Maximum Switching Surge Factor Calculation

[Ballgame]

I'm trying to find the calculation for determining the Maximum Switching Surge Factor for a 230kV Transmission Line.

This term is defined in the National Electric Safety Code as a switching-surge level for circuit breakers corresponding to 98% probability that the maximum switching surge generated per breaker operation does not exceed this surge level, or the maximum anticipated switching-surge level generated by other means, whichever is greater.

Anyone familiar with a methodology or calculation for coming up with this value??

Thanks

 

[7anoter4]

Sorry,I cannot find anywhere in NESC where "Maximum Switching Surge Factor" is defined. Could you pls. indicate the chapter no.?

 

[Ballgame]

Section 232D3a

(In the 2011 edition of NESC it is on page 93 about 2/3 of the way down the page.)

 

[7anoter4]

Yes I found it, thanks.But I think you have to see:
thread238-297714
and here the cuky2000 answer.