With the development of the network, optical fiber, as a medium used to transmit data in the integrated wiring system, is more and more used by people because of its advantages of high transmission rate and long distance.
As we all know, the optical fiber is non-conductive and can be protected from inrush current, and the optical cable also has good protection performance.
However, because the optical cable has a reinforced core, especially the direct buried optical cable has an armor layer, the optical cable can also be burned or damaged when the optical cable line is struck by lightning.
Fiber Optic Cabling
Today, I will explain to you in detail the main measures for lightning protection of optical cables and optical fibers in the construction of integrated wiring projects.
Measures 1. Lightning protection for straight optical cable lines
①In the way of intra-office grounding, the metal parts in the optical cable should be connected at the joint part, so that the reinforcing core, moisture-proof layer and armor layer of the optical fiber cable in the relay section are kept connected.
②According to the regulations of YDJ14-91, the moisture-proof layer, armor layer and reinforcing core should be electrically disconnected at the optical cable joint, and they are not grounded, and are in an insulated state to the ground, which can avoid the accumulation of induced lightning current in the optical cable. It can avoid that the lightning current in the ground is introduced into the optical cable from the grounding device due to the difference in the impedance of the lightning protection drain wire and the metal component of the optical cable to the ground loop.
The direct buried optical cable has an armor layer and a reinforcing core, and the outer sheath is a PE (polyethylene) sheath, which can effectively prevent corrosion and rat bites.
Measure 2. For overhead optical cables
The overhead suspension wire should be electrically connected and grounded every 2km. When grounding, it can be grounded directly or through a suitable surge protection device. In this way, the suspension wire has the protective effect of the overhead ground wire.
Measure 3. After the optical cable enters the terminal box, the terminal box should be grounded
After the lightning current enters the metal layer of the optical cable, the grounding of the terminal box can quickly discharge the lightning current and play a protective role.
