Temporary Overvoltage (TOV) Test Values for SPDs in Japan

In IEC 61643-11:2011 [1], the temporary overvoltage (TOV) test method and test values to confirm the safety of the SPD in TOV are specified. However, this TOV test values is based on the three phase 4 wire Y connection 230/400V system defined by the IEC 60364series, which are different from the actual situation in Japan.TOV caused by faults in low-voltage power systems in Japan increases the voltage between L and PE of 100 V AC system up to 330 V AC. In addition, TOV caused by faults in high-voltage power systems in Japan increases the voltage between N and PE up to 600VAC for 1 second.This paper is prepared to detail the mechanism of TOV in Japan and the particular TOV test values for SPD in Japan.