During the on-line design of OPGW optical cable, the design department shall determine whether it is necessary to set up a good conductor ground wire, determine the model and length of the good conductor ground wire, control the span condition of the maximum service tension of the ground wire and the size of the tower head, determine the appropriate limit value of OPGW short-circuit current capacity Ti 2T and the maximum service tension acceptable under the tower load condition, and combine the actual situation of the line with it Multiply the factor of 2.5-8 to become the limit value of rated failure strength of OPGW and the limit value. The cable diameter and weight of OPGW can be determined according to the load of the tower. Among them, the weight, diameter and failure strength of OPGW cable fittings are often interrelated. Under limited conditions, the product parameters of OPGW must be checked by the relevant lightning protection distance of "maximum protection tension across the distance - operation safety factor". When using OPGW, it is usually necessary to prevent tension, compression and fracture. Because of the great difference of OPGW structure, its mechanical properties will be deviated.
The construction unit needs to make relevant preparations according to the actual situation before installation. The specific preparatory work includes the following aspects:
① Mechanical equipment. Tension setting out method is the most commonly used method in OPGW erection. It can make OPGW in stress balance state, make the corresponding tension balance, and maintain the suspension state, so as to prevent the surface damage of outer armor layer.
② Site clearance. Before the OPGW is laid overhead, the construction site must be measured strictly and the garbage or waste on the site must be completely removed. At the same time, prepare protective frame, tension machine, traction machine and other equipment according to the actual terrain.
③ Optical cable transportation. During transportation, special attention shall be paid to prevent OPGW cable fittings and bridges from being placed horizontally, and it is strictly prohibited to stack them at will. The cable reel shall be wound according to the rotation arrow shown on the OPGW reel, and shall be protected from various forms of damage during loading and unloading.
④ Acceptance work. After the OPGW cable is transported to the site, the appearance inspection and opening test shall be carried out quickly to check whether the product meets the standard requirements. In general, OPGW materials shall be qualified, mainly involving guide cable, shockproof hammer, intermediate junction box and other materials. The specific layout of optical cable and the distribution of OPGW optical cable layout are of great help to the overhead laying work. In the process of arrangement, it is necessary to pay attention to relevant problems so as to play the expected role in the final installation.