# "High Tension" Wires? **URL:** \ **Category:** Factual Questions\ **Created:** [August 11, 2011, 12:49am UTC](https://boards.straightdope.com/t/high-tension-wires/592278 "2011-08-11T00:49:29Z")\ **Posts on this page:** 19\ **Page:** 1
**Author:** ![HuckleCat](https://avatars.discourse-cdn.com/v4/letter/h/ea5d25/32.png) [@HuckleCat](https://boards.straightdope.com/u/HuckleCat)\ **Post date:** [August 11, 2011, 12:49am UTC](https://boards.straightdope.com/t/high-tension-wires/592278/1 "2011-08-11T00:49:29Z")
This has always struck me as a misnomer. Shouldn’t it be “High Voltage” wires? Or perhaps “High, Tension Wires?” ---
**Author:** ![Jinx](https://avatars.discourse-cdn.com/v4/letter/j/c6cbf5/32.png) [@Jinx](https://boards.straightdope.com/u/Jinx)\ **Post date:** [August 11, 2011, 12:51am UTC](https://boards.straightdope.com/t/high-tension-wires/592278/2 "2011-08-11T00:51:41Z")
I say “Hi, tension wires!” Why so tense? 😃 ---
**Author:** ![Joey\_P](https://avatars.discourse-cdn.com/v4/letter/j/919ad9/32.png) [@Joey\_P](https://boards.straightdope.com/u/Joey_P)\ **Post date:** [August 11, 2011, 12:51am UTC](https://boards.straightdope.com/t/high-tension-wires/592278/3 "2011-08-11T00:51:51Z")
IIRC tension is French for voltage. ETA, confirmed by Google Translate ---
**Author:** ![HuckleCat](https://avatars.discourse-cdn.com/v4/letter/h/ea5d25/32.png) [@HuckleCat](https://boards.straightdope.com/u/HuckleCat)\ **Post date:** [August 11, 2011, 1:00am UTC](https://boards.straightdope.com/t/high-tension-wires/592278/4 "2011-08-11T01:00:04Z")
> [@Joey\_P](#): > > IIRC tension is French for voltage. > > ETA, confirmed by Google Translate Brilliant, Thank you Joey! ---
**Author:** ![engineer\_comp\_geek](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/engineer_comp_geek/32/504_2.png) [@engineer\_comp\_geek](https://boards.straightdope.com/u/engineer_comp_geek)\ **Post date:** [August 11, 2011, 1:09am UTC](https://boards.straightdope.com/t/high-tension-wires/592278/5 "2011-08-11T01:09:14Z")
Engineers use V for voltage and I for current (C is used for capacitance). The I comes from Inensite, which is also French. I tend to use the phrase “high tension” but a lot of engineers don’t like it and consider it to be slang. In real engineering work though I don’t use either one and instead refer to the line by its voltage (i.e. the “35 KV line” instead of the “high voltage line”). ---
**Author:** ![HuckleCat](https://avatars.discourse-cdn.com/v4/letter/h/ea5d25/32.png) [@HuckleCat](https://boards.straightdope.com/u/HuckleCat)\ **Post date:** [August 11, 2011, 1:20am UTC](https://boards.straightdope.com/t/high-tension-wires/592278/6 "2011-08-11T01:20:15Z")
> [@engineer\_comp\_geek](#): > > Engineers use V for voltage and I for current (C is used for capacitance). The I comes from Inensite, which is also French. > > I tend to use the phrase “high tension” but a lot of engineers don’t like it and consider it to be slang. In real engineering work though I don’t use either one and instead refer to the line by its voltage (i.e. the “35 KV line” instead of the “high voltage line”). Thanks ECG, its good to check my Laymans’ musing with a real engineer! I spend too much time wondering about power lines on my daily 126 mile round trip commute on the NJ Turnpike! ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [August 11, 2011, 1:52am UTC](https://boards.straightdope.com/t/high-tension-wires/592278/7 "2011-08-11T01:52:34Z")
> [@](#): > > The I comes from Inensite, which is also French. Do you have a cite for this? Everything I’ve read on the origin of I for current has just boiled down to “nobody knows”. (and should that be “in_t_ensite”?) ---
**Author:** ![johnpost](https://avatars.discourse-cdn.com/v4/letter/j/f17d59/32.png) [@johnpost](https://boards.straightdope.com/u/johnpost)\ **Post date:** [August 11, 2011, 1:58am UTC](https://boards.straightdope.com/t/high-tension-wires/592278/8 "2011-08-11T01:58:37Z")
i from the French for ‘current intensity’ ---
**Author:** ![Rick](https://avatars.discourse-cdn.com/v4/letter/r/9f8e36/32.png) [@Rick](https://boards.straightdope.com/u/Rick)\ **Post date:** [August 11, 2011, 2:55am UTC](https://boards.straightdope.com/t/high-tension-wires/592278/9 "2011-08-11T02:55:53Z")
> [@Chronos](#): > > Do you have a cite for this? Everything I’ve read on the origin of I for current has just boiled down to “nobody knows”. > > (and should that be “in_t_ensite”?) It’s the answer I got 6 years ago in a [thread](http://boards.straightdope.com/sdmb/showthread.php?t=338522) I started. ---
**Author:** ![engineer\_comp\_geek](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/engineer_comp_geek/32/504_2.png) [@engineer\_comp\_geek](https://boards.straightdope.com/u/engineer_comp_geek)\ **Post date:** [August 11, 2011, 4:44am UTC](https://boards.straightdope.com/t/high-tension-wires/592278/10 "2011-08-11T04:44:28Z")
> [@Chronos](#): > > Do you have a cite for this? Everything I’ve read on the origin of I for current has just boiled down to “nobody knows”. It’s what I was taught in EE 101 many years ago and there are plenty of cites for it. > [@](#): > > The symbol / is used for current under an international agreement which insures having the same symbols used in electrical work the world over. This is very convenient indeed in studying books written in foreign languages. The letter / is taken from the French word for current, “intensite.” from “Principles of electrical engineering” By William Henry Timbie, Vannevar Bush, 1922 I was taught it came from the writings of André Marie Ampère (the same guy the unit Ampere or Amp was named after) who called it “l’intensité du courant” but other than “because my professor said so” I don’t have a cite attributing it directly to Ampere. > [@Chronos](#): > > (and should that be “in_t_ensite”?) The SDMB hamsters were hungry and ate my T. That’s my story and I’m sticking to it. ---
**Author:** ![engineer\_comp\_geek](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/engineer_comp_geek/32/504_2.png) [@engineer\_comp\_geek](https://boards.straightdope.com/u/engineer_comp_geek)\ **Post date:** [August 11, 2011, 5:24am UTC](https://boards.straightdope.com/t/high-tension-wires/592278/11 "2011-08-11T05:24:03Z")
Ok, I’ve really got some cites now. A paper by Ampere himself showing his use of i for current. Here is one example in plain text that isn’t in the middle of a formula but there are many others throughout the paper: > [@](#): > > pour l’expression générale de l’action de deux élémens ds, ds’ de deux courans ayant pour **intensités i** et i’. (bolding mine) Source: A-M Ampère, Recuil d’Observations Électro-dynamiques, p.56, Paris: Chez Crochard Libraire 1822 PDF download available here: [http://www.ampere.cnrs.fr/textes/recueil/pdf/recueilobservationsd.pdf](http://www.ampere.cnrs.fr/textes/recueil/pdf/recueilobservationsd.pdf) From poking around on the net, it seems like the French used i for current throughout the 1800s, while the English used c (some cites say this is possibly due to anti-French sentiment at the time). Towards the end of the 1800s the use of c in England declined and everyone pretty much standardized on i. One cite: > [@](#): > > The person who did founding work with electrical current was a french physicist, Andr´e-Marie Amp´ere. The notion of current was first introduced by Amp´ere, who called it ”intensite’ du courant”, translated, ”the intensity of the flow”. We got the English word ’current’ from the latter part of the French term, ’courant’. The use of the letter I was the first symbol given to this quantity, and is still the one we use today despite some attempts to start using the letter C for current through the 1800’s, for example by Maxwell. One interesting thought is that this may be due to English disdain for the French at this time. From here: (warning - PDF) [http://www.wpi.edu/Pubs/E-project/Available/E-project-030509-114708/unrestricted/symbols.pdf](http://www.wpi.edu/Pubs/E-project/Available/E-project-030509-114708/unrestricted/symbols.pdf) I haven’t found the “international agreement” cited in the other book from my previous post. I believe it may have been the Conference of Electricians held in Paris in 1881, though that seems to have been mostly French and I would be a bit reluctant to call it “international”. ---
**Author:** ![guizot](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/guizot/32/3636_2.png) [@guizot](https://boards.straightdope.com/u/guizot)\ **Post date:** [August 11, 2011, 5:47am UTC](https://boards.straightdope.com/t/high-tension-wires/592278/12 "2011-08-11T05:47:56Z")
> [@Joey\_P](#): > > IIRC tension is French for voltage. > > ETA, confirmed by Google Translate It’s _also English_ for voltage, so why translate from the French?: [QUOTE=Oxford English Dictionary] _ **tension** _, n. 4. Electr. The stress along lines of force in a dielectric. Formerly applied also to surface density of electric charge, and until about 1882 used vaguely as a synonym for potential, electromotive force, and mechanical force exerted by electricity: still so applied, in industrial and commercial use, in low tension n. at sense 5a: see sense 5. 5. high tension n. a high degree of tension (of any kind). a. esp. in Electr., a term for a high degree of electromotive force or difference of potential: now chiefly used by makers of motor-cars, and of magnetic and induction coils. So low tension n. (See sense 4) Chiefly attrib. as in high or low tension system (of electric lighting, etc.); also high tension. or low tension charge, tension contact, tension current, tension fuse, etc. [/quote] Voltage is a kind of “pressure,” and so you’ll see in latin-derived languages the term _tension_ to refer to things like “high blood pressure.” ---
**Author:** ![CurtC](https://avatars.discourse-cdn.com/v4/letter/c/ce73a5/32.png) [@CurtC](https://boards.straightdope.com/u/CurtC)\ **Post date:** [August 11, 2011, 3:05pm UTC](https://boards.straightdope.com/t/high-tension-wires/592278/13 "2011-08-11T15:05:14Z")
I’ve seen signs in areas around those big fenced-in electrical transformers, that say both “High Voltage” and “Haute Tension.” I’ve always considered the phrase “high-tension lines” to have started from a non-technical person like a news reporter, and the usage stuck among reporters. Similar to how news reporters refer to the area where airplanes park as the “tarmac.” ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [August 11, 2011, 5:37pm UTC](https://boards.straightdope.com/t/high-tension-wires/592278/14 "2011-08-11T17:37:23Z")
OK, Ampere himself using it that way is a pretty solid cite. I’ll keep that in mind the next time a student asks me, thanks. ---
**Author:** ![brewha](https://avatars.discourse-cdn.com/v4/letter/b/91b2a8/32.png) [@brewha](https://boards.straightdope.com/u/brewha)\ **Post date:** [August 11, 2011, 5:44pm UTC](https://boards.straightdope.com/t/high-tension-wires/592278/15 "2011-08-11T17:44:37Z")
> [@engineer\_comp\_geek](#): > > Engineers use V for voltage and I for current (C is used for capacitance). The I comes from Inensite, which is also French. > > I tend to use the phrase “high tension” but a lot of engineers don’t like it and consider it to be slang. In real engineering work though I don’t use either one and instead refer to the line by its voltage (i.e. the “35 KV line” instead of the “high voltage line”). Well, according to my outspoken EE professor, “voltage” is a made up word and should never be used. Volt is the measure of electromotive force, just like Ohm is the measure of resistance. But, you don’t call resistance ohmerage, right? I wonder how he feels about the word amperage, though. I’m not stating any of this as fact - just what one guy told me during my mandatory EE class while getting my ME degree. ---
**Author:** ![ftg](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ftg/32/2801_2.png) [@ftg](https://boards.straightdope.com/u/ftg)\ **Post date:** [August 11, 2011, 6:17pm UTC](https://boards.straightdope.com/t/high-tension-wires/592278/16 "2011-08-11T18:17:26Z")
> [@brewha](#): > > Well, according to my outspoken EE professor, “voltage” is a made up word and should never be used. Volt is the measure of electromotive force, just like Ohm is the measure of resistance. But, you don’t call resistance ohmerage, right? But people who know their electrical terminology might use [ohmage](http://dictionary.reference.com/browse/ohmage). You practically can’t get more made up than with words like Volt, Ohm and Ampere. Turning people’s names into words _is_ making up words. It’s been my experience that most pedantic people are wrong. ---
**Author:** ![Boyo\_Jim](https://avatars.discourse-cdn.com/v4/letter/b/87869e/32.png) [@Boyo\_Jim](https://boards.straightdope.com/u/Boyo_Jim)\ **Post date:** [August 11, 2011, 6:29pm UTC](https://boards.straightdope.com/t/high-tension-wires/592278/17 "2011-08-11T18:29:55Z")
Ohmerage ia an homage to ohmage. ---
**Author:** ![Max\_Torque](https://avatars.discourse-cdn.com/v4/letter/m/e9bcb4/32.png) [@Max\_Torque](https://boards.straightdope.com/u/Max_Torque)\ **Post date:** [August 11, 2011, 6:52pm UTC](https://boards.straightdope.com/t/high-tension-wires/592278/18 "2011-08-11T18:52:20Z")
When I was in EE, I thought the whole system of standardized letters was absurd. I pictured the conversation going something like this: “Okay, we’ve got V for voltage and R for resistance. What’s next?” “Capacitance. Let’s use C.” “C it is. We’re on a roll. Okay, next up is…current. Crap, we just used C. Is there another letter we can use?” “How about I?” “I? What the hell does I have to do with current? Why not A for amps?” “No, we might need A later. Just put I.” “Fine, I it is. What variable is next?” “Lemme see…inductance.” “Son of a bitch…” ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [August 11, 2011, 8:12pm UTC](https://boards.straightdope.com/t/high-tension-wires/592278/19 "2011-08-11T20:12:26Z")
Personally, I prefer “voltage”, for teaching purposes, to “potential”. The latter is too easily confused with “potential energy”. Of course, the two concepts are closely related, but they’re _not_ the same. **Max Torque** , what’s funniest is when you’re grading a test from a student with an equation sheet, but who doesn’t know how to use it, and just grabs some random equation that has the right letters in it. I’ve seen quite a few students use a formula involving length when they were supposed to be looking for inductance. Or trying to find a magnetic dipole moment, but instead using the permeability of space.