ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals

Topic Options
Rate This Topic
#182079 - 11/17/08 01:36 PM SER sizing
highground Offline
Member
Registered: 11/14/04
Posts: 53
Loc: Chama, NM
What is the correct size of AL SER cable to use a feeder for a 100A subpanel in a residential setting? I seem to be getting different opinions from my two inspectors. I'm using the 2008 code.

Thanks in advance
Top
2017 / 2014 NEC & Related Books and Study Guides
#182083 - 11/17/08 02:13 PM Re: SER sizing [Re: highground]
George Little Offline
Member
Registered: 01/18/04
Posts: 1488
Loc: Michigan USA
I just read in the '08 NEC Article 3 Section 310.15(B)(6) and as I read it the feeder must be #1 Alm. Unless it carries the entire load of the dwelling and then it can be a #2 Alm.
The Code panel has waffled back and forth and reworded this one many times and now with the '08 I think the aforementioned sizes would be proper. That would be my call Until someone convinces me otherwise.
_________________________
George Little
Top
#182089 - 11/17/08 05:16 PM Re: SER sizing [Re: George Little]
gfretwell Offline


Member
Registered: 07/20/04
Posts: 9036
Loc: Estero,Fl,usa
I am with George, The confusion comes when people confuse a "main feeder" with a load side feeder in a residence.
_________________________
Greg Fretwell
Top
#182105 - 11/18/08 05:04 PM Re: SER sizing [Re: gfretwell]
Tom Offline
Member
Registered: 01/01/01
Posts: 1044
Loc: Shinnston, WV USA
I agree with the above posts. The confusion was even worse until they removed that pesky "s" at the end of feeder(s).

AFAIK, the CMP responsible for this always felt that the feeder was meant to carry the entire load and table 310.15(B)(6) has probably led to a lot of bad language & a few fistfights.
_________________________
Few things are harder to put up with than the annoyance of a good example.
Top
#182111 - 11/18/08 06:08 PM Re: SER sizing [Re: Tom]
Electricmanscott Offline
Member
Registered: 01/12/02
Posts: 1457
Loc: Holden, MA USA
I see undersized feeders all the time. Seems many mis-apply 310.15 B 6
Top
#182404 - 11/25/08 11:02 AM Re: SER sizing [Re: Electricmanscott]
macmikeman Offline
Member
Registered: 07/16/02
Posts: 717
Loc: Honolulu, Hawaii
Shortly my town will be adopting the 2008, and this will bring about new awareness of the requirements of feeder sizing, due to the fact that the NEC has made it clear that 310.15 B. 6 applies to a single feeder carrying all the load of a dwelling. Couple that with the new temperature rating for ser cable to the 60 deg column in 310.16 and the feeder sizes will increase by an avarage of two sizes on most new dwellings. Stictly my own opinion, but with the proper sized overcurrent protective device ahead of the "sub' feeder, the old sizing standard used for ser cables was already more than adaquate for the real life loads encountered. These new rules are huge overkill, but still it is in the code, so therefore it is just how it is, like it or not.
Top

Member Spotlight
Member Since: 07/05/02
Posts: 8211
New in the Gallery:
SE cable question
Featured:

2017 NEC and Related
2017 NEC
Now Available!

Shout Box


Who's Online
0 registered (), 44 Guests and 20 Spiders online.
Key: Admin, Global Mod, Mod
 
New in the Gallery:
SE cable question
 
Top Posters (30 Days)
Admin 51
HotLine1 43
gfretwell 17
Trumpy 16
Ruben Rocha 13
 
Newest Members
clee512, Jdscott2005, FAIZAN, Regitest2, sureshazhagai

ECN Electrical Forums - sponsored by Electrical Contractor Network - Electrical and Code Related Discussion for Electrical Contractors, Electricians, Inspectors, Instructors, Engineers and other related Professionals