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#172030 12/11/07 09:57 AM
Joined: Oct 2002
Posts: 830
S
Member
According to the wire table 310-16 ( 99 Code Book, I don't have my new book with me) # 8 wire is good for 50 amps in the 75 degree column, and I know this is good only if the terminals are rated 75 degrees, which they are. Does
8/3 with ground romex qualify for this rating also? I had an inspector tell me once that it didn't, but I can't find where he would have got that from unless it was in an old code at the time. Thanks, Steve...

sparkync #172031 12/11/07 10:30 AM
Joined: Dec 2003
Posts: 751
E
Member
He is maybe refering to 334.80, which limits the ampacity of NM cables to that of the 60 degree column.


Earl
earlydean #172034 12/11/07 12:37 PM
Joined: Jul 2004
Posts: 9,923
Likes: 32
G
Member
Yup that is what he is talking about and you can't get away with the "round up" trick you can with #6 since 40 is a standard breaker size. Even if you decide to go for SE/SER you still can't use the 75c column because of 338.10(B)(4)


Greg Fretwell
gfretwell #172072 12/11/07 11:45 PM
Joined: Nov 2007
Posts: 764
K
Member
Hi Greg,
I could be wrong, but I thought 338.10(B)4 excluded 334.80 Ampacity. confused

KJay #172079 12/12/07 01:36 AM
Joined: Jul 2004
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You are right. I should try to read a little better before I speak. My original thought was that it was OK, then I looked it up. wink


Greg Fretwell

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