The absolute best book on the market is Thomas L. Harman's Guide to the
National Electrical Code, 2005 NEC and previous editions available at
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I have been using and teaching from previous editions of this book for
over 25 years. It is the best on the market!
Here is a description:
Book Description
This edition covers the 2005 National Electrical Code. The text and
questions and answers have been completely revised where appropriate to
reflect the 2005 Code rule changes. New comprehensive examinations have
been added to the chapters and a new final examination has been added.
However, the successful style and format of the previous editions have
been retained. This book is in response to an increasing demand in the
industrial and academic communities for a detailed guide to the
National Electrical Code and the principles of electrical design based
on the Code. In particular, the information presented should serve the
aspiring Master Electrician as well as the practicing Master
Electrician, and the electrical technology student. Each area of
interest to the modern day electrician is discussed in detail with an
ample number of example problems and their solutions. This Guide
differs from other publications that treat the National Electrical Code
in that the emphasis here is on the types of questions and problems
that typically appear on Master Electrician's Examinations given
throughout the country. Since these examinations reflect the knowledge
expected of a Master Electrician in practice, their content has guided
the authors in selecting material for this Guide. The Master
Electrician should be competent in three major areas, the first two of
which are based on the National Electrical Code. The first two areas
are (a) the design of electrical wiring systems, and (b) the
construction and installation of electrical systems. The Guide covers
these subjects in Part I and Part II, respectively. The third major
area, presented in Part III of the Guide, is basic electrical theory
and practice. This material is, for the most part, outside the scope of
the Code although the Master Electrician is expected to be familiar
with the principles presented in Part III. This guide can serve as a
self-study text or it can form the basis for a one- or two-semester
course covering the rules of the National Electrical Code and related
material. The Guide presents all rules and problem-solving techniques
necessary to pass a Master Electrician's examination. The problems also
treat practical situations arising in the design and construction of
electrical installations. The only other reference text required is the
National Electrical Code itself. Part I of the Guide presents the rules
and wiring design calculations required to determine the ratings of
electrical services, feeders, and branch circuits for typical
electrical installations. Beginning with a general discussion of these
circuits, the chapters in Part I of the Guide present increasingly
complex situations. The final two chapters in Part I, Chapters 4 and 5,
present detailed calculations for the design of electrical systems in
dwellings and in industrial or commercial occupancies, respectively. A
quiz is given after each unit to summarize the knowledge in that unit
and provide practice for the reader. A lengthy examination after each
chapter covers the material presented in the chapter. Wherever a rule
from the National Electrical Code affects a calculation, reference is
made to the particular rule in the margin of the text. Part II of this
Guide covers the major sections of the National Electrical Code and
provides summaries of important rules, which govern the construction,
and installation of electrical equipment. A large number of tables,
problems, and quizzes organize the material logically to aid the
reader's understanding. Part III of the Guide begins with a treatment
of basic direct-current circuits. Subsequent sections present a review
of the properties of conductors, basic alternating-current circuits,
and equipment in ac circuits. The discussion and examples cover
material useful for the solution of design problems presented in other
parts of the Guide. The final portion of the Guide, Part IV, contains
examinations covering the material presented in the first three parts.
The final examinations included there are representative of
examinations for the Master Electrician's license given by various city
and state examination boards. The Appendices contain information of
general interest, such as a detailed list of useful electrical
formulas. Most important, the Appendixes contain the solutions to all
quizzes, tests, and final examinations given in the Guide. The
solutions to problems have been worked out in complete detail showing
the method used and the appropriate references to the National
Electrical Code. Notes to the Student Preparation for a Master
Electrician's License is a long and difficult procedure involving
practical experience and a thorough knowledge of the material presented
in this Guide. A fundamental knowledge of elementary algebra and simple
direct-current and alternating-current circuit theory is most helpful
in fully understanding the approaches to problem solving taken in the
Guide. If this material is not familiar to you, a self-study program or
a course at a local community college covering these basic subjects
would be helpful. For students with the proper background knowledge,
the Guide can be studied with the National Electrical Code to prepare
for required city or state electrician's examinations. Each principle
should be mastered before going on, although your study program may
begin with Part I, Part II, or Part III of the Guide, depending on your
previous knowledge or preference. When you feel prepared, take the
final examinations presented in Part IV of the Guide according to the
directions and time limits specified for each test. The examinations
may be scored by referring to the solutions given in the Appendices.
Although a score of 70 percent is passing, a score of 80 percent or
more on each examination indicates that you are well prepared for the
real thing. Notes to the Instructor This Guide is unique because it
presents the more difficult subject of electrical wiring design
calculations in Part I and the general Code rules and basic electrical
theory in Part II and Part III, respectively. This was done because
many students who take courses covering the National Electrical Code
are familiar with the general organization of the Code and its rules.
It is necessary for those students to concentrate on problem solving
rather than Code rules and basic theory that can be briefly presented
and understood by the student. In addition, typical Master
Electrician's examinations separate the questions concerned with wiring
design from those dealing with installation and general electrical
practice. To avoid confusing students, the instructor may divide this
course similarly and begin with the most important subject, that of
electrical design. The other Code rules and the basic theory support
this activity. If the students are not well prepared, the instructor
might decide to begin with Part III, basic electrical theory, proceed
to Part II, and finally present the design calculations of Part I.
These three parts are not dependent upon each other; each contains
quizzes and tests based on only the material presented in that part.
The examinations in Part IV, of course, cover the entire range of
topics presented in the Guide. As an adjunct to the material in the
Guide, it would be appropriate for the instructor to present rules that
are covered by local ordinances. Such material could be added to the
examinations given in the Guide. Notes to the Practicing Electrician or
Designer This Guide has been prepared to explain in detail the use of
the National Electrical Code, particularly as it applies to design of
electrical wiring systems. With this intent, the Guide does not attempt
to present design techniques that necessarily result in the most
efficient or economical electrical system. For instance, no provisions
are made for future expansion in the examples given in the Guide. The
authors assume that experienced electricians or designers will use
their own approaches to problem solving while using the Guide as a
reference. In the same way, the selection of equipment such as circuit
breakers and service equipment in the examples presented in the Guide
is based on the minimum Code requirements. The rating of such equipment
may be neither adequate nor convenient for a practical installation.
The judgment of the designer must be relied upon to determine the
design that best fits a particular installation. The problems presented
in Part I of the Guide deal with standard alternating-current circuits
used as services, feeders, or branch circuits. Other special electrical
systems such as two-phase alternating-current and direct-current
installations are not discussed. The unique rules for these circuits
concerning grounding, size of neutral, etc., will be found in the Code
and should be used in addition to or in place of the rules presented in
the Guide. Finally, the design requirements for circuits supplying
equipment such as x-ray machines are not covered in detail in the
Guide. Reference is made when necessary to the appropriate section of
the Code that covers such equipment. The author appreciates the various
comments received on the previous edition. In particular, a number of
students in the author's National Electrical Code classes have made
helpful suggestions that served to improve the presentation of the
material.