Copper Busbar Bending: Balancing Radius and Thickness

When bending copper busbars, the bending radius (R) is directly related to the busbar’s thickness. The bending radius must be proportionate to the copper busbar's thickness to prevent cracking or damage during the bending process. Generally, the relationship between the bending radius and thickness follows these principles:

1. Proportion Between Bending Radius (R) and Thickness

Standard Proportion: The bending radius (R) is typically 1 to 2 times the thickness of the copper busbar.

This relationship is expressed as:

R = k × t

Where:

• R is the bending radius;

• t is the copper busbar thickness;

• k is the proportionality constant, usually ranging from 1 to 2.

Example: For a copper busbar with a thickness of 10 mm, the bending radius (R) should range between 10 mm and 20 mm.

2. Why Is Controlling the Bending Radius Important?

• To Prevent Damage: A smaller bending radius (R) increases the risk of cracking on the outer layer of the copper busbar, especially for thicker busbars. Conversely, an excessively large radius may compromise dimensional accuracy and design specifications.

• To Maintain Mechanical Strength: A proper bending radius minimizes internal stress during the bending process, ensuring the copper busbar retains its mechanical integrity.

• To Optimize Electrical Performance: An appropriate bending radius helps preserve electrical conductivity. This is particularly important in high-current or high-frequency applications where electrical contact and thermal dissipation at the bend are critical.

3. Factors Influencing the Bending Radius

• Copper Busbar Material: The material composition (e.g., pure copper or copper alloy) affects bending flexibility. Pure copper's higher ductility allows for smaller bending radii than alloyed copper.

• Bending Process: The bending method (manual, mechanical, or CNC) also impacts the bending radius. CNC bending machines provide precise radius control, reducing errors.

4. Recommendations

• For thin copper busbars (1–3 mm thickness), use a bending radius close to 1× thickness.

• For thick copper busbars (above 10 mm thickness), the bending radius should approach 2× thickness.

When designing and fabricating electrical busbars, ensure the bending radius is sufficient to avoid material cracking and to maintain the copper busbar’s ability to handle electrical and mechanical stresses effectively.