60Hz Stability on Power Grid Going Away?

June 27, 2011


Washington - Jun 24, 2011 - The power grid in the United States is locked on 60Hz and has been since the 1930s. The stability of that 60Hz signal has been so good, it has been used as a time-base reference for most wall-powered clocks. But this long-lived time reference may become less stable.

The North American Electric Reliability Corporation NERC) is responsible for maintaining the accuracy of the line frequency. The group is planning a yearlong experiment to see if allowing the frequency to drift will cause any problems. The Associated Press reports it obtained a NERC presentation that says it is proposing a change to allow the frequency to drift. Power companies have long worked on keeping the frequency as stable as possible.

NERC says that by allowing the frequency to vary slightly, the power grid could be more reliable and power companies could save money. The test is tentatively set to start in mid-July 2011.

Some reports say that the variation could be greater on the East Coast than the West, predicting clocks could run up to 20 minutes fast over a year in the East, and up to 8 minutes fast in the West.

Apparently, some at NERC believe the slight fluctuation will not be a problem.

While GPS and Internet time standards will not be affected, many consumers rely in line-referenced clocks. So do broadcast stations. If the line reference is changed, stations will either spend more time adjusting their clocks or they will be forced to purchase clocks that use an alternate time reference.

But clocks are not the only devices that reference the 60Hz signal. Some motor-driven devices reference the signal as well. Turntable enthusiasts for example may experience some fluctuations.

Some experts doubt there will be any difficulties and note that the U.S. government provides a stable time reference online at time.gov and by phone at 202-762-1401.



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