Indal Handbook For Aluminium Busbar Hot Jun 2026
Detailed guidelines on temperature management, mechanical strength to withstand short-circuit forces, and voltage drop calculations. Fabrication & Jointing:
| Issue | INDAL Solution | | :--- | :--- | | (Al flows under pressure at 90°C) | Use Belleville washers (spring washers) that maintain constant pressure. Standard flat washers lose 50% clamping force after 3 thermal cycles. | | Oxidation | Apply zinc-filled or copper-filled inhibitor paste (e.g., Penetrox, Alnox). Do not use plain grease—it evaporates at 80°C. | | Dissimilar metals (Cu-Al) | Use bimetal plated washers or tinned Al lugs. Direct contact causes galvanic heating (additional 15-20°C rise). | | Torque | INDAL specifies 20-25 Nm for M10 bolts on 10mm thick bar. Over-torque strips threads; under-torque creates hot joints. | indal handbook for aluminium busbar hot
In the context of the Indal Handbook, "hot" usually refers to three distinct areas: How the busbar is manufactured. | | Oxidation | Apply zinc-filled or copper-filled
A busbar operating at 120°C in a dusty environment is a fire risk. Dust acts as a thermal blanket, preventing cooling. 3. Jointing Techniques for High-Heat Environments
A busbar is considered "thermally critical" when its operating temperature exceeds (for E91E grade) or approaches the melting point of the joint interface (660°C for Al, but joint failure occurs much earlier).
You can use a larger aluminum bar to match copper’s conductivity and still save significantly on costs.
Most standards recommend a maximum continuous operating temperature of 90°C to prevent annealing (softening) of the metal and to protect the integrity of the joints. 3. Jointing Techniques for High-Heat Environments
