For copper busbars, IEC 61439-1 and common engineering practice recommend 1. Choosing the right thickness ensures that the grounding system can safely handle fault currents and maintain stable electrical connections. Electrical current-carrying requirements determine the minimum width and thickness of the conductors. Mechanical considerations include rigidity, mounting holes, connections and other subsystem. An electrical ground bus bar is a conductive bar made from materials like copper or aluminum, and it serves as the central point for connecting multiple grounding conductors in an electrical system.