Table Of Content$54.50
ELECTRICIAN’S
EXAM
PREPARATION GUIDE
Eighth Edition
Based on the 2011 NEC®
by
John E. Traister
Revised and Updated by
Dale C. Brickner
FFRREEEE CCDD--RROOMM iinnssiiddee tthhee bbaacckk ccoovveerr::
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software that makes studying almost fun.
• Each answer is explained, and shows the pertinent NEC® section
at the click of the mouse.
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• Use the exam mode for a timed exam — just like the real one,
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Acknowledgments
I am indebted to several individuals and organizations who helped in the preparation of this book. One
group is the electrical examining boards throughout the United States. A list of these organizations
appears in Appendix I of this book. The following were especially helpful in furnishing reference
materials or else helping with the production.
National Fire Protection Association® (NFPA®)
C. Keeler Chapman,Artwork
Nicole L. Brickner,Typist and Organizer
Joe A. Fintz, Final Exam Verification
Ron Murray, Code Consultant
Floyd Richards, Question Verification & Code Consultant
Portions of this publication are reprinted with permission from NFPA 70®-2011 National Electrical
Code®, Copyright © 2010 National Fire Protection Association, Quincy, MA 02169. This reprinted
material is not the complete and official position of the National Fire Protection Association on the
referenced subject, which is represented only by the standard in its entirety.
National Electrical Code® and NEC® are registered trademarks of the National Fire Protection
Association, Inc., Quincy, MA 02169.
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Library of Congress Cataloging-in-Publication Data
Traister, John E.
Electrician's exam preparation guide :based on the 2011 NEC / by John E.Traister.-- 8th ed./
rev.and updated by Dale C.Brickner.
p.cm.
Includes index.
ISBN-13:978-1-57218-255-4
ISBN-10:1-57218-255-5
1. Electrical engineering--Examinations, questions, etc.2. Electrical engineering--Examinations--
Study guides.3. Electricians--Licenses--United States.4. National Fire Protection Association.
National Electrical Code (2011) I.Brickner, Dale C.II.Title.
TK169.T73 2011
621.319'24076--dc22
2010053276
©2011, 2008, 2005, 2002, 1999, 1996, 1993, 1991 Craftsman Book Company
Contents
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Chapter 1 Electrical Systems — General Requirements . . . . . . . . . . . . . . . 13
Chapter 2 Electrical Calculations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Chapter 3 Branch Circuits and Feeders . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
Chapter 4 Electric Services . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
Chapter 5 Distribution Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117
Chapter 6 Overcurrent Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137
Chapter 7 Utilization Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163
Chapter 8 Measuring and Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183
Chapter 9 Electric Motors and Motor Controls . . . . . . . . . . . . . . . . . . . . . 203
Chapter 10 Special Occupancies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 223
Chapter 11 Miscellaneous Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . 245
Chapter 12 Transformers and Capacitors . . . . . . . . . . . . . . . . . . . . . . . . . . 257
Chapter 13 Electrical Drawings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 269
Final Examination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 289
Using the Interactive Study Center CD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 340
Appendix I State Contractor’s Examination Offices . . . . . . . . . . . . . . . . . . 342
Appendix II Answers to Final Exam Questions . . . . . . . . . . . . . . . . . . . . . . . 345
Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 346
[Blank Page]
Introduction —
How to Use This Book
If you have been installing electrical systems for You can pass any electrician’s exam, but only if
some time as an apprentice, helper, or unlicensed you study carefully each of the questions in this
electrician, this book is for you. The information book. What you learn from studying is the foun-
between the covers of this book will cover every dation on which your professional career will be
subject that is likely to appear on most electri- built.
cian’s exams — either state or local.
Understand also that the licensing authority
If you are just starting your career as an appren- isn’t the enemy. They aren’t trying to keep you out
tice electrician, this book is also for you. It begins of the electrical business. They only want to set
at the beginning. You will have no trouble under- some basic standards and be assured that your
standing what is explained here. Read each page installations will be done in a workmanlike man-
carefully and you will soon earn the recognition ner and in accordance with the latest edition of the
that licensed professionals are entitled to in our National Electrical Code® (NEC®). The public
should be assured that all licensed electricians are
present society. The financial rewards are another
knowledgeable professionals. That’s good for
factor which will make your efforts worthwhile.
society in general, and it’s good for all profession-
In most communities, any electrician working al electricians and electrical contractors who live
without supervision must be licensed. For larger and work in your area.
electrical construction projects, many states now
Unfortunately, there are too many applicants
require the certification of journeyman electricians
who are not well prepared when they sit down to
as well as specialty electricians, such as splicers of
take the electrician’s exam. Taking an electrician’s
high-voltage cable. This trend is certain to contin-
exam without doing a good job of preparation is a
ue as legislatures recognize the need to protect the
complete waste of time — both yours and that of
public from incompetents. The state of Virginia,
the licensing authority. The results are predictable.
for example, is now requiring all persons doing
Don’t make that mistake.
electrical work to be licensed.
The most common reason for failure is that the
Most licensing authorities prepare demanding
applicant didn’t study properly because he didn’t
exams that are a good test of the examinee’s
know how, or studied the wrong material. This
knowledge. These exams help to guarantee that
book should put an end to that excuse. You have in
electrical systems installed in building construc-
your hands the most complete, easiest-to-use,
tion will meet minimum standards for protecting
most practical reference available for preparing to
the lives and health of building occupants (and the
take the tests that are actually given today. Read
buildings themselves) for many years to come.
this book carefully, examine every question,
This also helps to keep insurance rates to a mini-
understand all the answers. Do this, and there’s no
mum.
way you will be unprepared on examination day.
Begin your study for any electrician’s exam You are almost certain to score high.
with two points in mind: All the common questions and answers are here,
• Take the exam seriously but just knowing the answer is not always enough.
Sometimes it is just as important to understand
• Every minute spent studying this book why a particular answer is correct. That’s why
increases your chances of passing the exam many answers include a quotation or reference
5
Electrician’s Exam Preparation Guide
NEC Terminology
There are two basic types of rules in the NEC:
mandatory rules and advisory rules. Here is how to
recognize the two types of rules and how they
relate to all types of electrical systems.
Mandatory rules: All mandatory rules have the
terms shall or shall not in them. The terms mean
must. If a rule is mandatory, you mustcomply with it.
Permissive rules: All advisory rules have the
terms shall be permitted or shall not be required in
them. The terms in this case mean recommended but
not necessarily required. If a rule is advisory, com-
pliance is discretionary. If you want to comply with
it, do so. But you don't have to if you don't want to.
Be alert to local amendments to the NEC. Local
ordinances may amend the language of the NEC,
changing it from should to shall. This means that
you must do in that county or city what may only
be recommended in some other area. The office
that issues building permits will either sell you a
copy of the code that’s enforced in that county or
tell you where the code is sold.
The National Electrical Code (NEC)has become the
Bible of the electrical industry
Learning the Layout of the NEC
Begin your study of the NEC with Articles 100
and 110. These two articles have the basic infor-
mation that will make the rest of the NECeasier to
section from the National Electrical Code. understand. Article 100 defines terms you will
Sometimes you will find notes or clarifications need to understand when you apply the code.
under the answer when there is an important point Article 110 gives the general requirements for
you might miss. electrical installations. Read these two articles
over several times until you are thoroughly famil-
The National Electrical Code is used in practi- iar with all the information they contain. It’s time
cally every area of the United States for inspecting well spent.
electrical systems in building construction. Most
Once you’re familiar with Articles 100 and 110,
of the questions appearing on electrician’s exams
you can move on to the rest of the code. There are
will come directly from Articles and Sections of
several key sections you will use often in servicing
the latest NEC. Therefore a brief review of the
electrical systems. Let’s discuss each of these
individual NEC sections that apply to electrical
important sections.
systems is in order. Sample questions concerning
all sections of the NEC may be found in the chap-
Wiring and Protection
ters to follow.
Chapter 2 of the NEC discusses wiring design
This book, however, is not a substitute for the and protection, the information electrical techni-
NEC. You need a copy of the most recent edition cians need most often. It covers the use and iden-
and it should be kept handy at all times. The more tification of grounded conductors, branch circuits,
you know about the code, the more you are likely feeders, calculations, services, overcurrent protec-
to refer to it. tion, grounding, bonding and surge protection. This
6
Introduction — How to Use This Book
is essential information for any type of electrical Articles 312 through 392 give rules for race-
system, regardless of the type. ways, boxes, cabinets and raceway fittings. Outlet
boxes vary in size and shape, depending on their
Chapter 2 is also a “how-to” chapter. It explains
use, the size of the raceway, the number of con-
how to provide proper spacing for conductor
ductors entering the box, the type of building con-
supports and how to size the proper grounding
struction, and the atmospheric condition of the
conductor or electrode. If you run into a problem
areas. Chapter 3 should answer most questions on
related to the design or installation of a conven-
the selection and use of these items.
tional electrical system, you can probably find a
solution for it in this chapter. The NEC does not describe in detail all types
and sizes of outlet boxes. But manufacturers of
outlet boxes have excellent catalogs showing all of
Wiring Methods and Materials
their products. Collect these catalogs. They’re
Chapter 3 has the rules on wiring methods and essential to your work.
materials. The materials and procedures to use on
a particular system depend on the type of building Equipment for General Use
construction, the type of occupancy, the location
Chapter 4 of the NEC begins with the use and
of the wiring in the building, the type of atmos-
installation of flexible cords and cables, including
phere in the building or in the area surrounding the
the trade name, type, letter, wire size, number of
building, mechanical factors and the relative costs
conductors, conductor insulation, outer covering
of different wiring methods.
and use of each. The chapter also includes fixture
The provisions of this chapter apply to all wires, again giving the trade name, type, letter and
wiring installations except remote control switch- other important details.
ing (Article 725), low-energy power circuits
Article 404 covers the switches you will use to
(Article 725), signal systems (Article 725), com-
control electrical circuits.
munication systems and conductors (Article 800)
when these items form an integral part of equip- Article 406 covers receptacles and convenience
ment such as motors and motor controllers. outlets used to connect portable equipment to elec-
tric circuits. Get the manufacturers’ catalogs on
There are three basic wiring methods used in
these items. They will provide you with detailed
most modern electrical systems. Nearly all wiring
descriptions of each of the wiring devices.
methods are a variation of one of these three basic
Article 408 covers switchboards and panelboards,
methods:
including their location, installation methods,
• Sheathed cables of two or more conductors, clearances, grounding and overcurrent protection.
such as NM cable and AC armored cable
Article 410 on lighting fixtures is especially
(Articles 320 through 340)
important. It gives installation procedures for fix-
• Raceway wiring systems, such as rigid and tures in specific locations. For example, it covers
EMT conduit (Articles 342 through 366) fixtures near combustible material and fixtures in
closets. The NEC does not describe the number of
• Busways (Article 368)
fixtures needed in a given area to provide a certain
Article 310 in Chapter 3 gives a complete amount of illumination.
description of all types of electrical conductors.
Article 430 covers electric motors, including
Electrical conductors come in a wide range of
mounting the motor and making electrical connec-
sizes and forms. Be sure to check the working
tions to it.
drawings and specifications to see what sizes and
Articles 440 through 460 cover air conditioning
types of conductors are required for a specific job.
andheatingequipment, transformers and capacitors.
If conductor type and size are not specified,
choose the most appropriate type and size meeting Article 480 gives most requirements related to
standard NEC requirements. battery-operated electrical systems. Storage batter-
7
Electrician’s Exam Preparation Guide
ies are seldom thought of as part of a conventional Articles 511 and 514 regulate garages and similar
electrical system, but they often provide standby locations where volatile or flammable liquids are
emergency lighting service. They may also supply used. While these areas are not always considered
power to security systems that are separate from critically hazardous locations, there may be enough
the main AC electrical system. danger to require special precautions in the electrical
installation. In these areas, the NEC requires that
Special Occupancies volatile gases be confined to an area not more than 18
inches above the floor. So in most cases, convention-
Chapter 5 of the NEC covers special occupancy
al raceway systems are permitted above this level. If
areas. These are areas where the sparks generated by
the area is judged critically hazardous, explosion-
electrical equipment may cause an explosion or fire.
proofwiring (including seal-offs) may be required.
The hazard may be due to the atmosphere of the area
or just the presence of a volatile material in the area. Article 520 regulates theaters and similar occu-
Commercial garages, aircraft hangers and service pancies where fire and panic can cause hazards to
stations are typical special occupancy locations. life and property. Drive-in theaters do not present
the same hazards as enclosed auditoriums. But the
Articles 500 through 503 cover the different
projection rooms and adjacent areas must be prop-
types of special occupancy atmospheres where an
erly ventilated and wired for the protection of
explosion is possible. The atmospheric groups
operating personnel and others using the area.
were established to make it easy to test and
approve equipment for various types of uses. Chapter 5 also covers residential storage
garages, aircraft hangars, agricultural buildings,
Section 501 covers the installation of explosion-
service stations, bulk storage plants, health care
proof wiring. An explosion-proof system is
facilities, marinas and boatyards, mobile homes
designed to prevent the ignition of a surrounding
and parks, and recreation vehicles and parks.
explosive atmosphere when arcing occurs within
the electrical system.
Special Equipment
There are three classes of special occupancy
Article 600 covers electric signs and outline
locations:
lighting. Article 610 applies to cranes and hoists.
• Class I (Article 501): Areas containing Article 620 covers the majority of the electrical
flammable gases or vapors in the air. Class work involved in the installation and operation of
I areas include paint spray booths, dyeing elevators, dumbwaiters, escalators and moving
plants where hazardous liquids are used, walks. The manufacturer is responsible for most of
and gas generator rooms. this work. The electrician usually just furnishes a
feeder terminating in a means of disconnect in the
• Class II (Article 502): Areas where
bottom of the elevator shaft. The electrician may
combustible dust is present, such as grain-
also be responsible for a lighting circuit to a junc-
handling and storage plants, dust and stock
tion box midway in the elevator shaft for connect-
collector areas and sugar-pulverizing plants.
ing the elevator cage lighting cable and exhaust
These are areas where, under normal
fans. Articles in Chapter 6 of the NECgive most of
operating conditions, there may be enough
the requirements for these installations.
combustible dust in the air to produce
Article 625 covers electric battery charging system
explosive or ignitable mixtures.
requirements for plug-in hybrid electric vehicles
• Class III (Article 503): Areas that are (PHEV). Article 626 regulates installation of parking
hazardous because of the presence of easily spaces for electrified trucks. Connecting to Truck
ignitable fibers or flyings in the air, Stop Electrification (TSE) equipment will allow
although not in large enough quantity to truck operators to use on-board air conditioning,
product ignitable mixtures. Class III heating and appliances without running their engines.
locations include cotton mills, rayon mills Article 630 regulates electric welding equipment.
and clothing manufacturing plants. It is normally treated as a piece of industrial power
8
Introduction — How to Use This Book
equipment requiring a special power outlet. But there rooms, halls, stairways and entrances. There must
are special conditions that apply to the circuits sup- be enough light to allow the occupants to exit from
plying welding equipment. These are outlined in the building if the general building lighting is
detail in Chapter 6 of the NEC. interrupted. Exit doors must be clearly indicated
Article 640 covers wiring for sound-recording and by illuminated exit signs.
similar equipment. This type of equipment normally Chapter 7 of the NEC covers the installation of
requires low-voltage wiring. Special outlet boxes or emergency lighting systems. These circuits should
cabinets are usually provided with the equipment.
be arranged so that they can automatically transfer
But some items may be mounted in or on standard
to an alternate source of current, usually storage
outlet boxes. Some sound-recording electrical sys-
batteries or gasoline-drive generators. As an alter-
tems require direct current, supplies from rectifying
native, you can connect them to the supply side of
equipment, batteries or motor generators. Low-volt-
the main service so disconnecting the main service
age alternating current comes from relatively small
switch would not disconnect the emergency cir-
transformers connected on the primary side to a 120-
cuits. See Article 700.
volt circuit within the building.
Chapter 8 covers communication systems and is
Other items covered in Chapter 6 of the NEC
not subject to the requirements of Chapters 1
include: information technology equipment (Article
through 7, except where specifically referenced. In
645), sensitive electronic equipment (Article 647),
addition to communications circuits, Chapter 8 cov-
pipe organs (Article 650), X-ray equipment (Article
ers: radio and television equipment, antennas and
660), induction and dielectric heat-generating equip-
distribution systems, network-powered broadband
ment (Article 665), electrolytic cells (Article 668),
systems, and the newly-added Article 840 (premis-
electroplating (Article 669), industrial machines
es-powered broadband communication systems).
(Article 670), and irrigation machines (Article 675).
Articles 680 and 682 regulate installations of swim-
How to Prepare for the Exam
ming pools, fountains, spas, and natural or artificial-
This book is a guide to preparing for the jour-
ly-made bodies of water. Articles 685 through 692
neyman or master electrician’s exam. It isn’t a sub-
cover items like integrated electric systems, solar
stitute for studying the recommended references
photovoltaic (PV) systems, and fuel cells. The 2011
and it won’t teach you the electrical trade. But it
NEC added Article 694 to cover the increasingly
will give you a complete knowledge of the type of
popular small wind electric systems. This new arti-
questions asked in the electrician’s exam. It will
cle governs the wiring requirements as well as con-
also give you a “feel” for the examination and pro-
nection to other sources. It’s advisable to pay partic-
vide some of the confidence you need to pass.
ular attention to new code articles, as most states like
to include numerous questions on new code Emphasis is on multiple-choice questions
changes. Chapter 6 ends with Article 695, covering because that’s the style that nearly all tests utilize.
Fire Pumps. Questions are grouped into chapters. Each chapter
covers a single subject. This will help you discov-
If you ever have work that involves Chapter 6,
er your strengths and weaknesses. Then when you
study the chapter before work begins. That can save a
take the two “final” sample exams in the back of
lot of installation time. Here is another way to cut
this book, analyze the questions you miss. You’ll
down on labor hours and prevent installation errors.
probably notice you are weaker in some subjects
Get a set of rough-in drawings of the equipment
than others. When these areas have been discov-
being installed. It is easy to install the wrong outlet
ered, you will know that further study is necessary
box or to install the right box in the wrong place.
Having a set of rough-in drawings can prevent those in these areas.
simple but costly errors. In answering questions on the NEC, remember
this point: All exam questions are based on mini-
Special Conditions
mum NEC requirements. If the minimum wire size
In most commercial buildings, the NEC and permitted under the NEC to carry 20 amperes is
local ordinances require a means of lighting public No. 12 AWG and you answer No. 10 AWG (mini-
9
Electrician’s Exam Preparation Guide
mum size for 30 amperes) just to play it safe, your end of this book, which are based on actual state
answer is incorrect. and county examinations, you will have from two to
four minutes to answer each question, so you don’t
The preparatory questions in the front part of this
have time to daydream or mess around. If you
book have the answer after each question. When
want to pass the exam, you must take it seriously.
reading a question, cover the answer. Read the ques-
tion carefully. Mark your answer on a separate sheet Your study plan should allow enough time to
of paper before looking at the correct answer. Check review each reference at least three times. Read care-
to see if your answer is correct. If it isn’t, read the fully the first time. The next review should take only
code responses to find out why it is wrong. about 10% of the time that the first reading took.
Make a final review of all references and notes on the
How to Study day before the exam. This is the key to success in
passing the exam: Review, review, review! The more
Set aside a definite time to study, following a
you review, the better your grasp of the information
schedule that meets your needs. Studying a couple of
and the faster you will be able to find the answers.
hours two or three nights each week is better than
studying all day on, say, Saturdays. The average
The Examination
mind can only concentrate for approximately four
hours without taking a break. There’s no point in Questions on state and local examinations are
studying if you don’t retain much of the information. usually compiled by members of the electrician’s
Study alone most of the time, but spend a few hours examination board. Board members usually include
reviewing with another electrician buddy before several electrical contractors, a registered electri-
exam day. You can help each other dig out the facts cal engineer, electrical inspectors, and perhaps a
and concepts you will need to pass the exam. trade school instructor. Most electrician’s exams
will include questions on the NEC, general knowl-
Try to study in a quiet, well-lighted room that is
edge of electrical practice, theoretical questions,
respected as your study space by family members
and local ordinance rules. All of these fields are
and friends. If it’s hard to find a spot like that in
covered in this preparation guide. Questions about
your home, go to the local library where others are
the NEC, including rules and design calculations,
reading and studying.
comprise from 70% to 80% of the examination.
Before you begin to study, spend a few minutes
State examinations are usually given twice a year,
getting into the right frame of mind. That’s impor-
or perhaps every three months. County and local
tant. You don’t have to be a genius to pass the elec-
exams may be taken almost any time with prior
trician’s exam. But good motivation will nearly
notice to the local inspectors. Most have several basic
guarantee your success. No one can provide that
exams that are used in rotation. But the same exami-
motivation but you. Getting your license is a goal
nation will never be administered twice in a row.
you set for yourself; it’s your key to the future —
The people compiling the exams maintain a
a satisfying career in the electrical industry.
bank of several hundred questions covering each
As you study the NEC and other references,
test subject. Questions are selected at random, and
highlight important points with a marker. This
chances are that some of the questions on any
makes it easier to find important passages when exam have already been used on an earlier exami-
you’re doing the final review — and when you’re nation. Many of the questions appearing on actual
taking the exam. electrician’s exams will closely resemble ques-
Put paper tabs on the corners of each major sec- tions appearing in this book.
tion in all the references you will take into the The format of the actual examination, the time
exam room. On the portion of the tab that extends allowed, and the reference material which the
beyond the edge of the book, write the name of the applicant may be allowed to take into the exami-
section or the subject. That makes locating each nation room vary with each locality. Typically, an
section easier and quicker — an important consid- applicant is allowed six to eight hours to complete
eration on an open book test. Speed in locating the examination. Applicants are usually required
answers is important. In the sample exams at the to report to the examination room at 8 a.m. where
10
