No.11（2016）3.A study of the SPD separator configuration method for direct lightning strikes

Taiju Kurosawa

  A SPD (Surge Protective Device) is used to protect a low voltage power supply circuit against lightning. However, it may fail in a short circuited state due to deterioration of the SPD caused by repeated surges etc. Under the Japanese Industrial Standards JISC5381, the installation of a SPD separator such as a circuit breaker or fuse etc. to separate the SPD from the power supply system when the SPD is short circuited is stipulated. The role of the SPD separator is to ensure the lightning current does not cause any damage. In the event that the SPD is degraded and a short circuit current flows from the power supply line to the ground, it will quickly isolate the short circuit current. However, there is no ideal SPD separator for direct lightning strikes at the present moment. In this study, by connecting a link fuse in series with the SPD separator, we aimed to resolve the problems faced by a SPD separator for direct lightning strikes.

Keywords
SPD, MCCB, Fuse, Impulse current

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