Figure 2-41.-Cable tags.

All IC terminals are identified by insulated

These cable designations include (1) the service letter,

sleeving that is stamped with the lead number and the

(2) the circuit letter(s), and (3) the cable number. The

cable number the lead belongs to.

SERVICE is denoted by the letter C, which is the

designation for all cables and circuits that comprise

The wire terminals 3EP and 3EPP (fig. 2-42),

the IC system in naval ships. Each circuit is

respectively, are the positive and negative supply

distinguished by a single letter or double letters. These

terminals from cable C-E-52, which emanates from

letters identify the cable as a part of one of the

the IC switchboard and leaves from cable C-E-53.

numerous IC circuits. If two or more circuits of the

same system are contained in a single cable, the

The wire terminals 3EP3, 3EP5, 3EP6, and 3EP8

number preceding the circuit letter or letters is

from cable C-E-52 are the positive terminals of

omitted. The cable number is the number of the cable

push-button stations 3, 5, 6, and 8, respectively. The

functions of these wires are found on the elementary

of the particular circuit.

and isometric drawings of the 3EP (protected E call)

A typical IC cable designation is C-MB144. The

circuit for your ship.

letter C denotes the service (the IC system). The letters

MB denote the circuit, engine-order system, which

Numbers following the circuit letter indicate a

serial number assigned for the station, followed by the

may actually include wires of circuits 1MB, 2MB,

section wire number designating the function of the

3MB, and so on. The number 144 denotes cable

circuit. On systems containing synchros, the numerals

number 144 of circuit MB.

1, 2, and 3 are used for the connections to secondary

Permanently installed ships' cables are tagged as

windings. Where more than one synchro is employed

close as practicable to each point of connection, on

in a single instrument, the numerals 4, 5, and 6 apply

both sides of decks, bulkheads, and other barriers.

to the second synchro, and 7, 8, and 9 to the third

Cables located within a single compartment in such a

synchro. For example, l-MB 14 should be interpreted

manner that they can be readily traced are not tagged.

as follows:

1--starboard circuit

TERMINAL MARKING

MB--engine-order system

In single-letter circuits and dc supply circuits, the

1--station number, such as pilot house

positive terminal is designated by a single letter, M.

4--connection to secondary windings of the No.

Similarly, an arbitrary polarity of single-phase ac

2 synchro receiver in the instrument

circuits is designated by a single letter, M (assumed

instantaneous positive). The other side (representing

the opposite polarity of both dc and ac circuits is

designated by double letters, MM.

Double-letter circuits have supply lead markings

assigned as for single-letter circuits, except that the

second letter of the negative is doubled; for example,

positive MB, negative MBB.

Figure 2-42.--Wire terminal markings.

Figure 2-41.-Cable tags.

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