QUESTION

[donnie]

In the Electrical Contractor Magazine,OCT.2003 Issue, Page 23, the question and answer on the use of Nonmetalic sheathed cable, Does anyone have any Ideal where the writer is coming from, In reqards to his answer.

Just curious.

 

[electricman2]

Re: QUESTION

I think what he is saying is that #4 NM cable can be used beyond its normal 60C capacity of 70A in this particular application, that is, as a feeder for a one-family dwelling unit using a 100A service.
Hope this helps.

 

[donnie]

Re: QUESTION

electricman2

But still I don't see type NM cable listed in the table 310.15 (b) (6) for the higher ampacity use. And also art. 31.15 B 6, is not for just plain feeders but main power feeders.He also talks about the conductors having TW insulation and according to table 310.16 type TW is under the 60degree column.

 

[tom baker]

Re: QUESTION

There is a errata on this issue for the table, it should not list NM cable, it may if you have an earlier version of the NEC.