This seems alright to me. #2 ser AL running from a main service with 100 amp OCP to distribution/sub panel inside of house, main service riser is #2 AL. carpenter cut in to feeder during demo and cut ground and one hot half way through. So I cut the feeder at the damaged area, pulled it into a 12"x12" box. I spliced onto it with #4 cu ( Polaris connectors ) I should not have to derate the OCP down to 90 amp, based on 215.2(3) Feeder conductors for individual dwelling units or mobile homes need not be larger than service conductors. Any body see a reason why this would be a problem ?
feeders off main service 215.2(3)
- Thread starter acrwc10
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T 310.15(B)(6) rates #4 copper and #2 Alum as the same ampacity. I don't think the article means they must be the same physical size. As long as you have met the requirements of art. 310.15(B)(6) I see no problem with your install.
barbeer
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As the OP reads I agree that 310.15(B)(6) may be an issue, does not sound like "main feeders".
M. D.
Senior Member
barbeer said:
They are the same size as the service entrance ,..they are not ever required to be larger ... If this panel had feeder lugs the main disconnect,.. 100 amp ,.is all the ocpd that is required. At least that's the way I thought ,.I think,. I thought it ,.err,..,.. ummm... was:-?
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M. D. said:
Wow-- that's was deep.
winnie
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As I understand things, table 310.15(B)(6) does not _directly_ apply to the feeder in question. However, table 310.15(B)(6) does apply to the 100A _service_ upstream of the feeder, and that this 100A feeder doesn't need to have conductors larger than the 100A service conductors. So by implication you get to use 310.15(B)(6) sizing in this case.
Under this interpretation, if at some future date the service is increased to a 200A service, then ordinary 310.16 sizing would apply to this feeder, and the breaker would need to be changed to a 90A breaker.
-Jon
Under this interpretation, if at some future date the service is increased to a 200A service, then ordinary 310.16 sizing would apply to this feeder, and the breaker would need to be changed to a 90A breaker.
-Jon
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- Chapel Hill, NC
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- Retired Electrical Contractor
winnie said:
Actually T310.15(B)(6) does apply to some feeders. As long as the feeder carries the entire load of the building served then the table applies.
winnie
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Dennis Alwon said:
Agreed. For some reason I thought that the feeder in question (in the original post) did not carry the entire residential load, but reading again it seems clear that it does. In which case 310.15(B)(6) applies directly.
-Jon
barbeer
Senior Member
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- Pinellas County, FL
winnie said:
This was my initial thought and still is.........does it not say "sub" panel?
BUT since I just read the 2nd post by the OP, he verifies that it is the main feeder.:wink:
barbeer said:
Sorry for the confusion, I consider any panel after the main ocp panel a "sub panel" simple because it is not a "service Panel" Either way the feeder is no smaller then the main service conductors, one or more feeder it doesn't matter.
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- Chapel Hill, NC
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acrwc10 said:
It does matter. The 2008 clarifies this. One feeder that has the total load of the service then you may use T310.15(B)(6). If there are 2 feeders than you cannot use 310.15(B)(6).
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acrwc10 said:
The rules in 05 are the same, they just clarified them.
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