310.16 (B)(6)
- Thread starter bar714
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- Location
- Massachusetts
You would need to use 310.16. (Now 310.17)
- Location
- Logan, Utah
- Location
- Logan, Utah
- Location
- Massachusetts
You said I was wrong but then said the same table.
You must be CMP member because you have me very confused.
I hate to go down this Code.
As your feeders are not carrying the entire load of the residence, you cannot use '05-'08 310.15(B)(6) {'11 310.15(B)(7) }
As best I recall prior to the '08 Code, as long as your calculated load on each panel was less than 180 amps, you could use 4/0 SER with a 200 amp OCP device.
Starting in '08, many folks would not accept that installation unless you OCP device was 150 amps based on 338.10
In '11, the 150 amp protection would be required IF the SER was installed in insulation. If not in insulation, the 180 amp rating is o.k.
That said, enforcement of this varies considerably.
As your feeders are not carrying the entire load of the residence, you cannot use '05-'08 310.15(B)(6) {'11 310.15(B)(7) }
As best I recall prior to the '08 Code, as long as your calculated load on each panel was less than 180 amps, you could use 4/0 SER with a 200 amp OCP device.
Starting in '08, many folks would not accept that installation unless you OCP device was 150 amps based on 338.10
In '11, the 150 amp protection would be required IF the SER was installed in insulation. If not in insulation, the 180 amp rating is o.k.
That said, enforcement of this varies considerably.
- Location
- Logan, Utah
You said I was wrong but then said the same table.
You must be CMP member because you have me very confused.
I was referring to your parenthetical (310.17) which I believe you meant 310.15(B)(16) which is the new 2011 NEC Table number.
And Yes as a CMP member I swore a sacred Oath to confuse all code users.
Chris
- Location
- Logan, Utah
Under the 2008 NEC SER cable used as interior wiring for feeders is required to comply with 334.80 (See 338.10(B)(4)(a) 2008 NEC) This requires that the SER cable be limited to the 60 column of 310.16. That would limit the ampacity of the SER to 150 amps and therefore 240.4(B) would limit you to a 150 amp breaker.
Chris
- Location
- Logan, Utah
- Location
- Logan, Utah
Also as a side note, Table 310.15(B)(7) (2011 NEC) is going to be eliminated in the 2014 NEC and replaced with an 0.83 adjustment factor to the "service ampere rating" for conductor sizing. (See the ROC on 6-49a)
Chris
Chris
AMEN
- Location
- Massachusetts
Why not just fix Article 220 and stop with the band aids?
- Location
- Logan, Utah
I agree, delete 310.15(B)(7) and modify the rules in 220 so that we have a real world load. Then size the residential feeders and service entrance conductors like any other conductors.
See, I should be writing the code.
Chris
Things are never as bad as they can be
We just think it's difficult now. Read the 310.15(B)(7) proposal here
http://forums.mikeholt.com/showthread.php?t=149698
We just think it's difficult now. Read the 310.15(B)(7) proposal here
http://forums.mikeholt.com/showthread.php?t=149698
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