The minimum ambient temperature for regular computer cable laying is 0 ℃.

The maximum allowable working temperature for cables in the long term:

Minimum bending radius: For unarmored structures, it should not be less than 6 times the outer diameter of the cable, while for armored or copper tape shielded structures, it should not be less than the outer diameter of the cable12 times.

After stable charging for 1 minute at 20 ℃ with a DC 500V voltage test, the insulation resistance should meet the following requirements:

There should be no open circuit between the paired shields and between the paired shields and the total shield

The cores of the cable, as well as between the cores and the shielding or other metal layers, should withstand a 50Hz AC voltage of 2000V/1min or 1500V/5min without breakdown.

Polyethylene has high insulation resistance, good voltage resistance, low dielectric constant, and minimal temperature and frequency effects on dielectric loss. It not only meets the requirements of transmission performance, but also ensures the service life of cables.

In order to reduce mutual crosstalk and external interference between circuits, cables need to adopt shielding structures. Shielding materials include tin plated or non tin plated copper wire, copper tape, copper plastic composite tape, aluminum-plastic composite tape, etc. The metal tape is produced by winding, and the overlap rate should usually not be less than 15%, but specific standards have special provisions, such as TICW/06, which stipulates that the overlap rate of shielding metal tape should not be less than 25%; The metal wire is produced by weaving, and the weaving coverage rate should not be less than 80%. If there are high requirements for anti-interference, the coverage rate can be no less than 90%.

The shielding requirements for cables are adopted according to different occasions: sub shielding (only the twisted pair group has shielding, each twisted pair group has shielding), total shielding (the cable only has one layer of total shielding after the cable core is formed), sub shielding+total shielding (including both structures mentioned above). According to the higher requirements of users and usage scenarios, the overall shielding structure can adopt a composite shielding method, which includes two layers of shielding, consisting of metal tape wrapping and metal wire weaving.

Note: If the cable has a sub shielding structure, the shielding pairs should have good insulation performance, and polyester tape or other non hygroscopic tape should be wrapped around the outside of the sub shielding.

Computer cables belong to electrical equipment cables, and the structure and composition materials of electrical equipment cables are the most complex. According to the special requirements of operating temperature and working environment, there are various types of composition materials for each structure of computer cables, as follows:

Computer cable detailed model, structure, size parameters: