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#28702 08/28/03 04:40 PM
Joined: May 2002
Posts: 1,716
R
Roger Offline OP
Member
This time it's in Pauls homeland. Lets hope nothing serious.

-- Major power outage hits south London, cutting subway service during evening rush hour.
Watch CNN or log on to http://CNN.com (AOL Keyword: CNN) for the latest news.

#28703 08/28/03 06:03 PM
Joined: Aug 2001
Posts: 7,520
P
Member
Well, we haven't done it on quite the same scale as North America, but then everyone knows that everything is bigger in America! [Linked Image]

From the BBC News website:
Quote
The National Grid is investigating the cause of the fault but spokesman Sean Regan said any loss of power supply was "an unusual occurrence".

He added: "There was a fault in the 275,000 volt system affecting a ring around London, which occurred at 1826 BST.

"Power to the distribution network in London was restored at 1900 BST.

"Obviously it is going to take the regional distribution network some time to restore supplies to the end users of their system. Hopefully it shouldn't be long now."

Full story: http://news.bbc.co.uk/1/hi/england/london/3189755.stm

#28704 08/28/03 08:45 PM
Joined: Aug 2003
Posts: 24
K
Member
I am beginning to think that Ring circuits are hazardous to our health. I believe the US outage was a Ring event also.

Karl

#28705 08/29/03 01:38 PM
Joined: Sep 2002
Posts: 1,498
Likes: 1
C
C-H Offline
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Quote

I am beginning to think that Ring circuits are hazardous to our health.

Radials are worse. There was a major outage in the northern part of Stockholm, Sweden, one or two years ago, when a HV cable caught fire. The PoCo had to run a new cable above ground to get power back, which took days. A ring would have allowed you to supply at least some power to the area. Silly thing was that the same cable had failed a year before, with the same result. Slow learners... [Linked Image]

[This message has been edited by C-H (edited 08-29-2003).]

#28706 08/30/03 06:32 AM
Joined: Aug 2001
Posts: 7,520
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Apparently EDF in France uses a double-shunt arrangement for MV distribution in the Paris region. There's no mention of whether they employ it on HV transmission as well.

www.ieconsult.fr/ect155.pdf (Look at pg. 12)




[This message has been edited by pauluk (edited 08-30-2003).]

#28707 08/30/03 06:51 AM
Joined: Jul 2002
Posts: 8,443
Likes: 3
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Paul and others,
Whether you like it or not, LV systems are run Underground as a Ring Circuit, before they feed a house, or even as an Over-head circuit.
Normally makes fusing a hell of a lot easier!
And yes, most of our U/G cables are Aluminium.
Even in a PME Installation, there are still Ring circuits!. [Linked Image]

#28708 09/07/03 09:00 AM
Joined: Aug 2001
Posts: 7,520
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It looks as though the media coverage of the big U.S. blackout and the London power failure means that every small blip on the power grid is now going to result in demands for an inquiry:

Quote
An investigation has begun after parts of central Liverpool lost their power supply.

The power cut happened just before 1200 BST on Friday.

Shops and offices were affected for just a few seconds.


http://news.bbc.co.uk/1/hi/england/merseyside/3084814.stm


[This message has been edited by pauluk (edited 09-07-2003).]


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