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 sparkyinak
Yesterday at 03:17 PM
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 9
sparkyinak 8
Texas_Ranger 8
Trumpy 6
Who's Online
0 registered (), 226 Guests and 5 Spiders online.
Key: Admin, Global Mod, Mod
Topic Options
Rate This Topic
#90966 - 12/19/04 05:36 AM NEC Help
AndyP Offline
Member

Registered: 08/11/04
Posts: 17
What is the ampacity of the wire in #11 if it was installed to feed Light poles?

I look in Article 310.16 but I'm just confused.

lol man I'm tired. #11 meaning THHN 8 awg

[This message has been edited by AndyP (edited 12-19-2004).]

[This message has been edited by AndyP (edited 12-19-2004).]

Top
2014 / 2011 NEC & Related Books and Study Guides
#90967 - 12/19/04 05:43 AM Re: NEC Help
russ m Offline
Member

Registered: 02/22/03
Posts: 165
Loc: Burbank,IL,USA
"What is the ampacity of the wire in #11 if it was installed to feed Light poles?"

Whats #11 refer to?

Top
#90968 - 12/19/04 05:56 AM Re: NEC Help
AndyP Offline
Member

Registered: 08/11/04
Posts: 17
Never mind I think it's 55a

Top
#90969 - 12/19/04 06:09 AM Re: NEC Help
russ m Offline
Member

Registered: 02/22/03
Posts: 165
Loc: Burbank,IL,USA
Generally conductors below 100amp are rated according to the 60degree column of 310.16.

You must rate the wire to the lowest value of any component in the circuit. The degree rating of the breaker, and any devices, lugs, or equipment, have to be taken into concideration.

8 copper = 40amps for 3 or less conductors.
You have to derate if you have more than three conductors or have ambient temperatures greater than 86 degrees F.

To derate the wire use the 90 degree column if using thhn/thwn.

[This message has been edited by russ m (edited 12-19-2004).]

Top
#90970 - 12/19/04 06:15 AM Re: NEC Help
russ m Offline
Member

Registered: 02/22/03
Posts: 165
Loc: Burbank,IL,USA
while you may use the 90 degree column for derating, (use what ever column the wire is rated for) you still have to use the lower of the two values for your conductor ampacity. Meaning the the lower of the two, (1)60 degree column or (2)the derated 90 degree wire.

[This message has been edited by russ m (edited 12-19-2004).]

Top
#90971 - 12/19/04 06:19 AM Re: NEC Help
AndyP Offline
Member

Registered: 08/11/04
Posts: 17
Thanks

Top
#90972 - 12/19/04 06:19 AM Re: NEC Help
iwire Offline
Moderator

Registered: 01/05/03
Posts: 4343
Loc: North Attleboro, MA USA
Andy it is very unlikely you can use the 90 C column which lists 8 AWG @ 55 amps.

You may very well be able to use the 75 C column if the terminations you are using are rated 75 C. At 75 C 8 AWG CU is rated 50 amps.
_________________________
Bob Badger
Construction & Maintenance Electrician
Massachusetts

Top
#90973 - 12/19/04 06:28 AM Re: NEC Help
russ m Offline
Member

Registered: 02/22/03
Posts: 165
Loc: Burbank,IL,USA
It might be helpfull for you to look at article 110.14(C)

I had to edit the article number

[This message has been edited by russ m (edited 12-19-2004).]

[This message has been edited by russ m (edited 12-19-2004).]

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