Lesson 2/Learning Event 1
LINE TERMINATIONS AND DISTRIBUTION FRAMES
Describe the purpose, function and types of distribution
frames, telephone cables, and terminal blocks, describe the
Given information about the distribution frames, telephone
cables, cable color coding, terminal blocks, and cable
Demonstrate competency of the task skills and knowledge by
responding to the multiple-choice practice exercise; select
the ONE answer that BEST completes the statement or answers
the question covering line terminations and distribution
frames with 70 percent accuracy. (This objective supports
task 113-616-1007, Activate a Circuit.)
FM 11-486-12, DCAC 310-70-1, Volume III, FM 11-487-3.
Learning Event 1: DISTRIBUTING FRAMES
Distributing frames are open metal frameworks which provide neat and
accessible terminating facilities for outside cable pairs and in-house
wiring to patching bays and equipment items.
Protector groups mounted on
the framework give lightning and surge protection to station equipment. On
all types of distributing frames, cross-connections between terminal blocks
are made by means of relatively short lengths of paired wires, called
Distributing frames enable the greater part of the wiring in a
technical control center to remain permanent. If, for example, a cable pair
connection must be changed from one patch bay to another, it is only
necessary to move a jumper.
Distributing frames used in typical control
centers include main distributing frames (MDF), intermediate distributing
frames (IDF), and combined distributing frames (CDF).
An example of a
typical CDF is shown in figures 2-1 and 2-2.