Let’s use this process to research a question that’s very similar to the type you’ll see on an electrician’s exam.Question: As a general rule, what is the maximum number of disconnects permitted for a service?
A. TwoIn this example, the subject is service disconnects. When you go to the NEC Index, you won’t find the word “disconnect,” but you will find Disconnecting means. Look at the entries under that heading for an applicable reference. The subject Services fits the bill. In this case, the section referenced is
SUBJECT: Disconnecting means INDEX: Services SECTION: 230, Part VI
Go to Article 230. Part VI is entitled Service Equipment — Disconnecting Means. Now, look down the Section headings and you’ll come to 230.71 Maximum Number of Disconnects. The answer is there.
Answer: D. Six disconnects
When you customize your NEC by putting the Table of Contents and the Index together, you can find answers quickly and easily. In some cases, you may need to consult as many as four or five Section references. By listing them on a piece of scratch paper as suggested, you won’t need to constantly refer back to the Index.
Do Your Research
Sometimes you’ll have to do some investigating to find the right train of thought for a reference. Under Disconnecting means, there are 26 disconnect references. One of these is Services (Article 230, Part VI). That was actually pretty easy.
But what if you’d started with Services as your subject for the sample question? You might have looked in the Index under Services, not found the answer there, but continued down the page to Service Entrance Equipment, and found Disconnecting means, 230-VI that way. By trial and error, you’ll find the subject of the question, and locate the sources of information in the NEC. This wasn’t difficult, but it was a little more time-consuming.