Code for construction of optical cables

Cable construction is roughly divided into the following steps: Preparation → route engineering → Cable laying → cable connection → engineering acceptance.

1. Preparatory work

(1). Check the design materials, raw materials, construction tools and equipment are complete.

(2). To establish a high-quality construction team. This is important because optical fiber construction is more stringent than cable construction requirements, any construction of negligence will likely cause fiber loss increased, or even broken core.

2. Routing Engineering

(1). Optical cable before laying the first to make a careful exploration of the route of the cable, to understand the local road construction and planning, as far as possible to avoid pits, wheat fields, gas stations and other potential hidden dangers. After the route is determined, the length is measured and the precision is within 50m. Also need to add the natural bending and a variety of reserved length, a variety of reservations also include the insertion of holes in the bending, the bar on the reservation, joint ends reserved, the increase in the level of Radian and other special reservations. In order to make the optical cable in the case of rupture, it should be in every hundred meters to leave a certain amount of margin, the length of the margin is generally 5%~10%, according to the actual needs of the length of order, and in the coil when marked.

(2). Drawing path Construction Drawing. In the pre-planted pole number, draw the path construction map, and explain each pole or underground pipe outlet pole number and pipe length, and set the need to leave the amount of margin of length and position. This can effectively use the length of optical cable, reasonable configuration, so as to minimize the melting point.

(3). Two fiber optic connectors It is best to install in flat terrain, geological stability of the site, to avoid reservoirs, rivers, ditches and roads, preferably located in the pole or pipe outlet, aerial cable connectors should be left in the 0.5~1m around the pole, this work is called "" with the plate. A reasonable matching plate can reduce the weld contact. In addition, in the construction drawings should also explain the location of the weld, when the optical cable breaks, easy to quickly use the instrument to find breakpoints for maintenance. ---computer science (http://bianceng.cn)

3. Cable laying

(1). The same batch of optical fiber, its mold field diameter is basically the same, the optical fiber at a certain point after disconnecting, the two ends of the mode field can be considered consistent, so this disconnect point weld can make the Mode field diameter of the impact of optical fiber weld loss to a minimum. So require optical cable manufacturers with the same batch of bare fiber, according to the required length of the optical cable, serial number on each plate, and marked a (red), B (green) end, no jump number. The cable must be set up by number along the route to determine the routing order, and ensure that the front disk cable B and the rear of a cable to connect a end, so as to ensure the continuity of the two fiber End mode field diameter is basically the same, so that the weld loss value to the minimum.

(2). Aerial cable can be used 72.2mm galvanized steel strand cable puppet. Puppet and optical cable to be good grounding, there should be lightning protection, protection measures, and shockproof, wind-resistant mechanical properties. The horizontal and vertical distance between overhead puppet and power line is more than 2m, the minimum height is 5m from the ground, and the minimum distance from the roof is 1.5m. Aerial cable has 3 kinds of hanging type: Puppet hanging type, puppet winding type and self-supporting type. Self-bearing without steel stranded puppet, cable droop, under the wind force is poor, so commonly used hanging type.

(3). Aerial cable cloth. Because the length of the optical cable is much longer than the cable, the length may reach thousands of meters, so the rated tensile force and bending radius of the limit, in the construction of special attention can not be yanked and kink phenomenon. General cable can be allowed to pull about 150~200kg, optical cable turn bending radius should be greater than or equal to the outer diameter of the cable 10~15 Times, the construction of the cloth when the bending radius should be greater than or equal to 20 times times. In order to avoid because the cable is placed in the middle of the section, from the pole about 20m, to the two opposite direction erection, first set up the first half, in the second half of the cable from the disc down, press the "8" font mode on the ground, and then cloth put.

(4). When the cable is placed, the cable is strictly prohibited to play small circle and fold, twisted, and to be equipped with a certain number of walkie-talkie, "front heel, optical cable on the shoulder" of the cable method, can effectively prevent the occurrence of back buckle, but also pay attention to uniform, traction does not exceed the 80% of optical cable allowed, instantaneous maximum traction not more than 100%. In addition, the erection, in the optical cable corner or more complex terrain should be responsible for personnel, is strictly prohibited rolling. The aerial cloth puts on the cable use the pulley car, in the frame pole and the puppet hangs the pulley (generally each 10~20m hangs a pulley), in the optical cable leads the pulley, leads the downward wheel place to reduce the sag, reduces the tension. Then in the pulley between the traction rope, traction rope tied to the cable's traction head, with a certain traction to allow the cable to climb up the pole, hanging on the puppet. The spacing between cable hooks is 40cm, hook on the puppet of the buckle direction to be consistent, each of the poles must have a convex drip ditch, each cable in the joints should be left with the bar length plus 3m allowance, in order to continue the box floor welding operation, and every hundreds of meters must have a certain disk stay.

4. Cable continuation

Common optical cables are laminated, skeleton type and central beam tube type optical cable, the color of the core is divided into the order of this, orange, green, brown, gray, white, black, red, yellow, purple, pink, green, which is called the full-color spectrum of the core color, some cable manufacturers use "blue" to replace a color in the color spectrum. Multi-core optical cables put different colors of fiber in the same bundle tube into a group, such a multi-core cable may have several bundles of tubes. is the cross section of optical fiber cable, the red beam tube as the first bundle of optical cable tube, clockwise in turn is Bai Yi, Bai, white three ... The last one is the green beam tube. Optical fiber connection, the principle should be followed: when the core number is equal, the same beam tube of the corresponding color optical fiber docking, the core number is not at the same time, in order to connect the core number of large, and then the core number of small.