The current rating is calculated from the conductor cross-sectional area, material (copper or aluminium), and maximum temperature rise per IEC 61439-1 (typically 70K above 35 degrees C ambient for bare copper). The busbar sizing calculator determines the required busbar dimensions based on the continuous current rating, short circuit withstand, and thermal limits for switchgear assemblies. You can choose the type of busbar, either aluminium or copper or galvanized bars or iron busbar or silver in the results. More details about Bus bar: What is Busbar Current Carrying Capacity. Enter your system's parameters (e. Adjust the Safety Factor if needed (default is 25%).