Using number #2 for service entrance

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mstrlucky74

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I have #2 aluminum service entrance coming into the house and my friend who is an electrician is changing the meter pan but says the code changed and the #2 aluminum cable is no longer acceptable because its too small. My service is 100amps. Is this true? Thanks.
 
edward said:
What code is he referring to?

This is from 2011.


View attachment 8768
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But then you have 338.10(B)

(4) Installation Methods for Branch Circuits and Feeders.
(a) Interior Installations. In addition to the provisions
of this article, Type SE service-entrance cable used for interior
wiring shall comply with the installation requirements
of Part II of Article 334, excluding 334.80
.
Where installed in thermal insulation, the ampacity shall
be in accordance with the 60?C (140?F) conductor temperature
rating. The maximum conductor temperature rating
shall be permitted to be used for ampacity adjustment and
correction purposes, if the final derated ampacity does not
exceed that for a 60?C (140?F) rated conductor.
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Clear as mud yet?:D
 
edward said:
What code is he referring to?
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OP's profile shows 2008, and I do not think that that particular section has changed in a long time.
As long as the residence meets the restrictions for using that table, there should not be a Code problem (unless there are local amendments that apply) .
There is, however, ongoing discussion about why that lower size for service entrance was allowed in the first place and whether the higher current rating is still justified. Especially as loads are continually added to existing services in ways that were not originally planned.
 
GoldDigger said:
OP's profile shows 2008, and I do not think that that particular section has changed in a long time.
As long as the residence meets the restrictions for using that table, there should not be a Code problem (unless there are local amendments that apply) .
There is, however, ongoing discussion about why that lower size for service entrance was allowed in the first place and whether the higher current rating is still justified. Especially as loads are continually added to existing services in ways that were not originally planned.
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The table exists because of historical data provided by POCOs for 120/240 services.
 
IMO, #2 se cable is still sufficient for a 100 amp service. Yes the code on se cable changed but nothing in 310.15(B)(7) states that we must use art. 338. It states that se cable is a listed wiring method to use the table.
 
jumper said:
Eh.... you and Gus can battle this out....:D
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Yeah we usually do but this was asked at the state meeting in Raleigh and the cmp member who answered the question agrees with me....:p However he did say you have to use your smarts about it. My feeling if the op has had the #2 for all these years then it is not an issue. Whether the ahj makes them change it is another story
 
If the service entrance cables are no larger than the ser cable it is a legal install per 2011. 100 amp service diconnect fed by 2# can then feed out to a panel with 2# ser.
The feeder conductors to a dwelling unit shall

not be required to have an allowable ampacity rating greater

than their service-entrance conductors.
 
don_resqcapt19 said:
Table 310.15(B)(7) does not change the permitted ampacity of the conductors...it just specifies the minimum size conductor that is permitted for a dwelling unit service.
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Not just the service, but also a feeder. But the feeder or service must feed the entire dwelling load to use the table.
 
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