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 > Specific Vintage Equipment > Other Vintage Household Electrical or Electromechanical Items

Notices

Other Vintage Household Electrical or Electromechanical Items For discussions about other vintage (over 25 years old) electrical and electromechanical household items. See the sticky thread for details.

Reply
 
Thread Tools
Old 14th May 2018, 10:47 pm   #21
russell_w_b
Dekatron
 
russell_w_b's Avatar
 
Join Date: Jul 2007
Location: Penrith, Cumbria, UK.
Posts: 3,027
Default Re: European voltage in the UK?

Quote:
Originally Posted by Ilikevalvesme View Post
In MK, our voltage (on the west side at least)
Is the east side different, then? Fed from elsewhere?
__________________
Regds,

Russell W. B.
G4YLI.
russell_w_b is offline   Reply With Quote
Old 15th May 2018, 8:26 am   #22
Bookman
Pentode
 
Join Date: Aug 2017
Location: Taunton, Somerset, UK.
Posts: 211
Default Re: European voltage in the UK?

Quote:
Originally Posted by broadgage View Post
Actually changing transformer tappings throughout a country would be a huge undertaking, and I doubt that it will happen.
However the reports of increased voltages in mainland Europe suggest that it may be happening in some places.
Perhaps new transformers are being set to 240 volts at the transformer, to achieve about 230 on average at the load.

Of course an adjustment could be made over a very large area by leaving the local transformers alone, but slightly increasing the high voltage transmission voltage. Increasing the nominal 66KV up to 69KV would do it, presuming that all the downstream transformers will be happy with an input about 4.5% high.

In the UK, transformers are normally set at about 250 volts, so as to achieve about 240 on average at the customer. The nearest customer would get about 250 volts and the most distant about 230, with 240 being an average.

In London, no piecemeal voltage increases could be done without a lot of trouble. Many substation transformers are paralleled on the LV side with others nearby. So they can't be altered one at a time.

And even transformers not normally paralleled may be so connected during breakdowns, so the voltages need to match.
Transformers used in EHV systems have many taps (possibly 20) where the Voltage can be varied in small increments. Indeed, there are monitoring systems that will automatically change the setting but remember this has to be done on load so it is a complex mechanical device.
Remember also that EHV systems employ overhead line networks and that expensive distance protection is provided. These systems will invariably require fault impedance Voltage measurement.
From a domestic viewpoint there are literally thousands of 6600V/433V nominal distribution transformers scattered around the UK. The majority of these units will have manually adjusted off load taps that are 2.5%, 5% & 7.5%. It follows that the Voltage could vary on a daily basis and that measurements at a socket may be different to ones next door neighbour.
Note that automatic telephonically operated taps may have only recently been introduced as I worked on the original designs as late as 2005.

Saying all that there are annoying issues in so far as tungsten filament lamps that used to be rated 250V. Following harmonisation they became 220V which meant a reduction in life coupled with a substantial increase in sales for the suppliers?
Bookman is offline   Reply With Quote
Old 15th May 2018, 12:23 pm   #23
Ilikevalvesme
Pentode
 
Ilikevalvesme's Avatar
 
Join Date: Apr 2007
Location: Milton Keynes, Buckinghamshire, UK.
Posts: 181
Default Re: European voltage in the UK?

Quote:
Originally Posted by russell_w_b View Post

Is the east side different, then? Fed from elsewhere?
Not as far as I'm aware, just that I live on the west side so that's where I've taken a measurement!
Mark.
Ilikevalvesme is offline   Reply With Quote
Old 15th May 2018, 4:46 pm   #24
philthespark
Pentode
 
Join Date: Oct 2017
Location: Newton-le-Willows, Merseyside, UK.
Posts: 129
Default Re: European voltage in the UK?

The whole harmonisation thing was a joke from start to finish, I have spoken to more than one senior power engineer on networks, and they all say the same,"never happen here". It is as others have said, not as easy as flicking a switch or two to alter the voltage, a lot of components on the network would need to be replaced.
Interestingly enough, I've plugged a logging meter in at home and seen the voltage shift from as high as 254, to as low as 220 over a 24 hour period.
The funniest incident happened a few years back, I had issues with lights dimming etc and phoned the DNO, this young lad came out, tested the earth loop value and pronounced that all was well, from the results I had, clearly it wasn't.
I attached my test meters and as I increased the load, you could see the voltage drop, I actually got it down to about 150V when pulling about 40 amps. He then said that it was a joint on the service cable that must have failed, and promptly began tearing up the pavement. Along came a more senior engineer and informed him that, if he'd read the mornings briefing notes, he'd have realised that the ring feeding our street had developed a fault, and we were actually currently on the end of a long radial, hence the volt drop.
After a telling off from his boss, he left, a much wiser bloke, I bet he never failed to read the briefing notes after that.
philthespark is offline   Reply With Quote
Old 15th May 2018, 4:53 pm   #25
Refugee
Dekatron
 
Refugee's Avatar
 
Join Date: Apr 2012
Location: Worksop, Nottinghamshire, UK.
Posts: 3,384
Default Re: European voltage in the UK?

We are on the end of a radial being mid terrace.
When we get dim lights and flickering there is usually smoke and sparks from the overhead cable.
The fault report just goes "sparks have been seen there".
They just fix it quickly.
Refugee is offline   Reply With Quote
Old 15th May 2018, 5:53 pm   #26
rambo1152
Heptode
 
rambo1152's Avatar
 
Join Date: May 2010
Location: Manchester, UK.
Posts: 803
Default Re: European voltage in the UK?

Quote:
Originally Posted by broadgage View Post

And even transformers not normally paralleled may be so connected during breakdowns, so the voltages need to match.
That's what must have happened to our supply

https://www.flickr.com/gp/g3zvt/7QRTSQ
That was 6 months ago

Since the LV back-feed began our voltage has reduced from 245 to about 237.

We are still waiting for the new substation, the excavation has been back-filled and tarmacked to a high standard.

I was amazed that the reconfiguration could be done remotely without local intervention.
__________________
--
Graham.
G3ZVT
rambo1152 is online now   Reply With Quote
Old 15th May 2018, 6:26 pm   #27
Bookman
Pentode
 
Join Date: Aug 2017
Location: Taunton, Somerset, UK.
Posts: 211
Default Re: European voltage in the UK?

The vast majority of transformers in our distribution substations will be configured such that 2 transformers will be provided but that each transformer will have the capacity to supply the total needs of that particular substation.
The secondary of each transformer will feed a switchboard that will comprise of two incoming circuit breakers that supplies power to a common busbar connected within the switchboard.
Centrally located within the switchboard is a further circuit breaker which connects each half of the busbars if so requested; it is called a bus section breaker or bus tie as referred to in ANSI nomenclature.
There will be outgoing circuit breakers on each half of the busbar that will feed one end of the ring (loop) circuit referred to by other. In this configuration each transformer will run at 50% if the substation is running at maximum capacity.
The latter system is employed on a global basis as it has the effect of increasing significantly the life of the transformers. In the event there is a fault on either transformer or similar all one need do is close the bus section breaker which will parallel the two transformers and this doubles the capacity of the substation. The only drawback is that the fault level will increase by 100%.
All of the breakers are controlled remotely by the DNO by way of their DCS (Distributed Control System) and higher level SCADA (Supervisory Control and Data Acquisition System) using dedicated or BT telecontrol networks.
Bookman is offline   Reply With Quote
Old 15th May 2018, 8:09 pm   #28
russell_w_b
Dekatron
 
russell_w_b's Avatar
 
Join Date: Jul 2007
Location: Penrith, Cumbria, UK.
Posts: 3,027
Default Re: European voltage in the UK?

Quote:
Originally Posted by Bookman View Post
All of the breakers are controlled remotely by the DNO by way of their DCS (Distributed Control System) and higher level SCADA (Supervisory Control and Data Acquisition System) using dedicated or BT telecontrol networks.
Our DNO, ENW now use 4G to operate circuit breakers remotely, and say it works a treat! But not, as yet, in some of the more remote areas of Cumbria.

Interesting about calling the Bus-Section Switch a Bus-Tie. Never heard that one before!
__________________
Regds,

Russell W. B.
G4YLI.
russell_w_b is offline   Reply With Quote
Old 15th May 2018, 8:38 pm   #29
rambo1152
Heptode
 
rambo1152's Avatar
 
Join Date: May 2010
Location: Manchester, UK.
Posts: 803
Default Re: European voltage in the UK?

Here is the top of the non functioning transformer

Click image for larger version

Name:	IMG_7898.jpg
Views:	89
Size:	74.9 KB
ID:	162940

And here is the other cabinet, presumably containing the switchgear.

Click image for larger version

Name:	IMG_7899.jpg
Views:	144
Size:	96.2 KB
ID:	162941

I have never had the opportunity to see inside this cabinet, but should I expect to see some modern comms equipment in there?

Is the signalling carried over the HV cable?

Is this type of installation common, I don't think I have seen anything quite like it anywhere else.
__________________
--
Graham.
G3ZVT
rambo1152 is online now   Reply With Quote
Old 15th May 2018, 9:28 pm   #30
m0cemdave
Heptode
 
Join Date: Feb 2009
Location: Bletchley, Buckinghamshire, UK.
Posts: 574
Default Re: European voltage in the UK?

Quote:
Originally Posted by Ilikevalvesme View Post
I live on the west side so that's where I've taken a measurement!
Normally between 240 and 245 here in Bletchley...
m0cemdave is offline   Reply With Quote
Old 15th May 2018, 10:21 pm   #31
hannahs radios
Hexode
 
Join Date: Jan 2012
Location: Weymouth, Dorset, UK.
Posts: 328
Default Re: European voltage in the UK?

Bookman do you mean the 33/11Kv substations? I ask because ive only with one exception seen local11/0.4 Kv substations with a single transformer the only double tranny arrangment ive seen was in the centre of town and I think that was an odd system feeding into old DC cables
hannahs radios is offline   Reply With Quote
Old 16th May 2018, 5:25 am   #32
broadgage
Octode
 
Join Date: Jan 2010
Location: North Somerset, UK.
Posts: 1,117
Default Re: European voltage in the UK?

IME, most low voltage substations contain only a single transformer. Protection against failure is usually be feeding from adjacent parts of the network.
Small transformers for isolated groups of consumers or for a single consumer have no such facility. Transformer failures are handled by either quick replacement, or by use of a generator.

Duplicated LV transformers are generally due to either exceptional load growth, or as above, legacy cable systems intended for 3 wire DC and now supplied with 6 phase AC.

High voltage substations do indeed often have duplicate transformers so as to ensure continuity of supply in case of a failure.
broadgage is online now   Reply With Quote
Old 16th May 2018, 7:16 am   #33
Bookman
Pentode
 
Join Date: Aug 2017
Location: Taunton, Somerset, UK.
Posts: 211
Default Re: European voltage in the UK?

Quote:
Originally Posted by rambo1152 View Post
I have never had the opportunity to see inside this cabinet, but should I expect to see some modern comms equipment in there?

Is the signalling carried over the HV cable?

Is this type of installation common, I don't think I have seen anything quite like it anywhere else.
An extremely common item of which there will be thousands located around the country. It is unlikely that comms will be fitted to this type of unit unless it is feeding a critical load and even then it would be a common alarm linked to something else.
Don't forget that these are distribution items and as such there is a common communication link in so far as someone would soon telephone somebody if the power was off.
Bookman is offline   Reply With Quote
Old 16th May 2018, 4:45 pm   #34
hannahs radios
Hexode
 
Join Date: Jan 2012
Location: Weymouth, Dorset, UK.
Posts: 328
Default Re: European voltage in the UK?

Quote:
Originally Posted by broadgage View Post
IME, most low voltage substations contain only a single transformer. Protection against failure is usually be feeding from adjacent parts of the network.
Small transformers for isolated groups of consumers or for a single consumer have no such facility. Transformer failures are handled by either quick replacement, or by use of a generator.

Duplicated LV transformers are generally due to either exceptional load growth, or as above, legacy cable systems intended for 3 wire DC and now supplied with 6 phase AC.

High voltage substations do indeed often have duplicate transformers so as to ensure continuity of supply in case of a failure.
Thanks broadgage you've confirmed exactly what I thought the situation was. I didn't realise how HV subs were set up it's always interesting to know how it,s all done. One extra point on a local HV sub I noticed that on one tranny the fans were turning slowly and on the other not at all. Are they speed controlled? By the way I know it's a little off topic but can the mods indulge me a little please
hannahs radios is offline   Reply With Quote
Old 16th May 2018, 6:28 pm   #35
russell_w_b
Dekatron
 
russell_w_b's Avatar
 
Join Date: Jul 2007
Location: Penrith, Cumbria, UK.
Posts: 3,027
Default Re: European voltage in the UK?

Quote:
Originally Posted by broadgage View Post

Duplicated LV transformers are generally due to either exceptional load growth, or as above, legacy cable systems intended for 3 wire DC and now supplied with 6 phase AC.
Or as part of a commissioned contract that requires belt-and-braces avoidance of single point-of-failure: industry, broadcasting, MoD... Can be configured as both on load-sharing (depending on fault capacity of the board) or 'either/or' with planned changeover intervals for maintenance.
__________________
Regds,

Russell W. B.
G4YLI.
russell_w_b is offline   Reply With Quote
Old 16th May 2018, 7:02 pm   #36
G6Tanuki
Dekatron
 
G6Tanuki's Avatar
 
Join Date: Apr 2012
Location: Wiltshire, UK.
Posts: 6,237
Default Re: European voltage in the UK?

Quote:
Originally Posted by Bookman View Post
The vast majority of transformers in our distribution substations will be configured such that 2 transformers will be provided but that each transformer will have the capacity to supply the total needs of that particular substation.
Here there's only a single 'header' 33/11Kv transformer [OK it's a big one] and I'm last-man-on-the-end of the resulting local 3ph 11Kv overhead feed. Last time there were trees-falling-related service-interruption issues (a couple of winters back during a gale) the DNO brought in a Diesel genset to supply me and a couple of nearby farms [who really urgently needed power for their milking-machines] for a few days until they could assign line-techs to sort out what was very much a 'low priority' case.

My "230V" supply generally sits at around 235V as seen on one presentation-phase.
G6Tanuki is offline   Reply With Quote
Old 17th May 2018, 9:10 am   #37
Bookman
Pentode
 
Join Date: Aug 2017
Location: Taunton, Somerset, UK.
Posts: 211
Default Re: European voltage in the UK?

Your situation poses a further interesting question in so far as Voltage amplitudes and its control. In this it is not particularly a problem for LV single phase applications. It's more the three phase issues for your type of load; in particular any 3 ph machines associated with farming machinery. Here I am referring to how torque is directly proportional to Voltage Squared?
Bookman is offline   Reply With Quote
Old 17th May 2018, 4:05 pm   #38
philthespark
Pentode
 
Join Date: Oct 2017
Location: Newton-le-Willows, Merseyside, UK.
Posts: 129
Default Re: European voltage in the UK?

Quote:
Originally Posted by rambo1152 View Post
Here is the top of the non functioning transformer

Attachment 162940

And here is the other cabinet, presumably containing the switchgear.

Attachment 162941

I have never had the opportunity to see inside this cabinet, but should I expect to see some modern comms equipment in there?

Is the signalling carried over the HV cable?

Is this type of installation common, I don't think I have seen anything quite like it anywhere else.
That cabinet will probably just have some large isolators and fuses in it, a lot of the older ones have a live switching embargo on them, basically they are not to be switched live under any circumstances. I was supposed to be working on one in Doncaster about 3 years back, it was a private sub fed off an 11kV supply via a RMU (RING MAIN UNIT), however because of a live working embargo I had to liase with the DNO, and the railways. It was fed off a circuit that also fed a large railway depot that was being demolished, this sub had to be re-fed from an alternative source. I walked away from the job after the client, who knew sod all about distribution, started trying to dictate how and when it would be done. I got a call from a guy at networks a few months later, the client had messed everyone about that much that in the end the DNO had just cut him off!
Served him right, he had this idea that because he owned the sub, he had some kind of right to be connected to the grid, he was wrong!
philthespark is offline   Reply With Quote
Old 17th May 2018, 4:08 pm   #39
philthespark
Pentode
 
Join Date: Oct 2017
Location: Newton-le-Willows, Merseyside, UK.
Posts: 129
Default Re: European voltage in the UK?

here's a link to the network design manual, some of you may find it interesting, it shows how things are done and how loads are calculated, there's one or two surprises in there for people who don't work in our industry. enjoy

https://www.***********/document/337...gn-Manual-v7-7
philthespark is offline   Reply With Quote
Old 17th May 2018, 6:12 pm   #40
rambo1152
Heptode
 
rambo1152's Avatar
 
Join Date: May 2010
Location: Manchester, UK.
Posts: 803
Default Re: European voltage in the UK?

Your link didn't work but I managed to track it down anyway.

https://tinyurl.com/yb2wavqj
__________________
--
Graham.
G3ZVT

Last edited by rambo1152; 17th May 2018 at 6:17 pm. Reason: forum software will not handle the link. TinyURL alternative used.
rambo1152 is online now   Reply With Quote
Reply

Thread Tools



All times are GMT +1. The time now is 7:48 pm.


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 - 2018, vBulletin Solutions, Inc.
Copyright ©2002 - 2018, Paul Stenning.