The Indal handbook provides tables for Current Rating. If your busbar is operating in a "hot" environment (ambient temperature > 40°C), you must derate the current:
Following the INDAL handbook for aluminium busbar hot installation protocols is non-negotiable to avoid thermal runaway. indal handbook for aluminium busbar hot
Unlike copper, aluminium forms a tenacious oxide layer (Al²O³) in microseconds. When you torque a new busbar joint to the handbook's recommended 35 Nm (for an M12 bolt), the initial contact is only through microscopic peaks—the "asperities." When current flows, these tiny contact points become incandescently hot locally while the bulk bar remains cool. The Indal handbook provides tables for Current Rating
INDAL’s research shows this local heat (Joule heating) is actually beneficial. It softens the aluminium substrate under pressure, allowing the peaks to creep plastically. The joint settles into full-face contact. A busbar that runs "warm" for the first 48 hours is not failing; it is annealing its own interface. Following the INDAL handbook for aluminium busbar hot
For hot/high-load applications, the handbook typically specifies: