The copper rod of the small busbar can be connected to a flexible wire

Yes, a copper rod in a small busbar can be connected to a flexible wire using proper mechanical and electrical connection methods.

Practical Considerations

A copper rod busbar is a rigid conductor used for high-current distribution, while a flexible wire or flexible busbar is designed to absorb vibration, thermal expansion, and mechanical movement . Connecting the two is common in switchgear, battery packs, and power electronics where flexibility is needed at one end.

Connection Methods

1. Bolted or Clamped Connections
   • The most common method is to bolt the flexible wire or flexible busbar to the copper rod using a flat contact surface.
   • Ensure the contact area is clean, free of oxidation, and, if possible, plated (e.g., tin or silver) to reduce contact resistance .
   • Use washers and locknuts to maintain mechanical stability under vibration.
2. Crimped Lugs
   • Flexible wires can be terminated with copper lugs that are crimped and then bolted to the busbar.
   • This provides a secure, low-resistance connection suitable for high-current applications.
3. Soldering or Brazing (Optional)
   • For smaller currents or compact assemblies, brazing or soldering can join the flexible wire to the busbar.
   • This method is less common in high-current busbars due to thermal and mechanical stress concerns.

Material Compatibility

• Both the busbar and flexible wire should be copper to avoid galvanic corrosion and ensure similar thermal expansion .
• Flexible busbars are often laminated or braided copper, which allows bending without fatigue, making them ideal for connecting to rigid busbars .

Safety and Standards

• Ensure the current rating of the flexible wire matches or exceeds the busbar rating.
• Maintain proper insulation and spacing according to standards like IEC 61439 or UL 508A if used in switchgear or panelboards .
• Avoid sharp bends in the flexible wire to prevent mechanical stress and potential failure.

Summary

Connecting a copper rod busbar to a flexible wire is feasible and widely practiced. The best approach is to use bolted or clamped connections with proper lugs, ensuring good electrical contact and mechanical stability. Flexible copper busbars or braided wires are preferred for vibration tolerance and thermal expansion, while maintaining the same material (copper) ensures compatibility and long-term reliability .