VD4 MV Vacuum Circuit Breakers-12-24kV

For the modernization of existing assets (Retrofit), VD4 offers mature and flexible solutions:

• Direct Roll-in Replacement: By designing specialized adapter chassis, VD4 breakers can be made to interface perfectly with the primary contacts and secondary plugs of legacy panels (such as older KYN28 or early imported switchgear).
• Interlock Logic Synchronization: Ensuring that the VD4's mechanical interlocks (e.g., "five-prevention" safety interlocks) are fully compatible with the original cabinet structure to guarantee operational safety.
• Life-cycle Value Enhancement: This approach avoids the need to replace entire switchgear panels and cables. By upgrading only the core component—the circuit breaker—the system's short-circuit breaking capacity and operational reliability are significantly improved at a lower capital expenditure.

When switching capacitive loads, such as capacitor banks, vacuum circuit breakers face a significant risk of re-strikes. VD4's optimization solutions include:

• Advanced Contact Materials and Processing: Utilizing high-purity Copper-Chromium (CuCr) contact materials combined with vacuum degassing processes to minimize the dispersion of breakdown field strength.
• C2 Class Certification: The VD4 series is strictly tested and certified to Class C2 standards according to IEC 62271-100, indicating a very low probability of re-strikes during capacitive current switching.
• Point-on-Wave (Synchronous) Switching: For high-voltage or large-capacity capacitor banks, it is recommended to use VD4 in conjunction with synchronous controllers. By operating near the voltage zero-crossing point, the root cause of inrush currents and transient overvoltages can be physically eliminated.