The common specifications of telephone wires are two-core and four-core, and the wire diameters are 0.4 and 0.5 respectively, and 0.8 and 1.0 in some areas. In addition to two cores and four cores, there are four, six, eight, and ten cores. If the general family uses the mode of local calls, 2 cores are enough. If it is used by a company or some group phones, considering the needs of telephone broadband use, it is recommended to use a 4-core telephone line. If you are using a digital phone, it is recommended to use a 6-core telephone line.
HSYV 2x2x0.5 BC
Remarks: CCS is copper clad steel, BC is all copper.
HYV2x1/0.4 CCS, where HYV is the English model of the telephone line, 2 means 2 cores, and 1/0.4 CCS means a single copper-clad steel conductor with a diameter of 0.4mm.
By analogy, HYV4x1/0.4 BC, where HYV model, 4 represents 4 cores, and 1/0.5 BC represents a single pure copper conductor with a diameter of 0.5 mm.
In particular, HSYV 2x2x0.5, "S" stands for twisted pair, 2x2 stands for 2 pairs (4 cores) twisted pair, 0.5 stands for a single conductor with a diameter of 0.5 mm.
Compared with ordinary parallel telephone lines, twisted-pair telephone lines are mainly used for the improvement of transmission speed and lower loss in terms of power.