Metallic Sheath

Metallic Sheath is must for cables above 33 kV as the cable of voltage grade 66 kV & above are working with dielectric stress of above 6 kV / mm & at this level of dielectric stress presence of water triggers tree formation in the insulation resulting in cable failure. Water can enter the cable longitudinally as well as radically. Longitudinal water entry can be blocked by using water swell able tape on the core. Lead sheath can block the entry in radial direction. Lead sheath is extruded by continuous lead extruder which is equipped with micro-processor based temperature controllers & drives to achieve uniform thickness, better concentricity. Lead sheath in addition to other electrical & manufacturing advantages has a life span of minimum 40 to 45 years

Salient features of EHV / XLPE line

â–ª The only manufacturer in the country to have 2 Dry cure / Dry cooled 

   lines sourced from SCHOLZ Germany

  â–ª Highly sophisticated extruders for conductor shield, insulation and

  insulation shield, employing a three layer single head triple extrusion 

  method to eliminate contaminants in the insulating layers. These are

  sourced from ROYLE USA.

â–ª Microprocessor based equipments control all the parameters required 

   for the process within the specified limits .

â–ª Separate pressurized rooms for semitone shield & XLPE insulation to

  avoid contamination & this material is handled by vacuum loaders

â–ª Air systems with air showers on doors to eliminate dust entry

The complete solution

Polycab can provide complete solution to provide assistance in selecting the cables, manufacturing the cables to the desired specification & assist / provide turnkey execution of the cable installation.