What is twisted pair, where and how is it used?

For the organization of most data transmission networks, computer or telephone, cables are used. Such networks are called wired. In recent years, they are often laid using a special type of cable, called "twisted pair." The name reflects the type of location of the conductors relative to each other. Twisted pair are two isolated conductors twisted together with a certain twist pitch. Typically, these two wires have another layer of insulation.

There are cables that have two, four, eight pairs of conductors under one shell. And still such a cable is called "twisted pair", although there are several pairs there. Depending on the type of protection, there are unshielded and shielded cables. Screening reduces the effects of external and internal interference, improves connection reliability, reduces errors. To ensure the integrity of excessive bending and tearing the screen along the entire length of the cable is connected by a special non-insulated drain wire. Shielded twisted pair provides a higher transmission speed, partially eliminates the influence and interference from other objects.

Screens can have the form of a grid, braids, a continuous foil coating. There are cables with double protection, with a foil wrapped around the mesh braid. According to international practice, this type of conductor has the following designation: unshielded twisted pair - UTP, shielded - STP. If the cable has a common protective screen, but the individual pairs are not shielded, then such a wire is also classified as unshielded. The terminal equipment uses different types of cables. Which of them you need, see the passport or description.

Depending on the structure of the conductors used, the twisted pair can be either solid or stranded. Single-core cable consists of one wire of large diameter, multi-core cable is a bundle of thin wires. Their area of application is different. Single-core ones have a high stiffness, they do not bend well, they can break at repeated bends. Their Are used for laying in walls, pipes and boxes and then putting them into a socket. Stranded twisted pair has good flexibility, but it does not tolerate the connection to the sockets. This type of cable is used to connect the end devices with sockets.

The outer sheath of the conductors serves to protect them from moisture and mechanical damage. It has a different thickness and is made of different materials. According to European standards, only those cables that do not emit smoke and do not burn are suitable for external installation.

To facilitate the work use different colors for conductors for different purposes. For example, the black color of the outer shell is at the cable for the outer gasket, orange means that the shell material does not burn, and the inner conductors have a color, usually gray. Cables consisting of twisted pairs can have different shapes: round or flat (for laying under the floor covering).