The Electrical Contractor Network

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

Books, Tools and Test Equipment for Electrical and Construction Trades

Register Now!

Register Now!

We want your input!

Featured:
   

2017 NEC and Related
2017 NEC
Now Available!

   
Recent Posts
Industrail Control Panel bonding per 409.108
by HotLine1
52 minutes 53 seconds ago
Calling all Non-US members!! (Non-US only)
by aussie240
12/07/16 02:39 AM
Photo Upload Tutorial
by DanK
12/06/16 11:35 PM
Sprinklered equipment 26-008
by bigpapa
12/02/16 04:24 PM
On Delay Relay with Auto Reset
by Potseal
12/01/16 09:59 AM
New in the Gallery:
12.5A through 0.75mm˛ flex (just out of curiosity)
Shout Box

Top Posters (30 Days)
gfretwell 13
HotLine1 10
sparkyinak 8
Texas_Ranger 8
Potseal 6
Who's Online
0 registered (), 215 Guests and 4 Spiders online.
Key: Admin, Global Mod, Mod
Topic Options
Rate This Topic
#182079 - 11/17/08 01:36 PM SER sizing
highground Offline
Member

Registered: 11/14/04
Posts: 50
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
2014 / 2011 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: 1492
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: 9045
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: 1069
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: 1478
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: 718
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



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