Lightning Protection Measures for Fiber Optical Cables

Fiber optic cables have excellent protective performance so at people usually ignore the lightning protection. In recent years, the fiber cables have wider application, at the same time, cable lines were often struck by lightning. Fiber cables have great communication capacity, once happen accidents, it’s hard to repair and will cause huge loss. Lightning protection for fiber optical cables should based on the weather and terrain and other natural conditions.

1. For aerial cables
(1) Typically, connector boxes have the strengthened core structure, no matter which method has been adopted, the connection structure of metal plate must superior to bolted connection,  longitudinal slotted bolt is superior to transverse structure, which should be paid attention to when choosing connector boxes.

(2) For the aerial cables, should be grounded every 2km. The grounding can be connected directly or through suitable device. Such hanging line has a protective effect.

2. For buried fiber cable
(1) In area grounding, the metal parts of cables should be connected, keep the core cable and moisture barrier in a connectivity status. In both side of cables, should strength the grounding, the vapor barrier should be grounded through the arrester.

(2) For non-copper cables, according to the regulations of YDJ14-91, the connected ends of cables should be installed the moisture barrier and be insulated. Thus, can avoid the accumulation of lightning, and prevent discharge flow lines caused by the lightning. This method is proving to be effective, normally; the metal component in cables has insulation performance so the lightning is hard to enter the cable.

(3) The excellent device of grounding for terminal boxes and the electric resistance should meet requirements. In contrast to former, the metal sheath has no protection for lightning, once there is a breakage point in the outdoor cables; the lightning is easy to enter cables. If the grounding position is not so good, lightning can not go quickly and there has no protective effects.