Derating Wire

[mbrooke]

What code section again requires rolled up SJOW to be de-rated? ............

 

[infinity]

What do you mean by "rolled up"? Do you mean coiled?

 

[mbrooke]

What do you mean by "rolled up"? Do you mean coiled?

Yes coiled. I need a code reference but can't find one

 

[mbrooke]

Something like this:

https://upload.wikimedia.org/wikipedia/commons/thumb/a/a2/ElectricWireOnReel.JPG/1200px-ElectricWireOnReel.JPG

But with 14 and 12 gauge SJOOW cord... 400.5 A 3 would have to apply... but can't find anything specific.

I'll clarify why I'm asking...

 

[infinity]

I don't see anything in Article 400 that would apply when you had 3 CCC's or less.

 

[zbang]

How about 400.5(B) Ultimate Insulation Temperature ?

(Or- Manufacturer's instructions?)

 

[mbrooke]

I don't see anything in Article 400 that would apply when you had 3 CCC's or less.

A roll would be more than 3 CCCs from a thermodynamic perspective, would it not?

 

[zbang]

I don't see anything in Article 400 that would apply when you had 3 CCC's or less.

Looks like a lot of 400 would apply, well, pretty much all of it (Flexible cords and all that). Part 400.5(A) tells us "Table 400.5(A)(2) provides the ampacities for flexible cords and cables with not more than three current-carrying conductors." and a table footnote says "...allowable currents under Column B apply to 2-conductor cords..."

Then you get to (B)-

Ultimate Insulation Temperature. In no case shall conductors be associated together in such a way with respect to the kind of circuit, the wiring method used, or the number of conductors such that the limiting temperature of the conductors is exceeded.

SJOW is 90 degC cable. One could do the math for I2R loss and see where the equilibrium temperature is, but why bother (unless you like thermo calcs).

(I'm looking at 2011 since it was handy)