110.14(C)(1) again!!!!!!!

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About the only things with 90?C or greater terminations are:
Wirenuts
Power distribution blocks
600V Equipment built to ANSI switchgear standards
Medium voltage equipment.

One thing these items have in common, is the lack of connection directly to protective and utilization devices.

There are devices that require 90?C conductor insulation, but the wires must be sized using the lower 75?C values (e.g. luminaires and 100% rated protective devices).
 
MarineTech said:
Smart $,

Thanks for the pdf link. I found the article more direct than the NEC 2011, in emphasizing Table 310.15(B)(16) is device termination centric, as opposed to stand alone lugs terminating a conductor on a tap, for example.

It seems to me, perhaps it would be clearer if Table 310.15(B)(16) included additional terminology about its importance in terminations.

What do you think?

Best regards,

MarineTech
Click to expand...
Table 310.15(B)(16) is no more device termination centric than it is to stand alone lugs terminating a conductor on a tap. It is used simply to establish a working temperature of a termination based on wire size and the current through the conductor. It is "assumed" the termination temperature will be the same temperature as the wire, without having to compensate for all the nuances of various types of terminations.

I'm sure you've noticed the values in other ampacity tables for the same temperature rating are different... so why can't we use those? It's because the insulation and conditions of use beyond the terminal enclosure is considered to have an insignificant effect on the temperature developed at the termination. I'm certain it does to some degree, but this goes back to the nuances I mentioned earlier.

I believe the CMP feels Informational Note No. 2 to 310.15(A)(3) is sufficient. Complying with the NEC requires understanding of all requirements for the installation. That's what makes the difference between a (truly) qualified person and a DIY'er and those in between.
 
Smart $ said:
Table 310.15(B)(16) is no more device termination centric than it is to stand alone lugs terminating a conductor on a tap. It is used simply to establish a working temperature of a termination based on wire size and the current through the conductor. It is "assumed" the termination temperature will be the same temperature as the wire, without having to compensate for all the nuances of various types of terminations.

I'm sure you've noticed the values in other ampacity tables for the same temperature rating are different... so why can't we use those? It's because the insulation and conditions of use beyond the terminal enclosure is considered to have an insignificant effect on the temperature developed at the termination. I'm certain it does to some degree, but this goes back to the nuances I mentioned earlier.

I believe the CMP feels Informational Note No. 2 to 310.15(A)(3) is sufficient. Complying with the NEC requires understanding of all requirements for the installation. That's what makes the difference between a (truly) qualified person and a DIY'er and those in between.
Click to expand...

Smart $,

Thanks for the reply. Indeed, navigating the NEC can be a challenge.

MarineTech
 
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