ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
Top Posters(30 Days)
twh 3
Recent Posts
FPE in Germany
by Texas_Ranger. 11/19/17 07:30 AM
Ceiling fan distance from outdoor hot tub
by gfretwell. 11/16/17 02:18 AM
diazed fuses
by Texas_Ranger. 11/13/17 03:02 PM
Theft deterrent alarm
by gfretwell. 11/12/17 01:39 PM
EEPROM errors on XC7Z010-2CLG225I chip
by twh. 11/07/17 05:45 PM
New in the Gallery:
Gallery Test
Popular Topics(Views)
242,610 Are you busy
178,797 Re: Forum
170,043 Need opinion
Who's Online Now
1 registered members (crselectric), 46 guests, and 10 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate This Thread
#196970 - 11/03/10 11:20 AM OT: CALCULATING temperature of a conductor.  
LarryC  Offline
Member
Joined: Jul 2004
Posts: 783
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 01:37 PM Re: OT: CALCULATING temperature of a conductor. [Re: LarryC]  
gfretwell  Offline


Member
Joined: Jul 2004
Posts: 9,135
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 03:28 PM Re: OT: CALCULATING temperature of a conductor. [Re: gfretwell]  
LarryC  Offline
Member
Joined: Jul 2004
Posts: 783
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 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: 0.012s Queries: 15 (0.003s) Memory: 0.7522 MB (Peak: 0.8756 MB) Zlib enabled. Server Time: 2017-11-21 22:46:59 UTC