Compatibility Of Pre-insulated Bushings With Power Cables

To meet the insulation protection needs of medium and low voltage power transmission and distribution systems, pre insulated sleeve is gradually replacing traditional sheathing processes, becoming an important choice for improving line operational stability. From material compatibility to physical and mechanical properties, the compatibility of this product with modern cross-linked polyethylene (XLPE) cables has been proven through long-term operation.

Technical Compatibility of Power Cable Terminations and Intermediate Joints

Power cables undergo thermal expansion and contraction during operation, placing stringent requirements on the elastic recovery of the external sheathing material. pre insulated junction sleeve uses high-performance silicone rubber material, possessing excellent expansion ratio and resilience characteristics. After being fitted onto the cable stripping section, it relies on the material's own radial contraction force to tightly adhere to the cable's main insulation layer, eliminating air gaps.

The stability of this physical structure is particularly outstanding in harsh outdoor environments:

• Interface Pressure: The sheathing maintains a constant and persistent pressure on the cable interface after contraction, preventing moisture penetration along the ends.

• Dielectric Properties: Silicone rubber itself has extremely high breakdown strength, sufficient to withstand operating voltages from 10kV to 35kV.

• Construction Efficiency: No open flame heating or special tools are required, reducing the risk of partial discharge due to human error.

The construction logic for improving the insulation level of power distribution networks

Whether insulated joint sleeve is suitable for power cables is essentially an assessment of their tolerance to complex laying environments. In cable wells, tunnels, and areas with significant temperature differences, the bushing exhibits excellent tear resistance and hydrophobicity. Unlike heat-shrinkable materials, this cold-shrink technology expands and contracts synchronously with cable load changes after installation, reducing the probability of stress concentration.

In practical applications, for different cable specifications, the corresponding pipe diameter parameters must be strictly matched:

• Size Matching: Select a nominal specification slightly smaller than the cable's outer diameter to ensure clamping force after shrinkage.

• Surface Treatment: Remove any residue from the cable shielding layer before installation and apply special silicone grease to fill microscopic pits.

• Positioning Accuracy: Position according to the designed length, covering the weak points at the junction of the copper shield and insulation layer.

Through this structured protection method, pre-insulated bushings not only demonstrate suitability for power cables but also play a positive role in extending the service life of the line.