With the development of network, optical fiber, as a medium used to transmit data in the integrated cabling system, is more and more used by people because of its advantages such as high transmission rate and long distance. It is well known that optical fiber is have no electrical conductivity, can from impact current, fiber optic cable has good protection performance, the metal components of cable insulation value is higher, lightning current into the cable not easily, but because fiber optic cable has to strengthen the core, especially directly buried cable armoring layer, when optical fiber cable line from lightning, can also occur cable were destroyed or damaged.
Today, here and you explain in detail the main measures of optical fiber lightning protection in the construction of comprehensive wiring engineering.
Measure one: for the lightning protection of straight optical cable line:
(1) the internal grounding mode, the metal parts of the optical cable in the joint should be connected, so that the strengthening core of the trunk section of the optical cable, moisture-proof layer, armored layer to keep connected.
(2) in accordance with the provisions of YDJ14-91, moistureproof layer, armoured layer in cable tapping and strengthen core treatment of electrical disconnect should be done, and not ground, for the insulation status, can avoid induced the accumulation of lightning current in the cable, also can avoid because of lightning discharge flow and cable metal components to ground loop impedance difference caused by the earth introduced by grounding device lightning current in the cable.
Measures two:for overhead cable: overhead cable should be electrical connection and grounding every 2km, grounding can be directly grounded or through the appropriate surge protection device grounding. In this way the suspension line has the protection of the overhead ground line.
Measures Three:cable into the terminal box, the terminal box should be connected to the ground, in the lightning current into the cable metal layer, terminal box grounding can quickly let off the lightning current, play a protective role. It adopts directly buried optical cable with armored layer and reinforced core, and the outer sheath is PE (polyethylene) sheath, which can effectively prevent corrosion and rat bite.