SPD의 설치방법에 따른 보호특성

초록

The parasitic inductance that is in series with nonlinear components is a critical issue. Especially, the parastic inductance due to lead wires can significantly increase the clamping voltage of varistor. This paper presents the protection effects of surge protective device on equipment are measured as function of the magnitude of impulse current and the length of lead wire to the SPD. As a result, the voltage across the protected equipment has a large component owing to the inductance in the lead wire to SPD. The voltage across the equipment protected by SPD with the lead wire of 0.5m long is increased up to about 150[V] at 8/20us impulse with a peak of 3kA. It was known that the installation technique involved in minimizing the parastic inductance for protection against overvoltage is very importance.