Power line: 15 second drift in one day
Last Monday was Memorial Day in the US, a big start-of-summer holiday.
The power line clocks lost 15 seconds that day.
https://www.glypnod.com/TimeNuts/60Hz/60Hz-15sec-day.png
That's using UTC days rather than sundial days. The UTC day starts at 5
PM local time.
I don't think I've seen anything quite that dramatic before. This seems
like a good excuse to write some code to poke around in old data.
Does anybody know when they officially turned off time keeping?
I've noticed that there is often a drop in line frequency starting at 5PM
local, 0 UTC. Has anybody tried to recover time-of-day from a power line
by searching for that drop? You might be able to get within an hour or
two.
--
These are my opinions. I hate spam.
The long-time, cumulative accuracy of your mains frequency seems
variable by location. I've seen a cumulative error of 2 minutes here in
Southern California, with local time usually being slow. For example, I
last accurately set a 6-digit mains-synchronized clock on May 9, 2024;
now, some 28 days later, my mains-synched clock is 01:45 mm:ss slow.
Some insist regs prohibit this. If so, the regs are being ignored.
I have a mains-synched clock beside a GPS clock and take a photo to
document the comparison.
It is not a function of the clock. I have three kitchen appliance clocks
and they all agree with the 6-digit mains-synched clock within 1 second.
Yes, it is tedious to accurately (well, within one second) set appliance
clocks, but doable...
Best wishes,
Larry McDavid W6FUB
Anaheim, California (SE of Los Angeles, near Disneyland)
On 5/30/2024 12:33 AM, Hal Murray via time-nuts wrote:
Last Monday was Memorial Day in the US, a big start-of-summer holiday.
The power line clocks lost 15 seconds that day.
https://www.glypnod.com/TimeNuts/60Hz/60Hz-15sec-day.png
...
Does anybody know when they officially turned off time keeping?
...
As I recall, the western power grid system (WECC) discontinued line
frequency regulation for timekeeping purposes some time ago. The eastern
grid (EI) still maintains time and, here in Florida, line-operated
clocks typically stay within about +/- 15 seconds of my UTC clocks.
73,
John K9WT
On 6/7/2024 1:16 AM, Larry McDavid via time-nuts wrote:
The long-time, cumulative accuracy of your mains frequency seems
variable by location. I've seen a cumulative error of 2 minutes here
in Southern California, with local time usually being slow. For
example, I last accurately set a 6-digit mains-synchronized clock on
May 9, 2024; now, some 28 days later, my mains-synched clock is 01:45
mm:ss slow.
Some insist regs prohibit this. If so, the regs are being ignored.
I have a mains-synched clock beside a GPS clock and take a photo to
document the comparison.
It is not a function of the clock. I have three kitchen appliance
clocks and they all agree with the 6-digit mains-synched clock within
1 second. Yes, it is tedious to accurately (well, within one second)
set appliance clocks, but doable...
Best wishes,
Larry McDavid W6FUB
Anaheim, California (SE of Los Angeles, near Disneyland)
On 5/30/2024 12:33 AM, Hal Murray via time-nuts wrote:
Last Monday was Memorial Day in the US, a big start-of-summer holiday.
The power line clocks lost 15 seconds that day.
https://www.glypnod.com/TimeNuts/60Hz/60Hz-15sec-day.png
...
Does anybody know when they officially turned off time keeping?
...
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe send an email to time-nuts-leave@lists.febo.com
Maintaining grid reliability AND time error correction are odds with each other, since the correction requires operators to intentionally operate the grid away from the nominal 60.000 Hz, giving up safety margin. Keeping accurate grid time is relatively low on an operator's priority list, and there is a lot of discussion about doing away with it entirely, see for example https://www.nerc.com/pa/Stand/Project%20200705%20Balancing%20Authority%20Controls%20DL/Summary_Paper_Time_Error_Correction_12Sep08.pdf
Here are the current procedures in effect for Time Error Correction in California https://www.caiso.com/documents/rc0220.pdf
-Joe Fitzgerald
From: Larry McDavid via time-nuts time-nuts@lists.febo.com
Sent: Friday, June 7, 2024 1:16 AM
To: Hal Murray via time-nuts
Cc: Larry McDavid
Subject: [time-nuts] Re: Power line: 15 second drift in one day
The long-time, cumulative accuracy of your mains frequency seems
variable by location. I've seen a cumulative error of 2 minutes here in
Southern California, with local time usually being slow. For example, I
last accurately set a 6-digit mains-synchronized clock on May 9, 2024;
now, some 28 days later, my mains-synched clock is 01:45 mm:ss slow.
Some insist regs prohibit this. If so, the regs are being ignored.
I have a mains-synched clock beside a GPS clock and take a photo to
document the comparison.
It is not a function of the clock. I have three kitchen appliance clocks
and they all agree with the 6-digit mains-synched clock within 1 second.
Yes, it is tedious to accurately (well, within one second) set appliance
clocks, but doable...
Best wishes,
Larry McDavid W6FUB
Anaheim, California (SE of Los Angeles, near Disneyland)
On 5/30/2024 12:33 AM, Hal Murray via time-nuts wrote:
Last Monday was Memorial Day in the US, a big start-of-summer holiday.
The power line clocks lost 15 seconds that day.
https://www.glypnod.com/TimeNuts/60Hz/60Hz-15sec-day.png
...
Does anybody know when they officially turned off time keeping?
...
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe send an email to time-nuts-leave@lists.febo.com
FNET monitors time drift.
https://fnetpublic.utk.edu/time_error.html
On Fri, Jun 7, 2024, at 08:51, John Vendely via time-nuts wrote:
As I recall, the western power grid system (WECC) discontinued line
frequency regulation for timekeeping purposes some time ago. The eastern
grid (EI) still maintains time and, here in Florida, line-operated
clocks typically stay within about +/- 15 seconds of my UTC clocks.
73,
John K9WT
On 6/7/2024 1:16 AM, Larry McDavid via time-nuts wrote:
The long-time, cumulative accuracy of your mains frequency seems
variable by location. I've seen a cumulative error of 2 minutes here
in Southern California, with local time usually being slow. For
example, I last accurately set a 6-digit mains-synchronized clock on
May 9, 2024; now, some 28 days later, my mains-synched clock is 01:45
mm:ss slow.
Some insist regs prohibit this. If so, the regs are being ignored.
I have a mains-synched clock beside a GPS clock and take a photo to
document the comparison.
It is not a function of the clock. I have three kitchen appliance
clocks and they all agree with the 6-digit mains-synched clock within
1 second. Yes, it is tedious to accurately (well, within one second)
set appliance clocks, but doable...
Best wishes,
Larry McDavid W6FUB
Anaheim, California (SE of Los Angeles, near Disneyland)
On 5/30/2024 12:33 AM, Hal Murray via time-nuts wrote:
Last Monday was Memorial Day in the US, a big start-of-summer holiday.
The power line clocks lost 15 seconds that day.
https://www.glypnod.com/TimeNuts/60Hz/60Hz-15sec-day.png
...
Does anybody know when they officially turned off time keeping?
...
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe send an email to time-nuts-leave@lists.febo.com
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe send an email to time-nuts-leave@lists.febo.com
--
Ryan Stoner
At 07:51 AM 6/7/2024, John Vendely via time-nuts wrote:
As I recall, the western power grid system (WECC) discontinued line
frequency regulation for timekeeping purposes some time ago. The
eastern grid (EI) still maintains time and, here in Florida,
line-operated clocks typically stay within about +/- 15 seconds of
my UTC clocks.
That fits with my Memorial Day data collected here in Arkansas
(eastern grid)--maybe 3.5 seconds vs. Hal's graph showing 15 seconds.
Graph attached.
--
newell N5TNL
I am FNET #853 in the western interconnection.
Jeremy
On Fri, Jun 7, 2024 at 4:40 PM Ryan Stoner via time-nuts <
time-nuts@lists.febo.com> wrote:
FNET monitors time drift.
https://fnetpublic.utk.edu/time_error.html
On Fri, Jun 7, 2024, at 08:51, John Vendely via time-nuts wrote:
As I recall, the western power grid system (WECC) discontinued line
frequency regulation for timekeeping purposes some time ago. The eastern
grid (EI) still maintains time and, here in Florida, line-operated
clocks typically stay within about +/- 15 seconds of my UTC clocks.
73,
John K9WT
On 6/7/2024 1:16 AM, Larry McDavid via time-nuts wrote:
The long-time, cumulative accuracy of your mains frequency seems
variable by location. I've seen a cumulative error of 2 minutes here
in Southern California, with local time usually being slow. For
example, I last accurately set a 6-digit mains-synchronized clock on
May 9, 2024; now, some 28 days later, my mains-synched clock is 01:45
mm:ss slow.
Some insist regs prohibit this. If so, the regs are being ignored.
I have a mains-synched clock beside a GPS clock and take a photo to
document the comparison.
It is not a function of the clock. I have three kitchen appliance
clocks and they all agree with the 6-digit mains-synched clock within
1 second. Yes, it is tedious to accurately (well, within one second)
set appliance clocks, but doable...
Best wishes,
Larry McDavid W6FUB
Anaheim, California (SE of Los Angeles, near Disneyland)
On 5/30/2024 12:33 AM, Hal Murray via time-nuts wrote:
Last Monday was Memorial Day in the US, a big start-of-summer holiday.
The power line clocks lost 15 seconds that day.
https://www.glypnod.com/TimeNuts/60Hz/60Hz-15sec-day.png
...
Does anybody know when they officially turned off time keeping?
...
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe send an email to time-nuts-leave@lists.febo.com
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe send an email to time-nuts-leave@lists.febo.com
--
Ryan Stoner
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