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

ECN Shout Chat
Top Posters(30 Days)
Admin 18
Recent Posts
Anyone hiring inspectors?
by Admin. 03/26/17 02:42 PM
Old decora style outlets
by Admin. 03/25/17 11:40 AM
ESA Arc flash course
by TheShockDoctors. 03/24/17 10:15 AM
fuse rejectors
by HotLine1. 03/24/17 07:53 AM
Another Forum Update
by Admin. 03/22/17 03:04 PM
New in the Gallery:
SE cable question
Popular Topics(Views)
231,518 Are you busy
166,220 Re: Forum
160,664 Need opinion
Who's Online Now
1 registered members (sparky66wv), 58 guests, and 15 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate This Thread
#196970 - 11/03/10 12:20 PM OT: CALCULATING temperature of a conductor.  
LarryC  Offline
Member
Joined: Jul 2004
Posts: 781
Winchester, NH, US
I am trying to come up with a method to calculate the maximum current one can push thru a conductor until you reach a predetermined temperature.

What is stumping me is the following: I know the conductor initial temperature, initial resistance, energy that has been put into the conductor (power x time), and the specific heat of the conductor. How can I relate all of this information to determine a final temperature?

Initially I am assuming DC or low frequency AC. Eventually I want to expand the model to include skin effect from higher frequency AC and variable duty cycle waveforms.


Work Gear for Electricians and the Trades

#196971 - 11/03/10 02:37 PM Re: OT: CALCULATING temperature of a conductor. [Re: LarryC]  
gfretwell  Offline


Member
Joined: Jul 2004
Posts: 9,057
Estero,Fl,usa
I think you should start this by following the logic in the Neher–McGrath formula and work from there. Why reinvent the wheel?

This is from the handbook commentary in 310.15

Quote
A description of this calculation method was given in AIEE paper No. 5-660, “The Calculation of the Temperature Rise and Load Capability of Cable Systems,” by Neher and McGrath. This paper was presented to the AIEE general meeting in Montreal, Quebec, on June 24–28, 1956, and was published in AIEE Transactions, Part III (Power Apparatus and Systems), Vol. 76, October 1957, pp. 752–772. The AIEE (American Institute of Electrical Engineers) is now the Institute of Electrical and Electronics Engineers (IEEE).


You can probably find this paper on the net somewhere.


Greg Fretwell

#196975 - 11/03/10 04:28 PM Re: OT: CALCULATING temperature of a conductor. [Re: gfretwell]  
LarryC  Offline
Member
Joined: Jul 2004
Posts: 781
Winchester, NH, US
Thank you.

Google here I come.



Member Spotlight
BEAMEUP
BEAMEUP
WA
Posts: 27
Joined: December 2004
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: 0.013s Queries: 15 (0.003s) Memory: 0.7504 MB (Peak: 0.8745 MB) Zlib enabled. Server Time: 2017-03-26 18:50:09 UTC