Standard Requirements for Domestic Cable Assemblies in China
- National Standards Framework
China’s cable assembly standards are primarily established by the Standardization Administration of China (SAC) and align with international norms such as IEC (International Electrotechnical Commission) standards. Key standards include:
GB/T 5023 (Polyvinyl Chloride Insulated Cables): Specifies requirements for PVC-insulated cables used in fixed installations, including conductor resistance, insulation thickness, and voltage endurance.
GB/T 12706 (Power Cables with Extruded Insulation): Covers medium-voltage power cables, emphasizing insulation integrity, shielding effectiveness, and flame retardancy.
GB/T 9330 (Control Cables): Focuses on cables for control circuits, detailing flexibility, temperature resistance, and electromagnetic compatibility (EMC).
GB/T 19666 (Fire-Resistant Cables): Mandates flame retardancy, low smoke emission, and halogen-free materials for cables used in high-risk environments like tunnels and subways.
For connectors and terminations, standards such as GB/T 5095 (Electromechanical Components) define mechanical durability, contact resistance, and environmental resilience.
- Material and Construction Requirements
Conductors: Copper or aluminum conductors must meet strict purity and conductivity thresholds (e.g., GB/T 3956 for conductor classes).
Insulation and Sheathing: Materials must resist heat, chemicals, and abrasion. PVC, cross-linked polyethylene (XLPE), and silicone rubber are common, with performance metrics outlined in standards like GB/T 8815.
Shielding: Cables for sensitive applications (e.g., data transmission) require metallic shielding to minimize electromagnetic interference (EMI), as per GB/T 17737. - Performance and Testing Protocols
Cable assemblies must undergo rigorous testing to ensure compliance:
Electrical Tests: Voltage withstand tests (e.g., 3.5 kV AC for 5 minutes), insulation resistance measurements, and impedance checks.
Mechanical Tests: Tensile strength, bending cycles, and crush resistance evaluations.
Environmental Tests: Thermal aging, UV resistance, and salt spray tests to validate performance under extreme conditions.
Fire Safety Tests: Flame spread, smoke density, and toxicity tests (e.g., GB/T 18380 for vertical flame propagation).
- Certification and Compliance
Mandatory certification schemes, such as the China Compulsory Certification (CCC), apply to cables used in critical sectors like construction, automotive, and telecommunications. Products must bear the CCC mark, indicating adherence to safety and quality benchmarks. Additionally, industry-specific certifications (e.g., CRCC for railway applications) may apply. - Challenges and Emerging Trends
While standardization ensures baseline quality, challenges persist in harmonizing domestic standards with global frameworks and addressing innovations like high-speed data cables (e.g., Cat 6A/7) and renewable energy systems. Recent updates, such as GB/T 33594 for photovoltaic cables, reflect efforts to support green energy initiatives.