CHAPTER 6
ELECTRICAL AND ELECTRONICS PRINTS
When you have read and understood this chapter,
you should be able to answer the following learning
objectives.
Describe shipboard electrical and electronics
prints.
Describe aircraft electrical and electronics
prints.
Explain basic logic diagrams on blueprints.
This chapter is divided into two parts: electrical
prints and electronics prints. Each part deals with the
use of prints on ships and aircraft.
ELECTRICAL PRINTS
A large number of Navy ratings may use Navy
electrical prints to install, maintain, and repair equip-
ment. In the most common examples, Navy
electrician’s mates (EMs) and interior communica-
tions electricians (ICs) use them for shipboard
electrical equipment and systems, construction
electricians (CEs) use them for power, lighting, and
communications equipment and systems ashore, and
aviation electrician’s mates (AEs) use them for
aircraft electrical equipment and systems. These prints
will make use of the various electrical diagrams
defined in the following paragraphs.
A PICTORIAL WIRING DIAGRAM is made up
of pictorial sketches of the various parts of an item of
equipment and the electrical connections between the
parts.
An ISOMETRIC WIRING DIAGRAM shows the
outline of a ship or aircraft or other structure, and the
location of equipment such as panels, connection
boxes, and cable runs.
A SINGLE-LINE DIAGRAM uses lines and
graphic symbols to simplify complex circuits or
systems.
A SCHEMATIC DIAGRAM uses graphic
symbols to show how a circuit functions electrically.
An ELEMENTARY WIRING DIAGRAM shows
how each individual conductor is connected within the
various connection boxes of an electrical circuit or
system. It is sometimes used interchangeably with
SCHEMATIC DIAGRAM, especially a simplified
schematic diagram.
In a BLOCK DIAGRAM, the major components
of equipment or a system are represented by squares,
rectangles, or other geometric figures, and the normal
order of progression of a signal or current flow is
represented by lines.
Before you can read any blueprint, you must be
familiar with the standard symbols for the type of print
concerned. To read electrical blueprints, you should
know various types of standard symbols and the
methods of marking electrical connectors, cables, and
equipments. The first part of this chapter discusses
these subjects as they are used on ships and aircraft.
SHIPBOARD ELECTRICAL PRINTS
To interpret shipboard electrical prints, you need
to recognize the graphic symbols for electrical
diagrams and the electrical wiring equipment symbols
for ships as shown in Graphic Symbols for Electrical
and Electronic Diagrams, ANSI Y32.2, and Electrical
Wiring Equipment Symbols for Ships’ Plans, Part 2,
MIL-STD-15-2. Appendix 2 contains the common
symbols from these standards. In addition, you must
also be familiar with the shipboard system of
numbering electrical units and marking electrical
cables as described in the following paragraphs.
Numbering Electrical Units
All similar units in the ship comprise a group, and
each group is assigned a separate series of consecutive
numbers beginning with 1. Numbering begins with
units in the lowest, foremost starboard compartment
and continues with the next compartment to port if it
contains familiar units; otherwise it continues to the
next aft compartment on the same level.
Proceeding from starboard to port and from
forward to aft, the numbering procedure continues
until all similar units on the same level have been
numbered. It then continues on the next upper level
and so on until all similar units on all levels have been
numbered. Within each compartment, the numbering
6-1
