The IEC 61439 standard applies to busbar assemblies that will be installed in electrical applications with a voltage rating up to 1000 V (for AC) and 1500 V (for DC). This standard defines the design verification, test requirements, and thermal performance of the assemblies. Verification under IEC 61439 can be done by testing. Figure 1: High-performance VIOX industrial low voltage switchgear assembly, demonstrating modern compartment design, reliable circuit protection, and clear busbar phase identification for superior substation safety. What Does IEC 61439 Require for Low Voltage Switchgear Design? IEC 61439. Busbars must also withstand thermal and mechanical stresses during a short circuit. The IEC standard for busbar sizing provides formulas to calculate this: Thermal withstand (I²t): Where: Example Calculation: For a 100 mm² copper busbar with 1s fault duration: This means the busbar can withstand a. 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.
