Fiber closure is normally used for outdoor cables; they provide space for splicing together with outdoor fiber optic cables. The fiber optic connector closure and the internal fiber tray will protect the splice part of the spliced fiber and outdoor cable. Typically, the fiber optic connector closure is dome and horizontal. Dome optical fiber connector closed type cable is generally divided into two types, one is heat shrink type, the other is a mechanical seal type. The type of heat shrinkage means that the heat shrink tubing is achieved by a seal between the cable and the cable. Mechanical seal type, between the cable and cable through the deformation of the sealing ring cable will be discharged from the pipeline, the mechanical way for the compression seal ring, filled in the cable between the cable and the tube.
For fiber closure in the fiber optic cable, can be for the local weather and terrain and other natural conditions. Through the analysis of the closure of the fiber dome in these years, it is found that the following problems should be paid attention to in the construction and maintenance of the optical fiber joint closure.
The fiber closure is usually closed with a reinforced core, and the connection of the metal plate is better than that of the bolt, and the horizontal opening of the bolt is better than the vertical slotted structure, which is the choice of the fiber connector Attention to the problem. Aerial fiber optic splice closure of metal parts, should it can be to every 2 km of grounding, grounding metal parts directly to ground or through proper surge protection grounding, such steel strand has protective effect of overhead ground wire.
For the cable grounding of the telecommunication office, the metal part of the cable in the fiber closure shall be connected, and the core, moisture barrier and armored layer shall be connected and maintained. At the end of the unit (station) armor layer, strengthen the core should be grounded, moisture-proof layer through the arrester grounding. For fiber optic cable without copper wire, according to the provisions of YDJ14-91, in the fiber optic cable moisture-proof layer, armor layer and strengthen the core should be broken, not ground, ground insulation, cable cable to avoid the accumulation of lightning current. Practice has proved that this method is simple and effective, usually, the fiber optic cable in the metal parts of the insulation value is higher, lightning current is not easy to enter the fiber optic cable, in order to avoid joint protection cable damage.