UK Vintage Radio Repair and Restoration Powered By Google Custom Search Vintage Radio Service Data

Go Back   UK Vintage Radio Repair and Restoration Discussion Forum > General Vintage Technology > General Vintage Technology Discussions

Notices

General Vintage Technology Discussions For general discussions about vintage radio and other vintage electronics etc.

Closed Thread
 
Thread Tools
Old 7th Mar 2018, 3:02 pm   #21
Nymrod121
Octode
 
Nymrod121's Avatar
 
Join Date: Apr 2012
Location: Worcestershire, UK.
Posts: 1,615
Default Re: Electric clocks running slow warning

All one can hope for is that normal serb-ice will be resumed as soon as possible.
__________________
"Halt! - who goes there?"
'Baa-aa-aah ..." ('The Dish': 2000)
Nymrod121 is offline  
Old 7th Mar 2018, 3:09 pm   #22
Boater Sam
Banned
 
Join Date: Dec 2013
Location: Middlewich, Cheshire, UK. & Winter in the Philippines.
Posts: 3,897
Default Re: Electric clocks running slow warning

The power on undersea cables is DC, it is synchronised on its conversion back to AC at our end.
Boater Sam is offline  
Old 7th Mar 2018, 3:11 pm   #23
paulsherwin
Moderator
 
paulsherwin's Avatar
 
Join Date: Jun 2003
Location: Oxford, UK
Posts: 18,535
Default Re: Electric clocks running slow warning

Current grid status: http://www.gridwatch.templar.co.uk
paulsherwin is offline  
Old 7th Mar 2018, 3:28 pm   #24
ms660
Dekatron
 
ms660's Avatar
 
Join Date: Apr 2011
Location: Cornwall, UK.
Posts: 8,360
Default Re: Electric clocks running slow warning

I kept an eye on the Grid status during the worst of the "Beast from the East" basically the beast was supplying the power that its presence was demanding, 20% of total Grid power generation when I looked as I recall, coal was flat out, nuclear was trying to do the usual catchy-uppy and gas was throttled back due to power generation by the wind turbines, 'twas on the news.

Lawrence.
ms660 is offline  
Old 7th Mar 2018, 3:51 pm   #25
merlinmaxwell
Dekatron
 
merlinmaxwell's Avatar
 
Join Date: Jul 2008
Location: Maidenhead, Berkshire, UK.
Posts: 8,460
Default Re: Electric clocks running slow warning

I don't think they (the electricity suppliers) bother to keep the number of cycles correct, trying to maintain frequency limits seems hard enough for them. My mains derived Nixie clock is 3 minutes slow compared to the Magneta pendulum master clock (which is a shade fast because of the cold weather). The frequency is at the time of posting smack on 50Hz.
__________________
Cats have staff, it's dogs that have owners.
merlinmaxwell is online now  
Old 7th Mar 2018, 4:16 pm   #26
Sideband
Dekatron
 
Sideband's Avatar
 
Join Date: Oct 2003
Location: Croydon, Surrey, UK.
Posts: 5,429
Default Re: Electric clocks running slow warning

Our calibrated power meters here at this moment are reading 50.0001 very occasionally dropping to 49.9998. Not really enough to worry about!
__________________
On Spike Milligan's headstone......I told you I was ill...
Sideband is offline  
Old 7th Mar 2018, 4:45 pm   #27
broadgage
Octode
 
Join Date: Jan 2010
Location: North Somerset, UK.
Posts: 1,369
Default Re: Electric clocks running slow warning

Quote:
Originally Posted by dominicbeesley View Post
Is this a nationwide thing? Has the voltage also been cut?

We had a (non weather related) power cut a week and a half ago and since then my voltage has been lower than usual.

Here, it's usually around 245V during the day. My computer UPS kicks in around 217V and has been doing so for about 50% of the time (mostly in the evening). Some days it has been as low as 197V! I keep meaning to ring Northern Power (or whoever is responsible) and complain but I really don't have the patience or time to spend arguing with somebody.

Voltage is around 230-233V now, the highest I've noticed since the cut

My Decca Bradford has refused to sync since the low voltage, I'm glad I heard the UPS or I would have started tweaking.

I need to get my multi meter out and test here and other houses locally to see if this is a problem isolated to my house or the whole town or the whole UK?

D
A sustained low mains voltage often follows a power cut.
Immediately after a fault, supply may be restored via an alternative route that is longer or already heavily loaded and the voltage thus reduced.

As a simplified but illustrative example, consider a suburban road a mile long with a single main along the road and fitted with link boxes at several points.
Normally, the north end of the road is fed from substation A, the south end from substation B, and the middle part is connected via a main in a side street to substation F.
If substation A fails, then by inserting fuses or links in the link boxes, the customers normally supplied by A will be supplied by either B or by F .
The loading on B and on F will be increased, and the distance between transformer and customer also increased.

In practice the arrangements may be more complex, but the principle remains, that following a fault, power may be restored via different route.
broadgage is online now  
Old 7th Mar 2018, 5:10 pm   #28
mark_in_manc
Octode
 
Join Date: Nov 2011
Location: Manchester, UK.
Posts: 1,095
Default Re: Electric clocks running slow warning

Quote:
Originally Posted by bluepilot View Post
Looks like those pesky Serbs are causing the problem.
I sold a big old Crown audio PA amplifier to a Serb via ebay just after Christmas. He must have plugged it in.
mark_in_manc is offline  
Old 7th Mar 2018, 5:11 pm   #29
Heatercathodeshort
Dekatron
 
Heatercathodeshort's Avatar
 
Join Date: Jun 2005
Location: Warnham, West Sussex. 10 miles south of DORKING.
Posts: 6,890
Default Re: Electric clocks running slow warning

Last week during the very cold period I did notice some odd happenings. The Microwave took much longer to carry out regular tasks. I put it down to low voltage [Load shedding as it used to be called] but when I metered the supply it was 241, only a couple of volts below it's average here. Never thought of checking the actual frequency.

During the winter of 62/3 the mains dropped in Wimbledon to 180V with a much reduced picture size on our Ferguson 236T J.
Heatercathodeshort is offline  
Old 7th Mar 2018, 5:17 pm   #30
Dai Corner
Pentode
 
Join Date: Oct 2016
Location: Newport, South Wales, UK.
Posts: 244
Default Re: Electric clocks running slow warning

Article about the frequency deviation on the continent. Apparently the Swiss are in charge of monitoring their mains frequency which I found quite fitting and reassuring! Im not a heavy electrical engineer but guess their hydro power stations are easiest to keep at 50 Hz?

https://preview.entsoe.eu/news/2018/...-to-technical/
Dai Corner is offline  
Old 7th Mar 2018, 5:53 pm   #31
Hartley118
Octode
 
Hartley118's Avatar
 
Join Date: Aug 2015
Location: Cambridge, Cambs. UK.
Posts: 1,409
Default Re: Electric clocks running slow warning

I've still not seen an explanation as to why an average frequency error in Continental Europe should influence the average frequency in the UK.

Martin
__________________
BVWS Member
Hartley118 is online now  
Old 7th Mar 2018, 6:02 pm   #32
paulsherwin
Moderator
 
paulsherwin's Avatar
 
Join Date: Jun 2003
Location: Oxford, UK
Posts: 18,535
Default Re: Electric clocks running slow warning

It doesn't. Somebody's got confused somewhere.

As I suggested earlier, my guess is that the huge amount of wind generation being used in the last couple of weeks has caused problems for the grid managers. Both the wind and the demand have returned to normal levels now, so presumably the frequency deviations will have stopped.
paulsherwin is offline  
Old 7th Mar 2018, 6:10 pm   #33
Hartley118
Octode
 
Hartley118's Avatar
 
Join Date: Aug 2015
Location: Cambridge, Cambs. UK.
Posts: 1,409
Default Re: Electric clocks running slow warning

'Fake News' I guess!

Convenient to blame The Continent when it's actually a National Grid problem - and a rather interesting one.

Martin
__________________
BVWS Member
Hartley118 is online now  
Old 7th Mar 2018, 8:02 pm   #34
broadgage
Octode
 
Join Date: Jan 2010
Location: North Somerset, UK.
Posts: 1,369
Default Re: Electric clocks running slow warning

Could be an indirect link.
Low grid frequency in Europe implies a scarcity of generating capacity, that in turn might lead to ceasing exports to the UK.
The unexpected loss of several GW from Europe could precipitate a low frequency event in the UK.
broadgage is online now  
Old 7th Mar 2018, 8:10 pm   #35
Dave Moll
Dekatron
 
Dave Moll's Avatar
 
Join Date: Feb 2005
Location: West Cumbria (CA13), UK
Posts: 4,213
Default Re: Electric clocks running slow warning

219V is still (just) within the specified tolerance of 230V -6%/+10% (i.e. 216.2V to 253V).
__________________
Mending is better than Ending (cf Brave New World by Aldous Huxley)
Dave Moll is online now  
Old 7th Mar 2018, 8:12 pm   #36
paulsherwin
Moderator
 
paulsherwin's Avatar
 
Join Date: Jun 2003
Location: Oxford, UK
Posts: 18,535
Default Re: Electric clocks running slow warning

There were certainly some odd things happening during the Beast. I noticed that significant generation was by OCGT, which is normally considered an emergency source given the cost per unit. The total UK demand wasn't especially high for a winter day. This might be explained by the French and/or Dutch suddenly suspending supplies via the interconnectors, and indeed calling on the UK to supply emergency power. I can't remember the status of the various interconnectors at the time though.
paulsherwin is offline  
Old 7th Mar 2018, 8:34 pm   #37
hannahs radios
Hexode
 
Join Date: Jan 2012
Location: Weymouth, Dorset, UK.
Posts: 394
Default Re: Electric clocks running slow warning

There was one day Friday I think when the OCGT plant was run all day this is as Paul says unusual. I also notice that other gas generation was throttled back because of the gas shortage and the fact that the price of gas was the highest it's been all winter. The French link was running at less than full capacity for at least 2 days. I think really the grid coped well all things considered. Incidentally highest consumption was just over 50,000 Megawatts that's a LOT of electricity.
hannahs radios is offline  
Old 7th Mar 2018, 8:49 pm   #38
Dai Corner
Pentode
 
Join Date: Oct 2016
Location: Newport, South Wales, UK.
Posts: 244
Default Re: Electric clocks running slow warning

Historic data can be downloaded from http://gridwatch.templar.co.uk/download.php if anyone feels inclined to analyse it.
Dai Corner is offline  
Old 7th Mar 2018, 9:04 pm   #39
tealandsilver
Tetrode
 
Join Date: Nov 2017
Location: East Lothian, Scotland, UK.
Posts: 64
Default Re: Electric clocks running slow warning

Grid frequency is maintained in accordance with the Grid Code which all of the UK Generation companies adhere to. This sets grid frequency at 50Hz +/- 1%. The relevant link is posted below. I have spent most of my working life (>30 years) within power station control rooms and my own experience is that there is more volatility in grid frequency now, although this volatility is still within the 1% tolerance. The household voltage requirements are set (I believe) by Electricity Safety, Quality & Continuity Regs (ESQCR) and are 230V +10%/ -6%.
There are many factors which influence your household supply, one of the more significant being the distance that you are from your local substation and whether there are any other "large" consumers fed from the same distribution line.

CCGT generation (gas generators), wind farms, hydro and interconnected supplies to France, Ireland and the Netherlands can and are all used to balance and ensure Grid stability. I don't agree that modern generators are less able to "modulate", quite the opposite in my experience, I was very impressed by the speed at which modern CCGT sets can be spun up, synchronised and loaded. Modern forecasting techniques also now enable renewables to contribute in a much more controlled fashion than even just a decade ago.

https://www.nationalgrid.com/sites/d...rid%20Code.pdf

This second link allows access to see grid loading in real time.

http://www.gridwatch.templar.co.uk/
tealandsilver is offline  
Old 7th Mar 2018, 9:17 pm   #40
Glowing Bits!
Heptode
 
Glowing Bits!'s Avatar
 
Join Date: Oct 2011
Location: Wrexham, North Wales, UK.
Posts: 646
Default Re: Electric clocks running slow warning

Just out of curiousity, if the mains frequency varies slightly, is it possible to see a clock's sweeping hand speed up/slow down?
For the info of the forum, the frequency is moving between 49.8 - 50.1Hz, never in my life have I ever seen it hit 50 before, it usually stays at 49.9.
Glowing Bits! is offline  
Closed Thread

Thread Tools



All times are GMT +1. The time now is 9:38 am.


All information and advice on this forum is subject to the WARNING AND DISCLAIMER located at https://www.vintage-radio.net/rules.html.
Failure to heed this warning may result in death or serious injury to yourself and/or others.


Powered by vBulletin®
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Copyright ©2002 - 2019, Paul Stenning.