Utility-type cable
Cables used for utility systems are of somewhat specialized construction.
Some of these are as follows:
Compact strand (compact round): This type of construction allows for
smaller diameter and less weight than solid conductor.
Annular: This construction uses a hollow space or rope core in the
center of the cable.
Segmental: Consists of four segments stranded together and operated
in parallel.
Concentric cable: Consists of an inner and outer conductor with equivalent
cross sections, which are separated by insulation.
Sector: A multiconductor cable in which the conductor is shaped like
a sector in a circle.
6.2.2 Conductor Arrangement
Conductors may be arranged in various ways to form a cable. The common
arrangements used in power system applications are the following:
Single-conductor cable: A single conductor of either shielded or
nonshielded construction.
Three-conductor cable: Three single conductors bound together with a
nonmetallic tape. Three-conductor cables may also be bound together
by interlocking galvanized steel, aluminum, or bronze tape. This
type of cable is known as interlocked armor cable. Three-conductor
cables may come with ground wires, which are used for system
ground or equipment ground. Ground wires are usually located in
the interstices of the three-conductor cable. Three-conductor cable
can be either shielded or nonshielded.