Indal Handbook — For Aluminium Busbar

| Configuration | AC Current (Amps) | DC Current (Amps) | | :--- | :---: | :---: | | Single bar (flat vertical) | 1500 A | 1650 A | | Single bar (edge-mounted) | 1650 A | 1800 A | | Two bars per phase (spaced) | 2800 A | 3100 A |

✅ – Confirm alloy temper (e.g., 6101-T6, not generic “aluminium”) ✅ Cross-section area – At least 80% of copper equivalent when replacing copper (e.g., 80x5mm Al replaces 50x5mm Cu) ✅ Joint surface finish – Better than 1.6 µm Ra roughness ✅ Inhibitor compatibility – Does it contain zinc chromate or copper flakes? ✅ Thermal cycling test – Simulate 500 cycles from ambient to 105°C and re-check torque ✅ Touch temperature – Handle guards required if busbar exceeds 70°C in accessible areas Conclusion: The Living Legacy of the Indal Handbook The Indal Handbook for Aluminium Busbar is far more than a historical document. It represents decades of empirical research, failure analysis, and practical engineering wisdom. In an era of high copper prices and global supply chain volatility, aluminium busbars—properly designed using Indal’s principles—offer superior lifecycle value. Indal Handbook For Aluminium Busbar

| Bar Thickness (mm) | Utilisation Factor (AC/DC) | | :--- | :--- | | 6 mm | 97% | | 10 mm | 92% | | 15 mm | 84% | | 20 mm | 73% | | Configuration | AC Current (Amps) | DC

Aluminium busbars are not copper busbars. Treat them as a different engineering material, follow the Indal protocol, and your system will run cool, tight, and reliable for decades. Disclaimer: This article synthesizes public-domain principles from the original Indal technical literature. Always verify specific designs against current IEC, NEMA, or local electrical codes. In an era of high copper prices and

Whether you are designing a 500A distribution board or a 5000A heavy industrial switchgear bus duct, the handbook’s core tenets remain: respect the oxide, manage the expansion, control the torque, and when in doubt, derate.