Talk:Power factor/Archive 4

Greater than -1
I just reverted the addition of "or greater than -1." I don't think it's an improvement. It's ambiguous and unnecessary. Ambiguous because all numbers are either less than one or greater than -1. Unnecessary because the statement was true and precise as it was. Also a bit misleading because it implies that PF of -1 could have the voltage and current in phase. Kendall-K1 (talk) 05:28, 7 February 2018 (UTC)


 * Fuck me: not again!!! Please see the overly exhaustive discussion at Talk:Power factor/Archive 2 where Wtshymanski is the only person in the known universe who believes that negative power factor does not exist as a concept and will not accept it when every other person says it does (establishing a good consensus). His edit summary of, “Clarify for those who don’t think negative PF is a result of wiring mistakes” says it all. 148.252.129.216 (talk) 17:31, 8 February 2018 (UTC)


 * Well, me and the people who wrote the standard. But believe what you want to. The IEEE standard says power flows from a source to a load and so negative power factor is an error. --Wtshymanski (talk) 17:35, 8 February 2018 (UTC)


 * As you know full well (see the linked discussion above), the IEEE document that you relied upon stated both what you claimed and that negative power factor did exist, was acknowledged by Alex MacEachern, its author as being in error and duly corrected to eliminate your claim. So why not just drop the stick and back slowly away from the carcass? 148.252.129.216 (talk) 17:46, 8 February 2018 (UTC)


 * OK, I have had quite enough of this. Wtshymanski, you are so full of shit that I put on my rubber boots so that the overflow doesn't ruin my good shoes.


 * When your understanding of electrical engineering is correct, and it usually is, you do good work, but when your understanding is wrong you hang on and refuse to admit your error as the evidence against your batshit crazy ideas mounts up. You make snide comments about the editors who do understand the basic principles of electrical engineering, and you tell outright lies like "me and the people who wrote the standard".


 * You know that "the people who wrote the standard" acknowledged that two different sections gave two different answers about whether negative power factors exist, and you know that they corrected the standard so that it unambiguously states that negative power factors do indeed exist.


 * Your theories about negative power factor are WP:FRINGE pseudoscience, and will be treated as such. Please keep them out of Wikipedia. They are unsourced and do not belong here. Don't let the door hit your ass on your way out.


 * There once was a drunk driver who was driving the wrong way on the freeway. Upon hearing on the radio (over the honking horns) that there was a drunk driver who was driving the wrong way on the freeway, he peered through his windshield, noticed all of the headlights heading toward him, and exclaimed "My God! There are DOZENS of them!!" --Guy Macon (talk) 20:02, 8 February 2018 (UTC)


 * Wow, there's no coming back from that closely-reasoned riposte. I guess I've been put in my place. Eppur si muove. --Wtshymanski (talk) 21:53, 8 February 2018 (UTC)


 * How about simply admitting that you are wrong instead of acting like an asshat? Or, if you aren't willing to admit that you are wrong, what say you simply STFU rather than annoying us with your batshit crazy pseudoscience theories? What's next? Antivax? Creationism?


 * This has all been explained to you before:


 * "I'm not sure how to add comments to this discussion, but I will try. As one of the active participants in developing IEEE 1459, I regret that we failed to acknowledge that active power can flow both directions, and has a sign. I will try to get that fixed in the next edition. Negative power is not a matter of connecting meter leads incorrectly; it's a real-world situation. Consider a house that has a large solar panel/inverter on its roof. Let's say that in the middle of the day, the solar panel makes enough power that power flows from the house to the grid. In the middle of the night, power flows from the grid to the house. The simplest measurement solution is to define one of these directions as "positive power" -- typically, we define the power that flows from the grid to the house as positive power -- and that makes the other direction negative power. Anybody who believes that single phase non-distorted power flow is defined by Vrms x Irms x cos(theta) must also believe in negative power, because Vrms is always positive due to the "square" term in RMS, Irms is always positive due to the "square" term in RMS, and cos(theta) can take any value between -1 and 1.  I don't think references are necessary for this discussion, any more than we need a reference saying that -1 x 4 = -4 . Of course, power factor can take any value between -1 and +1 - there isn't any doubt about this topic in the electric power measurement community. Every modern electric power instrument for AC systems that has been built in the last quarter of a century happily measures both negative and positive power (Fluke, Dranetz, BMI, Schneider, Power Standards Lab) and calculates a signed Power Factor value as the ratio of a signed power to an unsigned VA." AMcEachern (talk) 23:03, 12 October 2012 (UTC)


 * "Ah! I think you have it precisely correct when you put "load" and "source" in quotation marks. Your interpretation is absolutely correct - power is negative when it flows from the thing identified, nominally, as the load towards the thing identified, nominally, as the source.  A quarter of a century ago, that was an extremely rare situation; today, it's far more common, with so many residences having photovoltaic systems.  At their revenue meters, we see positive power when power flows from the grid to the house, and negative power when it flows from the house to the grid. There's nothing complicated about that. You are also correct that the old convention of using "+" and "-" for lead/lag causes a lot of confusion, but fortunately this is also rare today -- not rare enough, probably!  But as long as we all agree that power factor is the ratio of power to volt-amps, I don't think there's any real dispute that power can be negative (at least among modern measuring authorities) so I don't think there's any real dispute that power factor can range from -1 to +1."AMcEachern (talk) 01:03, 15 October 2012 (UTC)


 * "Would you accept [the version as of 2012] of IEEE 1459 itself as the citation for positive and negative power, and therefore positive and negative power factor? if so, please examine Figure 1 in both Editions of IEEE 1459, which clearly shows both positive and negative power along the horizontal axis.  I agree that Figure 1 directly conflicts, in the same Standard, with the statement in 3.1.1.1 that says that power is always positive." AMcEachern (talk) 00:34, 16 October 2012 (UTC)


 * "I have temporarily placed a Draft IEEE paper [...] for your review; it includes a dozen citations over the last 100 years on the correct meaning of negative power factor.  I would welcome your comments and suggestions.  Among my colleagues in the academic and metrology community who have seen this draft, the general consensus is that the paper is correct but perhaps not worth publishing, because it is so widely known and accepted that power factor ranges from -1 to +1. And one professor of Electrical Engineering at Berkeley, who wants to remain nameless, jokingly asked me not to correct the Wikipedia article on PF because she uses it in her introductory lecture as a great example of why her students are forbidden to cite Wikipedia - there's an obvious technical error -- the range 0-1 -- on the very first line of the article...)


 * May I gently point out that we have no citations, as far as I know, for saying that power factor is between 0 and 1? My understanding is that you derive that conclusion from the [incorrect, with my apologies] statement in IEEE 1459 that power is always positive.  Based on the same level of analysis, could we use IEEE 1459 Fig 1 (which shows positive and negative power) as our citation for negative power factor?  Would that be a reasonable solution?" AMcEachern (talk) 18:18, 17 October 2012 (UTC)


 * "I asked you if we could use IEEE 1459 Figure 1 as the citation, but you ignored my question. I provided you with 12 citations on negative power factor in the Draft IEEE paper, and you made no comments. [...]


 * You are incorrect -- forgive me for being blunt -- that using a polarity for a value that can, in fact, be positive or negative such as the ratio W/VA alters it from a one-dimensional value to a two-dimensional value. Doing so simply places the value correctly on the number line, either to the left of zero or the right of zero. Ratios are often negative - there are negative percentages, for example. Ratios are, by their nature, values with single dimensions.


 * Lastly, and most importantly, like most metrology engineers I believe being truthful and correct is inherently useful. And I think this is especially important in defining basic measurement quantities. Young engineers use Wikipedia for their initial information - we know they shouldn't, but they do.  We older engineers should work hard to make the information in Wikipedia correct. [...]


 * At this point, I think I have done the best I can. I have provided you with technical citations from the IEEE 1459 standard, while acknowledging that the standard [which I edited, so I must take the blame] is ambiguous; I have provided you with a dozen citations; I have suggested that both ranges be presented; I have provided you with practical applications. If, in your opinion, all this is insufficient to even include in the article the possibility that there are multiple opinions, you have greater intellectual confidence than I do.


 * But, still, I'm an optimist -- I do hope you will find a way to, at a minimum, include both the 0 - 1 range and the -1 - +1 range, using all of the proposed citations that have been given to you for justification. Otherwise, we can look forward to continuing this conversation in a few years, after the next edition of IEEE 1459!  Cheers! AMcEachern (talk) 22:00, 17 October 2012 (UTC)


 * --Guy Macon (talk) 19:24, 9 February 2018 (UTC)


 * Useless. Explain why "active" power changes sign but "apparent" power doesn't. PF is ratio of active to apparent power. --Wtshymanski (talk) 23:13, 9 February 2018 (UTC)


 * Sorry, but competence is required. If you won't listen to IEEE 1459 (Figure 1 clearly shows both positive and negative power along the horizontal axis) and you won't listen to the dozens of high-quality sources that AMcEachern gave you (you have zero sources to support your bullshit theory) you certainly will not listen to me. I have better things to do than debate known crackpots. --Guy Macon (talk) 00:22, 10 February 2018 (UTC)


 * It occurred to me that someone new to engineering might be confused by Wtshymanski's question above, so here is the answer from our article on AC power:


 * Engineers use the following terms to describe energy flow in a system (and assign each of them a different unit to differentiate between them):
 * Active power,] P, or real power: watt (W)
 * Reactive power, Q: volt-ampere reactive (var)
 * Complex power, S: volt-ampere (VA)
 * Apparent power, |S|: the magnitude of complex power S: volt-ampere (VA)
 * Phase of voltage relative to current, φ: the angle of difference (in degrees) between current and voltage; $$\varphi=\arg(V)-\arg(I)$$. Current lagging voltage (quadrant I vector), current leading voltage (quadrant IV vector).
 * In this case, "magnitude" is pretty much the same thing as absolute value. The magnitude of +1 is 1. The magnitude of -1 is 1. --Guy Macon (talk) 00:56, 10 February 2018 (UTC)


 * Is Figure 1 of IEEE 1495 the same in the 2010 edition? Too broke to update all my IEEE standards to current practice. Does it explain why the sign of active power reverses, but not the sign of apparent power? --Wtshymanski (talk) 04:45, 10 February 2018 (UTC)


 * Figure 1 of IEEE 1495 IEEE 1459 is the same in every edition that has ever been published, and it is the same in the draft edition that is now going through the approval process (which, BTW, corrects the "power flows from sources to loads" error in the earlier editions).


 * Your question above was asked and answered by AMcEachern (primary author of IEEE 1459) back in 2012. The problem is that you refuse to accept the answer. Here is that answer again for any engineering students who might be reading this discussion.


 * "(1) RMS values are always positive, because they begin by squaring some either positive or negative instantaneous value, and the squaring function converts both to a positive number."


 * "(2) Volt-Amps [apparent power] is RMS volts x RMS amps, and is therefore always positive."


 * "(3) Power Factor is the ratio of Watts to Volt-Amps. "


 * "(4) For sinusoidal waveforms, Watts [active power] is RMS volts x RMS amps x cosine(angle between voltage and current sine waves) - this is mathematically equivalent, for sinusoidal waveforms, to watts is the integral, over an interval of time that is an integer multiple of half-periods, of the instantaneous product of the instantaneous voltage and the instantaneous current."


 * "(5) The cosine function has an output in the range of -1 to +1."


 * "(6) Watts, therefore, can be either positive or negative."


 * "(7) Power Factor, therefore, has a range of -1 to +1."


 * He also commented on your lack of citations:


 * "I'm not sure I understand your position on this matter. Could you clarify? In your last entry, you seemed to say that the issue was a lack of citations on negative power factor. I asked you if we could use IEEE 1459 Figure 1 as the citation, but you ignored my question. I provided you with 12 citations on negative power factor in the Draft IEEE paper, and you made no comments."


 * You have zero citations to support your position. There are multiple citations to high-quality sources establishing that negative power factor does exist. --Guy Macon (talk) 10:33, 10 February 2018 (UTC)
 * So to preserve the idea of negative power factor, we are struck by the idea that "active" power has a direction, but "apparent" power has no direction? Internal consistency. --Wtshymanski (talk) 21:38, 10 February 2018 (UTC)


 * Nobody but you has a problem with that. Everyone else (including the teachers who granted you a degree) has no problem at all with RMS values always being positive, and thus has no problem with RMS volts x RMS amperes always being positive. The reason nobody but you has a problem with RMS values always being positive is that for an alternating electric current, RMS is equal to the value of the direct current that would produce the same average power dissipation in a resistive load. So unless you have invented a resistor that gets colder as you pass current through it, power dissipation is always positive, therefore RMS is always positive, therefore apparent power is always positive. You may wish to familiarize yourself with our article on Root mean square if this continues to confuse you. If that article is too complex for you, you might try Square (algebra), paying careful attention to why the result is always positive. --Guy Macon (talk) 00:02, 11 February 2018 (UTC)
 * You forgot the reference I did cite - IEEE 1495-2000. --Wtshymanski (talk) 02:35, 12 February 2018 (UTC)


 * I did not catch the fact that in mid conversation you stopped talking about Figure 1 of IEEE 1459 and started talking about Figure 1 of IEEE 1495. I would note that you failed to mention IEEE 1495 in the discussion at Talk:Power factor/Archive 2. Would you be so kind as to provide a link to IEEE 1495? Google doesn't seem to be able to find it. --Guy Macon (talk) 05:17, 12 February 2018 (UTC)


 * I think ‘1495’ is a typo for ‘1459’. As far as I can ascertain, IEEE 1495 currently only exists as a draft document entitled, "Draft Guide for Harmonic Limits for Single Phase Equipment". Unlike other IEEE documents, no online version appears to exist so it does not look like it has been formally published yet. 85.255.237.171 (talk) 15:55, 12 February 2018 (UTC)


 * In particular, "IEEE 1495-2000" does not seem to exist. Assuming that Wtshymanski is actually talking about Figure 1 of IEEE 1459, The author of IEEE 1495 was quite clear when he wrote:


 * "Would you accept IEEE 1459 itself as the citation for positive and negative power, and therefore positive and negative power factor? if so, please examine Figure 1 in both Editions of IEEE 1459, which clearly shows both positive and negative power along the horizontal axis."


 * One can only wonder whether the refusal to admit errors in understanding of electrical power extends to refusal to admit typographical errors.


 * "The most hostile group was the one with high but unstable self esteem. These people think well of themselves in general, but their self-esteem fluctuates.  They are especially prone to react defensively to ego threats, and they are also more prone to hostility, anger and aggression than other people.


 * "These findings shed considerable light on the psychology of the bully. Hostile people do not have low self esteem; on the contrary, they think highly of themselves,  But their favorable view of themselves is not held with total conviction, and it goes up and down in response to daily events.  The bully has a chip on his shoulder because he thinks you might want to deflate his favorable self image."


 * -Roy F. Baumeister, Evil: Inside Human Violence and Cruelty, p 149
 * --Guy Macon (talk) 16:11, 12 February 2018 (UTC)


 * See Figure 1 on page 6 of [ https://edisciplinas.usp.br/mod/resource/view.php?id=800735 ] Figure 1 is labled "1983 IEEE. Reprinted, with permission, from the IEEE and R. H. Stevens [B19]". Does anyone know where we can find the original 1983 paper that this was copied from? --Guy Macon (talk) 16:34, 12 February 2018 (UTC)


 * Quite frankly: whichever way you look at this, there can be only two possible explanations as to why Wtshymanski continues to peruse this line.


 * 1. A single failure to understand the basic principles of his craft coupled with an unwillingness to admit when he is wrong.


 * 2. He is deliberately trolling in order to stir up a longer and longer discussion.


 * The past history of overly long discussions on talk pages point very firmly toward the latter. It is also worth noting that Wtshymanski made an edit to another article in which he fully accepted the concept of negative power factor and how it comes about (5th paragraph) because he did not question it. 85.255.237.171 (talk) 16:52, 12 February 2018 (UTC)


 * Another annoying behavior is posting snide comments to his user page, then deleting any comments on his user talk page that dispute his crackpot theories. Alas, it looks like we are going to have to deal with Wtshymanski and his hobby horse for the indefinite future. He is smart enough to avoid [A] editing the article to make it support his unsourced theory, and [B] spending enough time pushing his theory on the talk page so that he meets the criteria for a topic ban. Sigh. --Guy Macon (talk) 22:29, 17 February 2018 (UTC)


 * Another annoying behavior: Serious question: do we have enough evidence of disruption now to justify a topic ban on the topic of whether any electric power parameter (Power Factor, Real Power Apparent Power, Watts, Volt-Amperes, etc.) can be negative? --Guy Macon (talk) 23:27, 18 February 2018 (UTC)

"A typical multimeter will give incorrect results when attempting to measure the AC current in a non-sinusoidal waveform"
I question the use of "typical".

Have we reached the point where true-RMS meters are more typical than averaging meters? Such meters are now less than $10 USD on Amazon. --Guy Macon (talk) 10:58, 8 August 2018 (UTC)


 * I'm not sure we've quite reached that point. If I search Amazon for "multimeter" only six of the first 24 results have "true rms" or equivalent in the title. But I'd be ok changing "typical" to "traditional" or something like that. Kendall-K1 (talk) 11:12, 8 August 2018 (UTC)


 * I like "traditional". Before I make the change, does anyone object? --Guy Macon (talk) 18:43, 8 August 2018 (UTC)
 * Multimeters measure power factor? Articles are about their subjects. --Wtshymanski (talk) 17:02, 11 August 2018 (UTC)

I sense that we have consensus for a very minimal mention of multimeters, if any. Is that right? I'm going to revert the most recent addition, which seems to have nothing to do with power factor, and let's discuss it. Kendall-K1 (talk) 15:00, 25 August 2018 (UTC)


 * The long version gives the reader the idea what is wrong when using any meter. We should give a clear basic knowledge. This times the long version does fulfill the requirements more likely. -- Hans Haase (有问题吗) 15:04, 25 August 2018 (UTC)
 * But what does it have to do with power factor? Kendall-K1 (talk) 16:39, 25 August 2018 (UTC)


 * [EC] I am not part of any consensus for a very minimal mention of multimeters. I just didn't think it was important enough to get into Yet Another Heated Battle With Wtshymanski (YAHBWW). I am usually only willing to make such an effort when he posts one of his his pseudoscientific fringe theories, and most of what he posts is bog-standard electrical engineering, not pseudoscience.


 * This was in the article for a fairly long time for a good reason; anyone who is attempting to measure or calculate power factor is extremely likely to measure the voltage with a multimeter as well, and getting wrong numbers from using an averaging multimeter on a distorted waveform is extremely common. I have seen this with inexperienced technicians and especially with electricians: "The voltage on my DMM doesn't match the voltage on the power factor meter!". (The only reason we don't say that using a non-RMS power factor meter often results in an incorrect reading is because AFAIK non-RMS power factor meters don't exist.)


 * So I think it should be included, but I don't have strong feelings on this, and would have no objections if the consensus was to exclude it. --Guy Macon (talk) 16:56, 25 August 2018 (UTC)


 * This is the point. I see often correctly removed garbage, but in the case, it brings knowledge why measurements fail, not just how not to do it. I suggest to revert to long version, but if anyone is able to point it better, I am looking fwd to read. Ntl, until done, keep the long version. WP is not like buy a book to read it there, WP should give good basic knowledge to readers here. -- Hans Haase (有问题吗) 21:06, 25 August 2018 (UTC)


 * This paragraph is probably a good addition to Apparent power, but not to this article. This article is about power factor. Although you can use a true RMS multimeter to determine apparent power, that is the extent of one's ability. You cannot use a multimeter to determine true power (except in a circuit known to be purely resistive) and therefore cannot use it to determine power factor. Thus it is out of place in this article. DocFergus (talk) 13:05, 2 September 2018 (UTC)


 * Exclude - The discussion of typical multimeters is tangential at best to the subject of the article. There are many wrong ways to measure PF. It is enough to discuss the right way. Constant314 (talk) 18:47, 2 September 2018 (UTC)


 * I often move tangential information like this into a footnote. When you get to WP:GA that might not fly but in the meantime everybody's mostly happy.
 * I agree that we have probably reached the point where a "typical multimeter" may or may not be true RMS. I don't like describing stuff that was developed in my lifetime as "traditional" but maybe I need to adjust that with age. Maybe "simple multimeter" would work. ~Kvng (talk) 13:36, 5 September 2018 (UTC)
 * Since the typical multi-meter does not have a setting for measuring Kilowatts, KiloVARs or PF, it would not be suitable for measuring PF whether it used true RMS or other method. Constant314 (talk) 14:46, 5 September 2018 (UTC)

Summary
So we only have one editor who feels strongly that the multimeter thing should be included, is that right? And four who think it should be left out, plus another who would move it to a footnote? Kendall-K1 (talk) 15:04, 5 September 2018 (UTC)


 * How did you get "So we only have one editor who feels strongly that the multimeter thing should be included" from "So I think it should be included, but I don't have strong feelings on this"? Again, I have a slight preference for keeping the version that has been there for years, but if the consensus is to change the page and remove it, I am fine with that as well. --Guy Macon (talk) 15:59, 5 September 2018 (UTC)
 * Hans Haase is the strong include. I would count you as a weak include. Kendall-K1 (talk) 19:37, 5 September 2018 (UTC)
 * I don't even know why it is being debated since typical multimeters have no feature that can be used to measure power or power factor.Constant314 (talk) 21:01, 5 September 2018 (UTC)

First lead paragraph
Recent improvements by may have improved depth of the lead but the first paragraph is now more long and winding. Since it's a mixed bag I'm not inclined to revert the changes but they may need to be trimmed and uncurled. ~Kvng (talk) 12:44, 29 September 2019 (UTC)
 * I agree, it's way too in-depth for an introduction now. Some of it should be moved to the 'Definition and calculation' section (if it's not already there) and really the first few sentences should be enough to give a layperson the gist of what it's all about.  The content is worth keeping, just not so close to the start of the article. -- Malvineous (talk) 14:15, 29 September 2019 (UTC)


 * Yes I agree that paragraph is rather long, and I don't think splitting it into two paragraphs is what you're suggesting nor would it really help. I can't see any good way to trim it, except to completely oversimplify it (in other words, mention the difference between real and apparent power without saying why) and then insert a new introductory section combining that with some of section 1.0 in a general definition of power factor appearing before sections specifically dealing with the cases of linear and non-linear loads (Note that the current "Definition and calculation" section is specific to linear loads). That would be a bit of trouble and not really worth it in my opinion, as it wouldn't really change the order of presentation but just move some text out of the lede in order to obtain a better ratio of lede to body. But if anyone wants to undertake that, or thinks they can make the lede text more concise, then go for it! Interferometrist (talk) 14:50, 29 September 2019 (UTC)
 * Really, it does need to be "oversimplified". It is not desirable to write an accessible lead that incorporates all wrinkles of this topic. ~Kvng (talk) 11:58, 2 October 2019 (UTC)

Apparent vs displacement power factor
I have been researching power factor (as part of reading these values from an electrical meter) and have learned that there are two different ways of referring to power factor. One is "apparent power factor" and one is "displacement power factor". From reading about it, it seems that "apparent" includes cases like switching power supplies, while "displacement" only covers a leading or lagging current waveform. I can't see much discussion of this in the article, however as I have no qualifications in this area I am not confident in adding anything about this myself. I am wondering whether someone more educated than I am in this area would consider whether this is worth including? -- Malvineous (talk) 02:36, 18 April 2019 (UTC)


 * Displacement power factor is pretty much obsolete and unused. Back when most electrical loads were a combination of resistive, inductive, and capacitive, you could usually get away with assuming that there are no harmonics and simply calculating the cosine of the angle between voltage and current. Nowadays we have meters that are able to directly measure apparent power factor (which we now usually call "power factor") and loads that include rectifiers, SCRs, and other circuits that add harmonics to the current, so pretty much everybody works with apparent power factor.


 * One interesting aspect of this is utility meters. On occasion, when an old electromechanical meter is replaced with a new electronic meter, the method changes. This can trigger a new power factor penalty even though the load has not changed, which results in the customer complaining. In other cases the utility quietly chooses the method that allows them to charge you more.


 * I agree that this article should cover this better. In addition to your source, see . --Guy Macon (talk) 06:37, 18 April 2019 (UTC)


 * Many thanks for the details! My reason for asking is that I am interfacing with some industrial meters and they all report power factor in the range -2..+2, as this is apparently some "power factor quadrant" standard used for including both apparent and displacement power factor in the same measurement (this PDF seems to be the clearest explanation I have found for a non-expert).  My interest is also in regards to power factor correction, as I presumed you'd need to know the displacement power factor (even if it's no longer a simple capacitive or inductive load) to work out how to correct it.  (I am assuming that if the displacement power factor says the load is capacitive, then adding a capacitor will only make the power factor worse). -- Malvineous (talk) 14:28, 27 April 2019 (UTC)

Those -2 and +2 numbers are bogus. This basic question was asked and answered by Wikipedia user AMcEachern (primary author of IEEE 1459) on this page back in 2012 in response to a false claim that negative power factors do not exist. Here is that answer again:


 * "(1) RMS values are always positive, because they begin by squaring some either positive or negative instantaneous value, and the squaring function converts both to a positive number."
 * "(2) Volt-Amps [apparent power] is RMS volts x RMS amps, and is therefore always positive."
 * "(3) Power Factor is the ratio of Watts to Volt-Amps. "
 * "(4) For sinusoidal waveforms, Watts [active power] is RMS volts x RMS amps x cosine(angle between voltage and current sine waves) - this is mathematically equivalent, for sinusoidal waveforms, to watts as the integral, over an interval of time that is an integer multiple of half-periods, of the instantaneous product of the instantaneous voltage and the instantaneous current."
 * "(5) The cosine function has an output in the range of -1 to +1."
 * "(6) Watts, therefore, can be either positive or negative."
 * "(7) Power Factor, therefore, has a range of -1 to +1."

See IEEE 1459 Figure 1. --Guy Macon (talk) 15:32, 27 April 2019 (UTC)


 * The numbers definitely aren't bogus, they are just encoding more information into the power factor field. I'm still trying to understand it all but the -2..+2 values encode the true power factor (0..1), the direction of net current flow, and whether the power factor is predominantly capacitive or inductive.  My understanding is because if you see a power factor of 0.8, you don't know whether it's leading or lagging so to glean that information, the IEEE four-quadrant power factor diagram is used, with the four quadrants being encoded into the -2..+2 values.
 * I'm not sure I fully understand the AMcEachern points, but it seems that the sign on the power factor is used to express the direction of power flow. For example an induction motor transitioning into becoming a generator would result in the power factor sign changing due to the current changing direction.  However in this case my understanding is that the motor has a lagging power factor and upon transitioning to a generator it would move to a leading power factor, but it seems this change from lagging to leading is not reflected in the power factor figure (which I guess explains the need for the IEEE four-quadrant version being translated to -2..+2). -- Malvineous (talk) 14:36, 29 September 2019 (UTC)
 * I just did a quick look at power factor meters for sale. I did not see any with a range of -2 to 2.  Most commonly I saw 0 to 1.  One of the more expensive, the Fluke 345 ranged from 0.3 capacitive to 0.3 inductive.  Do you have a link to a power factor meter that ranges from -2 to +2 ? Constant314 (talk) 18:24, 29 September 2019 (UTC)
 * The Schneider Electric PM5350 is a meter that measures PF as -2..+2. The product page has a download for version 4 of the user guide, and on page 71 of this document it explains - sort of - how the -2..+2 mapping works. -- Malvineous (talk) 11:18, 8 December 2019 (UTC)
 * Had you followed the link in that manual, you would have discovered that the range -2 to +2 applies to power factor expressed as something that they call 'power factor register format' a format that that specific instruments stores the power factor in its own register. This is not the same as (but is related to) the more usual way of expressing power factor (in the range -1 to +1). It seems to be how this particular instrument quantifies power factor which historically would have been measured by a four quadrant circular scale on a conventional electromagnetic power factor meter. These quadrants were: leading positive; lagging positive; leading negative and lagging negative. It would appear to quantify not only the absolute value of the power factor itself but also in which quadrant the conventional meter's needle would be. An explanation of the relationship is on page 71 of that manual. 86.164.61.113 (talk) 13:51, 10 December 2019 (UTC)
 * Had you bothered to read the thread you replied to before insulting me, you would've seen that we had already established these facts (I even wrote above "the four quadrants being encoded into the -2..+2 values"). We were not discussing the -2..+2 PF reading but rather how the four quadrants relate to apparent PF vs displacement PF. -- Malvineous (talk) 15:01, 10 December 2019 (UTC)


 * Thanks, Wikipedia! --Wtshymanski (talk) 02:28, 10 December 2019 (UTC)


 * I looked at the manual. They don't say that power factor ranges from -2 to +2.  They say that their register uses those values to indicate quadrants.  Constant314 (talk) 03:37, 10 December 2019 (UTC)


 * That's correct. As we were discussing above, the -2..+2 values decode to quadrants and I was questioning how these quadrants fit into displacement and apparent power factor.  @Guy Macon was saying displacement power factor is obsolete and unused, but these quadrants only seem to address displacement PF, so I'm not sure where apparent PF fits into the picture.  More details about displacement power factor have since been included in the article which was the original reason for starting this thread, as it was not so clearly covered at the time. -- Malvineous (talk) 15:01, 10 December 2019 (UTC)

Problems with first two plot figures
On the currently-first plot figure, the caption includes the statement "The blue line shows all the power is stored temporarily in the load during the first quarter cycle and returned to the grid during the second quarter cycle,"

This statement doesn't seem to make sense.

First, I'm pretty sure those "quarter"s should be "half"s, referring to the feature that the dark blue (instantaneous) Power curve is positive in the first half-cycle, and negative in the second half-cycle.

Next, Power is rate-of-flow of energy (Energy/second) and is not something that can be "stored". What can be stored in the load is Energy. The negative portions of the blue Power curve mean negative flow-rate-of-energy, indicating the direction of (positive) energy flow is from load to grid.

So I think the statement would be better as:

The dark blue "Power" curve shows that, during the first half cycle, energy flows from grid to load. Then during the second half cycle, energy, that was stored in the load, flows back to the grid.

There is a similar problem with the wording of the caption for the second figure. Gwideman (talk) 18:35, 3 November 2020 (UTC)


 * The phrases "stored power" (instead of "stored energy") and "absorbed power" (instead of "absorbed energy") are unfortunately used all the time! Just like "current flow" (which is redundant, instead of "charge flow"), "flow of current" (instead of "flow of charge"), "power flow" (which is redundant, instead of "energy flow"), "flow of power" (instead of "flow of energy"), "AC voltage" (which is misleading, instead of just "AV" or "alternating voltage), "conventional current flows from positive to negative" (which isn't always true, for example inside a source that is supplying energy, or inside an inductor that is releasing energy from its magnetic field), "to charge a capacitor" (which is misleading, instead of "to charge the capacitor plates"), "to charge a battery" (which is misleading, instead of "to energize a battery"), "electromotive force (EMF)" (which is misleading because it is a voltage, not a force), and "magnetomotive force (MMF)" (which is misleading because it is a current, not a force), they're misleading/wrong/redundant. --Alej27 (talk) 05:38, 4 November 2020 (UTC)


 * Well I'm not sure if you're saying that these misnomers are so common we should just accept them, or if Wikipedia should lead the charge to clean up technical language. I would lean toward the latter, though the most important criterion is for articles to be understandable to the largest number of readers. Almost anyone reading about "power" should understand that it refers to the time rate of energy flow, so introducing the proper term shouldn't have made it any more difficult to understand. However it would probably be best if at some point in the lede it specifically said that at least in passing. I'll let someone else edit the lede, but I just wanted to address what was a valid concern raised about the caption, but didn't look for every such possible correction where these misnomers are employed and will leave that for others. Interferometrist (talk) 14:51, 4 November 2020 (UTC)


 * I meant the latter: I'd love if Wikipedia promoted correct use of technical language. For the future reader, I'll explain why the phrases in my previous reply are misleading/wrong/redundant.


 * * Electromotive force (EMF) and magnetomotive force (MMF) are not forces. In physics, force is defined rigorously, and EMF and MMF aren't forces in this sense. EMF is a type of voltage, measured in volts; MMF is somewhat a type of current, measured in ampere-turns; force is measured in newtons. The textbook University Physics with Modern Physics, volume 2 (12th edition) by Young, Freedman, Sears, and Zemansky, makes this observation on page 857: “The influence that makes current flow from lower to higher potential is called electromotive force (abbreviated emf and pronounced "ee-em-eff"). This is a poor term because emf is not a force but an energy-per-unit-charge quantity, like potential.”


 * * Conventional current doesn't always flow from positive to negative, or equivalently, real current doesn't always flow from negative to positive. It's common to say that (conventional) current flows from positive to negative. But that's in general not true, even if we're talking about basic devices. That phrase is incomplete because they're not specifying in which device conventional current flows from positive to negative. For example, in a battery supplying energy, conventional current flows from negative to positive. In an inductor supplying energy previously stored in its magnetic field, conventional current flows negative to positive. I showed/proved this with GIFs and explained in more details in this answer on Quora (I hope that just by sharing that link, this reply isn't considered as self-promotion or spam.)


 * * Flow of current and current flow are redundant phrases; we should say flow of charge and charge flow. To support my point, I'll quote page 571 of the textbook College Physics, volume 2 (8th edition) by Raymond Serway, Chris Vuille, and Jerry Faughn, in which they say: “The phrases flow of current and current flow are commonly used, but here the word flow is redundant because current is already defined as a flow (of charge). Avoid this construction!”


 * * Flow of power and power flow are redundant phrases; we should say flow of energy and energy flow. For the same reason as why flow of current is redundant, flow of power is too. Both instantaneous current and instantaneous power are defined as rates, and rates don't flow. Now, many electric power engineers will disagree with me on this, probably because in one-line diagrams (whether in power systems analysis or in distribution systems design) used in power flow studies (also known as load flow studies), it is common to show the direction of flow of active power and reactive power (the software ETAP is one example), so it indeed looks like active power and reactive power flow throughout the system, but this is redundant. First of all, what is active power and reactive power? Active power is another name for average power, so, instead of saying active power flows from this bus to this other bus, we should say, on average, energy flows from this bus to this other bus. Regarding reactive power, this is a little trickier, so I won't address it in this reply. You can read this answer on Quora that explains why the previous phrases are redundant.


 * * A device doesn't consume or absorb power, its power is the average rate at which it is using or delivering energy, respectively (I say “average” because power usually means the active/real/average power).


 * * Batteries are not charged, they're energized, assuming to charge means to gain/lose net electric charge. In this video (https://www.youtube .com/watch?v=cPQbkTkGsnI) (join the link), a physicist named Nick Lucid criticizes the phrase “to charge a battery”. It is misleading because the battery doesn’t lose or gain a net charge when it is used or recharged, it only loses or gains energy. He suggests another phrase: “to energize a battery”.


 * * Capacitors are not charged, but their plates are. In this answer on Stack Exchange, a person (maybe an electrical or electronics engineer) named Phil Frost, at around the fourth paragraph, criticizes the phrase “the charge of a capacitor” or “to charge a capacitor”. It is misleading because a “charged” capacitor as a whole has no net charge, because the plates have equal but opposite charge. What is true, is that the individual plates indeed store charge. So we should use another phrase: “the charge of capacitor plates” or “to charge the capacitor plates”. Nick Lucid agrees with this fact (https://www.youtube .com/watch?v=cPQbkTkGsnI&lc=UgyejVM0i19bF_2ufWR4AaABAg).


 * * AC voltage means alternating current voltage, which is non-sense; we should say AV (alternating voltage). It's common to say “this outlet is 120 V AC”. I understand this phrase, but it is redundant. If we substitute “AC" for what it stands for, we get “this outlet is 120 V alternating current”. Well, not necessarily the current is alternating; for example if you plug in a charger (or rather, energizer?), the current won't be alternating direction, so we shouldn't call it AC, however the voltage is still alternating. So we should say “this outlet is 120 V AV”, or simply “this outlet is 120 AV”.


 * There're other misnomers, like calling the AC-DC adapter of a phone or laptop charger (energizer?) as a transformer. It is wrong because the adapter not only contains a transformer, but also a bridge diode rectifier, capacitors for filtering, and a voltage regulator. Anyways, they should be fixed. --Alej27 (talk) 01:30, 5 November 2020 (UTC)


 * Look, that's all very interesting but has to do with linguistics and I cannot agree on changing the terminology in this (or other) page for the reasons given. Redundancy is common in language and shouldn't matter when it couldn't possibly be misunderstood by the reader. For instance, "AC current" is obviously redundant but can mean only one thing. And AC voltage is equally unambiguous unless you don't know that alternating current and voltage almost always go together. Saying the "wind blows" is equally redundant, you should say the "air blows" but this would never be misunderstood by anyone who knows that wind involves the blowing of air. The original objection, which I corrected, had to do with using the WRONG word (power instead of energy) in a generic sentence, but terms which are unambiguous and don't cause confusion needn't be changed (especially when it involves, for instance, two different terms for alternating voltage/current).
 * But this is an interesting list, and you are free to create a new page called "Physics terms which are misnomers" or whatever, and you already have enough citations for it. Good luck! Interferometrist (talk) 19:23, 5 November 2020 (UTC)
 * I agree with Interferometrist. Articles should use common language constructs. Constant314 (talk) 19:26, 5 November 2020 (UTC)


 * This is almost pure pedantry, and much is incorrect.


 * Current is not a flow a charge. It is the rate of flow of charge (and is defined as such), to the point that one ampere is defined as the flow of one coulomb per second.


 * Flow of current or current flow is the accepted terminology to describe electrical charge flowing from one place another (specifically quantising the rate of that flow).


 * Similarly: power is not a flow of energy but the rate of flow of energy (and is defined as such), to the point that one watt is defined as the flow of one joule per second.


 * Similarly: Flow of power is the accepted terminology to describe any form of energy flowing from one place another (specifically quantising the rate of that flow).


 * MMF and EMF may not be forces in the mechanical sense per se, but they are magnetic and electrical forces respectively inasmuch as they force something to move from one place to another (in the latter case charge).


 * Electron flow always flows from a more negative place to a more positive place if there is no EMF forcing it to do otherwise. Conventional current flow is only positive to negative because Andre Marie-Ampere arbitrarily decided it should be so (the electron being unknown at the time).


 * Capacitors' plates are not charged. If you have seen a demonstration of a charged Leyden jar being dismantled and all the parts handled by the earthed demonstrator and then reassembled. The fact that the rebuilt jar can then be be discharged is clear evidence that the plates do not store the charge. Pedantically: the plates do store a very small charge but it is insignificant.


 * Capacitors are charged in that they are capable of holding a charge. Capacitance is defined as 'the ability of a body to hold an electrical charge'.


 * Batteries are similarly charged because they too will hold a charge (even though internally they convert the energy contained in that charge to chemical energy). Lithium-ion batteries behave almost exactly like a capacitor subject to some limitations. Indeed, over their useful charge range they behave more like capacitors than some real capacitors do.


 * AC volts and AC current, and their DC counterparts, are standard nomenclature and universally understood (and even Thomas Edison and George Westinghouse used the terms to differentiate their respective electrical systems). Pedantically, it is not strictly correct, but encyclopaedias are written by what is universally understood not on what is pedantically correct. Further the terminology is simplicity itself to source. Almost any multi-meter is marked 'DCV', 'ACV', 'DCA' and (if you have a posh meter) ACA. 86.142.79.215 (talk) 18:34, 2 December 2020 (UTC)

Shouldn't we clarify that power factor is usually never expressed as a negative number?
I understand why power factor can be negative. Just like why average/real/active power can be negative. However, we don't usually say "this generator absorbs -20 kW" but instead "this generator supplies +20 kW". Similarly, we don't usually say the power factor of a generator is negative, even though under normal circumstantes its absorbed active power is negative (i.e. its generated active power is positive), which implies PF < 0 since PF = P/S where S > 0. --Alej27 (talk) 16:31, 4 November 2020 (UTC)


 * Listen this issue was already debated, extensively (to the point I never read most of it!) on an archived talk page here: [] - Interferometrist (talk) 19:33, 5 November 2020 (UTC)


 * Ups, I didn't know about that long discussion. --Alej27 (talk) 19:42, 5 November 2020 (UTC)


 * Whilst what you say is entirely correct for an electrical device that either exclusively generates power or absorbs power, you need to consider situations where power can either be absorbed or generated. The obvious example of this is a consumer who has installed solar cells. At night, such a consumer absorbs power from the grid which is usually considered positive power consumption (and the electricity meter records this positive power as an increasing display of energy consumption). However: during a sunny summer's day, the solar cells may well generate more power than the consumer is actually using. This surplus power is fed back to the grid and is considered to be negative power (in that it flows the other way). So much so that the electric meter now logs this negative power by running backwards. That is: the meter records this negative power with a decrease of recorded energy supplied. 86.142.79.215 (talk) 12:09, 3 December 2020 (UTC)

Specifying the circuits being discussed are LTI (of constant parameters) is not a leap too far
Anonymous user of IP 86.129.19.88 reverted my edit to this version. Their reason:

"This concept is a leap to far for an article of this nature. It only serves to obfuscate the issue being discussed. Simplicity is always better."

In my edit, I clarified that it is linear time-invariant circuits (and not any linear circuit) that don't change the shape of applied volage in the resulting current. In other words, I fixed a mistake. There are linear circuits that produce harmonics: linear time-variant circuits. However, the user reverted my edit, making the article wrong again.

In my edit, I didn't go into much details of what was a time-invariant circuit. Instead, I just changed the words "linear" for "linear time-invariant", and I even added a short example of such a circuit: a circuit whose R, L and C are constants.

"It only serves to obfuscate the issue being discussed." // I don't think so. It serves to clarify what is being discussed: LTI circuits, not just any linear circuit.

"Simplicity is always better." // Yes, simplicity is better, as long as it is correct, which was not the case. So that's why I corrected the article.

Don't you prefer to have a specific but correct explanation than a shorter but wrong explanation? --Alej27 (talk) 20:17, 20 June 2021 (UTC)


 * In ordinary parlance, a resistor, capacitor, or inductor (or a linear amplifier) without further qualification is considered linear and time-invariant EVEN THOUGH there is always SOME voltage or current that can overload or destroy it, but that doesn't change its basic character. A VARIABLE R/C/L is considered to be linear on the timescale of the signal even though it changes when someone turns the knob. Yes, if a 100Hz signal is processed by an LTI circuit while someone turns the knob on millisecond time scales then you get new frequencies, but that doesn't justify changing our normal way of speaking. If the R/C/L is dependent on voltage or current then it obviously isn't linear, but you have different names for such components. There is always non-ideal behaviour that needn't be pointed out when it isn't dominant. Otherwise we could never talk about a resistor or capacitor without specifying its stray inductance, leakage, temperature dependence etc. These are a higher level of detail that shouldn't be introduced into the basic explanations. Interferometrist (talk) 21:10, 2 July 2021 (UTC)


 * Here's the diff in dispute., I've added a link to Linear time-invariant system to help readers through this terminology you've introduced. I think it is a reasonable assumption that electrical parameters for the R, L and C devices are constant so stating that qualification is unnecessary. ~Kvng (talk) 14:10, 5 July 2021 (UTC)


 * I think the current version as edited by is good. It doesn't say the R/L/C are constants (so I think it is in agreement with ), but it also clarifies the wrong statement that linear circuits always produce sinusoidal outputs of same frequency to sinusoidal inputs (it's false, they don't, e.g. linear time-variant circuits). --Alej27 (talk) 17:26, 5 July 2021 (UTC)


 * Thinking back, long ago to my university lectures, it seems that in each class that the professor would say, once, near the beginning of the semester, that the math applied to linear time-invariant circuits. He did not elaborate.  He was being rigorous, but not tedious.   One time, I asked if a certain result always applied and the professor replied, “yes, for linear time-invariant circuits.”  I suppose hearing it often enough drummed it into my consciousness.  I think that is what we should do in this article.  Mention it once, with a wiki-link, without elaboration and move on. Constant314 (talk) 18:06, 5 July 2021 (UTC)


 * So in section Linear time-invariant circuits we should say something like "Linear time-invariant circuits (referred to simply as linear circuits for the rest of this article), for example, circuits consisting of combinations of resistors, inductors and capacitors have a sinusoidal response to the sinusoidal line voltage"? That'd be a good idea, since in the current version of the article, loads are still called as linear even though they are actually linear time-invariant (e.g. the power triangle doesn't hold true for linear time-variant loads). --Alej27 (talk) 07:54, 21 July 2021 (UTC)←


 * Sure, put in that parenthetical remark if it helps. When you don't specify otherwise, time-invariance is almost always assumed. You have to go to a lot of trouble to make an actual physical system that is not time-invariant, and even further to find an actual use for it. And in cases when something is labelled non-time-variant (like the "examples" I removed from the to-be-deleted "time-variant" page), there isn't any clear distinction between saying that and saying that it's a non-linear system with two inputs. So I don't know about any "time-varying loads", but perhaps you're referring to a motor under differing back torque, in which case you could just as well call that torque an additional input in a nonlinear system. So although "time-invariant" is a useful and correct qualifier, it hardly ever needs to be pointed out when you just say "linear system" or linear component. Interferometrist (talk) 15:34, 21 July 2021 (UTC)


 * I'm good with that. Constant314 (talk) 20:40, 21 July 2021 (UTC)

Typos
Seems like every page ought to have a section for just typographical errors. Anyway, this "The power factor...or equivalently the angle by which the voltage" seems to be missing a word. It should be "...equivalently the sine of the angle...". The whole sentence seems unnecessarily long, though. I would suggest The power factor is the cosine of the angle θ ... Captain Puget (talk) 22:41, 19 November 2021 (UTC)
 * Go for it! You might as well fix the article as comment on it on the talk page, especially for stuff like this. --Wtshymanski (talk) 21:57, 22 November 2021 (UTC)
 * No. Because it is the same angle. It is still the phase angle between current and voltage whichever way around you express it. Why we actually need to express it the other way around is another matter. 86.188.36.150 (talk) 18:05, 6 December 2021 (UTC)