The designation for lamp cord, two or more conductors twisted together. Rubber insulation, cotton braid. For pendant or portable use in dry places. No overall covering, 300V or 600V, 60°C.

Designation for center-to-center.

Same as designation for SJ except extra-flexible conductor.

Same as designation for SJO except extra-flexible conductor.

See Cellulose Acetate.

French for alternating current.

Designation for cellulose acetobutyrate.

A term loosely applied to wire ropes, wire strands, manila ropes and electric conductors. An electric cable is a length of single insulated conductor (solid or stranded) or two or more such conduc­tors each provided with its own insulation, which are laid up together. The insulated conductor or conductors may or may not be provided with an overall mechanical protective covering.

Equipment used for locating faults in cable during manufacture and after installation. For manufacturing, “sparkers” continuously monitor the integrity of the insulation (as it is being applied to the wire) by a voltage between the wire and the sparker electrode. For installed cable or wire, special equipment (from tone generators to pulse generators to capacitance measurers) may be needed to locate a problem within a few feet in a circuit that may be miles in length. See Spark Testing.

The radius that a cable can be bent before risking conductor and/or insulation damage.

A device used to give mechanical support to the wire bundle or cable at the rear of a plug or receptacle.

A mechanical adapter that attaches to the rear of a plug or receptacle to allow the attachment of a cable clamp.

Harnessing system for mounting wire and cables. Some clips are adjustable for tension control.

Determining the size of a conductor is usually based on the electrical circuit that the cable interconnects. If the circuit has been designed to require a 22 AWG wire, it cannot be reduced to 28 AWG just to reduce the capacitance. Also, the insulation wall thickness cannot be increased beyond reason since this increases the diameter of the cable, increasing costs and affecting terminations. Thus, the insulation chosen for the cable often becomes the critical variable.

The portion of an insulated cable lying under the protective covering(s).

A wrapping of tapes or cords around several conductors of a multiple-conductor cable used to hold them together. Note: this is usually supplemented by an outer covering of braid, jacket or sheath.

“U” channel sections of fiberglass cloth reinforced with epoxy used to protect wire and cable.

A technique to dynamically measure the diameter of a coated wire or cable as it is being produced on line. There are a number of technologies available to accomplish this task, but they can be classified as either non-contact or contact. This measuring instrument, usually found on an extruder, enables the operator or the automatic machine controls to adjust either the line speed or the extruder output screw speed to apply the proper amount of insulation over the bare conductor. Various types are available and are grouped into two categories: contact and non-contact.

Past contact methods once used feeler gauges that would contact the cable product to measure the size, with those readings used to manually control the extruder settings. Newer methods include the use of two synthetic sapphires at a low contact pressure, with the readings used to automatically make adjustments to the cable size by adjusting the cable or extruder speed.

Since the 1980s, non-contact diameter gauges have become increasingly important, with a form of light (typically lasers) the key. This technology can be used to automatically control cable size. There are different types of systems that use lasers. A laser-scanning system typically uses a laser beam directed at an inspection area that strikes a rotating multi-sided mirror that creates from 80 to 200 scans per second. Those scans are received by a photoelectric cell based on the relative time intervals of light and shadow as the light beam is interrupted periodically by the cable. It has a frequency of approximately 6 Hz. A laser-diffraction analysis system, a more sophisticated optical technology, can measure cable 500 times per second, with the results analyzed by laser diffraction analysis. Another non-contact system uses the same CCD technology used in video cameras. The “camera” monitors the cable as it passes by. The control system measures the number of pixels that are occupied by the cable image and translates it into a dimension. All three systems can employ closed-loop control of the extrusion process.