In Busbars in LV Switchgear Panels, the busbar is the low-resistance conductor that takes power from the incomer and distributes it to outgoing functional units or feeders. It is the panel's main conductor rail. IEC 61439 is a standard developed by the International Electrotechnical Commission (IEC) that covers design verification for low-voltage electrical products and assemblies. The IEC 61439. Guide to Low Voltage Busbar Trunking Systems Verified to BS EN 61439-6 Guide to Low Voltage Busbar Trunking Systems Verified to BS EN 61439-6 November 2014 Guide to Low Voltage Busbar Trunking Systems Verified to BS EN 61439-6 Companies involved in the preparation of this Guide Acknowledgements. High Voltage Busbars: Typically refer to busbars with a rated voltage of 1kV and above, including common voltages such as 10kV, 35kV, and 110kV. Low Voltage Busbars: Refer to busbars with a rated voltage below 1kV, commonly. ents), and the electrical equipment, formed by the internal connections and by the incoming and outgoing termina is regard, there has been an evolution which has resulted in the replacement of the previous Standard IEC 60439 with the present Stand rd IEC 61439. Since their introduction into the U., design engineers, integrators, and original equipment manufacturers (OEMs).