- The purpose of using a wire connector, or wire nut, is to join a device or switch into a circuit with the wiring of the building. But how it works begins with the splicing before it is attached. To splice wires, positive wiring must be matched with positive, and negative with negative. These wires can be identified by their coloring. Next, the wire should be examined to make sure there are enough strands to make a good contact. An electrical wire is a thin, bundled cable of conductive (usually copper) threads, and sometimes the end will be threadbare. Threadbare wiring is trimmed back to a point where the thickness is better, and if necessary more insulation is stripped away from the wire. Then the two wires are twisted together.
- The inside of a wire nut is a conductive screw cap. It is placed over a set of spliced wires and twisted on. The screw-cap fastens the nut to the wires, and the conductive surface increases the contact between the wires. The bare wiring needs to be long enough to be properly screwed in, but short enough that none of it extends out of the wire nut. This provides a more stable solution for joining wires than splicing and covering with electrical tape.
- The exterior of the wire nut is made of non-conductive plastic or ceramic material. This protects the surroundings of the wiring from electrical faults, and anyone who might come later to work in the wiring area.
- Wire nuts are sold in a variety of colors, allowing a person to arrange a scheme of identification. A simple example would be to use only red nuts for positive leads, and only blue nuts of negative leads.
