Vacuum Circuit Breaker 3150~4000A Fixed Contact Red Copper – Technical Overview A Vacuum Circuit Breaker (VCB) with a current rating of 3150~4000A is a critical component in medium to high-voltage electrical systems, designed to ensure reliable interruption of fault currents while maintaining operational efficiency. The fixed contact, made of high-purity red copper, plays a pivotal role in the breaker's performance, offering superior conductivity, thermal stability, and mechanical durability. 1. Design and Construction The fixed contact in a VCB is engineered to handle high continuous currents (3150A to 4000A) and transient fault currents. Red copper (C10100 or C11000) is chosen for its exceptional electrical conductivity (≥100% IACS) and low resistivity, minimizing energy losses. The contact surface is precision-machined to ensure uniform pressure distribution, reducing contact resistance and preventing localized heating. To enhance durability, the contact may feature silver or chrome plating, improving resistance to arcing and oxidation. The fixed contact is integrated into a vacuum interrupter, where the absence of air prevents ionization and ensures rapid dielectric recovery after arc extinction. 2. Key Performance Features - High Current Capacity: The robust red copper construction allows sustained operation at 4000A without excessive temperature rise. - Thermal Stability: Red copper’s high thermal conductivity (385 W/m·K) dissipates heat efficiently, maintaining performance under load cycles. - Mechanical Strength: The fixed contact withstands electromagnetic forces during short-circuit conditions (e.g., 50kA/1s). - Low Contact Resistance: Precision engineering ensures minimal resistance (<10μΩ), reducing power loss and overheating. 3. Operational Advantages - Long Service Life: Red copper’s resistance to wear and welding extends the contact’s lifespan, even under frequent switching. - Eco-Friendly: Vacuum technology eliminates SF6 gas, reducing environmental impact. - Low Maintenance: The sealed vacuum interrupter and corrosion-resistant contacts minimize upkeep requirements. 4. Applications This VCB is suited for industrial plants, substations, and renewable energy systems where high current interruption (up to 4000A) and reliability are critical. Its fixed contact design ensures stable connections in fixed-mounted breakers, commonly used in draw-out or panel-mounted configurations. 5. Compliance and Standards The design adheres to IEC 62271, ANSI C37.04, and other international standards for dielectric strength, short-circuit endurance, and temperature rise limits. In summary, the 3150~4000A VCB with a red copper fixed contact combines high conductivity, thermal resilience, and mechanical robustness, making it an optimal solution for modern power distribution networks. Its vacuum-based interruption technology ensures safety, efficiency, and sustainability. (Word count: 500)