2008 NEC 338.10(B)(4)(b): ampacity of USE feeder

[wwhitney]

Hello,

The last sentence of 2008 NEC 338.10(B)(4)(b) reads "Type USE cable installed as underground feeder and branch circuit cable shall comply with Part II of Article 340". Part II of Article 340 includes 340.80, which limits UF cable to 60C ampacity. Does this mean that if type USE cable is direct buried as a feeder, it is limited to 60C ampacity?

Thanks,
Wayne

 

[Ponchik]

That is the way that i read it.
However, you can use 90C column for derating purposes but OCPD can not exceed 60C.

 

[jumper]

That is the way that i read it.
However, you can use 90C column for derating purposes but OCPD can not exceed 60C.

USE is 75C for derating. USE-2 is 90C.

 

[Ponchik]

USE is 75C for derating. USE-2 is 90C.

Thanks Jumper,



from the NEC handbook:
Type USE cable contains conductors with insulation equivalent to RHW or XHHW. Type USE-2 contains insulation equivalent to RHW-2 or XHHW-2 and is rated 90?C wet or dry.

 

[Dennis Alwon]

I do not think that is the intent of that section. I believe I wrote a proposal to change that to read Part II excluding 334.80.