THW-2 #12 and #10 not listed in NEC 2008 Annex C Tables

[mshadel]

A question came up about how many #12 THW-2 conductors can be installed in a 1 inch EMT. Easy to answer, go to Annex C: Tables and look it up, but on all tables THW-2 is not listed for #12 and #10 conductors. My question is, is this a misprint or is there a reason why it is missing?

 

[infinity]

It's there {Table C.1} for #14 AWG and #8 conductors so I'm guessing that it's a misprint. Great test question.


Welcome to the Forum.

 

[mshadel]

What is the proper way find out if it is a misprint?

 

[Dennis Alwon]

There is a huge discrepancy between Table c.1 and the actual Tables in Chapter 9. Chapter 9 tells us that 1" emt has an area at 40% of .346 sq. in. #12 thw-2 has an area of .0181. .346/.0181= 19 conductors. I would not use Annex C.

 

[infinity]

Annex C tables are not part of the code. They're only there for informational purposes. Having said that I'm not sure who at the NFPA would care about their accuracy.

 

[480sparky]

Latest 2011 NEC Errata.

It also explains how to determine what printing run your NEC was.