A review on the testing method for low residual voltages in SPD

Technical issues on measuring the low residual voltage (Vres) in SPD determined in international standards are reviewed. The SPD for power supplies represents residual voltages more than 1.5kV but the SPD for applications in low voltage data, communications and signaling circuits shows several tens ~ hundreds volts. Thus, it is necessary to determine detailed technical specifications in a technical standard for implementing its accurate measurements. However, there are no such detailed specifications in international standards and that may cause confusions in operating a certification system based on the international standard for SPD performance. Therefore, in this study, technical issues on international standards for measuring the low residual voltages of SPD are reviewed.