Signal Cable

Signal cable

Signal cable is a signal transmission tool. Generally, the signal transmitted by the signal cable is very small. In order to avoid signal interference, there is a shielding layer outside the signal cable. The shielding layer of the wrapped conductor is generally conductive cloth, braided copper mesh or copper (aluminum). The shielding layer needs to be grounded. External interference signals can be introduced into the earth by this layer to prevent interference signals from entering the inner conductor and reduce the loss of transmission signals.

Signal cable laying shall meet the following requirements:

a) The buried depth of cables in the station is generally not less than 700mm, and the interval is not less than 1200mm; When crossing the line, the distance between the pipe top of protective steel pipe or concrete pipe and the subgrade surface shall not be less than 0.4m.

b) The cable route shall be in the area with flat terrain and good soil.

c) The cable route shall avoid the areas where acid, alkali, salt accumulation, calcareous, sewage, soft soil and heavy pressure may cause a large number of collapse, as well as the turnout tip, turnout center, rail joint, tower foundation of overhead contact system, etc.

d) The cable route shall be kept straight as far as possible. In case of bending, the allowable bending radius of the cable: the non armored cable shall not be less than 10 times of the outer diameter of the cable; The armored cable shall not be less than 15 times of the outer diameter of the cable; The inner shielded cable shall not be less than 20 times of the outer diameter of the cable.

e) When the through ground wire is in the same trench with the signal cable, it shall be buried in the soil below the cable (trough) and shall not be less than 300mm from the bottom of the cable (trough). Signal cable and power cable shall not be laid in the same trench and shall be laid separately; Physical isolation measures shall be taken when crossing is necessary.