ambient temp.

[ceb58]

Trying to figure derating for wire installed in emt mounted about 6'' behind and 12'' above steam radiators. I do not know the temp of the heat generated but I would guess it would be in the 56-60 deg C. So by 310.16 if I have 4-6 cond. #12 its good for 30amp 30*.80= 24 24*.71= 17 So to have 20amp circ. #10 would be needed 40*.80= 32 32*.71= 22.7 Any problems with the numbers?

 

[iwire]

If it's short distances you will probably not have to derate at all. Hopefully someone will post the code section on my mind.

 

[resistance]

If it's short distances you will probably not have to derate at all. Hopefully someone will post the code section on my mind.

For ampacity adjustments in a nipple not exceeding 24 inches see section 310.15(B)(2)a Ex.3

 

[ceb58]

If it's short distances you will probably not have to derate at all. Hopefully someone will post the code section on my mind.

No short runs all about 40 ft

 

[iwire]

For ampacity adjustments in a nipple not exceeding 24 inches see section 310.15(B)(2)a Ex.3

Thanks, but that is not the one.

I went and grabbed my book, I am talking about 310.15(A)(2) Exception.

No short runs all about 40 ft

Not quite what I meant.

If your entire run is 40' then up to a 4' section could run behind a radiator and not have to be adjusted. See the exception I posted.

 

[resistance]

I hear ya!

 

[ceb58]

Thanks, but that is not the one.

I went and grabbed my book, I am talking about 310.15(A)(2) Exception.



Not quite what I meant.

If your entire run is 40' then up to a 4' section could run behind a radiator and not have to be adjusted. See the exception I posted.

You da man.......... again

 

[resistance]

Ceb,

Iwire is correct.

 

[ceb58]

Ceb,

Iwire is correct.

Yes, I know. He thought he was wrong once but he was just mistaken