COUNTER FLOW THUNDERBOLT PROTECTION DEVICE

摘要

PROBLEM TO BE SOLVED: To efficiently make a lightning surge current flow to ground at the lightning strike to a tower body and the like of user facilities to protect facility equipment and a power distribution facility in the user facilities against a counter flow thunderbolt.SOLUTION: Provided is a device that is used for a system for supplying a secondary side voltage of a pole transformer 23 to facility equipment 14 via a low-voltage lead-in line 25 as a power supply voltage, the facility equipment 14 being grounded at a user side ground 11 via an SPD 13, and that protects the facility equipment 14 and a power distribution facility 2 and the like at the lightning strike to a tower body 10. In the device, discharge gaps 31 and 32 whose operation voltage is lower than the SPD 13 are connected between a user side ground 11 connected with the tower body 10 and the facility equipment 14, and a power distribution facility side ground provided at the power distribution facility 2 (a B-type ground 26a and an overhead earth wire ground 27a). SPDs 41 and 42 are connected between a secondary side of a pole transformer 23 and a ground line 26. These discharge gaps 31 and 32 and SPDs 41 and 42 configure a counter flow thunderbolt protection device 100.