Professional busbar sizing calculator with current-carrying capacity per IEC 61439, temperature rise analysis, short-circuit withstand (thermal & mechanical), skin/proximity effect derating, voltage drop, bolted joint analysis, and copper vs aluminum cost comparison. Free. Busbar design within Medium Voltage (MV) switchgear is a critical aspect, fundamentally ensuring the safe, reliable, and efficient operation of power systems. Ready to Design a Reliable Busbar System? A busbar is a metal bar, usually made of copper or aluminum, that carries. RiLine busbar systems for individual switchgear and controlgear up to 2100 A. Complete solutions for AC or DC applications.