Arching rings on 400kV overhead lines 1

[stratford]

Dear all. I want to place my question about the installation of arching rings on 400kV overhead lines. These rings are supposed to carry any transient overvoltage and try to break the air gap so they should be placed in the lower length between the live terminal and the earth. Can you give some pictures of these rings installation? On site the installation of the arching rings on the tension insulators are misplaced and as another result the chambers are fastened upside down.

 

[ScottyUK]

Does

http://www.nationalgrid.com/NR/rdon...12121268C/1321/NGTS_30303_Issue1_External.pdf

help?

You might do better in your search if you take the 'h' out of arc(h)ing.


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Sometimes I only open my mouth to swap feet...

 

[stratford]

HI Scotty and thanks for the pdf. n our plant the rings are not installed at the Step Up transformer bushing but on the tension insulators. he question is if they rings should be on the live part or upon the tension insulator. From what i read on the NGC pdf they rings should be installaed in such a way that the flash over will not affect the insulator or the bushing but will try to bridge the gap of the ring. Am i right?

 

[cuky2000]

The grading ring is provided in the insulator to achieve better uniform voltage gradient distribution in the air external along the insulator. Corona shield is provided to screen the top metal work, to reduce corona at operating voltage and to improve the impulse performance.

Below is a link with representative cases.

http://cuky2000.250free.com/Insulator and Voltage Gradient.jpg

 

[bacon4life]

This is of a S. Korean line that is 300 something kV on top and 161 kV on bottom.

http://i19.tinypic.com/521ldhw.jpg

 

[itsmoked]

Wow bacon. A lot of eggs in that one basket!

Keith Cress
Flamin Systems, Inc.-

http://www.flaminsystems.com

 

[stratford]

Hi bacon, thanks for the pic.
It seems that the corona rings are towards the insulators strings and not towards the active line as it happens on our site.