What Is a Multi-Core Flexible Cable? Technical Overview and Scope
Multi-core flexible cables are versatile electrical conductors designed for dynamic applications requiring repeated flexing, high mechanical resilience, and reliable signal or power transmission. Manufactured under Harmonized (HAR) standards such as EN 50525, these cables feature fine-stranded Class 5 or Class 6 flexible plain annealed copper conductors according to IEC 60228[1]. They are insulated and sheathed with specialized thermoplastic or thermosetting compounds—such as PVC (Polyvinyl Chloride)[2]or LSZH (Low Smoke Zero Halogen)[3]—to meet specific voltage ratings (300/500V to 450/750V), temperature performance targets (-15°C to +90°C), and fire safety criteria compliant with IEC 60332-1-2 flame retardancy tests[4].

Technical Parameter Comparison Matrix
| Standard Designation | Harmonized Code | Conductor Class | Insulation Material | Sheath Material | Voltage Rating (U0/U) | Max Operating Temp | Flame Retardancy Standard |
| BS EN 50525-2-11 | H05VV-F | Class 5 Flexible | PVC Type TI 2 | PVC Type TM 2 | 300/500V | +60°C | IEC 60332-1-2 |
| BS EN 50525-3-41 | H07Z-K | Class 5 Flexible | LSZH Cross-linked | None (Single Core) | 450/750V | +90°C | IEC 60332-1-2 / IEC 60754 |
| BS 7211 / EN 50525 | 2491B | Class 5 Flexible | LSZH Type EI 5 | None (Single Core) | 450/750V | +90°C | IEC 60332-1-2 / IEC 61034 |
| BS 6004 / EN 50525 | 2491X | Class 5 Flexible | PVC Type TI 1 | None (Single Core) | 450/750V | +70°C | IEC 60332-1-2 |
Core Specification Breakdown
H05VV-F (Harmonized Light Duty Flexible Cable)
- Standard: BS EN 50525-2-11
- Conductor: Class 5 fine-wired plain annealed copper (IEC 60228[1])
- Voltage Rating: 300/500V
- Construction: Flexible multi-core arrangement with PVC[2] insulation and an outer PVC jacket
- Application: Ideal for household appliances, office equipment, and light portable equipment subjected to medium mechanical stress in indoor dry conditions.
H07Z-K (Harmonized High-Temperature LSZH Flexible Wiring)
- Standard: BS EN 50525-3-41
- Conductor: Class 5 flexible copper conductor
- Voltage Rating: 450/750V
- Construction: Single-core, halogen-free, cross-linked insulation (EI 5 compound)
- Application: Specifically engineered for internal wiring in control panels, switchgear, and public installations where fire, toxic fumes, and smoke emissions pose critical risks.
2491B (BS Standard Single-Core LSZH Panel Wire)
- Standard: BS 7211 / Harmonized equivalent H07Z-K
- Voltage Rating: 450/750V (0.75 to 630 )
- Thermal Performance: Continuous operation up to +90°C
- Safety Compliance: Low Smoke Zero Halogen[3] emission compliant with IEC 60754-1/2 and IEC 61034-2, preventing corrosive acid gas formation during combustion.
2491X (BS Standard Single-Core PVC Panel Wire)
- Standard: BS 6004 / Harmonized equivalent H07V-K
- Voltage Rating: 450/750V (300/500V for sizes under 1.5 )
- Temperature Limits: -15°C to +70°C static, higher operational limits under controlled installation
- Application: General internal conduit installation, power distribution cabinets, and static flexible connections within enclosed machinery pathways.

CJDL CABLE Engineering Insight
For light portable and household equipment, H05VV-F remains the practical default for indoor dry conditions, while LSZH types such as H07Z-K and 2491B are the right choice where fire, smoke, and toxic fume risks dominate—control panels, switchgear, and public installations. All CJDL CABLE flexible cables are manufactured and routinely tested to EN 50525, with Class 5 conductors to IEC 60228 and flame retardancy verified to IEC 60332-1-2.
References
[1] Wikipedia. IEC 60228 Standard Conductors of Insulated Cables [EB/OL]. 2026-09-09.
[2] Wikipedia. Polyvinyl chloride [EB/OL]. 2026-09-09.
[3] Wikipedia. Low smoke zero halogen [EB/OL]. 2026-09-09.
[4] Wikipedia. IEC 60332 Fire Performance Tests on Electric Cables [EB/OL]. 2026-09-09.