Arcing between cable termination sleeve and sheath in 33kV

[vijaypandiyan]

Hello all,

In one of 33kV incoming cable chamber, we felt some bad smell. When we investigated, we found hissing noise. We switched off room lights and found slight corona discharge (kind of) between the cable termination and sheath which is connected to earth. We suspect the termination was not done properly or cable insulation is weak.

Kindly let me know your opinions.

Thanks,
Vijay

 

[7anoter4]

No live parts of the termination are exposed-they are concealed and insulated [ excepting the terminal].
The "corona" effect you saw it could be from the terminal creepage -due to polluted atmosphere. A minimum length from terminal live part to grounding wire on the termination surface has to be 33/sqrt(3)*22 mm [> 420 mm]. See for instance:

http://electricalquestionsguide.blogspot.co.il/2013/04/creepage-distance-insulator-substation.html

 

[waross]

There may be a problem with the stress cone.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[vijaypandiyan]

7anoter4 : This is inside switchgear where the power cable is brought from bottom entry and connected to bus bar. This cable sleeve is earthed at the cable entry point. SO I think we have considerable distance between live part and sheath.



Thanks,
Vijay