urd ampacity

[phorton]

Im looking for the ampacity of #2 urd directly buried. Using 310.16(B)(16) in the 75 C column gives ampacity of 90 before correction factor in 310.15(B)(2)(a) of 1.11 for ampacity of 99.9 going to the next larger standard for 100 amp?

 

[ActionDave]

What is the application? 310.15 got shredded in '11 code. Basically #2 AL is good for 90A if you are not running it across a rooftop.

 

[augie47]

If your conductor is "URD" with no other rating, such as "RHW", you will not find it's ampacity listed in the NEC as URD is not an approved NEC conductor.

 

[fmtjfw]

Im looking for the ampacity of #2 urd directly buried. Using 310.16(B)(16) in the 75 C column gives ampacity of 90 before correction factor in 310.15(B)(2)(a) of 1.11 for ampacity of 99.9 going to the next larger standard for 100 amp?

For example Manufacturer's ratings: http://www.cmewire.com/catalog/power/sec14-SUD-Al/14-SUD-Al-01-AMP.pdf

Google the company that made yours.

 

[phorton]

For example Manufacturer's ratings: http://www.cmewire.com/catalog/power/sec14-SUD-Al/14-SUD-Al-01-AMP.pdf

Google the company that made yours.

Yes I have seen those ratings, and with absence of anything in the book I have been told to treat it as 75 C wire.
The application is direct burial, non-residential.

Thanks

 

[augie47]

Apparently I don't have the Code where you are referencing your 1.1. multiplier, but in general, select your conductor type, find the ampacity in the appropriate Table (such as 310.16), and apply correction factors for ambient, fill, etc.
Once you have calculated that ampacity, look at 110.14 in regard to termination
restrictions. In most cases the termination restrictions will limit the allowed ampacity to the 75? rating.