Low Voltage Busbars: Refer to busbars with a rated voltage below 1kV, commonly 220V and 380V, widely used in industrial and commercial building distribution systems. 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. When designing electrical power systems, one of the most critical aspects is selecting the right size for busbars. They carry large currents and must be properly sized to ensure safety, performance, and. Rated voltage does not exceed 1 000 V AC or 1500 V DC. Special service conditions, for example in ships and in rail vehicles provided that the other relevant specific requirements are complied with. Electrical equipment of. 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. Technical specifications The technical specifications are for general information purposes only. All illustrations are not binding. Low voltage busbars are used in systems where the voltage level is below 1000 volts.