[NTLUG:Discuss] OT: Hz

[Steve Baker]

I'd be very surprised if a small variation in the mains frequency would
have a huge impact on a normal electrical device.

It is certainly true that in the dim and distant past, things like
electromechanical alarm clocks depended on the mains frequency to keep
time - and it's also true that when you use a transformer to convert one
voltage into another (such as inside the power supply of a PC), then the
voltage can be affected by a change in the frequency.

However, the change that the power companies are talking about is tiny -
they aren't talking about letting it vary between (say) 55Hz and 65Hz.

Previous standards required them to keep the frequency between 59.95 to
60.05 with an average over a few hours being to withing a gnat's eyebrow
of 60.000Hz.

What's changing is not the commitment to staying within +/- 0.05Hz but to
maintaining an AVERAGE of 60.0001 or better over a day.  So your frequency
might go up to 60.04 for a day or two - where at present, they'd be
required to drop the frequency back down for a while to compensate.

Overall, that means that those old electromechanical clocks will gain or
lose time at a rate of a few seconds a day - but nothing else will run any
differently.

So I REALLY don't believe that anything other than a clock will be able to
tell the difference.

  -- Steve


Fred James wrote:
> OT: Hz
>
> Question:  Is there an reasonably simple, reasonably inexpensive, way to
> monitor the electric input (voltage, but particularly Hz) in one's home?
>
> Reason for question:
> Not long ago I read an article (in the UK press) in which electric
> companies (TXU for one) admitted that (without any fanfare) they were
> going to lower the standards as regards Hz ... going to loosen up a bit
> and allow the cycles per second to fluctuate over a wider range (+/-),
> because they could save quite a bit of money that way.  Everyone
> admitted that they had no idea of exactly what the impact would be ...
> although they suspected that clocks (plugged in to the wall) would no
> longer keep accurate time, they were particularly in the dark as to what
> might happen to electronics and appliances with embedded systems (DVD
> players for one obvious example).
>
> Recently some of our appliances have been exhibiting behavior that lead
> to us preforming various diagnostic test, with the result that there
> does not appear to be any internal problem(s).  We even went through the
> costly steps of replacing some parts that one might expect from the
> symptoms, with no change in behavior.  Further, the behavior in question
> is far more erratic than one might expect in these cases.
>
> Thank you in advance for any help you may be able to offer
> Regards
> Fred James
>
>
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 -- Steve