Excavations for conducting optical fibers are a key stage in the implementation of the infrastructure of modern telecommunications networks. In the era of growing demand for quick and reliable internet connections, proper preparation of the area and the correct conduct of fiber optics becomes a priority for both operators and investors. In the article we will discuss the most important aspects related to excavations for fiber optic installations, including the selection of appropriate methods, challenges related to geological conditions, as well as the importance of legal provisions and technical norms that are aimed at ensuring durability and security of installations.
What depth must fiber trench have?
Increasingly, cable lines are replaced by overhead lines, carried out using equipment such as rope suspensions or clamps. Underground, however, not only power lines, but also optical fibers are carried out not only. Fiber dumps must be made with great precision to ensure adequate protection of cables against mechanical damage and the impact of external factors. In Poland, the soil freezing zone, which is about 0.7-0.8 meters, is of key importance. Therefore, to minimize the risk of damage to optical fibers caused by the freezing and movement of the soil, the excavation should have a depth of at least 70-80 cm. At this depth, a HDPE casing pipe of the appropriate diameter is placed, which is an additional protective layer for a delicate fiber inside. This pipe protects the cable against pressure and other mechanical damage that could cause it to squeeze, and as a result - a decrease in signal damping.
In addition, at a depth of about 20 cm above the cover pipe, the warning tape is laid. This is an important element of protection that informs about the presence of optical fiber during any future earthworks, reducing the risk of accidental damage to the installation. It is also important that the excavation route is as simple as possible, with a minimum number of corners, which further protects the optical fiber from damage and ensures connection stability. A correctly made excavation, taking into account all these factors, is crucial for ensuring longevity and reliability of fiber optic network.
Laying optical fibers
Laying optical fibers is a precise process that requires taking into account numerous technical parameters to ensure optimal efficiency and durability of the installation. Before starting work, it is crucial to meet the temperature requirements: fiber optic cables should be stored in the range from -40 ° C to +70 ° C, laid at -5 ° C to +55 ° C, and operated in conditions from -30 ° C to +60 ° C (or -40 ° C to +70 ° C for self -character cables).
When laying cables, you should follow the norms regarding mechanical resistance, in accordance with the IEC 60794-1-22, which includes attempts to resist stretching, crushing, bending, twisting, mechanical strokes, cyclical temperature changes and longitudinal water penetration. To avoid damage, it is worth using equipment such as optical fiber fluid.
In practice, fiber optic cables should be laid in excavations at a depth of at least 0.6 m, with an additional marking of warning tape. The cover pipe must be placed on sand bed, protected against damage and sealed. It is also important that the cable sections are carried out in straight lines, and all changes to the direction and place of the beginning and end of the route must be marked accordingly. Episodes from the line gate to ODF wardrobe should be made in one string, without muff connections, and all pipelines must be tight and resistant to pollution. In addition, cables in cable channels should be fastened on ladders and protected with frost -resistant bands. Such a careful approach to the installation guarantees long and reliable operation of the fiber optic system.
How is optical fibers in buildings?
In buildings, running fiber optic cables requires diligence and compliance with numerous standards to ensure the safety and efficiency of the system. At the installation stage, it is key to collecting about 30 meters of supply of each cable in enclosed boxes, which must be grounded and marked in accordance with the standards. When conducting overhead lines, solutions such as cable handles are used, but in the case of optical fiber, additional protection is necessary. Internal cables should be carried out in corrugated, hard -toe protective tubes, resistant to crushing, and their transitions through fire sets must be properly sealed to maintain fire resistance and protect against water infiltration.
In buildings, cables can be run in various ways: on cable ladders or support constructions attached to the walls and ceilings, in cable channels under the floor, in curtain pipes located under or on plaster and in cable windows. When driving cables in vertical channels, they should be fastened every 6 meters or on each floor to ensure stability and avoid damage.
An important aspect is also to ensure redundant roads for cables reserving, which should be conducted on separate routes, with a minimum of 2 meters of distance between routes and between culverts in the wall of the building. Cable markers should be used along the entire route, both metal and plastic, which will inform about the relationship of the line, owner, cable type and contractor. These markings should be mounted every 10 meters, with level changes and on both sides with culverts.
To ensure full functionality of the system, the cables should be carried out in a way that allows them to be easily maintained and possible modifications in the future. Compliance with these requirements guarantees not only the reliability and efficiency of the installation, but also the fulfillment of fire standards and protection against mechanical damage.
