Figure 8 Power cable: Technical Overview and Applications
Introduction to Figure 8 Power Cable
The Figure 8 Power Cable, named for its distinctive cross-sectional shape resembling the numeral "8", is a flat parallel cable design consisting of two insulated conductors bonded side-by-side. This cable type is formally classified under IEC 60320 C7/C8 standards for non-rewirable appliance couplers, with typical conductor sizes ranging from 0.5 mm² to 1.5 mm² and voltage ratings up to 250V AC at 50/60 Hz.
Key specifications include:
Temperature rating: -30°C to 70°C operational range
Insulation resistance: ≥100 MΩ/km at 500V DC
Conductor material: tinned copper (typically 32/0.2mm stranding)
Insulation thickness: 0.5mm-0.8mm PVC or rubber compound
Bending radius: Minimum 5× cable diameter
Technical Characteristics
The Figure 8 cable's electrical performance meets IEC 60227 Class 5 flexible cable standards, with a maximum current carrying capacity of 2.5A for 0.5mm² conductors and 10A for 1.0mm² versions. The flat design provides a 3.5mm-6mm overall thickness, enabling space-efficient routing. The parallel conductor arrangement results in 20-30% lower inductance compared to round cables of equivalent gauge, reducing electromagnetic interference (EMI) in sensitive applications.
Mechanically, the bonded insulation provides ≥15N/mm tensile strength while maintaining 3000+ flex cycles (IEC 60245-2 test standard). The PVC insulation typically has a 70°C maximum operating temperature with 105°C short-term tolerance, while rubber variants extend this to 90°C continuous.
Application Scenarios
The Figure 8 cable's design characteristics make it suitable for multiple applications:
Consumer Electronics: Widely used with C7/C8 connectors for devices drawing ≤10A, including audio equipment (amplifiers, receivers), gaming consoles, and small appliances. The flat profile facilitates neat cable management behind entertainment centers.
Medical Equipment: In low-power medical devices (patient monitors, portable ultrasound) where the double-insulated design meets IEC 60601-1 safety requirements. The non-polarized nature allows universal orientation.
LED Lighting Systems: For connecting LED drivers and low-voltage transformers in commercial lighting installations, with 300V rated versions available for dimmable systems.
Industrial Control: In control panels for sensors and HMI devices, where the oil-resistant variants (marked "H05RR-F") withstand factory conditions.
Portable Equipment: The lightweight construction (~15g/m for 0.75mm²) makes it ideal for travel adapters and mobile device chargers.
Maintenance and Care Procedures
Proper handling extends the cable's service life beyond its typical 10-year design lifespan:
Installation Best Practices:
Maintain minimum bend radius of 25mm during installation to prevent conductor fatigue
Avoid sharp edges - use grommets when routing through enclosures
Do not exceed 1.5N pulling force during installation
Operational Maintenance:
Inspect insulation every 6 months for cracks or deformation (especially at stress points)
Clean with isopropyl alcohol (≤70% concentration) - avoid abrasive cleaners
Periodically check connector engagement force (2-5N insertion/removal)
Storage Conditions:
Coil loosely with 100-150mm diameter - avoid tight bundling
Store at 10-30°C in 40-60% RH environments
UV protection required for outdoor storage (PVC degrades at ≥0.5W/m² UV exposure)
Safety Considerations
When working with Figure 8 cables, observe these precautions:
Never modify molded connectors - this voids UL/CE certifications
Replace cables showing >10% conductor exposure or insulation hardening
In industrial settings, perform IR tests annually (minimum 1MΩ at 500V DC)
Use Strain Reliefs in permanent installations to prevent conductor pull-out
