All-dielectric self-supporting optical cable (ADSS cable) is a non-metallic optical cable composed entirely of dielectric materials and including the necessary supporting system. It can be hung directly on telephone poles and telephone towers. Mainly used for communication lines of overhead high-voltage power transmission systems. It can also be used for communication lines in overhead laying environments such as lightning-prone areas and large-span environments.
Self-supporting capacity refers to the strength of the cable itself to withstand its own weight and external loads. The name describes the environment in which the cable is used and its key technologies: because it is self-supporting, its mechanical strength is important; all dielectric materials are used because the cable is in a high-voltage, high-electrical environment and must be able to withstand strong currents. Impact: Because it is using a pole overhead, there must be a support boom that will be attached to the pole. That is, ADSS cables have three key technologies: cable mechanical design, hanging point determination, matching hardware selection and installation.
Mechanical properties of ADSS cable
The mechanical properties of the optical cable are mainly reflected in the maximum working tension, average working tension and ultimate tensile strength of the optical cable. The national standard for ordinary optical cables clearly stipulates the mechanical strength of optical cables for different purposes (such as overhead, pipeline, direct burial, etc.). ADSS cable is a self-supporting overhead cable, so it must be able to withstand the long-term influence of its own gravity, and must be able to withstand the baptism of strong wind, sunlight, rain and other natural environments, ice and snow. If the mechanical properties of the ADSS cable are unreasonably designed and do not adapt to the local climate, the cable will have potential safety hazards and its service life will be affected. Therefore, for each ADSS cable project, professional software must be strictly designed according to the natural environment and span of the cable to ensure that the cable has sufficient mechanical strength.
Determination of Suspension Point of ADSS Cable
Since the ADSS optical cable and the high-voltage power line are galloping on the same path, its surface not only requires the same UV resistance as the ordinary optical cable, but also requires a high-voltage and strong-electricity test. long-term electrical environment. The capacitive coupling between the cable and the high voltage phase line and ground will create different space potentials on the cable surface. Under the influence of meteorological environment such as rain, snow, frost, dust, etc., the potential difference generated by the local leakage current on the wet and dirty surface of the cable. The resulting thermal effect can cause moisture to evaporate from the surface of the cable parts. The large amount of heat, the accumulated heat, can burn through the surface of the cable, creating tree-like traces called traces. Over time, the outer sheath can be damaged by aging. From the surface to the inside, the mechanical properties of the aramid yarn decrease, eventually leading to cable breakage. At present, it is mainly solved from two aspects. One is to use special anti-tracking sheath material, and the outer sheath is extruded from aramid yarn, that is, AT anti-tracking sheath is used to reduce the corrosion of the surface of the optical cable by strong electricity; in addition, the pole is installed on the pole using professional software superior. Calculate the spatial potential distribution and draw the electric field intensity distribution map. According to this scientific basis, the specific suspension point of the cable on the tower is determined so that the cable will not be subjected to a stronger electric field.
ADSS fiber optic cable installation hardware
ADSS cables are secured to the tower with mounting hardware. The installation accessories must be used together with the optical cable, and the accessories used for the optical cable with different number of poles, spans and different outer diameters are different. Therefore, in the design, what hardware is used on each fiber optic rod, which fiber optic rods are connected, and the reel length of each fiber optic cable should be fully designed in place. Serious problems, such as loose cables or broken fibers, can occur if the accessories are not properly selected.
Post time: May-06-2022