Differences in Surge Protective Device Standards

This white paper documents the differences in Surge Protective Device (SPD) classifications, parameters, and test methods as outlined in UL 1449 5th Edition and IEC 61643 standards. It explains the importance of understanding these differences for selecting the appropriate SPD for various applications. The paper details key parameters such as Impulse Current (Iimp), Maximum Discharge Current (Imax), and Nominal Discharge Current (In), along with their testing methodologies. It also describes the various SPD categories, including Type 1, Type 2, Type 3, Type 4, and Type 5, highlighting their installation requirements and testing conditions. Furthermore, the paper outlines the test methods for both UL 1449 and IEC 61643, emphasizing the significance of Voltage Protection Rating (VPR) and Voltage Protection Level (Up) in assessing SPD performance. By comparing these standards, the document aids engineers in making informed decisions regarding surge protection systems, ensuring compliance and safety in electrical installations.