How to connect the small busbars of the high-voltage switchgear

To connect a small busbar in high-voltage switchgear, ensure proper surface preparation, use compatible connectors, apply anti-oxidation compounds, and secure with correctly rated bolts for reliable conductivity and safety.

Busbar Preparation

Material Identification: Determine whether the busbar is copper, aluminum, or a composite. Copper busbars are common for superior conductivity, while aluminum is used for cost efficiency. Surface Cleaning: Polish the contact surfaces with fine sandpaper (0-grade for copper) to remove oxidation and achieve a mirror finish.

Anti-

Oxidation Treatment: Apply a suitable anti-oxidation compound: for copper, use a power compound grease compliant with EN 50165; for aluminum, use an aluminum-specific anti-oxidation agent.

Connector Selection

Material Compatibility: Use bronze connectors for copper-copper joints, aluminum alloy connectors for aluminum-aluminum joints, and bi-metallic connectors for copper-aluminum transitions to prevent electrochemical corrosion. Insulation: For copper-aluminum connections, cover joints with heat-shrink tubing rated ≥125°C to withstand high temperatures. Mechanical Strength: Ensure connectors are rated for the busbar's current and mechanical load, especially in high-voltage applications.

Connection Procedure

Alignment: Position the busbar and connector accurately to avoid mechanical stress or misalignment. Bolting: Use stainless steel bolts that match the connection holes. Tighten to the manufacturer's recommended torque to ensure good electrical contact and prevent loosening under thermal cycling.

Sectionalizing Considerations: If the switchgear has multiple busbars or a bypass bus, ensure the small busbar is connected according to the single-line diagram and operational requirements, allowing for maintenance isolation without interrupting supply.

Safety and Verification

Inspection: Verify all connections are clean, properly torqued, and insulated where required. Testing: Perform continuity and insulation resistance tests before energizing the switchgear. Documentation: Follow the switchgear manufacturer's instructions and local standards (e.g., EN 62271) for high-voltage installations.

By following these steps, the small busbar will be securely connected, ensuring reliable power distribution, minimal resistance, and safe operation within the high-voltage switchgear system.