Introduction -- How to Use This
If you have been installing electrical systems for some time as
an apprentice, helper, or unlicensed electrician, this book is for
you. The information between the covers of this book will cover
every subject that is likely to appear on most electrician's exams -
either state or local.
If you are just starting your career as an apprentice
electrician, this book is also for you. It begins at the beginning.
You will have no trouble understanding what is explained here. Read
each page carefully and you will soon earn the recognition that
licensed professionals are entitled to in our present society. The
financial rewards are another factor which will make your efforts
In most communities, any electrician working without
supervision must be licensed. For larger electrical construction
projects, many states now require the certification of journeyman
electricians as well as specialty electricians, such as splicers of
high-voltage cable. This trend is certain to continue as
legislatures recognize the need to protect the public from
incompetents. The State of Virginia, for example, is now requiring
all persons doing electrical work to be licensed.
Most licensing authorities prepare demanding exams that are a
good test of the examinee's knowledge. These exams help to guarantee
that electrical systems installed in building construction will meet
minimum standards for protecting the lives and health of building
occupants (and the buildings themselves) for many years to come.
This also helps to keep insurance rates to a minimum.
Begin your study for any electrician's exam with two points in
- Take the exam seriously
- Every minute spent studying this book increases your chances
of passing the exam
You can pass any electrician's exam, but only if you study
carefully each of the questions in this book. What you learn from
studying is the foundation on which your professional career will be
Understand also that the licensing authority isn't the enemy.
They aren't trying to keep you out of the electrical business. They
only want to set some basic standards and be assured that your
installations will be done in a workmanlike manner and in accordance
with the latest edition of the National Electrical Code (NEC).
The public should be assured that all licensed electricians are
knowledgeable professionals. That's good for society in general, and
it's good for all professional electricians and electrical
contractors who live and work in your area.
Unfortunately, there are too many applicants who are not well
prepared when they sit down to take the electrician's exam. Taking
an electrician's exam without doing a good job of preparation is a
complete waste of time - both yours and that of the licensing
authority. The results are predictable. Don't make that mistake.
The most common reason for failure is that the applicant didn't
study properly because he didn't know how, or studied the wrong
material. This book should put an end to that excuse. You have in
your hands the most complete, easiest-to-use, most practical
reference available for preparing to take the tests that are
actually given today. Read this book carefully, examine every
question, under- stand all the answers. Do this, and there's no way
you will be unprepared on examination day. You are almost certain to
All the common questions and answers are here, but just knowing
the answer is not always enough. Sometimes it is just as important
to understand why a particular answer is correct. That's why many
answers include a quotation or reference section from the National
Electrical Code. Sometimes you will find notes or clarifications
under the answer when there is an important point you might miss.
The National Electrical Code is used in practically every area of
the United States for inspecting electrical systems in building
construction. Most of the questions appearing on electrician's exams
will come directly from Articles and Sections of the latest NEC.
Therefore a brief review of the individual NEC sections
that apply to electrical systems is in order. Sample questions
concerning all sections of the NEC may be found in the
chapters to follow.
This book, however, is not a substitute for the NEC. You
need a copy of the most recent edition and it should be kept handy
at all times. The more you know about the code, the more you are
likely to refer to it.
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 word
shall in them. The word shall means must. If a rule is
mandatory, you must comply with it.
Advisory rules: All advisory rules have the word
should in them. The word should in this case means
recommended but not necessarily required. If a rule is
advisory, compliance 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.
Learning the Layout of the NEC
Begin your study of the NEC with Articles 100 and 110.
These two articles have the basic information that will make the
rest of the NEC easier to understand. Article I 00 defines
terms you will need to understand the code. Article 110 gives the
general requirements for electrical installations. Read these two
articles over several times until you are thoroughly familiar with
all the information they contain. It's time well spent.
Once you are familiar with Articles 100 and 110 you can move on
to the rest of the code. There are several key sections you will use
often in servicing electrical systems. Let's discuss each of these
Wiring Design and Protection
Chapter 2 of the NEC discusses wiring design and
protection, the information electrical technicians need most often.
It covers the use and identification of grounded conductors, branch
circuits, feeders, calculations, services, overcurrent protection
and grounding. This is essential information for any type of
electrical system, regardless of the type.
Chapter 2 is also a "how-to" chapter. It explains how to provide
proper spacing for conductor supports, how to provide temporary
wiring and how to size the proper grounding conductor or electrode.
If you run into a problem related to the design or installation of a
conventional electrical system, you can probably find a solution for
it in this chapter.
Wiring Methods and Materials
Chapter 3 has the rules on wiring methods and materials. The
materials and procedures to use on a particular system depend on the
type of building construction, the type of occupancy, the location
of the wiring in the building, the type of atmosphere in the
building or in the area surrounding the building, mechanical factors
and the relative costs of different wiring methods.
The provisions of this article apply to all wiring installations
except remote control switching (Article 725), low-energy power
circuits (Article 725), signal systems (Article 725), communication
systems and conductors (Article 800) when these items form an
integral part of equipment such as motors and motor controllers.
There are three basic wiring methods used in most modern
electrical systems. Nearly all wiring methods are a variation of one
of these three basic methods:
- Sheathed cables of two or more conductors, such as NM cable
and BX armored cable (Articles 330 through 339)
- Raceway wiring systems, such as rigid and EMT conduit
(Articles 342 to 358)
- Busways (Article 364)
Article 310 in Chapter 3 gives a complete description of all
types of electrical conductors. Electrical conductors come in a wide
range of sizes and forms. Be sure to check the working drawings and
specifications to see what sizes and types of conductors are
required for a specific job. If conductor type and size are not
specified, choose the most appropriate type and size meeting
standard NEC requirements.
Articles 312 through 392 give rules for raceways, boxes, cabinets
and raceway fittings. Outlet boxes vary in size and shape, depending
on their use, the size of the raceway, the number of conductors
entering the box, the type of building construction and atmospheric
condition of the areas. Chapter 3 should answer most questions on
the selection and use of these items.
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 their products. Collect these catalogs. They
are essential to your work.
Equipment for General Use
Chapter 4 of the NEC begins with the use and installation
of flexible cords and cables, including the trade name, type,
letter, wire size, number of conductors, conductor insulation, outer
covering and use of each. The chapter also includes fixture wires,
again giving the trade name, type, letter and other important
Article 404 covers the switches you will use to control
Article 406 covers receptacles and convenience outlets used to
connect portable equipment to electric circuits. Get the
manufacturers’ catalogs on these items. They will provide you with
detailed descriptions of each of the wiring devices.
Article 408 covers switchboards and panelboards, including their
location, installation methods, clearances, grounding and
Article 410 on lighting fixtures is especially important. It gives
installation procedures for fixtures in specific locations. For
example, it covers fixtures near combustible material and fixtures
in closets. The NEC does not describe the number of fixtures
that will be needed in a given area to provide a certain amount of
Article 430 covers electric motors, including mounting the motor
and making electrical connections to it.
Articles 440 through 460 cover air conditioning and heating
equipment, transformers and capacitors.
Article 480 gives most requirements related to battery-operated
electrical systems. Storage batteries are seldom thought of as part
of a conventional electrical system, but they often provide standby
emergency lighting service. They may also supply power to security
systems that are separate from the main AC electrical system.
Chapter 5 of the NEC covers special occupancy areas. These
are areas where the sparks generated by electrical equipment may
cause an explosion or fire. The hazard may be due to the atmosphere
of the area or just the presence of a volatile material in the area.
Commercial garages, aircraft hangers and service stations are
typical special occupancy locations.
Articles 500 through 501 cover the different types of special
occupancy atmospheres where an explosion is possible. The
atmospheric groups were established to make it easy to test and
approve equipment for various types of uses.
Section 501-4 covers the installation of explosionproof
wiring. An explosionproof system is designed to prevent the
ignition of a surrounding explosive atmosphere when arcing occurs
within the electrical system.
There are three classes of special occupancy locations:
- Class I (Article 501): Areas containing flammable
gases or vapors in the air. Class I areas include paint spray
booths, dyeing plants where hazardous liquids are used, and gas
- Class II (Article 502): Areas where combustible dust
is present, such as grain-handling and storage plants, dust and
stock collector areas and sugar-pulverizing plants. These are
areas where, under nor- mal operating conditions, there may be
enough combustible dust in the air to produce explosive or
- Class III (Article 503): Areas that are hazardous
because of the presence of easily ignitable fibers or flyings in
the air, although not in large enough quantity to produce
ignitable mixtures. Class III locations include cotton mills,
rayon mills and clothing manufacturing plants.
Articles 511 and 514 regulate garages and similar locations where
volatile or flammable liquids are used. While these areas are not
always considered critically hazardous locations, there may be
enough danger to require special precautions in the electrical
installation. In these areas, the NEC requires that volatile
gases be confined to an area not more than 4 feet above the floor.
So in most cases, conventional raceway systems are permitted above
this level. If the area is judged critically hazardous,
explosionproof wiring (including seal-offs) may be required.
Article 520 regulates theaters and similar occupancies where fire
and panic can cause hazards to life and property. Drive-in theaters
do not present the same hazards as enclosed auditoriums. But the
projection rooms and adjacent areas must be properly ventilated and
wired for the protection of operating personnel and others using the
Chapter 5 also covers residential storage garages, aircraft
hangars, service stations, bulk storage plants, health care
facilities, mobile homes and parks, and recreation vehicles and
Article 600 covers electric signs and outline lighting. Article
610 applies to cranes and hoists. Article 620 covers the majority of
the electrical work involved in the installation and operation of
elevators, dumbwaiters, escalators and moving walks. The
manufacturer is responsible for most of this work. The electrician
usually just furnishes a feeder terminating in a disconnect means in
the bottom of the elevator shaft. The electrician may also be
responsible for a lighting circuit to a junction box midway in the
elevator shaft for connecting the elevator cage lighting cable and
exhaust fans. Articles in Chapter 6 of the NEC give most of
the requirements for these installations.
Article 630 regulates electric welding equipment. It is normally
treated as a piece of industrial power equipment requiring a special
power outlet. But there are special conditions that apply to the
circuits supplying welding equipment. These are outlined in detail
in Chapter 6 of the NEC.
Article 640 covers wiring for sound-recording and similar
equipment. This type of equipment normally requires low-voltage
wiring. Special outlet boxes or cabinets are usually provided with
the equipment. But some items may be mounted in or on standard
outlet boxes. Some sound-recording electrical systems require direct
current, supplied from rectifying equipment, batteries or motor
generators. Low-voltage alternating current comes from relatively
small transformers connected on the primary side to a 120-volt
circuit within the building.
Other items covered in Chapter 6 of the NEC include: X-ray
equipment (Article 660), induction and dielectric heat-generating
equipment (Article 665) and machine tools (Article 670).
If you ever have work that involves Chapter 6, study the chapter
before work begins. That can save a lot of installation time.
Here is another way to cut down on labor hours and prevent
installation errors. Get a set of rough-in drawings of the equipment
being installed. It is easy to install the wrong outlet box or
reinstall the right box in the wrong place. Having a set of rough-in
drawings can prevent those simple but costly errors.
In most commercial buildings, the NEC and local ordinances
require a means of lighting public rooms, halls, stairways and
entrances. There must be enough light to allow the occupants to exit
from the building if the general building lighting is interrupted.
Exit doors must be clearly indicated by illuminated exit signs.
Chapter 7 of the NEC covers the installation of emergency
lighting systems. These circuits should be arranged so that they can
automatically transfer to an alternate source of current, usually
storage batteries or gasoline-driven generators. As an alternative,
you can connect them to the supply side of the main service so
disconnecting the main service switch would not disconnect the
emergency circuits. See Article 700.
How to Prepare for the Exam
This book is a guide to preparing for the journeyman or master
electrician's exam. It isn't a substitute for studying the
recommended references and it won't teach you the electrical trade.
But it will give you a complete knowledge of the type of
questions asked in the electrician's exam. It will also give you
a "feel" for the examination and provide some of the confidence you
need to pass.
Emphasis is on multiple-choice questions because that's the style
that nearly all tests utilize. Questions are grouped into chapters.
Each chapter covers a single subject. This will help you discover
your strengths and weaknesses. Then when you take the two "final"
sample exams in the back of this book, analyze the questions you
miss. You will probably notice you are weaker in some subjects than
others. When these areas have been discovered, you will know that
further study is necessary in these areas.
In answering questions on the NEC, remember this point:
All exam questions are based on minimum NEC requirements If
the minimum wire size permitted under the NEC to carry 20
amperes is No.12 AWG and you answer No.10 AWG (minimum size for 30
amperes) just to play it safe, your answer is incorrect.
The preparatory questions in the front part of this book have the
answer after each question. When reading a question, cover the
answer with a card or ruler of an appropriate size. Read the
question carefully. Mark your answer on a separate sheet of paper
before moving the card or ruler that covers the correct answer. Then
slide the card or ruler and check to see if your answer is correct.
If it isn't, read the code responses to find out why it is wrong.
How to Study
Set aside a definite time to study, following a schedule that
meets your needs. Studying a couple of hours two or three nights
each week is better than studying all day on, say, Saturdays. The
average mind can only concentrate for approximately four hours
without taking a break. There is no point in studying if you don't
retain much of the information. Study alone most of the time, but
spend a few hours reviewing with another electrician buddy before
exam day. You can help each other dig out the facts and concepts you
will need to pass the exam.
Try to study in a quiet, well-lighted room that is respected as
your study space by family members and friends. If it's hard to find
a spot like that in your home, go to the local library where others
are reading and studying.
Before you begin to study, spend a few minutes getting into the
right frame of mind. That's important. You don't have to be a genius
to pass the electrician's exam. But good motivation will nearly
guarantee your success. No one can provide that motivation but
you. Getting your license is a goal you set for yourself; it's
your key to the future - a satisfying career in the electrical
As you study the NEC and other references, highlight
important points with a yellow marker. This makes it easier to find
important passages when you are doing the final review - and when
you are taking the exam.
Put paper tabs on the comers of each major section in all the
references you will take into the exam room. On the portion of the
tab that extends beyond the edge of the book, write the name of the
section or the subject. That makes locating each section easier and
quicker - an important consideration on an open book test. Speed in
locating answers is important. In the sample exams at the end of
this book, which are based on actual state and county examinations,
you will have from two to four minutes to answer each question, so
you don't have time to day dream or mess around. If you want to pass
the exam, you must take it seriously.
Your study plan should allow enough time to review each reference
at least three times. Read carefully the first time. The next review
should take only about 10% of the time that the first reading took.
Make a final review of all references and notes on the day before
the exam. This is the key to success in passing the exam: Review,
review, review! The more you review, the better your grasp of
the information and the faster you will be able to find the answers.
Questions on state and local examinations are usually compiled by
members of the electrician's examination board. Board members
usually include several electrical contractors, a registered
electrical engineer, electrical inspectors, and perhaps a trade
school instructor. Most electrician's exams will include questions
on the NEC, general knowledge of electrical practice,
theoretical questions, and local ordinance rules. All of these
fields are covered in this preparation guide. Questions about the
NEC, including rules and design calculations, comprise from 70%
to 80% of the examination.
State examinations are usually given twice a year, or perhaps
every three months. County and local exams may be taken almost any
time with prior notice to the local inspectors. Most have several
basic exams that are used in rotation. But the same examination will
never be administered twice in a row.
The people compiling the exams maintain a bank of several hundred
questions covering each test subject. Questions are selected at
random, and chances are that some of the questions on any exam have
already been used on an earlier examination. Many of the questions
appearing on actual electrician's exams will closely resemble
questions appearing in this book.
The format of the actual examination, the time allowed, and the
reference material which the applicant may be allowed to take into
the examination room vary with each locality. Typically, an
applicant is allowed six to eight hours to complete the examination.
Applicants are usually required to report to the examination room at
8 a.m. where the proctors take about 15 minutes to explain the rules
of taking the exam. The applicants then work on the "morning" exam
until noon. After an hour break for lunch, the "afternoon" exam
begins at 1p.m. and applicants are given until about 4p.m. to
complete this portion.
The Answer Sheet
Most answer sheets used today are designed for computer grading.
Each question on the exam is numbered. Usually there will be four or
five possible responses for each question. You will be required to
mark the best answer on the answer sheet. The following is a sample
of a multiple-choice question:
1.) Richmond is the capitol city of what state?
You should mark answer C for question 1 on the answer
Answer sheets will vary slightly for each examining agency so be
sure to follow any instructions on that sheet. Putting the right
answers on the wrong section will almost certainly cause you to
The Night Before
Give your mind a rest! If you have not prepared correctly for the
exam by this time, then you can't cram it all into your brain in one
night. So take it easy. If the place of the examination is more than
an hour's drive from your home, you might want to stay at a motel in
the city where the examination is being held. Getting up at, say,
4a.m. and driving a couple of hours in heavy traffic will not help
you to pass the exam. On the other hand, a drive to the location the
afternoon before the exam, a good dinner and a relaxing evening
watching TV will help your possibilities of passing. Just don't stay
up too late.
There are, however, exceptions to this rule. Some people find it
difficult to sleep comfortably the first night at a strange
location. If this is your case, you would be better off getting a
good night's sleep at home and driving to the location the next
Just be sure to have all of your reference material with you and
get a good night's sleep before the day of the exam. If you have
prepared yourself correctly, you will pass with flying colors.
On the day of your examination, listen carefully to any oral
instructions given and read the printed directions. Failing to
follow instructions will probably disqualify you.
You will seldom find any trick questions, but many will require
careful reading. Certain words like shall, should, always, never,
can make a big difference in your answer.
Sometimes several of the answers may seem possible, but only one
will be correct. If you are not sure of the answer, use the process
There are several ways to take an exam, but the following is the
method I used to pass the Virginia State Electrical Contractor's
Exam a few years ago. This method is merely a suggestion; if another
way suits you best, by all means use it.
When the exam booklets were passed out and the applicants were
given permission to open them, I spent the first two or three
minutes going over the entire exam booklet, noting the total number
of questions. This knowledge allowed me to pace myself. I noted a
total of 100 questions on the morning exam which allowed less than 3
minutes I could spend on each one.
I then started with question No. 1. When a tough question was
encountered or I found one that I was not sure of, I merely skipped
over this until I came to one that I definitely knew the answer.
This way I had gone through the entire test booklet one time and had
answered about 50% of the questions in a little over one hour. I was
quite sure that I had answered all of these questions correctly.
However, 70% is usually the minimum passing grade and at this point,
I had only 50% of the questions answered. But I still had about
three hours to spend on the tougher questions,
I then started back at the beginning of the exam and went down
the list of questions until I found one that was unanswered. This
process continued until I had answered all questions to the best of
my ability. I spent the remaining time reviewing my previous
answers, making changes as necessary.
After lunch, the "afternoon" portion of the exam was handed out, and
I used the same procedure as before. I found out a few days later
that I had scored 94% on this examination.
| What’s New In This Edition?
All questions and answers in this book have been updated to
comply with the new 2002 NEC. Additional questions and
answers, along with new illustrations, have been provided to
encompass new NEC installation requirements. Wherever a
change has occurred from the 1999 NEC, you will see an
icon denoting that a change has been made. This icon appears
Softcover - 352 Pages
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