The sag tension table is an important data material reflecting the aerodynamic performance of ADSS optical cable. A complete understanding and correct use of these data are necessary conditions for improving the quality of the project. Usually the manufacturer can provide 3 kinds of sag tension meters under constant conditions, namely, the installation sag is constant (the installation sag is a fixed percentage of the span); the installation tension is constant and the load tension is constant. The three types of tension tables give a detailed description of the sag tension performance of ADSS optical cables from different sides.
It is only used to illustrate the sag tension characteristics of ADSS optical cable products under given conditions of use. It is different from actual engineering applications and must be paid attention to. It should be noted that the span in the sag tension meter is the actual span. To be precise, it is the actual span of the isolated span, that is, the span when the tensile section is only one segment. In actual engineering, the representative span of the tensile section should be obtained first, and then the sag and tension data corresponding to the gear with the same or similar value of the representative span should be found from the sag tension table. Remember that the sag at this time is generally a compound sag. The horizontal sag and the vertical sag are calculated by the wind deflection angle, where the sag is represented, the tension is represented, and the theoretical value of the span is calculated based on the actual data. . In the control conditions, the wind load control is related to the mechanical performance of the ADSS optical cable. It usually occurs in the case of a large span of more than 600m and a strong wind of more than 30ms. The weight of the ADSS optical cable is lighter than the wire, and its wind deflection angle is greater than the wind Deflection angle, easier to stretch. This may cause the ADSS optical cable to collide with the wire in the strong wind.
Although the design calculation is more complicated, in the case of small spans, such as when the representative span is less than 100m, the overhead wire sag is usually 0.5m, and when the representative span is between 100m and 120m, the overhead wire sag is 0.7 m, the lowest point of the sag of the ADSS optical cable should not be lower than the lowest point of the wire’s sag. In actual construction, in the continuous gear of the tensile bar, the middle gear or the larger gear distance close to the middle gear is often selected, and the one with the smaller suspension point height difference is used as the observation gear. If the number of gears is between 7 and 15, two observation gears should be selected at both ends respectively. Common observation methods include equal length method and different length method to observe sag, and tension measurement method can also be used to observe sag.
ADSS optical cable engineering design and construction is a complex system engineering, involving many aspects such as mechanical, electrical, meteorological conditions, and the quality of construction personnel. It requires both a scientific attitude and effective working methods. With the continuous progress of the power information network project, more and more construction and daily maintenance experience will be accumulated, which will enable the application of ADSS optical cables to get greater development.