Paper Insulated Lead Covered 33kV Cables

Fig. 1 – Single core cable was generally used for switchgear connections within large substation sites.
Fig. 2 - This cable was the main 33kV circuit cable installed on the network up to the mid 1990's, prior to the introduction of XLPE cables.
The standard conductor size used was 185mm.
Fig.3 – 3 core HSL cable was installed in short sections for connections up poles to overhead lines.
Cable Construction
A. Copper or aluminium conductors
• 3 core range of conductor sizes on the network 70-300mm2 with a diameter range between 80.9 – 107.2mm
B. Layers of paper insulation impregnated with mineral oil compound – thickness 6.8mm
C. Conductive layer on each core - insulation screening
D. Lead sheath with bitumen coating
E. PVC oversheath
F. Bitumen coated paper and hessian bedding layers
G. Steel wire armours
H. Bitumen coated hessian tape serving (oversheath)
I. Separate lead sheath around each core, on 3 core HSL cable