where to find nm kcmils

[don_resqcapt19]

Bob,

Don, I have my doubts about 'eight percent or less'

Is it possible that was supposed to be 80% as Jon mentioned?

More than likely, but no one on the CMP took issue with the number.
Don

 

[JohnE]

John,

If the CMP intened that, they would not have even put the rule in the code. There would never be an application where you have to derate.
Don

Now you have me thinking. I need to digest things, but thanks for entertaining all my thoughts. I'll be in touch.

John

 

[1793]

Does this help?

Does this help?

Where is the c mils of Nmb (romex)? I am trying to figure out how many 14-2 conductors I can run through a 1-1/2'' hole.

maybe I am asking the wrong question. I asked my crew leader how many 12-2 nm or 14-2 wires we can fit in the 3/4'' hole we bore in the wood stud, he didn't know. He said he was told not more than 3 12-2 nm conductors. I want to know how to figure it out for myself for future jobs. Any help would be great.

For fill requirements, circle area, I use the following:

Romex say 12/2 measure widest part, about 3/8" which is .375.
Find the radius .375/2=.1875
Circle area = Pi * R(squared)
R(squared) .1875*.1875=.0351562
3.14 * .0351562=.1103904 circle area

now you need the total circle area available.

For example Chapter 9 Table 4, 4" Sch 40 PVC allowed at 60% fill is 7.532
so 7.532 / .1103904 = 68 12/2 romex in Sch 40 PVC nipple.

Edited for 4" information