Mains Frequency huge Variation

[digit107]

Hi, on my mains I seem to be getting huge variations from the normal 50hz for several minutes at a time. It goes down to 48hz then back to 50-51hz and then will then jump from 51hz sometimes to 65hz but usually hover around 53-57hz for around 2 minutes at a time.

This happens fairly often, what effect would this be having on any appliances? Im on a legacy rural power supply which first feeds a farm and then 4 properties via a pole transformer.

The pylons comes from a newly built industrial estate which has some fairly substantial refrigeration units.

Actually my plug in meter has just read 91hz for a second and now 15hz surely this cant be right??

 

[digit107]

Actually I feel silly now, it seems whenever my laptop power supply is plugged into the socket it causes the frequency to vary like a yoyo. Im not sure why it would cause this? its an apple charger. Maybe my power monitor plug is just faulty??

 

[digit107]

Actually I feel silly now, it seems whenever my laptop power supply is plugged into the socket it causes the frequency to vary like a yoyo. Im not sure why it would cause this? its an apple charger. Maybe my power monitor plug is just faulty??

 

[Wilko]

Good morning D, yes it sounds like your power monitor is having a problem. There can be variations in the supply frequency, but these are in the order of 0.1 Hz and are carefully balanced to give us 50 per second over a longer period. Maybe just try it in another outlet?

 

[HandySparks]

Good morning D, yes it sounds like your power monitor is having a problem. There can be variations in the supply frequency, but these are in the order of 0.1 Hz and are carefully balanced to give us 50 per second over a longer period. Maybe just try it in another outlet?

Yes, definitely your measuring device at fault. Perhaps being confused by noise on the supply.

Check current frequency here:
G. B. National Grid status - http://www.gridwatch.templar.co.uk/

 

[Barry White]

This begs the question. Why are you measuring mains frequency? Are you having problems with something?

 

[DPG]

If the mains in your area was so far out of sync with the grid you would notice much more than a variation on your meter Daz

 

[Marvo]

Yeah, even a 0.1 hz error would prompt a correction in the generation plant. Switch mode power supplies such as PC power supplies, laptop and phone chargers etc are very unruly things that cause shifts in phase angle etc. It's possible that the input filtering on your frequency tester isn't effective and the noise from the power supply is causing wildly inaccurate readings.