How to ensure cable performance

How to ensure the cable performance

many users and installers are faced with the problem of how to carry out low-cost and efficient data transmission between buildings in the park environment

the selection of route, transmission distance and application environment will affect the selection of cable medium. Incorrect or inappropriate selection will shorten the limited period of wiring investment, and reinstallation will also stop the operation of the network system

for outdoor applications, optical fiber system is usually the choice for park connection. The real cost of optical fiber lies in the termination of optical fiber cabling system and optoelectronic equipment. When users only need to transmit 10Mbps or 100Mbps within a distance of 50 meters between buildings, optical fiber is generally not used

embedding the conventional category 5 copper cable underground or laying overhead may lead to the transmission failure of a network along the wiring line, so choosing the existing outdoor direct 2013 buried enhanced category 5 cable will bring cheap links. The design of these outdoor local area cables should be fully understood before deciding to choose them

moisture protection has been used in communication cables for many years. These aluminum polymer materials have overlapping seals as protection, reducing the penetration path of water vapor to prevent the entry of water. However, an unprotected dry cable will need to suffer liquefaction due to infiltration for up to half a year to a year, and a dry cable with moisture protection will be completely protected. The cable designed in this way is similar to the foil shielded local cable, and the termination is universal and simple

therefore, the designer of the wiring system must consider the application environment, including the following environment and parameters affecting the cable

whether the cable is placed under the eaves:

. As long as the unsmoothed oil enters the bearing and is directly exposed to sunlight or ultra-high temperature, the standard local universal tensile testing machine flat sample jaw 0 ⑵ 0mm1 pair of cables can be used, and it is recommended to use pipes; On the outer wall. Moreover, the experimental results can be recorded and analyzed to avoid direct sunlight on the wall and man-made damage

in the pipe (plastic or metal). For example, in the pipe, pay attention to the damage of plastic pipe and the heat conduction of metal pipe

suspended applications/overhead cables. Consider cable sag and pressure. What kind of bundling method are you going to use? Whether the cable is directly exposed to sunlight

it is laid directly in the underground cable trench, which has the smallest control range. The installation of cable trench shall be regularly checked for dryness or humidity

underground pipeline. In order to facilitate future upgrading, cable replacement and isolation from surface pressure and surrounding environment, laying pipelines is a better method. But don't expect the pipeline to remain dry forever, which will affect the choice of cable types

factors affecting cable performance include:

ultraviolet (UV) - do not apply cables without UV protection to direct sunlight, but choose black polyethylene or PVC sheathed cables, such as brand Rex's 4 pairs of enhanced category 5 megaoutdoor outdoor outdoor cables, which have metal moisture-proof protective layers and black polyethylene sheaths, and are suitable for most building connections, whether they are overhead laying Both ground installation and pipeline construction can be adopted

heat - the temperature of the cable in the metal pipe or trunking is very high, and many polymer materials will reduce their service life at this temperature, so black polyethylene or PVC sheath should be selected

water - water is the real killer of local cables. Moisture in the local twisted pair cable will increase the capacitance of the cable, thus reducing the impedance and causing near end crosstalk. In order to effectively prevent moisture and water vapor, a metal shielding protective layer is required

mechanical damage (repair cost) - the repair of optical cables is very expensive, and at least two terminations are required at each breakpoint

grounding - if the shielding layer of the cable needs to be grounded, the corresponding standards must be observed

total route length (not only between buildings) - Outdoor local twisted pair cables are used between buildings, and the total length should be limited to 90 meters. For 100mps or 1000Mbps networks, the laying distance cannot exceed this limit. If the laying distance is between 100 meters and 300 meters, optical cables should be selected

the following simple experiments can be used to test whether the wiring investment is safe: use 20m enhanced category 5 UTP cables to terminate at both ends respectively; Carefully pull off the cable sheath at the midpoint of the cable to expose a small section of copper cable (1 cm); Test the cable according to an/nzs class D standard; Immerse the cut part of the cable in water for minutes, and then retest. The results are shown in the following table:

parameters dry cable wet cable difference

impedance (Ohm) 109 75 -34

length (m) 2027 +7

delay (NS) 97133 +36

attenuation 5.1 7 +2.6

near end crosstalk (redundancy) 1510 -5 (end)