Low-voltage (LV) and medium-voltage (MV) cables may look similar, but their internal designs and installation requirements are fundamentally different. Understanding these distinctions is crucial for ensuring the safety, reliability, and cost-effectiveness of any power system. At Shenghua Cable Group, we engineer our cables with a clear purpose: each voltage class is meticulously designed to meet its specific electrical and environmental challenges.

The fundamental task of cable design is to safely contain and control the electrical field. As voltage increases, the electrical stress intensifies dramatically, demanding entirely different engineering solutions.

• Design Focus:​ Manage relatively modest electrical stress, prioritizing current-carrying capacity and basic protection.

• Typical Shenghua Construction:

  • Conductor:​ Copper or aluminum, with relatively smaller cross-sections.

  • Insulation:​ A single layer of PVC or XLPE, providing essential electrical isolation.

  • Protection:​ Usually a single sheath for moisture and mild mechanical protection; often unarmored for indoor use.

  • Application:​ Final circuit wiring within buildings—lighting, sockets, and equipment power.

• Design Focus:​ Must strictly control and evenly distribute the intense electrical field to prevent partial discharge and breakdown. This is where Shenghua's advanced engineering excels.

• Typical Shenghua Construction:

  • Conductor:​ Larger cross-sections, sometimes with special shapes to optimize the electrical field.

  • The Insulation System (Key Differentiator):​ High-grade XLPE is the main insulator, but it is always​ surrounded by semi-conductive screens​ (conductor screen and insulation screen). These layers smooth out irregularities and evenly distribute the electrical field, eliminating dangerous concentrations.

  • Shielding & Protection:

    • Metallic Shield:​ Copper tape or wire braid to carry fault currents, provide grounding, and shield against EMI.

    • Armor:​ Galvanized steel wire or tape for robust mechanical protection in demanding environments like direct burial or industrial sites.

    • Outer Sheath:​ A tough, abrasion and corrosion-resistant jacket.

These profound design differences naturally lead to significantly different installation practices. Shenghua provides not just the cable, but also the critical technical support for proper installation.

• Installation:​ Often permitted for direct burial (with suitable protection) or in trays/conduits in non-hazardous areas. Bending radius requirements are more forgiving.

• Termination & Jointing:​ Connections are relatively straightforward, using standard compression lugs or connectors, with lower on-site skill demands.

• Testing:​ Post-installation tests focus on continuity and insulation resistance.

• Installation (Shenghua Guidance is Key):

  • Bending Radius:​ Strict adherence to minimum bend radius (typically >12-20x cable diameter) is mandatory to prevent permanent damage to insulation and screens.

  • Pulling Tension:​ Must be precisely calculated and controlled.

• Termination & Jointing: The Critical Phase

  • Stress Control:​ Stress cones​ or pre-molded terminations​ are absolutely essential. These components reshape the electrical field at the cut end of the semiconductor screen, preventing concentrated stress that leads to failure.

  • Cleanliness & Craftsmanship:​ A clean, controlled environment is vital. Installation procedures (stripping dimensions, semiconductor layer treatment, grounding) must be executed with precision.

  • Temperature Monitoring:​ Critical for heat-shrink or similar jointing techniques.

• Testing:​ High-voltage acceptance testing​ (e.g., DC withstand or VLF testing) is mandatory to validate the integrity of the entire insulation system and installation workmanship.

Think of it this way:​ Installing LV cable is like laying reliable household plumbing, while installing MV cable is akin to installing precision high-pressure industrial gas lines—the requirements for material integrity, joint sealing, and installation accuracy are exponentially higher.

Choosing the right cable is foundational to system safety and longevity. Shenghua Cable Group​ provides the complete solution: from precisely engineered LV and MV cables designed to international standards, to the technical expertise and support needed for their correct installation. Trust Shenghua to deliver not just products, but the reliability and safety your power system depends on.