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

>> Home   >> Electrical-Photos   >> Classifieds   >> Subscribe to Newsletter   >> Store  
 

Photo of the Week:

100 Year old Lightbulb
100 Year old Bulb

Advertisement:-Left
Recent Gallery Topics:
What in Tarnation?
What in Tarnation?
by timmp, September 10
Plumber meets Electrician
Plumber meets Electrician
by timmp, September 10
Who's Online Now
1 members (gfretwell), 108 guests, and 20 robots.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
#46345 12/19/04 08:36 AM
Joined: Aug 2004
Posts: 20
A
AndyP Offline OP
Member
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).]

Horizontal Ad
#46346 12/19/04 08:43 AM
Joined: Feb 2003
Posts: 169
R
Member
"What is the ampacity of the wire in #11 if it was installed to feed Light poles?"

Whats #11 refer to?

#46347 12/19/04 08:56 AM
Joined: Aug 2004
Posts: 20
A
AndyP Offline OP
Member
Never mind I think it's 55a

#46348 12/19/04 09:09 AM
Joined: Feb 2003
Posts: 169
R
Member
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).]

#46349 12/19/04 09:15 AM
Joined: Feb 2003
Posts: 169
R
Member
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).]

#46350 12/19/04 09:19 AM
Joined: Aug 2004
Posts: 20
A
AndyP Offline OP
Member
Thanks

#46351 12/19/04 09:19 AM
Joined: Jan 2003
Posts: 4,391
I
Moderator
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
Horizontal Ad
#46352 12/19/04 09:28 AM
Joined: Feb 2003
Posts: 169
R
Member
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).]

#46353 12/19/04 11:13 AM
Joined: Oct 2000
Posts: 3,685
Likes: 4
Administrator
Member


Link Copied to Clipboard
Advertisement:-Right


Tools for Electricians
Tools for Electricians
 

* * * * * * *
2023 National Electrical Code (NEC)
2023 NEC + Exam Prep Study Guides Now Available!
 

Member Spotlight
Joe Tedesco
Joe Tedesco
Boston, Massachusetts USA
Posts: 2,749
Joined: October 2000
Top Posters(30 Days)
Popular Topics(Views)
340,650 Are you busy
266,020 Re: Forum
246,946 Need opinion
New Page 2
Powered by UBB.threads™ PHP Forum Software 7.7.5