Article 310.16 derating

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Pierre C Belarge said:
If one has ever taken the UL classes/seminars, the 75C requirement has been discussed in detail during the classes/seminars.


The termination location is not the sole portion of the circuit to be required to be rated. All the components of the circuit are. As of now, I am not aware of any enclosures rated higher than 75C. Just changing a termination to 90C rating is not sufficient to change the circuit rating. The bus, terminations (both sides), enclosure, conductors, etc... Adding onto the conductor does not satisfy the change necessary to the whole circuit in regards to the 75C requirement.
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This is why I brought up making the transition beyond the confines of the enclosure.

SQD has a good PDF in their site, that explains this very well.
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A clip from said document....

90Cexample.gif


Link to document: http://ecatalog.squared.com/pubs/Electrical Distribution/0110DB9901R2-02.pdf
 
I made a paint drawing to show what I had in mind after smart brought up the enclosure issue. I did not consider that in my first posts.

Here is what I came up with before seeing the Square D document.:smile:

7590Condutor.jpg
 
So what exactly are the qualifications of equipment, to be listed at the 90C' and used at that rating? I thought it was basically applicable to MV equipment. not so much our average equipment.
 
OK

OK

OK, once again y'all are teaching me (THANKS). I use quite a few T&B compression lugs. I just went to the van and pulled paperwork out of one of the boxes. I could not find any temperature rating on the lug. I went to the web site and could not find any temperature rating on the lug. Do lugs have temperature ratings?

The specific lug I'm looking at is T&B part number 54107
 
hardworkingstiff said:
I use quite a few T&B compression lugs. I just went to the van and pulled paperwork out of one of the boxes. I could not find any temperature rating on the lug. I went to the web site and could not find any temperature rating on the lug. Do lugs have temperature ratings?

The specific lug I'm looking at is T&B part number 54107
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I found this in a T&B Catalog

* Aluminum lugs with a “9” indicate 90oC rating.
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Page 5 of this http://tnblnx3.tnb.com/emAlbum/albums/Color-Keyed US/colorkeyed_book.pdf
 
iwire said:
I made a paint drawing to show what I had in mind after smart brought up the enclosure issue. I did not consider that in my first posts.

Here is what I came up with before seeing the Square D document.:smile:

7590Condutor.jpg
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Based on your drawing, I did misunderstand you. This makes sense, but is rarely seen installed...maybe because so many in the field are not award of this. I was in a room years ago when Jim provided us with this info, it was like a revelation to me. Remember, even the boxes/enclosures one is installing the devices in still have to be rated for 90C.
 
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