SECONDARY INSULATION - A high resistance dielectric material which is placed over primary insulation to protect it from abrasion.
SECTOR STRAND - A group of wires laid in triangular shape with rounded corners, for use as one conductor of a three conductor cable with 120° angle between faces, and with 90° angle for a four conductor cable.
SEGMENTAL CONDUCTOR - In single conductor cables one million (1,000,000) CM or more, the conductors are divided into three or four segments, insulated from each other by paper tapes, to reduce current resistance in AC circuits.
SELENIUM CURE - Process used in curing Neoprene® and rubber jacketed wires and cables. The process makes a dense, tough, durable jacket. Neoprene® is a trademark of the DuPont de Nemours Co.
SELF-EXTINGUISHING - The characteristic of a material whose flame is extinguished after the igniting flame is removed.
SELF-SUPPORTING AERIAL CABLE - A cable consisting of one or more insulated conductors assembled or cabled with a steel core or attached to a separate steel cable, which supports the weight of the cable. It may be from pole to pole or in a vertical position on a tower.
SELF-SUPPORTING CABLE - A cable with a steel support strand capable of supporting the cable weight across spans.
SEMI-CONDUCTING JACKET - A jacket having a sufficiently low resistance so that its outer surface can be kept at substantially ground potential by a grounded conductor in contact with it at frequent intervals.
SEMI-CONDUCTOR - Any of a class of solids whose electrical conductivity is between that of a conductor and that of an insulator in being nearly as great as that of a metal at high temperatures and nearly absent at Low temperatures.
SEMI-RIGID - Rigid to some degree or in some part.
SEMI-TIGHT BUFFER - Type of optical fiber cable construction where each fiber is loosely surrounded by a protective coating to a diameter of 900 microns.
SEPARATOR - Layer of insulating material between: (a) Conductors and insulation; and (b) Between cable components and jacket.
