Small busbar splicing method

Small busbars can be spliced using bolted, clamped, riveted, soldered, welded, or forming techniques, each offering different mechanical and electrical advantages.

1. Bolted Joints

Bolted joints are the most common method for splicing busbars. The bars are overlapped, and bolts are inserted through pre-drilled or punched holes in the overlapping area. Flat or Belleville washers are used to distribute pressure evenly and improve electrical contact. Bolted joints are reliable, versatile, and can be assembled on-site, but they may slightly distort the current path and require careful torque application to maintain low resistance and mechanical integrity .

2. Clamped Joints

Clamped joints also involve overlapping the busbars, but instead of bolts, external clamps are applied around the joint. This method avoids drilling holes, resulting in lower joint resistance and more uniform contact pressure. Clamps provide additional mass to moderate temperature fluctuations under cyclic loads. While clamped joints require more space and are generally more expensive, they are easy to assemble and maintain .

3. Riveted Joints

Riveting is similar to bolting but uses rivets to mechanically secure the overlap. Riveted joints can be efficient if properly executed, providing good electrical and mechanical performance. However, they are more difficult to assemble and less common in field applications .

4. Soldered or Welded Joints

Soldering or welding can create permanent, low-resistance connections. Friction stir welding is sometimes used for prefabricated shaped busbars. These methods are highly reliable electrically but are less practical for field assembly and may require specialized equipment .

5. Forming Techniques

Forming methods involve mechanically shaping the busbars to create high contact pressure along the overlap without auxiliary elements, or using semi-tubular rivets for interlocking. This approach can reduce galvanic corrosion and maintain low resistance, especially in hybrid aluminum-copper busbars .

Practical Considerations

• Torque and contact pressure: Proper torque is critical for bolted joints to ensure low resistance and mechanical stability .
• Environmental factors: Corrosion resistance and thermal expansion should be considered, particularly for outdoor or high-current applications.
• Field assembly: Bolted and clamped joints are preferred for on-site installation due to ease of assembly and maintenance.
• Flexibility: Flexible braided or laminated busbars may require specialized clamps or connectors to accommodate bends and corners .

By selecting the appropriate splicing method based on mechanical, electrical, and environmental requirements, small busbars can be joined effectively while maintaining performance and reliability.