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OT: CALCULATING temperature of a conductor. #196970
11/03/10 11:20 AM
11/03/10 11:20 AM
L
LarryC  Offline OP
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
Re: OT: CALCULATING temperature of a conductor. [Re: LarryC] #196971
11/03/10 01:37 PM
11/03/10 01:37 PM
G
gfretwell  Offline

Member
Joined: Jul 2004
Posts: 9,166
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
Re: OT: CALCULATING temperature of a conductor. [Re: gfretwell] #196975
11/03/10 03:28 PM
11/03/10 03:28 PM
L
LarryC  Offline OP
Member
Joined: Jul 2004
Posts: 783
Winchester, NH, US
Thank you.

Google here I come.


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