2014 NEC NECA Analysis of Change- 310.15(B)(3)(c) Exception

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I think a lot of us agree, but only because we don't really agree with the rule that the exception applies to. While the testing used to get the rule into the code clearly showed increased conductor temperatures on rooftops, there was no evidence of failures of existing installations. This was seen as just one more manufacturer driven code change...a change that was based on testing done by the Copper Development Association and designed to sell more copper.
 
don_resqcapt19 said:
I think a lot of us agree, but only because we don't really agree with the rule that the exception applies to. While the testing used to get the rule into the code clearly showed increased conductor temperatures on rooftops, there was no evidence of failures of existing installations. This was seen as just one more manufacturer driven code change...a change that was based on testing done by the Copper Development Association and designed to sell more copper.
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I agree with you.
 
ActionDave said:
I don't see any analysis, just facts. That's what '14 code says.
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So you see the Exception to 310.15(B)(3)(c) applying to remove ALL ambient adjustments demanded by Section 310.15(B)(2).....I disagree......the exception is (according to the location and NEC Style Manual) applying to item (c)...and the adder....not to remove the ambient adjustments demanded in Section 310.15(B)(2)...

I disagree...because I sat in on this discussion at the ROC.....but we can yet again agree to disagree........you will always still have an ambient correction if temperature values differ than that of Table 310.15(B)(16)....and heat affects ampacity......so you believe...that the exception applies to all of Section 310.15(B)(3).......and you seem to think it also applies to not having to adjust for ambient corrections in 310.15(B)(2)(a) as well....

Interesting.........
 
don_resqcapt19 said:
I think a lot of us agree, but only because we don't really agree with the rule that the exception applies to. While the testing used to get the rule into the code clearly showed increased conductor temperatures on rooftops, there was no evidence of failures of existing installations. This was seen as just one more manufacturer driven code change...a change that was based on testing done by the Copper Development Association and designed to sell more copper.
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Ahhh.......disagreeing with something and following the NEC is two things....again it's always about the manufacturers. Also it applies to AL conductors also.....guess they are in bed together also....;)..in fact it was presented BY someone who is strongly in the Aluminum Camp......and less in the Copper Camp......read the ROP 6-41 and ROC 6-37 for more details.

So it is not Copper driven.......but our next mission is Voltage Drop as mandatory....we just need to sell more Copper....:angel:
 
don_resqcapt19 said:
This was seen as just one more manufacturer driven code change...a change that was based on testing done by the Copper Development Association and designed to sell more copper.
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No, this code change sells less copper.

If any industry drove this code change, it would be the polyethlyene industry. To sell XHHW-2 over PVC and Nylon in THWN-2.
 
Carultch said:
No, this code change sells less copper.

If any industry drove this code change, it would be the polyethlyene industry. To sell XHHW-2 over PVC and Nylon in THWN-2.
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You have the cart before the horse, the main rule went in first, the exception came later.
 
MasterTheNEC said:
So do you agree with this 2014 NEC NECA Analysis............:sick:
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I disagree completely with the analysis/interpretation.
The wording of the exception is found in the section on conductors on rooftops. The plain English interpretation is that all that is being excepted is the temperature adder. But the wording "...conductors shall not be subject to this ampacity adjustment." leaves that subject to dispute.

I do find it unreasonable that an exception in the specific clause on rooftop wiring could be taken to imply exemption from all temperature based ampacity adjustments for this wire type regardless of where it is used.
I also find it nonsensical that the basic temperature based ampacity adjustment applies to this wire type everywhere but on a rooftop.

In short, I think that the commentary is flat out wrong.

It would have been better if the wording of the exception specifically referenced the temperature adder and not the "ampacity adjustment".

PS: Just like the Handbook, the Analysis of Change does not have the normative standing of the Code itself. And in this case I think they blew it.
 
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MasterTheNEC said:
Ahhh.......disagreeing with something and following the NEC is two things....again it's always about the manufacturers. Also it applies to AL conductors also.....guess they are in bed together also....;)..in fact it was presented BY someone who is strongly in the Aluminum Camp......and less in the Copper Camp......read the ROP 6-41 and ROC 6-37 for more details.
...
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The testing that drove the original rule was done by the copper association.

It was another change that was all based on testing and theory without any real world evidence of a problem.

I said I didn't like the original rule, and that I liked the exception because it lets me get rid of the original rule.
 
don_resqcapt19 said:
You are too late...the energy codes have already done that.
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Yeah...and I am sure all of the inspectors who do electrical inspections reference that in their codes.....to gain TEETH we need it in the NEC...:).....we will use those ASHRAE and Green Code and others to give teeth to the proposal...look out 2020.
 
don_resqcapt19 said:
The testing that drove the original rule was done by the copper association.

It was another change that was all based on testing and theory without any real world evidence of a problem.

I said I didn't like the original rule, and that I liked the exception because it lets me get rid of the original rule.
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The exception only applies to Section 310.15(B)(3)(c)...was my point, not as stated to remove the requirements of Section 310.15(B)(2).....as it states in image.
 
GoldDigger said:
I disagree completely with the analysis/interpretation.
The wording of the exception is found in the section on conductors on rooftops. The plain English interpretation is that all that is being excepted is the temperature adder. But the wording "...conductors shall not be subject to this ampacity adjustment." leaves that subject to dispute.

I do find it unreasonable that an exception in the specific clause on rooftop wiring could be taken to imply exemption from all temperature based ampacity adjustments for this wire type regardless of where it is used.
I also find it nonsensical that the basic temperature based ampacity adjustment applies to this wire type everywhere but on a rooftop.

In short, I think that the commentary is flat out wrong.

It would have been better if the wording of the exception specifically referenced the temperature adder and not the "ampacity adjustment".

PS: Just like the Handbook, the Analysis of Change does not have the normative standing of the Code itself. And in this case I think they blew it.
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Agreed.....but the presentation is used by a HUGE group of members....and I just wanted to point that out.....
 
MasterTheNEC said:
Yeah...and I am sure all of the inspectors who do electrical inspections reference that in their codes.....to gain TEETH we need it in the NEC...:).....we will use those ASHRAE and Green Code and others to give teeth to the proposal...look out 2020.
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I don't know if you are joking or not.

If you are serious I find it very disturbing and a conformation of using the code to make sales.
 
iwire said:
I don't know if you are joking or not.

If you are serious I find it very disturbing and a conformation of using the code to make sales.
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Only you would read it that way...........I will be nice.....

After all the threads in here fighting that manufacturers don't do those things......like Don said.....the Energy Code and Green Codes are taking care of that......already


But I happen to believe Voltage Drop is important.....so if I did support it the reason would be for the merit of the intent.

P.S. Yes Bob....I'm Joking
 
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MasterTheNEC said:
Yeah...and I am sure all of the inspectors who do electrical inspections reference that in their codes.....to gain TEETH we need it in the NEC...:).....we will use those ASHRAE and Green Code and others to give teeth to the proposal...look out 2020.
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I don't see how an energy use rule would be within the purpose of the NEC.
 
MasterTheNEC said:
The exception only applies to Section 310.15(B)(3)(c)...was my point, not as stated to remove the requirements of Section 310.15(B)(2).....as it states in image.
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I looked right over the wording, both when read this post and when I taught the changes using that book.
 
MasterTheNEC said:
Only you would read it that way.
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No, I doubt that I am the only one that reads it like that. You work for a manufacturer to shape the code for the benefit of the manufacturer. You are not being put on a CMP for the benefit of society.


..........I will be nice.....
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Be whatever you want, I am a big boy.


But I happen to believe Voltage Drop is important.....so if I did support it the reason would be for the merit of the intent.
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It is important but it is a design issue not a safety issue.
 
iwire said:
No, I doubt that I am the only one that reads it like that. You work for a manufacturer to shape the code for the benefit of the manufacturer. You are not being put on a CMP for the benefit of society.




Be whatever you want, I am a big boy.




It is important but it is a design issue not a safety issue.
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I can relate to how it can be a safety issue.....when it is grossly overlooked......
 
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