High Voltage (HV) self-amalgamating semi-conducting tape is a specialized material used in medium and high voltage cable jointing systems. Its primary role is to maintain electrical continuity and manage the electric field within the joint by creating a uniform potential gradient, especially at critical stress points such as conductor screens and insulation interfaces.

Key Characteristics:

1. Self-Amalgamating:

• Made from materials like semi-conducting ethylene propylene rubber (EPR) or silicone.
• When stretched and wrapped, it fuses to itself, forming a void-free, homogenous layer without the need for external adhesives or heat.

1. Semi-Conductive Properties:

• Specifically designed to have controlled electrical conductivity.
• Helps to equalize potential and manage electrical stress in HV joints and terminations.

1. Flexible and Conformable:

• Easily molds to irregular surfaces and contours of cable components.
• Maintains contact with conductor screen, insulation, and other components, reducing air gaps that could lead to partial discharge.

1. High Temperature and Environmental Resistance:

• Performs reliably under the thermal and electrical stresses typical in HV environments.
• Resistant to moisture, ozone, and UV degradation.
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Functions in HV Cable Jointing:

1. Reinstatement of Conductor Screen:

• After stripping the cable insulation and screen for jointing, this tape is used to rebuild the semi-conductive screen over the insulation.
• Ensures electrical continuity with the existing screen of the cable.

1. Electric Field Control:

• Applied around the insulation screen cut area to smoothen the transition and prevent high-stress concentration, which could lead to electrical breakdown.
• Works in conjunction with stress control materials like mastic or stress grading tapes/tubing.

1. Shielding Interface:

• Provides a shielding interface between metallic components and the high-voltage conductor or insulation layers.
• Often used underneath metallic screen wires in joint construction.