ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
Top Posters(30 Days)
Trumpy 5
Recent Posts
What do you do?
by ghost307. 09/22/17 08:26 AM
Another generator question
by gfretwell. 09/21/17 02:41 PM
Supporting conduit bodies
by ghost307. 09/18/17 12:12 PM
Thermal Imaging Camera upgrade
by Potseal. 09/18/17 11:57 AM
Linear Power Supply Quits Under Load
by JoeTestingEngr. 09/15/17 11:37 PM
New in the Gallery:
Gallery Test
Popular Topics(Views)
240,875 Are you busy
176,628 Re: Forum
168,538 Need opinion
Who's Online Now
0 registered members (), 38 guests, and 12 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
akmaster
akmaster
alaska
Posts: 70
Joined: June 2012
Show All Member Profiles 
Featured:

2017 Master Electrician Exam Preparation Combos
2017 NEC Electrician
Exam Prep Combos:
Master / Journeyman

 

Shout Box
Powered by UBB.threads™ PHP Forum Software 7.6.0
Page Time: 0.013s Queries: 15 (0.003s) Memory: 0.7436 MB (Peak: 0.8593 MB) Zlib enabled. Server Time: 2017-09-23 00:14:47 UTC