Specifications of copper tubes for small busbars at the top of the screen

Copper tubes for small busbars are typically made from high-purity copper (≥99. 9% Cu), with excellent electrical conductivity, suitable temper, and compliance with standards like ASTM B187.

Material and Purity

Copper busbars are generally manufactured from high-purity copper, such as Cu-ETP (Electrolytic Tough Pitch) or OF-Cu (Oxygen-Free Copper), with a minimum copper content of 99. 9% and electrical conductivity up to 101% IACS for OF-Cu. Deoxidized copper with phosphorus (DHP) is also used for applications requiring high-temperature brazing or welding, though its conductivity is slightly lower (~85% IACS),.

Temper and Mechanical Properties

Copper tubes for busbars are available in various tempers to balance flexibility and mechanical strength: Soft tempers: Suitable for bending, cold heading, and forming small-radius curves. Hard tempers: Favorable for machining, shearing, and applications requiring dimensional stability. Special hard tempers can be used for 90° bends or shallow forming without compromising conductivity.

Dimensions and Cross-SectionThe cross-sectional area of copper tubes is critical for current-carrying capacity. Small busbars often use rectangular or square tubes, with thickness and width selected to handle the required current while minimizing voltage drop. Copper's high conductivity allows for smaller cross-sections compared to aluminum for the same current rating.

Electrical PerformanceCurrent-carrying capacity is calculated according to standards such as DIN 43671, considering ambient temperature (typically 35°C) and final operating temperature (up to 65°C),. Copper busbars provide low voltage drop and high current density, making them ideal for switchgear, control panels, and battery banks. Surface Treatment and CoatingsTin-plated copper is commonly used to improve corrosion resistance and solderability.

Galvanic refinement is possible for applications requiring shunts or precise electrical connections.

Installation Considerations

Copper tubes can be welded, brazed, or bolted depending on the application. Proper fixing materials and supports are recommended to ensure mechanical stability and maintain electrical performance.

Summary

For small busbars at the top of a screen or panel, the recommended specifications are: Material: Cu-ETP or OF-Cu, ≥99. 9% purityTemper: Soft for bending, hard for machiningCross-section: Sized according to current requirementsCoating: Optional tin plating for corrosion resistanceStandards: ASTM B187, DIN 43671 for current capacityInstallation: Compatible with welding, brazing, or bolting These specifications ensure high conductivity, mechanical reliability, and long-term performance in electrical distribution systems.