Electrical cables are engineered composites designed to transmit power or signals safely and efficiently. Their layered construction protects against electrical, mechanical, and environmental stresses. Understanding the parts of an electrical cable—from the central conductor to the protective outer sheath—helps in selecting the right cable for residential, commercial, industrial, or specialized applications. In 2025, with advanced materials like XLPE and LSZH gaining prominence, knowing these components ensures compliance, longevity, and optimal performance.

1. Introduction to Electrical Cable Structure

A typical electrical cable consists of multiple layers, each serving a specific purpose. Single-core cables have fewer components, while multi-core designs include fillers and collective screens. The exact configuration varies by voltage rating (low, medium, high), application (power, control, instrumentation), and environment (indoor, outdoor, underground).

2. Conductor: The Core Current Carrier

The conductor is the central element that carries electrical current. Usually made of copper (high conductivity) or aluminum (cost-effective for larger sizes), it is stranded (Class 2 or 5 per IEC 60228) for flexibility or solid for smaller gauges. Tinned copper enhances corrosion resistance in marine or humid settings.

3. Insulation: Electrical Isolation Layer

Surrounding the conductor, insulation prevents current leakage and shorts. Common materials include PVC (economical), XLPE (cross-linked polyethylene for higher temperatures up to 90°C), EPR (ethylene propylene rubber for flexibility), and paper/oil for high-voltage. In multi-core cables, each conductor is individually insulated, often color-coded for identification.

4. Screening and Shielding

Medium- and high-voltage cables, plus instrumentation cables, feature semi-conductive screens over insulation to uniform electric fields and metallic screens (copper tape or wires) for fault current return and EMI protection. This layer reduces partial discharge and electromagnetic interference.

5. Bedding and Fillers

In multi-core cables, fillers (e.g., polypropylene strings) maintain round shape, while bedding (extruded layer) provides a smooth base for armor or collective screens. Water-blocking tapes or powders here prevent longitudinal moisture migration in outdoor/underground cables.

6. Armor: Mechanical Protection

Armor protects against physical damage in direct burial or harsh environments. Types include steel wire armor (SWA) for rodent/impact resistance, steel tape armor (STA) for lighter protection, and aluminum wire for single-core AC cables to minimize eddy currents.

7. Outer Sheath: Environmental Barrier

The outermost layer shields against moisture, UV, chemicals, and abrasion. PVC is common and versatile; PE for better water resistance; LSZH (low smoke zero halogen) for fire safety in enclosed spaces; and thermoplastic/thermoset compounds for specialized needs.

8. Summary of Cable Parts

9. Final Thoughts

The parts of an electrical cable work synergistically to ensure safe, reliable performance under diverse conditions. From basic low-voltage wiring to complex medium-voltage power cables, each layer addresses specific risks. As standards evolve toward sustainability and enhanced safety in 2025, modern cables increasingly incorporate eco-friendly, flame-retardant materials without compromising functionality. Understanding these components empowers better specification and installation decisions.

For cables with optimized construction and materials, contact Henan Province Jianyun Cable Co., Ltd. for professional guidance and high-quality products.