Insulation-displacement connector

An insulation-displacement contact (IDC), also known as insulation-piercing contact (IPC), is an electrical connector designed to be connected to the conductor(s) of an insulated cable by a connection process which forces a selectively sharpened blade or blades through the insulation, bypassing the need to strip the conductors of insulation before connecting. When properly made, the connector blade cold-welds to the conductor, making a theoretically reliable gas-tight connection.

Modern IDC technology developed after and was influenced by research on wire-wrap and crimp connector technology originally pioneered by Western Electric, Bell Telephone Labs, and others. Although originally designed to connect only solid (single-stranded) conductors, IDC technology was eventually extended to multiple-stranded wire as well.

Initially, IDCs were seen only in extra-low voltage applications, such as telecommunications, networking and signal connections between parts of an electronic or computer system. However, they are now also used in some domestic and industrial low voltage (power) applications, as can be seen in the illustration. The benefits claimed for their use in these applications include up to 50 percent faster installation, due to the reduction in the stripping, twisting and screwing down processes.

Ribbon cable is designed to be used with multi-contact IDC connectors in such a way that many IDC connections can be made at once, saving time in applications where many connections are needed. These connectors are not designed to be reusable, but can often be re-used if care is taken when removing the cable.

Pin 1 is typically indicated on the body of the connector by a red or raised "V" mark. The corresponding wire in a ribbon cable is usually indicated by red coloration, a raised molded ridge, or markings printed onto the cable insulation. On the connector pin 2 is opposite pin 1, pin 3 is next to pin 1 along the length of the connector, and so on. On the cable, the wire connected to pin 2 is next to the wire connected to pin 1 (the red coded wire), and so on.

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