Wiring Principle of Small Busbar in High Voltage Switchgear

Small busbars in high-voltage switchgear typically use bare copper or aluminum conductors, either as stranded wires or tubular bars, with appropriate connectors for reliable high-current connections. Conductor Types1.

Stranded-

Wire Busbars: Stranded wires are commonly used for small busbars where flexibility is required or where the busbar spans a distance between supports. They are secured with dead-end clamps to maintain mechanical stability and ensure reliable electrical contact. Stranded conductors allow easier handling and installation in compact switchgear enclosures.

2. Tubular Busbars: Tubular conductors, often made of copper or aluminum, provide high mechanical strength and superior corona resistance. They are typically supported by column insulators (ceramic or composite) in high-voltage applications.

Tubular busbars are preferred when rigidity and minimal sag are required.

Material Considerations

Copper: Offers high conductivity and is commonly used for small busbars in indoor switchgear. Copper-to-copper connections typically use bronze connectors to prevent corrosion. Aluminum: Lightweight and cost-effective, aluminum busbars require aluminum alloy connectors for aluminum-to-aluminum connections.

Copper-

Aluminum Connections: Must use bi-metallic connectors to prevent electrolytic corrosion.

Connection and Insulation

Small busbars in high-voltage switchgear are usually bare conductors, relying on air insulation and spacing for safety. Proper connectors are essential to terminate busbars to equipment terminals, ensuring low-resistance contact and mechanical stability. In indoor installations with limited space, busbars may be enclosed in metallic casings for mechanical protection and insulation, which can reduce heat dissipation and slightly lower current ratings.

Summary

For small busbars in high-voltage switchgear: Material: Copper or aluminum (or alloys)Configuration: Stranded wires for flexibility, tubular bars for rigidityConnectors: Bronze for copper, aluminum alloy for aluminum, bi-metallic for mixed connectionsInsulation: Typically air-insulated, with optional metallic enclosures for protection in compact spaces. These choices ensure reliable current distribution, mechanical stability, and long-term service life in high-voltage switchgear systems.