not in the actual code they are subject to a civil suit charging malicious prosecution just like they would be if they enforced any other rule that has not actually been adopted by the unit of government that they work for. This does not happen often as most of the time it is not worth the time and money to go to court. I has happened a few times on large projects where the cost of compliance with the made up rule was high. In those cases the EC installed per the AHJ and recovered the excess costs after the project was finished.

I think this thread should be closed as I intended to get a consensus on a goal to get this code re-written properly and done once and for all.
As I see this crowd will not let it happen.

Appearently you haven't really been reading the thread. There have been a number of comments that have said the rule in question is not a good rule. What I haven't seen from you is a suggestion as to how to re-write the rule to make it workable.

 

[Sierrasparky]

If they enforce something that is in the handbook and not in the actual code they are subject to a civil suit charging malicious prosecution just like they would be if they enforced any other rule that has not actually been adopted by the unit of government that they work for. This does not happen often as most of the time it is not worth the time and money to go to court. I has happened a few times on large projects where the cost of compliance with the made up rule was high. In those cases the EC installed per the AHJ and recovered the excess costs after the project was finished.

You don't Get it do you. People look to the book with the logo and called hand book for interpretation or in simple terms explanation as to how that section of the code works. I am not unaware that the NEC lawyers place all kinds of disclosures in these books. If the NEC does not want someone to use the book as intended they should not Endorse it by placing a Logo all over it. People need to take responsibility for their actions.

Inspectors are people and most of the time they are not experts. They rely on books like these however they are toilet paper or kindling for a cold day.

Apparently you haven't really been reading the thread. There have been a number of comments that have said the rule in question is not a good rule. What I haven't seen from you is a suggestion as to how to re-write the rule to make it workable.

I have made some suggestions but I need input from those in the field as well as practicing PE's, I am not going to make the same mistake that those before me have made. The CMP seems to be very narrow minded on this issue for a reason not identified as of yet. I seriously doubt that the CMP made this rule because no one was up sizing the ground in long runs for voltage drop.

One thing as I read some ROP's is that one person had issue because cables out there do not have the ground sized for up sizing as a reason. I would think that a cable company would be interesting in this issue.

where is the engineering to support the current code or a change. I don't feel I m qualified to assert those figures.

 

[don_resqcapt19]

You don't Get it do you. People look to the book with the logo and called hand book for interpretation or in simple terms explanation as to how that section of the code works. I am not unaware that the NEC lawyers place all kinds of disclosures in these books. If the NEC does not want someone to use the book as intended they should not Endorse it by placing a Logo all over it. People need to take responsibility for their actions. ...

Yes, people do need to take responsibility for their actions, and that includes people using the handbook or the adivce they see in forums like this. They need to understand that neither one is any type of official ruling on what a code section means.