ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
Top Posters(30 Days)
Potseal 11
Recent Posts
Why cables look like they do
by LongRunner. 04/26/17 09:36 AM
Dimmable LED 2x4 lay in fixtures
by HotLine1. 04/24/17 05:43 PM
Old decora style outlets
by Lostazhell. 04/22/17 07:59 PM
Permit Snafus...AHJs and Contractors Jump in
by gfretwell. 04/22/17 01:11 PM
How do you find a good employee?
by HotLine1. 04/22/17 10:44 AM
New in the Gallery:
SE cable question
Popular Topics(Views)
234,782 Are you busy
169,548 Re: Forum
162,819 Need opinion
Who's Online Now
0 registered members (), 59 guests, and 7 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate This Thread
#214531 - 12/18/14 11:28 PM derating rooftop conductors  
BigB  Offline
Member
Joined: Mar 2004
Posts: 719
Tucson, AZ USA
When derating THWN-2 copper conductors for ambient that will eventually terminate in a sub panel with a 125 amp rating can I use the 90C column?


2017 / 2014 NEC & Related Books and Study Guides

#214533 - 12/19/14 04:54 AM Re: derating rooftop conductors [Re: BigB]  
Tesla  Offline
Member
Joined: Jun 2004
Posts: 1,273
Sacramento, CA
The sole and only reason for that column IS derating.

For there are no 90 degree rated devices out there.

One then uses the lesser computed ampacity limit.

So, yes, you start with the 90 degree column.


Tesla


Member Spotlight
RH1
RH1
California
Posts: 22
Joined: August 2009
Show All Member Profiles 
Featured:

2017 NEC and Related
2017 NEC
Now Available!

Shout Box
Powered by UBB.threads™ PHP Forum Software 7.6.0
Page Time: 0.009s Queries: 15 (0.002s) Memory: 0.7426 MB (Peak: 0.8585 MB) Zlib enabled. Server Time: 2017-04-27 07:15:56 UTC