What’s With the Wonky Time on my Clock?

Today's question: My digital alarm clock is going crazy, gaining minutes like mad. My wife's is a little steadier. We always notice that my (very old) clock gains time when there's something wonky with some sort of regulator on the power production side. What exactly is happening, and when will it be fixed?

Thanks for your question. Without knowing specifics, such as what community the clock is located in or its operating principle, I can only comment in general terms. I will try to explain how a clock determines time, how the electrical system might influence the time, and what Yukon Energy does to control time.

Some clocks use our system frequency of 60 cycles a second as a reference for determining time. Others generate their own reference. For example, grandfather clocks use a pendulum, while many digital devices have a small crystal that oscillates at a very precise frequency. Those that generate their own reference will obviously not be influenced by our system.

For the benefit of those clocks that are plugged into a wall socket and therefore do rely on our system for accuracy, we use a device that is essentially a sophisticated electric wall clock. We synchronize that wall clock with a very accurate satellite signal. Yukon Energy monitors the frequency closely so that it doesn't wander from the "correct" time by more than 10 seconds. As long as we do this properly, the drift in any clock should be barely noticeable. Certainly it should not be swinging by minutes each day.

You might recall that around Easter of last year, Yukon Energy did have issues with our wall clock, as explained in a blog post at the time (http://blog.yukonenergy.ca/blog/the_power_of_time/). We now have a backup system that provides a check for when the main system begins to deviate. We are therefore pretty confident that our system frequency is keeping correct time. That's why I suspect the issue with the clock in question is likely due to another cause.

A number of communities are not supplied directly from the Yukon Energy system. Instead they have their own local diesel generation. These systems are not owned or operated by Yukon Energy so we can't comment on any issues related to their system frequency.