ADSS Fiber Optic Cable Construction Precautions

With the continuous development of the power grid, the requirements for communication are becoming more and more important, and the construction of fiber optic cable networks in power systems has developed rapidly. At present, the ADSS fiber optic cable of the power system is basically erected on the same tower as the 110kV and 220kV transmission lines. The installation of the ADSS fiber optic cable is fast and convenient, and it has been widely promoted and used, but at the same time, many potential problems have also arisen. Today, let's analyze what problems should be paid attention to when ADSS fiber optic cables and transmission lines are installed on the same tower (pole)?

The location of various tower hanging points, in summary, the determination of the hanging point should mainly consider the following factors:

1. The field strength of the hanging point should not be greater than 20kV/cm to reduce electrical corrosion and maintain the expected life of the fiber optic cable.

  2. Use low-hanging as much as possible to reduce the additional bending moment of the tower, reduce the amount of reinforcement and reinforcement of the tower, and save engineering investment.

3. Try to avoid the intersection of fiber optic cables and electric wires to prevent whiplash. Avoiding the intersection of ADSS fiber optic cable and electric wire in the side view and top view is the prerequisite for avoiding whiplash and ensuring that the fiber optic cable and electric wire do not contact. If the crossing is unavoidable, the intersection point should be set as close as possible to the towers on both sides. At the same time, it is necessary to check that the electric wires and fiber optic cables do not collide and contact when they swing asynchronously with wind and the sag changes with the seasons without wind (mainly referring to the intersection points in the top view). To achieve the above requirements, it is mainly achieved by adjusting the position of the hanging point and properly selecting the sag of the fiber optic cable.

4. The lowest point of cable sag must not exceed the lowest point of wire sag, so as to ensure the crossing distance and avoid external damage.

5. The determination of the hanging point of the fiber optic cable should be convenient for the deployment of the fiber optic cable, the installation of accessories, and the non-collision with the support member when the wind is deflected, so as not to wear the fiber optic cable.

6. When determining the location of the hanging point, special attention should be paid to the change of the arrangement of the wires, the cross-connection of the fiber optic cable between lines of different voltage levels, and the conditions when the two ends of the line enter and exit the station. For example, the double-circuit branch tower transitions to a single-circuit, and the conductors transition from vertical arrangement to horizontal or triangular arrangement; when the two sides of the dry-shaped tower are combined with different straight-line pole towers, the fiber optic cables that appear on the dry-shaped tower hang high on one side and hang low on the other side. Situation; the combination of two sides of the cat head-shaped straight tower and pole towers in different arrangements; when the fiber optic cable is crossed between different lines; It is called special hanging point in the design.

7. The ADSS fiber optic cable is a metal-free fiber optic cable, and the sag basically does not change with the temperature. In order to prevent the fiber optic cable from colliding with the electric wire, the fiber optic cable sag should be selected, and the fiber optic cable and the electric wire should have no intersection point in the side view as much as possible. When hanging, it should also meet the annual average temperature and the tension of the fiber optic cable under the design maximum load condition is not greater than the maximum operating tension.

In general, after the development in recent years, the safety of ADSS fiber optic cable can be fully guaranteed after going through layers of checks in production, transportation, construction, acceptance and other links. After market inspection and revision, more and more experiences have been summed up, and the application of ADSS fiber optic cables in power systems is becoming more and more mature.