Accuracy of Electric Clocks in the US

Jonathan Hardis posted this on the LEAPSECS list:

http://six.pairlist.net/pipermail/leapsecs/2011-June/003043.html

Starting on July 14, 2011, the North American electric power grid will
begin a one year experiment in which they will not make time
corrections.

Material posted on the NERC (North American Electric Reliability
Corporation) web site implies that currently electric clocks in the
Western US are kept within 2 seconds of UTC, with a 10 second
tolerance in the Eastern US.

See:

http://www.nerc.com/page.php?cid=6 |386

http://www.nerc.com/files/NERC_TEC_Field_Trial_Webinar_061411.pdf

http://www.naesb.org/pdf2/weq_bklet_011505_tec_mc.pdf

This probably opens some more markets for GPS.

Ed M. wrote:

*WHAT* markets???????
That system only directly addressed _average_ *long term*
deviations. GPS based would be going for "short term" "high
precision" market - like using a nuke to swat a mosquito ;/

wrote:



Some of my clocks are set by the WWVB broadcast, some run on batteries
at their own leisure. My VCR clock, run at line frequency always says
12:00.

I don't see GPS helping a lot there.

On 2011-06-19 14:10 , Ed M. wrote:

Do electronic clocks (like clock radios or microwave oven clocks) use a
crystal or the 60 Hz of the grid as reference?

IAC, here in Quebec there will be no impact - I assume because the
correction will be maintained.

(All HQ interfaces to the NPCC is HVDC).

--
gmail originated posts filtered due to spam.

On Sun, 19 Jun 2011 15:34:47 -0400, Alan Browne


I don't know about Canada, but in the USA the Electric Utilities keep
tight control on the 60 Hz alternating current. Sometime late at
night, each night as I recall, they make a correction for the DAY by
incrementing or decrimenting the frequency briefly to get back to the
correct display.