Dear Sirs,

We wish to have some information on Gas Curing TEMPERATURE PROFILE of a CV line for 132kV peroxide XLPE insulated ( approx. 20mm thickness of insulation ) power cable to avoid OVALITY of insulation shape ? Whether the Rotation may affect on non oval shape of insulation ?

Thanks and best regards,
Chimiza

Hello There Chimiza,

There are a number of factors that affect the ovality of the insulation when the thicknesses are large. We recommend the following for good processing:

- The catenary angle should be fairly high - Say 18 to 25 degrees. From an insulation sag perspective of course, the higher the angle, the better.
- A triple crosshead is preferred along with a conductor preheater.
- The plastic temperatures should be as low as possible in the extruders.
- The profile temperature in the CV tube should not be excessively high.
- Rotating the cable in the CV tube will reduce insulation sag.
- An X-ray diameter and eccentricity monitor at the splice box is recommended.
- A secondary eccentricity monitor at the exit of the pull out capstan is also recommended to verify there has been no insulation sag.
- Gradient cooling is preferred to lessen shrinkback.

As far as an actual CV tube thermal profile is concerned, use the computer program you got with your CV line. Check with your supplier for program upgrades or newer versions.

There is significant processing experience to be learned and documented as the wall thicknesses increase. We wish you good luck in this venture.

Kindest regards,
Peter J. Stewart-Hay
Principal
Stewart-Hay Associates
www.Stewart-Hay.com

Hello there vettecoupe,

I thank you very much for your kind response and assistance.

Please kindly advise me if you know any website address through that I can find some useful articles on CV line processing particularly for the large insulation thicknesses.

Best regards,
chimiza

Hello again Chimiza;

I am very sorry but I am not aware of any web sites dealing with the processing of high voltage XLPE in a CCV line.

I suggest you contact your CV line manufacturer to see what assistance they can provide. Every wire and cable company that manufactures these kind of products originally "learned by doing" at great expense. Thus they will not be willing to give away this kind of know-how or intellectual property.


Kindest regards,
Peter J. Stewart-Hay
Principal
Stewart-Hay Associates
www.Stewart-Hay.com