(1) The construction of ADSS optical cables is usually carried out on live line poles and towers. Insulated endless ropes, insulated safety belts, and insulated tools must be used during construction. The wind force should not exceed level 5, and a safe distance from lines of different voltage levels must be maintained. That is, 35KV is greater than 1.0m, 110KV is greater than 1.5m, and 220KV is greater than 3.0m.
(2) Since the fiber core is extremely brittle, the tension and lateral pressure during construction should not be too large.
(3) During construction, the optical cable should not rub or collide with other objects such as the ground, houses, pole towers, and the edge of the cable drum.
(4) The bending of the optical cable is limited. Generally, the bending radius of the operation is ≥ D, and D is the diameter of the optical cable. The bending radius during construction is ≥ 30D.
(5) The optical cable will be damaged if it is twisted, and longitudinal twisting is strictly prohibited.
(6) The fiber core of the optical cable is easily broken by moisture and water, and the end of the cable must be sealed with waterproof tape during construction.
(7) The outer diameter of the optical cable is matched with the representative span, and it is not allowed to adjust the plate at will during construction. At the same time, the fittings correspond to the outer diameter of the optical cable, and it is strictly forbidden to use them indiscriminately.
After the construction of each optical cable is completed, there are usually enough remaining cables for suspension and fusion at the tower, and the optical fiber distribution frame is installed in the substation.
Sag tension gauge
The sag tension table is an important data that reflects the aerodynamic performance of the ADSS optical cable. A complete understanding and correct use of these data is a necessary condition for improving the quality of the project.
Usually, manufacturers can provide sag tension gauges under three constant conditions, that is, 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. These three types of tension tables have made a specific description of the sag tension performance of ADSS optical cable from different sides.
It is only used to illustrate the sag tension characteristics of ADSS optical cable products under given use conditions, which is different from actual engineering applications and must be taken seriously. It should be noted that the span in the sag tension table is the actual span, to be precise, the actual span of the isolated stall, that is, the span of the tension section is only for a period of time.
In actual engineering, the representative span of the tension section should be obtained first, and then the sag and tension data corresponding to the stall with the same or similar value as the representative span can be found from the sag tension table.
Remember that the sag at this time is generally a compound sag, and the horizontal sag and vertical sag are obtained through the windage angle. Here, the actual data is calculated on the basis of the theoretical values of sag, tension, and span. .
In the control condition, the wind load control is related to the mechanical properties 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 that of the wire, and its wind deflection angle is greater than that of the wire. Angled, easier to elongate. This may cause the ADSS optical cable to collide with the conductor in the strong wind.
Although the design calculation is more complicated, in the case of small spans, such as when the span is less than 100m, the erection sag is usually taken as 0.5m, and when the span is between 100m and 120m, the erection sag is 0.7 m, the lowest point of sag of ADSS optical cable should not be lower than the lowest point of wire sag.
In actual construction, among the continuous sections of tension rods, the middle section or a larger span close to the middle section is often selected, and the one with the smaller suspension point height difference is used as the observation section. If the number of gears is between 7 and 15, two observation gears should be selected at both ends. The common observation methods include the equal-length method and the different-length method to observe the sag, and the tension measurement method can also be used to observe the sag.
The design and construction of ADSS optical cable engineering is a complex system engineering, which involves many aspects such as machinery, electricity, 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 experience in construction and daily maintenance will be accumulated, so that the application of ADSS optical cables will be further developed.
Post time: Dec-27-2022