Mixing
Just how accurate is the frequency of US Wall Outlets?
Clash Royale CLAN TAG#URR8PPP
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I have a submersible pump for which I'm trying to determine the variability in flow rate, to high precision. Since this is just an impeller driven by an AC load, what is the % error in frequency of a US wall outlet? Is there a commonly accepted 'ballpark' value, such as 60 hz +/-0.5 hz?
My suspicion is that for most electrical grids, this largely depends on the citywide usage throughout the day.
I apologize because I have an inkling that my question is poorly presented -- that being said, if anyone knows of where I can find real-time data regarding the West Los Angeles electrical grid, I'm all ears. Thanks!
ac frequency
asked 5 hours ago
Austin Prater
516
 |Â
show 4 more comments
up vote
1
down vote
favorite
I have a submersible pump for which I'm trying to determine the variability in flow rate, to high precision. Since this is just an impeller driven by an AC load, what is the % error in frequency of a US wall outlet? Is there a commonly accepted 'ballpark' value, such as 60 hz +/-0.5 hz?
My suspicion is that for most electrical grids, this largely depends on the citywide usage throughout the day.
I apologize because I have an inkling that my question is poorly presented -- that being said, if anyone knows of where I can find real-time data regarding the West Los Angeles electrical grid, I'm all ears. Thanks!
ac frequency
asked 5 hours ago
Austin Prater
516
1
Related: mains frequency accuracy worldwide. Answers cover Australia and North America.
– The Photon
5 hours ago
1
Also, there is no "West Los Angeles grid". Pretty much the entire western US and Canada from the Rockies west are a single synchronized grid.
– The Photon
5 hours ago
The whole grid is connected together, you cannot have variations in frequency without large circulating current (which no supplier wants. Typically the grid frequency will not vary by more than 1mHz (somewhat old but this may help: leapsecond.com/pages/mains). The time is adjusted so mains synced clocks read the correct time in every 24hr period, so constant small adjustments are negotiated over the suppliers.
– Jack Creasey
5 hours ago
Also related: How precise is the frequency of the AC electricity network?.
– The Photon
5 hours ago
4
You'd be better off measuring the flow rate directly, rather than trying to predict it from things like mains frequency and motor characteristics.
– Dave Tweed♦
5 hours ago
 |Â
show 4 more comments
up vote
1
down vote
favorite
up vote
1
down vote
favorite
I have a submersible pump for which I'm trying to determine the variability in flow rate, to high precision. Since this is just an impeller driven by an AC load, what is the % error in frequency of a US wall outlet? Is there a commonly accepted 'ballpark' value, such as 60 hz +/-0.5 hz?
My suspicion is that for most electrical grids, this largely depends on the citywide usage throughout the day.
I apologize because I have an inkling that my question is poorly presented -- that being said, if anyone knows of where I can find real-time data regarding the West Los Angeles electrical grid, I'm all ears. Thanks!
ac frequency
asked 5 hours ago
Austin Prater
516
I have a submersible pump for which I'm trying to determine the variability in flow rate, to high precision. Since this is just an impeller driven by an AC load, what is the % error in frequency of a US wall outlet? Is there a commonly accepted 'ballpark' value, such as 60 hz +/-0.5 hz?
My suspicion is that for most electrical grids, this largely depends on the citywide usage throughout the day.
I apologize because I have an inkling that my question is poorly presented -- that being said, if anyone knows of where I can find real-time data regarding the West Los Angeles electrical grid, I'm all ears. Thanks!
ac frequency
ac frequency
asked 5 hours ago
Austin Prater
516
asked 5 hours ago
Austin Prater
516
asked 5 hours ago
Austin Prater
516
asked 5 hours ago
Austin Prater
516
asked 5 hours ago
Austin Prater
516
516
1
Related: mains frequency accuracy worldwide. Answers cover Australia and North America.
– The Photon
5 hours ago
1
Also, there is no "West Los Angeles grid". Pretty much the entire western US and Canada from the Rockies west are a single synchronized grid.
– The Photon
5 hours ago
The whole grid is connected together, you cannot have variations in frequency without large circulating current (which no supplier wants. Typically the grid frequency will not vary by more than 1mHz (somewhat old but this may help: leapsecond.com/pages/mains). The time is adjusted so mains synced clocks read the correct time in every 24hr period, so constant small adjustments are negotiated over the suppliers.
– Jack Creasey
5 hours ago
Also related: How precise is the frequency of the AC electricity network?.
– The Photon
5 hours ago
4
You'd be better off measuring the flow rate directly, rather than trying to predict it from things like mains frequency and motor characteristics.
– Dave Tweed♦
5 hours ago
 |Â
show 4 more comments
1
Related: mains frequency accuracy worldwide. Answers cover Australia and North America.
– The Photon
5 hours ago
1
Also, there is no "West Los Angeles grid". Pretty much the entire western US and Canada from the Rockies west are a single synchronized grid.
– The Photon
5 hours ago
The whole grid is connected together, you cannot have variations in frequency without large circulating current (which no supplier wants. Typically the grid frequency will not vary by more than 1mHz (somewhat old but this may help: leapsecond.com/pages/mains). The time is adjusted so mains synced clocks read the correct time in every 24hr period, so constant small adjustments are negotiated over the suppliers.
– Jack Creasey
5 hours ago
Also related: How precise is the frequency of the AC electricity network?.
– The Photon
5 hours ago
4
You'd be better off measuring the flow rate directly, rather than trying to predict it from things like mains frequency and motor characteristics.
– Dave Tweed♦
5 hours ago
1
1
Related: mains frequency accuracy worldwide. Answers cover Australia and North America.
– The Photon
5 hours ago
Related: mains frequency accuracy worldwide. Answers cover Australia and North America.
– The Photon
5 hours ago
1
1
Also, there is no "West Los Angeles grid". Pretty much the entire western US and Canada from the Rockies west are a single synchronized grid.
– The Photon
5 hours ago
Also, there is no "West Los Angeles grid". Pretty much the entire western US and Canada from the Rockies west are a single synchronized grid.
– The Photon
5 hours ago
The whole grid is connected together, you cannot have variations in frequency without large circulating current (which no supplier wants. Typically the grid frequency will not vary by more than 1mHz (somewhat old but this may help: leapsecond.com/pages/mains). The time is adjusted so mains synced clocks read the correct time in every 24hr period, so constant small adjustments are negotiated over the suppliers.
– Jack Creasey
5 hours ago
The whole grid is connected together, you cannot have variations in frequency without large circulating current (which no supplier wants. Typically the grid frequency will not vary by more than 1mHz (somewhat old but this may help: leapsecond.com/pages/mains). The time is adjusted so mains synced clocks read the correct time in every 24hr period, so constant small adjustments are negotiated over the suppliers.
– Jack Creasey
5 hours ago
Also related: How precise is the frequency of the AC electricity network?.
– The Photon
5 hours ago
Also related: How precise is the frequency of the AC electricity network?.
– The Photon
5 hours ago
4
4
You'd be better off measuring the flow rate directly, rather than trying to predict it from things like mains frequency and motor characteristics.
– Dave Tweed♦
5 hours ago
You'd be better off measuring the flow rate directly, rather than trying to predict it from things like mains frequency and motor characteristics.
– Dave Tweed♦
5 hours ago
 |Â
show 4 more comments
3 Answers
3
active
oldest
votes
up vote
7
down vote
Typical accuracy of the AC Mains in North America is extremely accurate. Over a long period of time (hours), total error is such that an electric clock with synchronous motor has exactly zero error.
The instantaneous frequency may vary by some tiny fraction of one Hertz but the long term error is actively corrected.
I'm assuming that your impeller pump uses an induction motor. The slip in that motor will introduce far more error in your measurement than frequency changes of the AC Mains.
answered 5 hours ago
Dwayne Reid
16.7k11544
Is the error held to zero for timekeeping (as wikipedia implies), or is there any other reason? And would you assume every country has zero long term error, or is it a very hard task which only more advanced countries can accomplish? (en.wikipedia.org/wiki/Utility_frequency)
– piojo
3 hours ago
1
@piojo check out the info in the other comments, but you may be better, if you are certain it has not been asked before, to ask your own new question.
– Solar Mike
2 hours ago
add a comment |Â
up vote
4
down vote
If your submersible pump uses an induction motor - more than likely - then its rotational speed will be mains frequency minus slip frequency. The slip frequency will vary with load, including motor/pump friction, pump head and viscosity of water which varies with temperature.
Mains frequency drift won't be your problem.
answered 4 hours ago
Transistor
73.7k570159
add a comment |Â
up vote
1
down vote
Frequency of AC power grid in North America is monitored by a network of Universities. You can see the live gradient map at FNET here in real time. It is maintained to about 0.1% across the continent.
However, this doesn't look like having any relevance to accuracy of impeller-based water pump, since the flow will depend on pressure differences and viscosity. Maybe a peristaltic-based pump might give you some accuracy proportional to AC mains frequency, but it will give you a constant flow rate, so it is totally unclear what you are trying to measure.
answered 3 hours ago
Ale..chenski
23.5k11756
add a comment |Â
3 Answers
3
active
oldest
votes
3 Answers
3
active
oldest
votes
active
oldest
votes
active
oldest
votes
up vote
7
down vote
Typical accuracy of the AC Mains in North America is extremely accurate. Over a long period of time (hours), total error is such that an electric clock with synchronous motor has exactly zero error.
The instantaneous frequency may vary by some tiny fraction of one Hertz but the long term error is actively corrected.
I'm assuming that your impeller pump uses an induction motor. The slip in that motor will introduce far more error in your measurement than frequency changes of the AC Mains.
answered 5 hours ago
Dwayne Reid
16.7k11544
Is the error held to zero for timekeeping (as wikipedia implies), or is there any other reason? And would you assume every country has zero long term error, or is it a very hard task which only more advanced countries can accomplish? (en.wikipedia.org/wiki/Utility_frequency)
– piojo
3 hours ago
1
@piojo check out the info in the other comments, but you may be better, if you are certain it has not been asked before, to ask your own new question.
– Solar Mike
2 hours ago
add a comment |Â
up vote
7
down vote
Typical accuracy of the AC Mains in North America is extremely accurate. Over a long period of time (hours), total error is such that an electric clock with synchronous motor has exactly zero error.
The instantaneous frequency may vary by some tiny fraction of one Hertz but the long term error is actively corrected.
I'm assuming that your impeller pump uses an induction motor. The slip in that motor will introduce far more error in your measurement than frequency changes of the AC Mains.
answered 5 hours ago
Dwayne Reid
16.7k11544
Is the error held to zero for timekeeping (as wikipedia implies), or is there any other reason? And would you assume every country has zero long term error, or is it a very hard task which only more advanced countries can accomplish? (en.wikipedia.org/wiki/Utility_frequency)
– piojo
3 hours ago
1
@piojo check out the info in the other comments, but you may be better, if you are certain it has not been asked before, to ask your own new question.
– Solar Mike
2 hours ago
add a comment |Â
up vote
7
down vote
up vote
7
down vote
Typical accuracy of the AC Mains in North America is extremely accurate. Over a long period of time (hours), total error is such that an electric clock with synchronous motor has exactly zero error.
The instantaneous frequency may vary by some tiny fraction of one Hertz but the long term error is actively corrected.
I'm assuming that your impeller pump uses an induction motor. The slip in that motor will introduce far more error in your measurement than frequency changes of the AC Mains.
answered 5 hours ago
Dwayne Reid
16.7k11544
Typical accuracy of the AC Mains in North America is extremely accurate. Over a long period of time (hours), total error is such that an electric clock with synchronous motor has exactly zero error.
The instantaneous frequency may vary by some tiny fraction of one Hertz but the long term error is actively corrected.
I'm assuming that your impeller pump uses an induction motor. The slip in that motor will introduce far more error in your measurement than frequency changes of the AC Mains.
answered 5 hours ago
Dwayne Reid
16.7k11544
answered 5 hours ago
Dwayne Reid
16.7k11544
answered 5 hours ago
Dwayne Reid
16.7k11544
answered 5 hours ago
Dwayne Reid
16.7k11544
16.7k11544
Is the error held to zero for timekeeping (as wikipedia implies), or is there any other reason? And would you assume every country has zero long term error, or is it a very hard task which only more advanced countries can accomplish? (en.wikipedia.org/wiki/Utility_frequency)
– piojo
3 hours ago
1
@piojo check out the info in the other comments, but you may be better, if you are certain it has not been asked before, to ask your own new question.
– Solar Mike
2 hours ago
add a comment |Â
Is the error held to zero for timekeeping (as wikipedia implies), or is there any other reason? And would you assume every country has zero long term error, or is it a very hard task which only more advanced countries can accomplish? (en.wikipedia.org/wiki/Utility_frequency)
– piojo
3 hours ago
1
@piojo check out the info in the other comments, but you may be better, if you are certain it has not been asked before, to ask your own new question.
– Solar Mike
2 hours ago
Is the error held to zero for timekeeping (as wikipedia implies), or is there any other reason? And would you assume every country has zero long term error, or is it a very hard task which only more advanced countries can accomplish? (en.wikipedia.org/wiki/Utility_frequency)
– piojo
3 hours ago
Is the error held to zero for timekeeping (as wikipedia implies), or is there any other reason? And would you assume every country has zero long term error, or is it a very hard task which only more advanced countries can accomplish? (en.wikipedia.org/wiki/Utility_frequency)
– piojo
3 hours ago
1
1
@piojo check out the info in the other comments, but you may be better, if you are certain it has not been asked before, to ask your own new question.
– Solar Mike
2 hours ago
@piojo check out the info in the other comments, but you may be better, if you are certain it has not been asked before, to ask your own new question.
– Solar Mike
2 hours ago
add a comment |Â
up vote
4
down vote
If your submersible pump uses an induction motor - more than likely - then its rotational speed will be mains frequency minus slip frequency. The slip frequency will vary with load, including motor/pump friction, pump head and viscosity of water which varies with temperature.
Mains frequency drift won't be your problem.
answered 4 hours ago
Transistor
73.7k570159
add a comment |Â
up vote
4
down vote
If your submersible pump uses an induction motor - more than likely - then its rotational speed will be mains frequency minus slip frequency. The slip frequency will vary with load, including motor/pump friction, pump head and viscosity of water which varies with temperature.
Mains frequency drift won't be your problem.
answered 4 hours ago
Transistor
73.7k570159
add a comment |Â
up vote
4
down vote
up vote
4
down vote
If your submersible pump uses an induction motor - more than likely - then its rotational speed will be mains frequency minus slip frequency. The slip frequency will vary with load, including motor/pump friction, pump head and viscosity of water which varies with temperature.
Mains frequency drift won't be your problem.
answered 4 hours ago
Transistor
73.7k570159
If your submersible pump uses an induction motor - more than likely - then its rotational speed will be mains frequency minus slip frequency. The slip frequency will vary with load, including motor/pump friction, pump head and viscosity of water which varies with temperature.
Mains frequency drift won't be your problem.
answered 4 hours ago
Transistor
73.7k570159
answered 4 hours ago
Transistor
73.7k570159
answered 4 hours ago
Transistor
73.7k570159
answered 4 hours ago
Transistor
73.7k570159
73.7k570159
add a comment |Â
add a comment |Â
up vote
1
down vote
Frequency of AC power grid in North America is monitored by a network of Universities. You can see the live gradient map at FNET here in real time. It is maintained to about 0.1% across the continent.
However, this doesn't look like having any relevance to accuracy of impeller-based water pump, since the flow will depend on pressure differences and viscosity. Maybe a peristaltic-based pump might give you some accuracy proportional to AC mains frequency, but it will give you a constant flow rate, so it is totally unclear what you are trying to measure.
answered 3 hours ago
Ale..chenski
23.5k11756
add a comment |Â
up vote
1
down vote
Frequency of AC power grid in North America is monitored by a network of Universities. You can see the live gradient map at FNET here in real time. It is maintained to about 0.1% across the continent.
However, this doesn't look like having any relevance to accuracy of impeller-based water pump, since the flow will depend on pressure differences and viscosity. Maybe a peristaltic-based pump might give you some accuracy proportional to AC mains frequency, but it will give you a constant flow rate, so it is totally unclear what you are trying to measure.
answered 3 hours ago
Ale..chenski
23.5k11756
add a comment |Â
up vote
1
down vote
up vote
1
down vote
Frequency of AC power grid in North America is monitored by a network of Universities. You can see the live gradient map at FNET here in real time. It is maintained to about 0.1% across the continent.
However, this doesn't look like having any relevance to accuracy of impeller-based water pump, since the flow will depend on pressure differences and viscosity. Maybe a peristaltic-based pump might give you some accuracy proportional to AC mains frequency, but it will give you a constant flow rate, so it is totally unclear what you are trying to measure.
answered 3 hours ago
Ale..chenski
23.5k11756
Frequency of AC power grid in North America is monitored by a network of Universities. You can see the live gradient map at FNET here in real time. It is maintained to about 0.1% across the continent.
However, this doesn't look like having any relevance to accuracy of impeller-based water pump, since the flow will depend on pressure differences and viscosity. Maybe a peristaltic-based pump might give you some accuracy proportional to AC mains frequency, but it will give you a constant flow rate, so it is totally unclear what you are trying to measure.
answered 3 hours ago
Ale..chenski
23.5k11756
edited 3 hours ago
answered 3 hours ago
Ale..chenski
23.5k11756
answered 3 hours ago
Ale..chenski
23.5k11756
answered 3 hours ago
Ale..chenski
23.5k11756
23.5k11756
add a comment |Â
add a comment |Â
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1
Related: mains frequency accuracy worldwide. Answers cover Australia and North America.
– The Photon
5 hours ago
1
Also, there is no "West Los Angeles grid". Pretty much the entire western US and Canada from the Rockies west are a single synchronized grid.
– The Photon
5 hours ago
The whole grid is connected together, you cannot have variations in frequency without large circulating current (which no supplier wants. Typically the grid frequency will not vary by more than 1mHz (somewhat old but this may help: leapsecond.com/pages/mains). The time is adjusted so mains synced clocks read the correct time in every 24hr period, so constant small adjustments are negotiated over the suppliers.
– Jack Creasey
5 hours ago
Also related: How precise is the frequency of the AC electricity network?.
– The Photon
5 hours ago
4
You'd be better off measuring the flow rate directly, rather than trying to predict it from things like mains frequency and motor characteristics.
– Dave Tweed♦
5 hours ago