High Voltage Cable Liquid Silicone Rubber Overmolded Part

# High Voltage Cable Liquid Silicone Rubber Overmolded Part

Product Overview

The High Voltage Cable Liquid Silicone Rubber (LSR) Overmolded Part is a precision-engineered insulation and structural component designed to address the extreme operating demands of high-voltage (HV) power transmission and distribution systems. Manufactured via one-shot or two-shot injection overmolding processes, this part forms a seamless, void-free bond between LSR and cable conductors, shielding layers, or terminal connectors, eliminating the risk of partial discharge, moisture ingress, and insulation failure common to assembled or heat-shrink cable accessories.

Core features include inherent electrical insulation performance, high resistance to thermal aging, UV radiation, and extreme weather, as well as customizable geometries tailored to specific cable dimensions and installation requirements. Unlike traditional EPDM or PVC cable accessories, our LSR overmolded parts maintain stable dielectric properties across a wide temperature range (-60°C to 220°C) and are compatible with continuous operating voltages from 10kV to 220kV, making them suitable for both indoor and outdoor, underground, and subsea HV cable applications. The integral overmolding structure removes assembly gaps, reduces installation labor, and extends the service life of HV cable systems to a minimum of 40 years, outperforming conventional alternatives by 2x to 3x in long-term reliability.

Technical Specifications

Material Properties

All LSR materials used for this product are high-purity, platinum-cured medical/industrial grade formulations, with optional functional additives for enhanced performance:

Physical Performance

The overmolded part meets the strict mechanical and electrical requirements for HV cable accessories per IEC 60502, GB/T 12706, and IEEE 48 standards:

Process Parameters

The overmolding process is tightly controlled to ensure consistent bonding and zero internal defects:

Product Advantages

1. Superior Long-Term Electrical Reliability

The seamless overmolded structure eliminates air gaps and interfaces between the insulation layer and cable core, reducing partial discharge levels to <5pC at rated operating voltage – 90% lower than heat-shrink or cold-shrink assembled accessories. The stable dielectric properties of LSR ensure no insulation degradation even after 1000 thermal cycles between -40°C and 150°C, avoiding the common breakdown failure of EPDM parts after 5-10 years of outdoor operation.

1. Extreme Environmental Adaptability

Unlike PVC or EPDM, LSR overmolded parts maintain 90% of their mechanical and electrical performance after 10 years of exposure to UV radiation, salt spray, acid rain, and ozone, making them suitable for coastal, high-altitude, desert, and other harsh environment applications. The low compression set property ensures a permanent, tight seal between the part and cable terminals, preventing moisture ingress even for underground and subsea cable systems with water pressure up to 10bar.

1. High Process Precision and Customization Flexibility

Our injection overmolding process achieves a dimensional tolerance of ±0.05mm for complex geometries, including integrated stress cones, strain relief structures, and mounting flanges, eliminating the need for secondary machining. We support customization for all standard cable sizes (10mm² to 2500mm² cross-section) and special shapes, such as right-angle cable joints, bifurcated cable terminations, and connector-integrated overmolded parts, to match specific installation requirements.

1. Reduced Total Cost of Ownership

The integral overmolded structure cuts on-site assembly time by 70% compared to traditional assembled cable accessories, eliminating the need for skilled labor and special installation tools. With a 40-year service life, the part reduces maintenance and replacement costs by 60% over the cable system lifecycle, and the halogen-free, low-smoke LSR material complies with fire safety standards for tunnel and indoor installations, avoiding additional fire protection investment.

Applications

Our High Voltage Cable LSR Overmolded Parts are widely used across the following industries and scenarios:

• Power Transmission and Distribution: 10kV-220kV overhead line cable terminations, underground cable intermediate joints, substation bushing connectors, and ring main unit cable interfaces, where they provide reliable insulation and sealing for urban and rural power grids.
• **Renewable Energy Systems: Wind turbine tower internal HV cable connections, photovoltaic power station combiner box cable terminations, and tidal energy subsea cable joints, where they withstand extreme temperature fluctuations, vibration, and salt spray corrosion.
• Industrial and Infrastructure: High-speed railway catenary cable connections, urban rail transit traction power cable joints, tunnel and underground pipe gallery cable accessories, and data center HV power distribution cable terminations, where low-smoke halogen-free fire performance and long-term reliability are critical.
• Special Equipment: Offshore drilling platform HV cable systems, shipboard power cable connections, and medical HV equipment (such as X-ray and MRI machine) cable interfaces, where high insulation performance and biocompatibility (for medical grades) are required.

Application note: For subsea or high-humidity applications, we recommend selecting the optional hydrophobic coating and fluorosilicone material grade to further improve water resistance and oil resistance. For vibration-prone scenarios such as wind turbines, a hardness of 60-70 Shore A is recommended to balance structural rigidity and shock absorption performance.

Selection Guide

Hardness Selection

• 30-40 Shore A: Suitable for scenarios requiring high flexibility and strain relief, such as cable bending sections and movable equipment cable connections, providing excellent elongation and vibration damping.
• 50-60 Shore A: General-purpose grade for most static cable terminations and intermediate joints, balancing insulation performance, mechanical strength, and sealing effect.
• 70-80 Shore A: Recommended for structural load-bearing parts, high-pressure underground cable joints, and flange-mounted connections, providing high dimensional stability and resistance to extrusion deformation.

Size Specifications

We support overmolding for all standard HV cable sizes, with common pre-engineered specifications including:

Custom sizes and geometries are available upon request, with 3D drawing verification provided before production to ensure compatibility with your cable and connector dimensions.

Material Grade

• Industrial Grade: Cost-effective standard formulation, RoHS 2.0 and REACH compliant, suitable for most general power grid and industrial applications with no special environmental requirements.
• Weather-Resistant Grade: Added UV stabilizers and anti-tracking agents, meeting IEC 60587 Class 1A 4.5kV tracking resistance, ideal for outdoor, high-altitude, and coastal applications.
• Low-Smoke Halogen-Free Grade: Zero halogen content, UL94 V-0 flame retardant rating, low smoke emission during combustion, compliant with IEC 60332-3 and EN 50267 standards, required for tunnel, rail transit, and indoor public infrastructure applications.
• Medical Grade: ISO 10993 biocompatibility certified, low volatile content, suitable for HV cable connections in medical diagnostic and treatment equipment.

Quality Assurance

All our High Voltage Cable LSR Overmolded Parts undergo a strict multi-stage quality control process to ensure compliance with international and industry standards:

1. Incoming Material Inspection: Each batch of LSR raw materials is tested for viscosity, curing performance, and dielectric properties before entering production, with traceability codes retained for 10 years.
2. In-Process Quality Control: Real-time monitoring of injection pressure, mold temperature, and curing time during the overmolding process, with dimensional inspection of every 10th part using a coordinate measuring machine (CMM) to ensure tolerance compliance.
3. Finished Product Testing: 100% of finished parts undergo a 3.5× rated voltage power frequency withstand voltage test, partial discharge test (≤5pC acceptance threshold), and seal integrity pressure test. Random sampling from each batch undergoes 1000-hour aging testing, thermal cycle testing, and mechanical performance testing.
4. Certifications: Our products are certified by IEC 60502, GB/T 12706, UL 94, RoHS 2.0, REACH, and optional ISO 10993 for medical grades. We provide a full test report with each shipment, including electrical performance, dimensional, and material composition data.

We offer a 5-year standard warranty for all overmolded parts, with an extended 10-year warranty option for qualified applications, covering material defects and manufacturing faults under normal operating conditions. Our technical team provides on-site installation guidance and post-sales support to ensure optimal performance of the parts in your cable system.