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This article draws upon principles similar to those found in the authoritative , providing a comprehensive overview of engineering calculations, material selection, and thermal management. 1. Introduction to Aluminium Busbars (The Indal Approach)
Using braided aluminum connectors to bridge the gap between fixed equipment (like transformers) and busbars. indal handbook for aluminium busbar hot
Because aluminium is prone to "creep" (deformation under constant pressure and heat), Indal recommends using Belleville (conical) washers . These maintain constant pressure even as the metal expands and contracts during thermal cycles. 4. Ampacity and Temperature Rise
Belleville washer (coned-disc spring) sets must be used on all bolts. These springs maintain pressure on the joint even when the aluminium expands and contracts, preventing loosening. I=Io×k1×k2×k3cap I equals cap I sub o cross
According to legacy INDAL documentation and modern IEC 61439 standards (which Hindalco supports), the permissible temperature limits for aluminium busbars are defined by the insulation and joint type:
Highly conductive (min 61% IACS) but softer. Because aluminium is prone to "creep" (deformation under
| Property | Value/Comparison | Implication for Design | | :--- | :--- | :--- | | | ~61% of Copper | Aluminum requires a larger cross-section (approx. 160% of copper) to carry the same current with similar losses. | | Coefficient of Thermal Expansion | ~23.1 μm/m·K (vs. 16.5 for Copper) | Aluminum expands significantly more, requiring special joint designs (e.g., Belleville washers) to maintain constant pressure through thermal cycles. | | Weight | ~1/3 the weight of Copper | The largest advantage. Lighter weight reduces structural support needs and simplifies installation. |