ser cable

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Dennis Alwon said:
That can be answered 2 ways. If their is no other loads in the exterior meter combo then 4/0 SER AL will suffice. Now, as I see it but don't agree with it, the code would require 300 MCM SER AL if their was another load in the meter combo. Now the SER does not serve the entire load of the dwelling-- ridiculous ? Yes, but that is the official ruling from Ron and my understanding of the 2008 NEC.
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That's one of the common "interpertations" in this area (one of 3). I quit arguing any of them because between 338.10, 310.15(B)(6) na d 215.2
each AHJ is going to come to his own conclusion.
The part I love about this one is the "logic" that as the load decreases (moving some to the exterior panel) we increse the size of the interior panel feeder.
It is going to be a while until all minds/eyes see this in the same light.
 
augie47 said:
That's one of the common "interpertations" in this area (one of 3). I quit arguing any of them because between 338.10, 310.15(B)(6) na d 215.2
each AHJ is going to come to his own conclusion.
The part I love about this one is the "logic" that as the load decreases (moving some to the exterior panel) we increse the size of the interior panel feeder.
It is going to be a while until all minds/eyes see this in the same light.
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I would agree that this section requires maintenance. IMO the intent was not to require the amacity to go up as the load went down and that is why right after the code talks about the main power feeder is says
"The feeder conductors to a dwelling unit shall not be required to have an allowable ampacity rating greater than their service-entrance conductors."

I understand that statement is open to some interpretation but I believe the intent was not to require the illogical.

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So what is the general consensus here.....Can 4/0 AL SER be used as a 200A feeder based on 310.15(B)(6) or do we need to upsize to 300kcmil because of 334.80?
 
Twoskinsoneman said:
I would agree that this section requires maintenance. IMO the intent was not to require the amacity to go up as the load went down and that is why right after the code talks about the main power feeder is says
"The feeder conductors to a dwelling unit shall not be required to have an allowable ampacity rating greater than their service-entrance conductors."

I understand that statement is open to some interpretation but I believe the intent was not to require the illogical.

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​
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This may be redundant but
The term feeder in this section would refer to a feeder that supplies the entire load to the dwelling unit. Such as:
A disconnect serving as the service equipment is located on a pedestal, and not attached to the structure. The conductors from that disconnect may be feeders to the structure and may supply the entire load to that structure. I believe that in this case (and possibly others) the term feeder is included in 310.15 (B) (6) to insure that those conductors, which supply the entire load, are not automatically sized out of Table 310.16, but allowed the use the more generous ampacities of table 310.15 (B) (6)
 
A/A Fuel GTX said:
So what is the general consensus here.....Can 4/0 AL SER be used as a 200A feeder based on 310.15(B)(6) or do we need to upsize to 300kcmil because of 334.80?
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Don't know how thoughts may have changed since December, but here's a poll from 12/31/08:
http://forums.mikeholt.com/showthread.php?t=108405&highlight=310.15(B)(6)
Not sure if that specificially addresses the issue as you like.
A more updated poll might be interesting, but this is one horse I'm tired of beating.
 
A/A Fuel GTX said:
So what is the general consensus here.....Can 4/0 AL SER be used as a 200A feeder based on 310.15(B)(6) or do we need to upsize to 300kcmil because of 334.80?
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334.80 enters into it if the ser doesn't carry the entire load of the service. Why? I don't know but 310.15(B)(6) allows it to be used if it does carry the entire load. It is a very bizarre article, IMO.

Art 338.10(B)(4) just says we must use 60C rating for SE cable when used as a feeder or branch circuit. 310.15(B)(6) doesn't care what the temp. rating of the cable is. It specifically allows SE Cable in the heading of the Table.
 
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