1: ADSS cable line with the disk:
According to the length of the construction line with a long plate of optical cable. Generally add 6% on the basis of the actual line length. Since the ADSS cable can not be connected at any point, it must be connected to the tension bar or the tension tower of the line. And when doing fiber splicing, you need to reserve. The length of each optical cable should not be too long nor too short. The length of the plate is too long for construction inconvenience, if the length of the plate is too short, the number of successive connections will be large, the attenuation of the passage will be large, which will affect the transmission quality of the optical cable.
ADSS cable line construction relative to the power line construction has its own particularity, such as ADSS cable must be tension line, can not be pressure, and should have the minimum bend radius parameters. This article will be ADSS cable line construction preparation, precautions, construction records and file preservation described in three areas.
2.1 construction preparation
Optical cable appearance inspection: After receiving the optical cable, users should timely inspect the cable tray and the outer optical cable to ensure that the optical cable received is not damaged. Check the center hole of the cable tray for any possible damage to the optical cable outer jacket or to prevent the cable from rolling and unfolding obstacle.
Quantity check: Check the total number of optical cables, the length of each plate is consistent with the contract requirements.
Quality Inspection: Optical fiber time-domain reflectometer (OTDR) to check whether the cable is damaged in transit. The inspection data can be used to compare with post-installation inspection data and can be used as part of the data record to assist with emergency repairs in the future.
Installation of gold inspection: the required fittings for the installation of models, the number of inventory, if inconsistent with the contract requirements and suppliers immediately contact the factory, properly resolved before the actual construction.
2.2 Construction Notes
ADSS cable construction is usually carried out on the charged line tower, the construction must use the insulation without knot rope, insulating seat belts, insulation tools, the wind should not exceed 5 levels.
As ADSS fiber core brittle fracture, the construction tension should not exceed the arc sag provided by the manufacturer and the tension meter specified range, cable can not be pressure.
ADSS cable construction in the ground can not be with the ground, houses, towers, cable tray edge and other objects friction and collision.
The installation should ensure that the minimum bend radius (30 times the dynamic diameter of the optical cable, static optical cable diameter of 10 times).
Cable will be damaged by distortion, vertical distortion is strictly prohibited.
Fiber cable core damp and easy to break into the water, the construction of fiber optic cable end must be sealed with waterproof tape.
The outer diameter of the optical cable is matched with the representative of the span, the construction may not arbitrarily set plate. Fitting and cable diameter corresponding to non-indiscriminate use.
Cables are usually reserved for each cable is long enough to hang in the tower and welding, fiber optic patch panels should be installed in the substation.
ADSS cable suspension point to consider the following factors: field strength distribution, the minimum distance from the ground, the minimum distance from the wire, while the actual installation work should be strictly in accordance with the selected point of operation to protect the safety of optical fiber cable.
Traction, temporary positioning rod, welding and other locations must consider the design, logistics and equipment and other factors.
In the construction of fixed cable, cable must be divided into several sections of the line, the length of each section depends on the location of the weld, the vehicle can pass, the feasibility of installation of equipment, obstacles and cable tray length and other factors.
When selecting the location of the tractor and tensioner relative to the tower, it must not overload the tower or overload the cable. The distance between the traction machine and the tower should be 4 to 5 times the height of the tower, so that the load on the optical cable, the pulley and the tower can be reduced. According to ANSI / IEEE 524 regulations, a temporary sling is provided to prevent tower overloading. Tensioner and cable tray support must be in line with the last two towers to prevent cable distortion and pulleys on both sides of the cable wear.
Temporary positioning rod and the application of the hardware depends on the expected load tension of the cable size, the choice of fittings should consider the impact of wind vibration. When adjusting the cable sag, a temporary downward sling should be installed to prevent structural imbalance. At this time temporary positioning rod from the tower distance should not be less than 2 times the tower height. Before installing the fiber optic cable, all temporary slings should be tightened.
When installing routes crossing roads, highways, railways or transmission lines, some supporting facilities should be added. On cross-terrain construction, field personnel should keep in touch with tractor and Tensioner operators.
Analysis of each traction section of the terrain, to ensure the safety of construction. If the construction encountered obstacles, can not drag or drop the optical cable or optical cable directly hit an obstacle, so as to avoid damage to the outer optical cable jacket.
At the fiber optic splice, leave enough fiber and fiber length to facilitate the splice, and the length of the fiber optic cable should be brought down from the tower to the splice. Cable fusion should be done on the ground rather than in the air. Spliced optical cable should exist in the junction box placed on the tower or buried in the ground, the end of the optical cable to be closed with water blocking.
For construction safety and effectiveness, it is recommended to release the cable at a speed of about 3 km / h. The cable should maintain a balanced speed. During the pulling process, the operator of the tension machine should pay attention that the pulling tension can not exceed the required maximum tension. It is recommended that the pulling force should not exceed half the tension at the initial sag. Due to the length of the cable, the number of pulleys used, the change of course and the height of the tower, etc., it may be necessary to apply a larger tension when applying a larger span cable. In this case, special care should be taken because the tension at the towing end The display value is much larger. To prevent the drum from rotating too fast, a small but steady reverse force should be applied to the drum shaft. When the cable will be put away, the reverse force should be reduced in time, because at this time the tension on the cable will increase.
2.3 construction records and document preservation
A complete record is a necessary guarantee that communications work properly. As optical fiber cable communication involves many departments such as design, construction, operation and maintenance, all departments should collaborate with each other and keep all records in a safe manner for future work after the completion of construction.
Line Terrain Index Diagram: This chart documents the route and the road conditions that have passed. In this way, in the future work can quickly find the need to reach the place. For joint points, roads or river intersections, should be marked on the map.
Line composition diagram: This figure includes the number of the optical fiber cable, the length of the optical fiber, the number of optical fibers and the number of cores used in the joints of the lines, intersections of roads or rivers.
Installation Diagram: This chart records the condition of the equipment and tower at each tower, as well as the pole distance, grounding and so on.
Fiber Optic Circuit Diagram: This diagram shows the actual fiber optic circuits, the number of cores used, the number of spare cores, the optical fiber color scale and the subsequent processing of the optical fiber.
Acceptance data record: The recorded input optical power, received optical power, attenuation and other data should be recorded under acceptance. Also included is a graph of each fiber (1310 nm and 1550 nm) measured with a time-domain reflectometer (OTDR), splice loss, connector insertion loss, and photos of the fiber and pigtails.
Documents provided by the manufacturer: Cables supplied by the manufacturer and data on the optical fiber in each set shall be plotted against different tower types and arc sag and tensiometer as requested by the user.
The original record should be copied in multiple copies, the construction and maintenance units need to be saved, there should be a copy at the end of the system. After the renovation of the line and emergency maintenance, the records should be revised in time. ADSS optical cable requires close cooperation between users and manufacturers and strictly controlled in all aspects of design, production, construction and maintenance. Satisfying the above conditions, ADSS optical fiber cables can operate stably so as to ensure the long-term benefits of power communication.
Post time: Mar-18-2021