Many people are confused about the hanging of aerial optical cables. In fact, there are two methods for aerial optical cables laying: one is “fixed-pulley traction method”, including “manual traction method” and “mechanical traction method”; the other is “cable tray moving and releasing method”. Next, we will take a detailed look at the concrete operation of the latest methods of aerial cable construction technology.
(1) Fixed-pulley traction method. When hanging the optical cable, the cable tray should be set first, and the big pulley for laying the optical cable shall be fixed on the pole at the up and down positions. A small pulley (guide pulley) shall be hung every 10-20 m on the suspension line in each pole, and the traction rope shall be put into the small pulley. Then, make the traction head, connect the traction rope with the optical cable, and prepare for laying.
① When applying manual traction method, please manually tighten the optical cable tray to gradually release the optical cable, and then one person shall be arranged on every two poles for auxiliary traction (if necessary, install guide pulley on the angle pole). Gradually tighten the traction rope at the traction end to slowly release the optical cable. In order to fully ensure the safety of optical fiber, three contact telephones shall be set at the cable laying end, cable receiving end and cable traction head of optical cable line, and always keep the contact unblocked. When the single tray optical cable is too long, it is generally placed in two times: after the first half of the tray is placed, put it on the ground with an “8” shape; and then the second half of the tray is placed in another direction.
② When mechanical traction is adopted, the main machine of mechanical traction shall be placed at the retrieving cable end, and the auxiliary traction machine shall be placed at the appropriate position of the cable laying end. Put the cable tray at the cable laying end, manually tighten the cable tray to gradually release the cable from the top, and apply machinery instead of manual traction to achieve the purpose of cable laying. When manufacturing the traction end, make sure that the traction force mainly acts on the reinforcement of the optical cable. With allowable traction force limit of optical cable, the length of optical cable laid in one time shall be determined according to the terrain conditions. In addition, the traction speed of optical cable traction machine shall be determined in advance. When the traction tension exceeds the standard figure, there shall be automatic cut-off or alarm device.
③ After laying optical cable, the length of optical cable for the joint and for each pole shall be reserved. Finally, hang the remaining cable with the wrapped end on the pole.
When laying the aerial optical cable of hanging type, the expansion bend can be properly made on the pole in the middle load area, heavy load area, overweight load area. It is generally required to be reserved on each pole. In the light load area, one reservation can be made every 3-5 poles; in the ice-free area, it is ok to make no reservation (but the optical cable cannot be pulled too tight, and pay attention to the natural sag).
The central part of the pole shall be protected by polyethylene bellows with a reserved length of 2m (generally not less than 1.5m). Both sides and binding parts shall be reserved, and shall not be tied up, so that it could expand freely when the temperature changes and the optical cable could thus be protected. When the optical cable passes through the cross-shaped suspension line or T-shaped suspension line, the protective pipe shall also be installed.
④ When the aerial optical cable is led upward, the aerial fiber optic cable installation method and requirements can refer to the following figure. The steel pipe (led upward to protect the steel pipe) is used to protect the lower part of the pole to prevent human injury; the upper suspension part shall be bound at the place 30cm away from the pole, and there should be an expansion bend (pay attention to the bending radius of the expansion bend and ensure the safety of optical cable with the condition of severe temperature change).
⑤ Generally, hooks are used for fixing and hanging aerial optical cables. The distance between optical cable hooks shall be 50cm, and the allowable deviation shall not exceed ± 3cm.
The buckle direction of the hook on the suspension line shall be the same, and the hook plate shall be complete without mechanical damage. The distance between the first hook on both sides of the pole and the clamp plate of suspension line shall be 25cm, and its allowable deviation shall not exceed ± 2cm.
(2) Cable tray moving and releasing method. Such hanging method is to set the optical cable tray on the truck (fix one end of the optical cable at the suspension line of the electric pole), manually push the optical cable tray, so that the optical cable is laid along the overhead line, while the optical cable is hung on the suspension line. After the laying work with one pole spacing, the optical cable can be fixed on the suspension line with next pole spacing. This method is simple, but the operation of truck is limited by conditions. In general, the following requirements shall be met.
It should be noted that the distance between the overhead line and the roadside is not more than 3m, and the suspension line should be located at the lowest layer of other lines on the overhead line. Unitek focuses on the R & D and sales of optical fiber and cable products. Optical fiber jumper, optical fiber adapter, MPO / MTP data center and other optical fiber products are all in line with international and domestic standards such as ICE, ROSH, and YD/T. We hope that you can firmly grasp the latest hanging methods above and apply them to actual wiring operation.