Due to the different laying methods of communication fiber optic cable, the specific fiber optic cable maintenance work is also different, but most of them can be maintained for technical fiber optic cable.
1. The technical fiber optic cable maintenance.
The technical maintenance of the fiber optic cable line includes the inspection of the fiber optic cable attenuation constant, the back scattering of the fiber optic cable, the electrical performance of the metal wire pair in the fiber optic cable, and the insulation resistance index of the steel tape to the ground of the outer sheath of the direct-buried fiber optic cable.
(1) Fiber attenuation constant:
Within the service life of the fiber optic cable digital communication system, due to the influence of aging, temperature and maintenance process, etc., the total attenuation of the fiber optic cable in the relay section will change to a certain extent, but compared with the total attenuation value at the time of completion, it should not exceed 0.1dB /km, and when the fiber needs to be connected during the emergency repair process, the joint consumption of the single-mode fiber optic cable should be less than 0.2dB. After the official repair or reconstruction project is completed, the average joint consumption of the single-mode fiber optic cable should not exceed 0.1 dB.
(2) The electrical performance of the metal wire pair in the fiber optic cable:
Since the metal fiber optic cable contains copper wires, the resistance and insulation resistance of the wires should be different from those of communication cables. Generally, at a temperature of 20°C, the resistance of a copper core wire with a diameter of 1.2 μm is not the same. It should be greater than 31.9Ω/km. Under 500V, the insulation resistance between each core wire and all other core wires connected with the metal sheath should not be less than 5000MΩ/km.
(3) The insulation resistance of the steel strip to the ground of the outer sheath of the directly buried optical cable:
Due to the special environment, the steel tape is used in the sheath to improve the mechanical properties of the direct buried optical cable. In order to ensure its normal operation, the insulation resistance of the steel tape to the ground should not exceed 2MΩ/km.
In order to do a better job in fiber optic cable maintenance and ensure the normal operation of the fiber optic cable system, in addition to regular and irregular inspections, records and archives should be made for each fiber optic cable maintenance, so that when an emergency occurs.
