HIGH VOLTAGE CABLE HAVING HIGH SIC INSULATION LAYER BETWEEN LOW SIC INSULATION LAYERS AND TERMINAL CONSTRUCTION THEREOF

• US 3,828,115 A
• Filed: 07/27/1973
• Issued: 08/06/1974
• Est. Priority Date: 07/27/1973
• Status: Expired due to Term

• Current Assignee: Hubbell, Inc.
• Original Assignee: Andrew Jr. Hvizd
• Inventors: Hvizd, Andrew Jr.
• Primary Examiner(s): Askin, Laramie E.
• Application Number:
  US05/383,323
• Time in Patent Office: 375 Days
• Field of Search: 174/73R,73SC,80,12R,12SC,12C,15SC,16SC,107,12R,12C,12SC
• US Class Current: 174/73.1
• CPC Class Codes: H01B 7/0291 comprising two or more layers of insulation having different electrical properties
• CPC Class Codes: H01B 9/027 composed of semi-conducting layers
• CPC Class Codes: H02G 15/072 of the condenser type
• CPC Class Codes: H02G 15/184 with devices for relieving electrical stress

Abstract

The number of voids in the insulation of high voltage cable is significantly reduced by utilizing a multiple layer construction and therefore, the dielectric strength thereof is optimized by minimizing ionization therein. A field refraction barrier is disposed within the insulation to relax the electrical stress concentrations which would otherwise be encountered due to surface impurities at the interfacial boundries of the multiple layer construction. In cables having an electric shield coaxially arranged about a load conductor, this field refraction barrier disperses the voltage gradient therebetween at terminations and splices and therefore, stress relief cones can be omitted therefrom in many instances.

Claims

2. The high voltage cable of claim 1 wherein a metallic shield of high electrical conductivity is disposed coaxially about said core and peripherally about said insulation, each said refraction barrier being effective to disperse voltage gradients between said core and said shield at terminations and splices of said cable.

3. The high voltage cable of claim 2 wherein a terminal lug is applied thereto, said shield and said insulation being removed from a portion of said core and said terminal lug being affixed thereto, said shield being removed from said insulation for a distance back from said terminal lug.

4. The high voltage cable of claim 2 wherein a splicing lug is applied therein, said splicing lug joining discontinuous ends of said core and establishing electrical continuity therebetween, said shield including means for establishing electrical continuity around said splicing lug at a distance therefrom.

5. The high voltage cable of claim 2 wherein layers of high specific inductive capacity material are disposed to separate said insulation from said core and said shield.

6. The high voltage cable of claim 2 wherein layers of semi-conductive material are disposed to separate said insulation from said core and said shield.

7. The high voltage cable of claim 1 wherein each said layer of low specific inductive capacity material is at least 5 times the thickness of each said layer of high specific inductive capacity material.

8. The high voltage of claim 7 wherein a metallic shield of high electrical conductivity is disposed coaxially about said core and peripherally about saiD insulation said refraction barrier being effective to disperse voltage gradients between said core and said shield at terminations and splices of said cable.

9. The high voltage cable of claim 8 wherein layers of high specific inductive capacity material are disposed to separate said insulation from said core and said shield.

10. The high voltage cable of claim 8 wherein layers of semi-conductive material are disposed to separate said insulation from said core and said shield.