Electrician's Exam Preparation Guide to the 2002 NEC

Introduction -- How to Use This Book:

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 worthwhile.

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 mind:

• 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 built.

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 score high.

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.

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 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 important sections.

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 details.

Article 404 covers the switches you will use to control electrical circuits.

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 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.

Special Occupancies

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 generator rooms.

• 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 ignitable mixtures.

• 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 area.

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 parks.

Special Equipment

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.

Special Conditions

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 industry.

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.

The Examination

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?

(A) Texas
(B) Maryland
(C) Virginia
(D) Alabama

 

You should mark answer C for question 1 on the answer sheet.

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 fail.

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 morning.

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.

Examination Day

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 of elimination.

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.

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 below.

Softcover - 352 Pages
8-1/2 x 11 in.