Pairkabler

Pairkabler, commonly known as twisted pair cables, are cables containing insulated conductors arranged in pairs, with each pair twisted to reduce electromagnetic interference and enable balanced signaling. They are widely used for voice and data communications, most notably in telephone networks and local area networks (LANs).

Most widely used are unshielded twisted pair (UTP) and shielded twisted pair (STP/FTP). A typical cable contains four twisted pairs, enabling multiple simultaneous signals. Conductors are color-coded in pairs, for example blue/white-blue, orange/white-orange, green/white-green, and brown/white-brown. The common impedance for balanced Ethernet applications is around 100 ohms. In STP, a metallic shield surrounds one or more pairs or the entire cable to further reduce interference; cables may use a PVC jacket or a low-smoke, zero-halogen jacket.

Performance is defined by category standards. Cat5e supports up to about 1 Gbps and frequencies up to 100 MHz; Cat6 and Cat6a support higher frequencies (250–500 MHz) and multi-gigabit speeds, up to 10 Gbps over shorter distances. Standards include TIA/EIA-568 and ISO/IEC 11801; color-coding and pinouts for connectors such as RJ-45 are specified. Shielding, twist rate, and installation practices affect crosstalk and attenuation.

Applications include Ethernet networks (LANs), telephone lines, and other data communications. A typical maximum length for Ethernet over twisted pair is 100 meters per link. Proper installation practices, including bend radius, separation from power cables, and correct termination with appropriate connectors, are important for maintaining performance.