Indal Handbook For Aluminium Busbar

"Gentlemen, the Indal handbook shows that a 200mm x 20mm aluminium busbar carries the same current as a 120mm x 12mm copper bar. But the aluminium bar weighs one-third as much. Your building's roof structure won't need reinforcement. Your expansion joints will last longer because aluminium’s thermal expansion is closer to concrete than copper’s. And at current prices, the aluminium busbar run will cost 40% less. The risk is not the metal. The risk is bad joints. We will use tin-plated copper connectors, Belleville washers, and this torque schedule from page 47."

A critical section of the handbook details how environmental factors dictate busbar sizing. If a busbar runs too hot, it can degrade nearby insulation or accelerate joint oxidation. The Standard Calculation Formula The current-carrying capacity ( Indal Handbook For Aluminium Busbar

As AC frequency increases, current tends to crowd toward the outer edges of the conductor. This effectively reduces the usable cross-sectional area and increases the AC resistance ( Raccap R sub a c end-sub ) relative to the DC resistance ( Rdccap R sub d c end-sub "Gentlemen, the Indal handbook shows that a 200mm

| Width (mm) | Thickness (mm) | Cross-section per Phase (sq. mm) | AC Current (A) at 35°C Ambient, 50°C Rise | | :--- | :--- | :--- | :--- | | 50.8 | 6.35 | 322.58 | 670 | | 50.8 | 9.53 | 484.12 | 830 | | 76.2 | 6.35 | 483.87 | 960 | | 76.2 | 9.53 | 726.19 | 1180 | | 101.6 | 6.35 | 645.16 | 1235 | | 101.6 | 9.53 | 968.25 | 1495 | | 127 | 6.35 | 806.45 | 1505 | | 127 | 9.53 | 1210.31 | 1860 | Source: Compiled from INDAL CHART reference data Your expansion joints will last longer because aluminium’s

: It offers standard charts for continuous current carrying capacity ( cap I sub o ) based on common bar sizes (e.g., Derating and Correction Factors