The mechanical properties of ADSS optical cable are mainly reflected in the maximum operating tension, average operating tension and ultimate tensile strength of ADSS optical cable. The national standard for ordinary optical cables clearly stipulates the mechanical strength that optical cables should have in different ways of use (such as overhead, pipeline, direct burial, etc.). The ADSS optical cable is a self-supporting overhead optical cable, so it must bear the long-term effect of its own gravity, and must also be able to withstand the baptism of the natural environment, such as strong winds and scorching sun, rain, snow and ice. If the mechanical performance design of the ADSS optical cable is unreasonable and incompatible with the local weather, there will be safety hazards in the optical cable and the service life will be compromised. Therefore, for each ADSS optical cable project, professional software must be strictly designed according to the natural environment and span of the optical cable routing to ensure that the optical cable has sufficient mechanical strength.
The produced ADSS optical cable can be divided into two types: layer-stranded type and central bundle tube type in terms of structure. Among them, the layer-stranded type optical cable has a FRP strengthening core in it, and its weight is slightly heavier than the bundle type. At the same time, because it operates in a high-voltage environment, it can be divided into AT sheath anti-corrosion type and PE sheath standard type according to the electric field strength.
The characteristics of ADSS optical cable are as follows:
(1) Designed for power systems, it is a self-supporting aerial optical cable with a fully insulating medium, and its structure does not contain any metal materials;
(2) The fully insulated structure and high withstand voltage index are conducive to erecting construction on overhead power lines that are running live without affecting line operation;
(3) The use of high tensile strength anti-lun material can withstand strong tension, meet the large span requirements of overhead power lines, and prevent bird pecking and man-made gunshots;
(4) The coefficient of thermal expansion of ADSS optical cable is small. When the temperature changes greatly, the arc of the optical cable line changes very little, and its weight is light, and its ice and wind load are also small.
Service life of ADSS optical cable
The ADSS optical cable is erected on the high-voltage transmission line, and its general life span is more than 25 years. There are many factors that affect its life span. The main factors are:
(1) The gradient of the high-voltage induction electric field near the tower changes greatly, and the high-voltage induction electric field has strong electric corrosion on the optical cable. PE type for general KV and below overhead power lines, AT type for 110KV and above lines;
(2) For double-circuit towers, due to the power failure of the first circuit of the line or the transformation of the line, it should be considered when selecting the hanging point;
(3) When the line passes through the working area with salt mist and acid gas, the chemical substance will corrode the outer sheath of the optical cable, and its electric protection cover will be damaged, which is vulnerable to arc damage;
(4) Improper construction causes damage or wear to the outer skin, etc., and its surface is easy to corrode when it is operated in a long-term high-voltage electric field, and the optical cable with a flat and smooth outer sheath can effectively reduce electrical corrosion and prolong its life