Catherine Wang's Posts (43)

Sort by

Optical cable handover box is a kind of handover equipment which provides end-to-end and jump-over for main layer and distribution layer optical cables. After the cable is introduced into the cable junction box, the main layer cable and the distribution layer cable are connected by jumping fibers after being fixed, terminated and distributed.

The thing placed inside is the end of the optical cable, and the function of the end of the optical cable is to gather two or more signals of the original unrelated computer room together, and then use tail fiber to connect two unrelated cables according to need. Its signal source is the computer room.

Optical intersection boxes collect all optical signals. Optical signals can not be used directly. Photoelectric conversion equipment is needed to convert optical signals into electrical signals. Therefore, if you want to use the signals in optical intersection boxes directly, it is very expensive.

Similar to the optical cabinet, there are also electrical cabinets. The appearance of the electrical cabinet is not different from that of the optical cabinet. However, the signals collected in the electrical cabinet are electrical signals, which can be directly used without conversion. The signal source of the electrical cabinet is also the computer room.

f:id:unitekfiber:20190824121330j:plain



Fiber optic cable junction box is a kind of outdoor connection equipment. The most fundamental requirement for it is to be able to withstand dramatic changes in climate and harsh working environment. It should have the characteristics of waterproof gas condensation, waterproof and dust-proof, pest and rodent prevention, and strong impact damage resistance. It must be able to withstand the harsher external environment. Therefore, waterproof, moisture-proof, dust-proof, impact-proof, pest and rodent-proof requirements are relatively high on the outside of the box; temperature and humidity control requirements are very high on the inside of the box. According to international standards, the highest standard for these projects is IP66. But there are not many cases that can meet this standard.

At present, the main cabinets used in China are KRONE cabinet in Germany, which is made of unsaturated polyester glass fiber reinforced material (SMC) and has good performance in waterproof, moisture-proof and impact-proof. The imitation of domestic reference KRONE boxes is mainly iron metal boxes (generally up to IP65 standard). For metal box, because of its poor performance in waterproof gas condensation, it is doomed not to be widely used and gradually eliminated. Some domestic imitations are quite different from KRONE imported from Germany in terms of waterproof gas condensation and shock resistance due to material performance problems. In addition, due to the poor anti-aging performance of sealant strip, the performance of waterproof and dust-proof is also common. Of course, it is acceptable to reduce performance requirements and investment when the external environment of the installation location of the cable junction box is better.

Shenzhen Yutai Photoelectric Communication Co., Ltd. is a professional fiber optic cable supplier, providing high-quality optical cables. Welcome to buy.

Read more…

Fiber optic cable line failure is called cable line failure because of external factors or fiber itself. Fiber optic cable interruption does not necessarily lead to business interfix, which causes business interfix to be handled in the order of fault repair, without affecting the order of service interfix that does not constitute a fault.

Classification of Faults in Optical Cable Lines

Fully Broken Optical Cable
(1) Assuming there are reservations on both sides of the site, centralized reservations are adopted and a joint is added.
(2) There are joints near the fault point and there are enough reservations on the spot. Adopting pull reservations, use the original joints to dispose of them;partial optical fiber interfix
(3) On the premise of not affecting other optical fibers, open skylight connection method is recommended to stop the repair of faulty optical fibers.
Cause Analysis of Cable Line Faults


Circuit Faults Caused by External Force Elements

(1) External excavation: to deal with the breakdown of excavator construction, pipeline optical cable is tested due to the opening of the fault point near the hand well and reflected on whether the cable can be damaged in the hand well, and bidirectional testing of the suffixed optical cable is carried out.
(2) Vehicle hang-up: When dealing with vehicle hang-up faults, we should first test the two directions of fiber optic cable stop at the fault point, confirming the number of fiber optic cable block points, and then dispose them pertinently.
(3) Shooting: This kind of fault will not make all optical fibers suffix, but part of the cable or optical fibers are damaged, and this kind of fault is difficult to find.


Line Faults Caused by Fiber Optics

(1) Natural fibre breakage: As the fibers are drawn from glass and plastic fibers, they are relatively fragile. Static fatigue will occur over time, and the aging of the fibers will lead to natural fibre breakage.
(2) The influence of ambient temperature: too low temperature will cause water freezing in the junction box, longitudinal shrinkage of the cable sheath, putting the the pressure on the optical fiber to increase attenuation or optical fiber suffix.


Circuit Faults Caused by Artificial Elements

(1) Obstacles: Artificial failures caused by technicians in maintenance, installation and other activities.
(2) Stealing: criminals cut optical cables to block them.
(3) Damage: man-made and deliberate destruction, constituting the blocking of optical cables.

f:id:unitekfiber:20190824121043j:plain



Fault Disposal of Optical Cable Line

(1) All-resistance fault with optical cable replaceable in the same route. The attendants in the computer room should block the business on the optical fibers with other good core substitutes in accordance with the emergency plan at the first time, and then repair the faulty optical fibers as soon as possible.
(2) If there is no all-resistance fault that can be replaced by optical fibers, the emergency plan should be followed to implement the direct repair and termination of replacing or blocking points. When replacing or repairing, the criterion of "first important is the critical circuit, second important is the secondary circuit" should be followed.
(3) Non-total resistance occurs in the optical cable and residual optical fibers are available. The service on the faulty core is replaced by the spare core or other optical cables.
(4) There are no residual fibers or co-routing fibers. Assuming that the blocked fibers are equipped with important circuits, other non-important circuits are used to replace the blocked fibers with fibers, and the faulty cores are repaired urgently by infix splicing.
(5) The transmission quality is stable and the system is sometimes good or bad. Assuming that there is an alternative free core or other co-routing optical cable, the service on the optical fiber can be transferred to other optical fibers.

Shenzhen Yutai Photoelectric Communication Co., Ltd. is a professional fiber optic cable supplier, providing high-quality optical cables. Welcome to buy. 

Read more…

According to the physical and electrical properties of optical cables, the laying of optical cables must meet certain requirements. In addition, the laying of optical cables in different environments also have their own requirements.


The laying of optical cables shall strictly comply with the following requirements:

(1) Length and integrity: The length of each cable should be controlled within 800m, and there is no relay in the middle.

(2) Minimum installation bending radius of optical cable: under static load, the minimum bending radius of optical cable is 10 times than the diameter of optical cable; under load conditions during wiring operation, such as pulling the optical cable out of the pipe, the minimum bending radius is 20 times than the diameter of optical cable; the minimum installation bending radius of four-core optical cable must be greater than 2in (5.08 cm). 

(3) Installation stress: The maximum installation stress applied to 4/6 core cable shall not exceed 100lbf (45kgf); when multiple 4/6 core cables are installed at the same time, the maximum installation stress per cable shall be reduced by 20%. For example, for 4x4 core cable, the maximum installation stress shall be 320lbf (144kgf).

f:id:unitekfiber:20190824121438j:plain



Explanation: It is required that the traction force of the cable should not exceed 80% of the allowable tension of the cable, and the maximum instantaneous traction force should not exceed the allowable tension of the cable. The main traction force should be applied to the strengthened components of the cable, and the fiber can not bear the tension directly.

(4) Installation pulling force of optical fiber jumper: the maximum pulling force of single-core soft wire is 27 LBF (12.15 kgf), and the maximum pulling force of double-core soft wire is 550 LBF (22.5 kgf), and the distance of interconnection equipment should not exceed 100 ft (30 m).

(5) Judging the A.B end of optical cable: Before construction, we must first judge and determine the A.B end of optical cable. A-terminal should be oriented towards network hub
direction, while the B-terminal should be oriented to the user's side. The end of the laying cable should be in the same direction, and it must not be mistaken.

(6) No matter laying optical cables in buildings or between buildings, separate pipe holes should be occupied. If the original pipe and copper cable are used together, the plastic sub-pipe should be put through the hole. The inner diameter of the plastic sub-pipe should be 1.5 times than the outer diameter of the optical cable. The optical cable should be laid in the plastic sub-pipe, and the same sub-pipe should not be used with the copper cable. When laying optical cables are in parallel with other weak current systems in buildings, they should be laid separately and fixed, and the minimum net distance between the cables should meet the design requirements.

Shenzhen Yutai Photoelectric Communication Co., Ltd. is a professional fiber optic cable supplier, providing high-quality optical cables. Welcome to buy.

Read more…