What does index k in short-circuit current Ik mean? 2

[Krustabas]

Does anyone know the meaning of index “k” in many of the short-circuit related parameters, for example, Ik (short-circuit current), Uk (short-circuit voltage), Sk (short-circuit power)?

This index is used many books and standards in many languages. I suspect it comes from German “kurzschluss” (short-circuit) although I cannot verify it. This index nicely fits also in Russian textbooks (where the word “short” starts with a “k”).

In my native language, this index does not match anything and it is strange to use it unless I clearly know its origin.

 

[waross]

kilo

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[VEBill]

Even the most detailed PDFs available make no mention of the meaning or origin of the k in I[sub]k[/sub].

Strange.

'Kurzschluss' is a good guess.

 

[benta]

I[sub]K[/sub] is indeed short-circuit current and appears in many Germen textbooks as such. Your reference to "Kurzschluss" is right.

 

[Krustabas]

I do not find subscript “k” in the books of C.P.Steinmetz (Theory and calculation of alternating current phenomena, 1900), W.W.Lewis (Transmission line engineering, 1928), C.F.Wagner & R.D.Evans (Symmetrical components, 1933), E.Clarke (Circuit analysis of AC power systems, 1943), P.M.Anderson (Analysis of faulted power systems, 1995). Although subscript “k” is used in IEEE Std 551 (Violet book), it seems to me that the origin of “k” has to be European.

I have found extensive use of subscript “k” in E.Arnold (Die Wechselstromtechnik, Erster Band, 1910). I guess I will find this subscript in earlier German texts as well. Taking into account that the German language was the only dominant scientific language in late 19th and early 20th centuries in which subscript “k” has a direct meaning, all points to “kurzschluss”.

 

[IRstuff]

I think you are getting overly hung up about the subscript; it can be ANYTHING the author chooses, and so long as the book is internally consistent, it's fine. It's not like there's some sort of global subscript police saying, "Oh no, your book has to be burned because you used I_sc, instead of I_k."

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

https://www.youtube.com/watch?v=BKorP55Aqvg

faq731-376 forum1529 Entire Forum list

http://www.eng-tips.com/forumlist.cfm

 

[Krustabas]

I agree that as an author I can use any notation I prefer, as long it is consistent, mathematically correct, does not deviate too much from standards (such as ISO, IEC) and so on. However, knowing the reason behind “k” could help me select more appropriate subscript in my language (in this case there are no subtleties so it will not be difficult). Anyway, it is interesting to know (thankfully no student has asked me about it yet).

 

[zappedagain]

For a few more variations, when talking about entity parameters, the IEC uses Io and UL uses Isc for output short circuit current.

Z