The optical fiber wire is the most comprehensive wire in the wiring engineering. As a highly functional data transmission medium, the optical fiber cable has the characteristics of large transmission rate and long transmission distance, and is favored by people.
The non-conductivity of the optical fiber effectively solves the current impact problem that other wires cannot be avoided due to material limitation. In addition, the optical fiber cable has good protection performance, and the internal metal structure has high insulation value to the ground, so that lightning current is not easy to enter the optical cable, but the optical cable reinforcement of the core and the armor layer of the direct buried optical cable have also become the cause of the lightning strike of the optical cable wire, which may cause the cable wire to be burned and damaged.
How to do lightning protection measures for fiber optic cables:
Measure 1
Direct buried cable are part of the more vulnerable to lightning strikes. Lightning protection measures for direct buried optical cable wires:
1. Use the internal grounding method to connect all the joints of the metal parts in the optical cable to ensure that the reinforcing core, moisture-proof layer and armor layer of the cable trunking section are in communication.
2. According to the YDJ14-91 wiring standard, the reinforcing core, moisture-proof layer and armor layer of the cable joint are electrically disconnected and are not grounded, so as to prevent current-induced external lightning current accumulation in the cable, It is also possible to avoid the difference in loop current impedance between the lightning protection drain wire and the metal component of the cable, so that the lightning current enters the cable from the grounding device.
Measure 2
Lightning protection measures for overhead cables:
The overhead cable suspension wire shall be lightning-proof through electrical connection and grounding. The grounding protection shall be grounded every 2km. There are two grounding methods, one is direct grounding and the other is grounding through a suitable surge protection device. The two grounding methods are reasonably operated according to the actual situation. After the grounding, the overhead ground wire can protect the cable hanging wire.
Measure 3
The cable terminal box is grounded to provide a good lightning discharge. When the optical cable is connected to the terminal box, the terminal box is grounded. At this time, the lightning current entering the terminal box of the optical cable can flow into the underground through the grounded terminal box in time to protect the optical cable wire.
The direct-buried optical cable can strengthen the protection of the reinforcing core and the armor layer, and the outer PVC environmental protection sheath can effectively prevent corrosion and rat bites.