Mains frequency variation

[Circlotron]

Sometimes the effect of mains frequency comes up in discussion and some people claim it even goes up and down by 10Hz or so! Here is an online meter telling you the frequency of the UK electricity grid right NOW. http://www.dynamicdemand.co.uk/grid.htm

[dark_avenger]

10Hz is abit steep, alot of things would stop functioning properly even a few Hz out i would think...

[theAnonymous1]

I don't live in the UK and I'm no expert, but just going by the face of the meter at the link given, a 10Hz variation would be a total disaster.

[Circlotron]

My point was that claims of 10Hz are ridiculous.

[jcx]

I'm pretty sure my mains freq is 10 Hz higher!

I design instrumentation for worldwide sales, the "universal" linear supply power transformers are designed to "work" with the varying line freq and V of differing countries

but since iron and copper aren't free, the magnetizing current at high line V, low frequency (you 50 Hz types) sometimes cause fuse selection problems with low power equipment, I can't convince the transformer manufacturer that a 10x change in excitation current is a little steep for a 20% increase in Bmax

[Nordic]

With our strained power supply, things are going weird, even clocks running slow.... This is being explained as the frequency dropping as load increases...

[AndrewT]

Hi,
watching the frequency vary over the last twenty minutes shows that the power engineers are doing their job.
The frequency has risen from 49.98Hz to 50.02Hz ready for the lunch time demand surge.

edit,
50.05Hz and rising @ 1200hrs
50.056Hz @ 1203hrs

[OzMikeH]

Cheap LED digital clocks will show any errors over time.

There may be some variation, but they need to guarantee X cycles in 24 hours to keep mechanical timers working correctly.

Off-peak power signalling does make a bit of a mess sometimes.

[Pjotr]

And for those on the European continent, here is the real-time mains frequency they deal with:

http://www.ucte.org/

Cheers

[Speedskater]

Some digital clocks don't filter noise pulses very well. They count the noise pulses as cycles and after time these errors add up.