Using the National Electrical Code During the Electrician's Exam

The idea behind developing the National ElectricalII, III, IV, etc. Then, under each Part are the
Code, aside from fire and shock prevention, wasSections which are again broken down into
to help explain how certain electrical devices orSubsections. The Part of an Article or Section isn't
systems work the way they do. For example:included in the Article number, but will often be
How does a GFCI work? Why can't an individualincluded after the Article number in the Index. For
current-carrying conductor be installed in a metalexample, in the Index under Grounding, you'll find
raceway? Why can the protection for a 20-ampBonding, 250-V. That tells you that the subject of
conductor feeding a motor be protected withBonding is covered in Part V of Article 250.
40-amp protection? Why can't a 15-amp singleI find it helpful to circle in red each Part heading
receptacle be installed on a 20-amp circuit? How(marked with Roman numerals: I, II, III, etc.) of
can a bird rest on an energized power line and notevery Article, and write that numeral at the top
be electrocuted? When you learn how and whyof the page. That way, when you look for a
elements of an electrical system work, you canparticular Part of that Article, it'll be easier to find -
better understand the National Electrical Code -especially during a timed test.
and you'll be able to easily answer these questionsNow, let's look at my approach to studying the
and other questions like them given in mostCode. I decided to take a subject that's pretty
electrical exams.dull, the NEC, and make it as interesting as
In preparing for the electrical exam, a typicalpossible. Rather than starting at the beginning of
study plan should allow enough time to read eachthe Code and going page by page, I'll skip around
NEC reference at least three times - withoutin the code book and deal with various subjects,
putting you to sleep. Read carefully the first time.like we're in a real classroom environment.
It may take some time. In fact, the second timeServices
you read it should only take 10% of the firstEvery wiring system consists of three parts: the
time. Try and make the Code referenceservice, the feeders, and the branch circuits. The
interesting by thinking of jobs you've done in theminimum size of the service entrance conductors
past and how the Code reference you're readingis determined by the total volt-amps of all feeder
about applies to that job. The reference will stickand branch circuit loads.
in your memory if you can link it to an on-the-jobThere are two methods used by a utility
event. Make a final review of all your referencescompany to deliver power to a building: overhead
and notes on the day before the exam. Theservice drop or underground service lateral.
more you review, the better you'll remember andOverhead Service-Drop Conductors (Part II,
the faster you'll be able to find the answers onArticle 230.22)
the day of the test.An overhead service drop, by definition, consists
Everyone wants to finds things quickly in the NEC,of the overhead conductors from the last pole to
but unless you become familiar with itsthe structure, including the connection to the
organization, it will take considerable effort onservice entrance conductors at the service head
your part, and you'll probably struggle during a(see Article 100 - Definitions).
timed electrical exam. There are two ways toThe service entrance conductors are the
find things in the NEC. You can use the Index, orconductors between the service-drop conductors
look through the Table of Contents to locate yourand the service disconnecting means, which is
references.located either inside or outside the building or
For example, what if you want to look upstructure. The required location of the service
grounding? You may not initially know that Articledisconnecting means for all structures is clearly
250 concerns grounding, so the Table ofdefined. It must be located at a readily-accessible
Contents, which is organized by Article numberlocation, and be as close as possible to where the
(then subject), won't be very helpful to you atservice conductors enter the building. See Article
first. I suggest using the Index until you know the230.70(A).
Articles and their numbers. A few examples ofFinding Information in the NEC
Articles you'll refer to frequently are:Using the information we've covered so far, let's
Article 230, Servicestry finding the answer to a question pertaining to
Article 240, Overcurrent ProtectionArticle 230, Service. When you're dealing with an
Article 250, Groundingelectrical question, the easiest way to find the
How to Read a Code Sectionanswer is to:
Let's look at how the Code is organized and whatFirst find the subject of the question.
you need to understand to find a code section.Then, in the Index, find the word or words that
What if the subject you want to research isbest describe the subject of the question.
indicated by 250.20(A)(1) in the Index? What theFinally, list the reference(s) following that word in
heck does that mean? The numbers before thethe index on a piece of scratch paper.
period indicate the Chapter and Article number.Use the following breakdown to help analyze the
Articles in each chapter all begin with the chapterquestion and find the answer:
number where you'll find them; Article 100 is inSUBJECT ________________ INDEX
Chapter 1, Article 200 in Chapter 2, and so on.________________ SECTION
The number after the period indicates the Section.________________
So, you're being sent to Section 20 of Article 250,Using this method can help you study for the
in Chapter 2. And finally, letters and numbers inexam and pass with a higher score, as you'll be
parentheses indicate Subsections.familiar with how to quickly find what you're
Articlessearching for, in the shortest amount of time.
An Article may also be broken down into Parts: I,