Talk:Phantom voltage

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Justification: The topic of phantom voltage comes up frequently in web discussion groups. People working on electrical stuff measure the voltage on a disconnected wire and are confused because they get a reading. Some web reference is needed to point them to to explain this.

I'm actively seeking some better references.

drh 15:11, 24 January 2007 (UTC)

Agreed. Especially the confusion with `phantom power` in professional audio. These two concepts crop up all the time. Perhaps tagging this article with the proper electronics category would gain it some more exposure, and hence a contributor to clean it up. 65.112.197.16 21:32, 17 July 2007 (UTC)

[edit] Undo

I manually undid the changes by woodturner9, and in the process probably lost some other edits. There's no scientific basis for attributing ordinary phantom voltage in electrical power wiring to inductive coupling.

Inductive coupling IS a factor in signal wiring, but that's a different topic. If someone wishes to start a page on that topic and link it to this one that's fine.drh (talk) 12:31, 5 December 2007 (UTC)

[edit] Response

To the contrary, inductive coupling is the PRIMARY source of so called "phantom voltage" at low (AC line) frequencies. It's factually incorrect to refer to this as capacitive coupling. Engineers have been fighting this misinterpretation for decades, and we shouldn't be adding to the misunderstanding. There simply is not enough capacitive coupling at frequencies less than 1 KHz or so for any significant capacitive coupling to occur.

The page as changed refers to capacitance of a cable, citing numbers for NM-B cable. However, this is the capacitance per unit length, which has nothing to due with the capacitave coupling between two conductors.

Perhaps the best resolution of this dispute is to find some real, definitive references, rather than relying on web pages that may perpetuate the misinformation. I'll see what I can find. Woodturner9 (talk) 11:34, 6 December 2007 (UTC)

Inductive coupling would only occur if there were current flowing, and there is none to speak of in the most common phantom voltage scenarios. Either it's capacitive coupling or magic, and my EE degree says capacitive coupling.24.159.203.105 (talk) 19:36, 13 January 2008 (UTC)

By that logic, it couldn't be capacitive coupling either, since both would require current flow. In fact, there is and must be current flow for both capacitive and inductive coupling. There HAS to be current flow for the meter to register ANYTHING, it's just a small current.

If your EE degree says it's capactive coupling, I'd stop listening to your EE degree :-) I have taught these subjects at university for many years (my BS, MS, and PhD are in EE), and it is clearly inductive coupling. I probably should add some of the textbook references, so folks can look it up if they want to learn more. —Preceding unsigned comment added by Decolores9 (talk • contribs) 20:55, 21 February 2008 (UTC)