Recommended Busbar Sizes
Calculation Details
Standard Copper Busbar Sizes
| Size (W × T mm) | Cross Section (mm²) | Capacity (A) | Status |
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Frequently Asked Questions
How to calculate copper busbar size for a given current?
To calculate copper busbar size, use the formula: Current Capacity = K × Width × Thickness, where K depends on temperature rise and installation conditions. For a 30°C temperature rise with a single copper strip in vertical orientation, K ≈ 3.5. For example, a 100A current needs approximately 100 / 3.5 = 28.6 mm² cross-section, which can be achieved with a 20×5 or 25×5 busbar.
What current can a copper busbar carry?
A copper busbar's current carrying capacity depends on its cross-sectional area, temperature rise, orientation, and number of strips. As a general rule, a single copper busbar in vertical orientation with 30°C rise can carry approximately 3.5 amps per mm² of cross-section. A 40×5 busbar (200 mm²) can carry approximately 700A under these conditions.
What is the standard busbar size for 1000 amps?
For 1000 amps with copper busbar at 30°C rise (single strip, vertical), you would need approximately 286 mm² cross-section. A standard size like 120×10 would be sufficient. Commonly, a 100×10 or 80×10 with appropriate derating factors would be selected. For higher currents, multiple strips (2 or 3 per phase) are typically used.