What are the requirements for lightning arrester installation?

1. In the AC power supply and distribution system, in order to prevent system failure caused by SPD aging short circuit, there should be overcurrent protection device on the SPD installation line, and SPD with degraded display function should be selected;

2. The arrester should be installed in the protected equipment as much as possible. If it cannot be installed in the protected equipment, the SPD must be installed in the installation box and installed on the nearby wall or near other places where the equipment is protected. The length of the SPD connecting wire should not exceed 0.5m. The grounding lead should be avoided as far as possible in parallel with the power cable, and should be thick, short and straight;

4. When the line length of SPD1 to SPD2 is less than 10 meters, when the line length of SPD2 to SPD3 is less than 5 meters, decoupling inductance should be added between SPDs;

5. The power supply SPD of each level must be installed at the AC input end of the AC power distribution equipment. It should be connected by Kevin wiring (disconnect the indoor grounding connection line and the grounding lead-in connection, and separate the two ends of the disconnection respectively. To the ground of the SPD);

6, SPD and air switch and 35mm standard guide rails are reliably fixed, the power supply level SPD connection wire line shall not be less than 16mm2, the grounding wire diameter shall not be less than 25mm2; the power supply secondary SPD connection wire shall not be less than 10mm2, the grounding wire diameter Not less than 16mm2; the power supply three-stage SPD connection wire shall not be less than 6mm2, the grounding wire diameter shall not be less than 10mm2; the signal lightning arrester connection wire shall not be less than 2.5mm2, and the grounding wire diameter shall not be less than 6mm2;

7. The power supply SPD should be grounded with the shortest and straight path. The grounding line of SPD should avoid “V” shape and “U” shape bend. The bending angle of the connection should not be less than 90°, and the grounding wire must be tied and fixed, and the tightness is moderate. ;

8. The SPD connection line should be beautiful, especially the straight line, turn and joint, to ensure the SPD is clean and beautiful, and the connection is firm and reliable;

9. After the SPD is installed, it must be checked and confirmed by the technical supervisor of the construction unit to ensure that the SPD installation is correct and reliable. The grounding requirement of the SPD should be less than 4 ohms; if the whole lightning protection system uses the common grounding, the impact grounding resistance requirement should be ≤ 1 ohm;