# Harmonics in Electrical Systems **URL:** \ **Category:** Factual Questions\ **Created:** [September 16, 2016, 7:59pm UTC](https://boards.straightdope.com/t/harmonics-in-electrical-systems/766107 "2016-09-16T19:59:59Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![ZurBob](https://avatars.discourse-cdn.com/v4/letter/z/71e660/32.png) [@ZurBob](https://boards.straightdope.com/u/ZurBob)\ **Post date:** [September 20, 2016, 5:37am UTC](https://boards.straightdope.com/t/harmonics-in-electrical-systems/766107/21 "2016-09-20T05:37:00Z")
Based upon your atomic clock, when are our operators allowed to make or break connection with the Eastern grid? ---
**Author:** ![ZurBob](https://avatars.discourse-cdn.com/v4/letter/z/71e660/32.png) [@ZurBob](https://boards.straightdope.com/u/ZurBob)\ **Post date:** [September 20, 2016, 5:39am UTC](https://boards.straightdope.com/t/harmonics-in-electrical-systems/766107/22 "2016-09-20T05:39:18Z")
You’ve been reading too much Wikipedia. ---
**Author:** ![Francis\_Vaughan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/francis_vaughan/32/3093_2.png) [@Francis\_Vaughan](https://boards.straightdope.com/u/Francis_Vaughan)\ **Post date:** [September 20, 2016, 5:44am UTC](https://boards.straightdope.com/t/harmonics-in-electrical-systems/766107/23 "2016-09-20T05:44:44Z")
> [@ZurBob](#): > > I can tell you this much: Frequency is not the sole determinant of voltage… No idea what he is talking about. From context, **Stranger On A Train** was not talking about the base frequency but alluding to the presence of harmonics - thus the dirty power and the change in RMS voltage. (Clearly a perfect sine wave varying in frequency retains the same RMS voltage. Unless the load is reactive.) In systems with significant reactive loads these harmonics can sometimes lead to issues that matter, and that is really the point of most of the conversation here. But as beaten to death, there is scant reason to imagine this library’s installation will be so beset, or that the inverter’s output will be anything like dirty enough to matter. My first reaction was to think that this sales guy is just trying a new angle and selling unnecessary power factor correction capacitors. Sure, if there are some residual harmonic components from the inverter present, there will be some microscopic inefficiency that tweaking the power factor of the building might just make a measurable different to. But really, the sun would go cold before you saw a return on investment. ---
**Author:** ![ZurBob](https://avatars.discourse-cdn.com/v4/letter/z/71e660/32.png) [@ZurBob](https://boards.straightdope.com/u/ZurBob)\ **Post date:** [September 20, 2016, 5:54am UTC](https://boards.straightdope.com/t/harmonics-in-electrical-systems/766107/24 "2016-09-20T05:54:10Z")
> [@Dr.Strangelove](#): > > I’m not sure what you’re disagreeing with, if anything. The long-term average is indeed determined by the atomic clocks at NIST. A clock based on counting cycles (like a synchronous analog clock) will keep excellent time for many years. In the shorter term, there may be variation of ~0.1%. > > That smaller operators have no need for such high precision timekeeping is irrelevant, since as you say they just sync up to larger units and the rest of the grid. Though even this is changing–GPS time (also based on atomic clocks) gives a stable timebase and helps decrease phase error (which can be wasteful). Not sure how prevalent this is but the tech is out there. Averages may well be determined by NIST time as a baseline. But it is not necessitated down to 0.000000001 percent of accuracy for production. _ **It is not necessary.** _ Atomic clock synchronization of power production isn’t necessary, regardless of what you may feel, regardless of the capacity of the producer. Where is your cite? ---
**Author:** ![Francis\_Vaughan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/francis_vaughan/32/3093_2.png) [@Francis\_Vaughan](https://boards.straightdope.com/u/Francis_Vaughan)\ **Post date:** [September 20, 2016, 6:15am UTC](https://boards.straightdope.com/t/harmonics-in-electrical-systems/766107/25 "2016-09-20T06:15:58Z")
> [@ZurBob](#): > > Averages may well be determined by NIST time as a baseline. But it is not necessitated down to 0.000000001 percent of accuracy for production. _ **It is not necessary.** _ Atomic clock synchronization of power production isn’t necessary, regardless of what you may feel, regardless of the capacity of the producer. > > Where is your cite? The question is about long term averages. Where long term is days. For decades the power has been synced to a time standard, and has provided such long term accuracy. Recently there has been argument about a reduction of accuracy, allowing the power generators more freedom, which may translate into slightly reduced running costs. The relaxation is partly justified with the huge reduction of timekeeping that is synced to the mains. But for decades households across the planet used clocks that were so synchronised. Any clock that was plugged into the mains was synced to it, whether analogue or digital. The long term average frequency ensured that year in, year out, those clocks were never wrong by more than a guaranteed margin. Except for power failures. Now our mobile phones get a sync from the cell, which is itself tied to an atomic clock. Or your computer runs an NTP client, which is similarly slaved. ---
**Author:** ![ZurBob](https://avatars.discourse-cdn.com/v4/letter/z/71e660/32.png) [@ZurBob](https://boards.straightdope.com/u/ZurBob)\ **Post date:** [September 20, 2016, 6:18am UTC](https://boards.straightdope.com/t/harmonics-in-electrical-systems/766107/26 "2016-09-20T06:18:02Z")
> [@Francis\_Vaughan](#): > > From context, **Stranger On A Train** was not talking about the base frequency but alluding to the presence of harmonics - thus the dirty power and the change in RMS voltage Francis: If you say so, OK:smack: ---
**Author:** ![ZurBob](https://avatars.discourse-cdn.com/v4/letter/z/71e660/32.png) [@ZurBob](https://boards.straightdope.com/u/ZurBob)\ **Post date:** [September 20, 2016, 6:35am UTC](https://boards.straightdope.com/t/harmonics-in-electrical-systems/766107/27 "2016-09-20T06:35:29Z")
> [@Francis\_Vaughan](#): > > The question is about long term averages. Where long term is days. For decades the power has been synced to a time standard, and has provided such long term accuracy. Recently there has been argument about a reduction of accuracy, allowing the power generators more freedom, which may translate into slightly reduced running costs. The relaxation is partly justified with the huge reduction of timekeeping that is synced to the mains. But for decades households across the planet used clocks that were so synchronised. Any clock that was plugged into the mains was synced to it, whether analogue or digital. The long term average frequency ensured that year in, year out, those clocks were never wrong by more than a guaranteed margin. Except for power failures. Now our mobile phones get a sync from the cell, which is itself tied to an atomic clock. Or your computer runs an NTP client, which is similarly slaved. Not sure what your point is but… Averages concerning power production are usually defined, at most, on a 24 hr. basis. To my knowledge, there has never been a _ **guaranteed clock performance statute** _ implemented in my state. ---
**Author:** ![Francis\_Vaughan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/francis_vaughan/32/3093_2.png) [@Francis\_Vaughan](https://boards.straightdope.com/u/Francis_Vaughan)\ **Post date:** [September 20, 2016, 6:54am UTC](https://boards.straightdope.com/t/harmonics-in-electrical-systems/766107/28 "2016-09-20T06:54:56Z")
> [@ZurBob](#): > > To my knowledge, there has never been a _ **guaranteed clock performance statute** _ implemented in my state. It would make no sense it there were, if your state ties into the national grid. Any individual state creating any sort of frequency statue would risk becoming incompatible with the national grid. The only place where a frequency performance statute makes sense is at the national grid level, and therefore one would assume was a federal responsibility. ---
**Author:** ![Dr.Strangelove](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr.strangelove/32/6613_2.png) [@Dr.Strangelove](https://boards.straightdope.com/u/Dr.Strangelove)\ **Post date:** [September 20, 2016, 6:55am UTC](https://boards.straightdope.com/t/harmonics-in-electrical-systems/766107/29 "2016-09-20T06:55:54Z")
> [@ZurBob](#): > > Averages may well be determined by NIST time as a baseline. But it is not necessitated down to 0.000000001 percent of accuracy for production. _ **It is not necessary.** _ Atomic clock synchronization of power production isn’t necessary, regardless of what you may feel, regardless of the capacity of the producer. If you agree that NIST provides the baseline time, then we aren’t disagreeing at all. I said they calibrate against atomic clocks for their long-term average, and they do. However, you also say that this isn’t _necessary_, but that’s not true. In the past 100 million seconds, there have been 6 billion cycles of the grid, +/- around 600 cycles. That’s 100 ppb accuracy, which is better than you can get with any standard timepiece. ---
**Author:** ![Dr.Strangelove](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr.strangelove/32/6613_2.png) [@Dr.Strangelove](https://boards.straightdope.com/u/Dr.Strangelove)\ **Post date:** [September 20, 2016, 7:01am UTC](https://boards.straightdope.com/t/harmonics-in-electrical-systems/766107/30 "2016-09-20T07:01:39Z")
> [@ZurBob](#): > > To my knowledge, there has never been a _ **guaranteed clock performance statute** _ implemented in my state. You don’t need one. What matters is that they follow the NERC standard, which says that if a clock based on the grid frequency drifts more than N seconds from NIST time, then the Balancing Authority is notified, which orders a frequency offset to compensate until the deviation is under a threshold. ---
**Author:** ![ZurBob](https://avatars.discourse-cdn.com/v4/letter/z/71e660/32.png) [@ZurBob](https://boards.straightdope.com/u/ZurBob)\ **Post date:** [September 20, 2016, 7:09am UTC](https://boards.straightdope.com/t/harmonics-in-electrical-systems/766107/31 "2016-09-20T07:09:10Z")
> [@Dr.Strangelove](#): > > If you agree that NIST provides the baseline time, then we aren’t disagreeing at all. I said they calibrate against atomic clocks for their long-term average, and they do. > > However, you also say that this isn’t _necessary_, but that’s not true. In the past 100 million seconds, there have been 6 billion cycles of the grid, +/- around 600 cycles. That’s 100 ppb accuracy, which is better than you can get with any standard timepiece. Sorry, but precision in this case is more important than accuracy. ---
**Author:** ![ZurBob](https://avatars.discourse-cdn.com/v4/letter/z/71e660/32.png) [@ZurBob](https://boards.straightdope.com/u/ZurBob)\ **Post date:** [September 20, 2016, 7:15am UTC](https://boards.straightdope.com/t/harmonics-in-electrical-systems/766107/32 "2016-09-20T07:15:38Z")
> [@Francis\_Vaughan](#): > > It would make no sense it there were, if your state ties into the national grid. Any individual state creating any sort of frequency statue would risk becoming incompatible with the national grid. The only place where a frequency performance statute makes sense is at the national grid level, and therefore one would assume was a federal responsibility. Sooo? You can’t have it both ways. ---
**Author:** ![Dr.Strangelove](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr.strangelove/32/6613_2.png) [@Dr.Strangelove](https://boards.straightdope.com/u/Dr.Strangelove)\ **Post date:** [September 20, 2016, 7:20am UTC](https://boards.straightdope.com/t/harmonics-in-electrical-systems/766107/33 "2016-09-20T07:20:11Z")
> [@ZurBob](#): > > Sorry, but precision in this case is more important than accuracy. Tell that to my oven clock. Look, I get the point you’re making. They could do just as well calibrating against a cheap Casio quartz watch, _as long as that watch was itself regularly set against NIST time_. You don’t need any better than that in the short term–I haven’t said otherwise. ---
**Author:** ![ZurBob](https://avatars.discourse-cdn.com/v4/letter/z/71e660/32.png) [@ZurBob](https://boards.straightdope.com/u/ZurBob)\ **Post date:** [September 20, 2016, 7:21am UTC](https://boards.straightdope.com/t/harmonics-in-electrical-systems/766107/34 "2016-09-20T07:21:39Z")
> [@Francis\_Vaughan](#): > > It would make no sense it there were, if your state ties into the national grid. Any individual state creating any sort of frequency statue would risk becoming incompatible with the national grid. The only place where a frequency performance statute makes sense is at the national grid level, and therefore one would assume was a federal responsibility. Assume what you will. To my knowledge, there is no Federal statute regarding such. So, where do we go from here? ---
**Author:** ![ZurBob](https://avatars.discourse-cdn.com/v4/letter/z/71e660/32.png) [@ZurBob](https://boards.straightdope.com/u/ZurBob)\ **Post date:** [September 20, 2016, 7:27am UTC](https://boards.straightdope.com/t/harmonics-in-electrical-systems/766107/35 "2016-09-20T07:27:12Z")
> [@Dr.Strangelove](#): > > Tell that to my oven clock. > > Look, I get the point you’re making. They could do just as well calibrating against a cheap Casio quartz watch, _as long as that watch was itself regularly set against NIST time_. You don’t need any better than that in the short term–I haven’t said otherwise. Understood. Thank you. However, the implication from my perspective was otherwise. ---
**Author:** ![Francis\_Vaughan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/francis_vaughan/32/3093_2.png) [@Francis\_Vaughan](https://boards.straightdope.com/u/Francis_Vaughan)\ **Post date:** [September 20, 2016, 7:38am UTC](https://boards.straightdope.com/t/harmonics-in-electrical-systems/766107/36 "2016-09-20T07:38:50Z")
> [@ZurBob](#): > > Assume what you will. To my knowledge, there is no Federal statute regarding such. > So, where do we go from here? [http://www.ferc.gov/whats-new/comm-meet/2009/052109/E-14.pdf](http://www.ferc.gov/whats-new/comm-meet/2009/052109/E-14.pdf) ---
**Author:** ![ZurBob](https://avatars.discourse-cdn.com/v4/letter/z/71e660/32.png) [@ZurBob](https://boards.straightdope.com/u/ZurBob)\ **Post date:** [September 20, 2016, 7:39am UTC](https://boards.straightdope.com/t/harmonics-in-electrical-systems/766107/37 "2016-09-20T07:39:52Z")
> [@Dr.Strangelove](#): > > Tell that to my oven clock. > > Look, I get the point you’re making. They could do just as well calibrating against a cheap Casio quartz watch, _as long as that watch was itself regularly set against NIST time_. You don’t need any better than that in the short term–I haven’t said otherwise. Understood. Thank you. However, the implication from my perspective was otherwise. But for the fact that you said that generator producers were supplicant to atomic timepieces. ---
**Author:** ![ZurBob](https://avatars.discourse-cdn.com/v4/letter/z/71e660/32.png) [@ZurBob](https://boards.straightdope.com/u/ZurBob)\ **Post date:** [September 20, 2016, 7:55am UTC](https://boards.straightdope.com/t/harmonics-in-electrical-systems/766107/38 "2016-09-20T07:55:53Z")
> [@Francis\_Vaughan](#): > > [http://www.ferc.gov/whats-new/comm-meet/2009/052109/E-14.pdf](http://www.ferc.gov/whats-new/comm-meet/2009/052109/E-14.pdf) Ok, So what? Give a specific reference to your point, otherwise I may allude to a page (out of context) that might counter your intent.🙂 ---
**Author:** ![Francis\_Vaughan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/francis_vaughan/32/3093_2.png) [@Francis\_Vaughan](https://boards.straightdope.com/u/Francis_Vaughan)\ **Post date:** [September 20, 2016, 8:19am UTC](https://boards.straightdope.com/t/harmonics-in-electrical-systems/766107/39 "2016-09-20T08:19:03Z")
> [@ZurBob](#): > > Ok, So what? Give a specific reference to your point, otherwise I may allude to a page (out of context) that might counter your intent.🙂 Page one really: > [@](#): > > Pursuant to section 215 of the Federal Power Act (FPA), the Federal Energy Regulatory Commission (Commission) approves regional Reliability Standard > BAL-004-WECC-01 (Automatic Time Error Correction), as submitted by the North American Electric Reliability Corporation. So you have the Federal act establishing the authority, and you have the standard which the authority directs that time be maintained. Very annoyingly the NERC website is unreachable right now. This might help understand the standard, and it ties the time correction back to NIST. [http://www.nercipedia.com/active-standards/bal-004-wecc-02-automatic-time-error-correction/](http://www.nercipedia.com/active-standards/bal-004-wecc-02-automatic-time-error-correction/) ---
**Author:** ![ZurBob](https://avatars.discourse-cdn.com/v4/letter/z/71e660/32.png) [@ZurBob](https://boards.straightdope.com/u/ZurBob)\ **Post date:** [September 20, 2016, 8:55am UTC](https://boards.straightdope.com/t/harmonics-in-electrical-systems/766107/40 "2016-09-20T08:55:00Z")
> [@Francis\_Vaughan](#): > > Page one really: > > So you have the Federal act establishing the authority, and you have the standard which the authority directs that time be maintained. > > Very annoyingly the NERC website is unreachable right now. This might help understand the standard, and it ties the time correction back to NIST. [http://www.nercipedia.com/active-standards/bal-004-wecc-02-automatic-time-error-correction/](http://www.nercipedia.com/active-standards/bal-004-wecc-02-automatic-time-error-correction/) Um…OK. Is there a point? I’m trying to work with you guys… [Previous page](https://boards.straightdope.com/t/harmonics-in-electrical-systems/766107.md?page=1) [Next page](https://boards.straightdope.com/t/harmonics-in-electrical-systems/766107.md?page=3)