How to connect a tubular busbar

Tubular busbars can be connected using bolted, clamped, riveted, soldered, or welded joints, with material-specific connectors ensuring mechanical strength, low resistance, and corrosion prevention.Common Connection Methods

1. Bolted Joints Bolted joints involve overlapping the tubular busbars and inserting bolts through the overlap, often with flat washers to distribute pressure evenly. This method is reliable, allows field assembly, and provides good mechanical and electrical integrity. However, drilling or punching holes can slightly distort current flow, and contact pressure may be less uniform than other methods, which can be mitigated by using larger washers or proper torque control . 2. Clamped Joints Clamped joints also use overlapping busbars but apply external clamps instead of bolts. This creates nearly uniform contact pressure without disturbing current flow, resulting in lower joint resistance. Clamps add mass to moderate temperature fluctuations under cyclic loads. They require more space and are generally more expensive than bolted joints but simplify fabrication since no holes are needed . 3. Riveted Joints Riveting is similar to bolting but is less common due to difficulty in controlling contact pressure and challenges in dismantling or tightening in service. Riveted joints can be efficient if carefully executed but are generally less flexible for field adjustments . 4. Soldered or Welded Joints For prefabricated busbars, soldering or welding (including friction stir welding) can create permanent, low-resistance connections. These methods are typically used in factory settings rather than on-site due to the need for precise control and specialized equipment .

Material-Specific Connectors

• Copper-Copper Connections: Use bronze connectors to prevent corrosion and maintain conductivity.
• Aluminum-Aluminum Connections: Use aluminum alloy connectors.
• Copper-Aluminum Connections: Use bi-metallic connectors to avoid electrolytic corrosion .

Best Practices

• Torque and Contact Pressure: Proper torque is more critical than full overlap for ensuring low resistance and long-term reliability. Current concentrates under the pressure washers, so effective clamping is essential .
• Mechanical Support: Tubular busbars are often supported by insulators (ceramic for HV/MV applications) to maintain alignment and prevent mechanical stress .
• Maintenance: Regular inspection, cleaning, and retightening of connections help prevent overheating, corrosion, and resistance buildup . By selecting the appropriate joint type and connector material, and ensuring proper torque and mechanical support, tubular busbar connections can achieve high electrical performance, mechanical stability, and long-term reliability.