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How to use your NEC code book on an open-book electrician exam

By TradePass · Updated September 26, 2026 · Section numbers are NEC 2026

1. Why open book is harder than it sounds

Having the book in front of you feels like a safety net. The clock says otherwise. Here is how much time each exam actually gives you per question:

Two to three minutes has to cover reading the question, finding the rule, reading it properly and choosing an answer. A search through the wrong chapter can use it all up. The people who pass open-book exams have usually answered most questions from memory and used the book to confirm, keeping their lookup time for the questions that need it.

Code editions differ by state. Make sure your book and your study material match the edition on your exam. The section numbers in the rest of this guide are NEC 2026, and older editions number some of them differently.

2. How the NEC is organized

You will find things faster if you decide which part of the book an answer lives in before you open it. Article 90 sets out the arrangement:

• Chapters 1 to 4 apply generally: definitions and general requirements (Chapter 1), wiring and protection (2), wiring methods and materials (3), and equipment for general use (4). In NEC 2026, Chapter 1 also holds the load calculations in Article 120.
• Chapters 5, 6 and 7 cover special occupancies, special equipment and special conditions. They can add to or change the general rules, which is why a question about a pool, a hazardous location or a fire pump often has a different answer from the Chapter 2 rule.
• Chapter 8 covers communications systems and mostly stands apart from the rest.
• Chapter 9 holds the tables: conduit and tubing fill, conductor dimensions and conductor properties.
• Informative annexes are explanatory. They are useful for worked examples but are not requirements.

A simple habit: if the question names a special place or piece of equipment, check Chapters 5 to 7 before you settle on a Chapter 2 or 3 answer.

NEC 2026 also standardized how many articles open. Across a dozen Chapter 3 articles, and in Articles 230 and 430, section .2 is now Listing Requirements and .3 is Reconditioned Equipment. That pushed some older low-numbered sections to new numbers, so do not trust a memorized ".2" from an older edition.

3. Working the index

For a specific question, the index is usually faster than the table of contents. Use it like this:

1. Pick the noun, not the verb. In "What size equipment grounding conductor is required for a 60 A circuit?", look up Equipment grounding conductors, not "size" or "required".
2. Scan the sub-entries. Main entries have indented sub-entries (sizing, installation, identification and so on). The right sub-entry saves you reading a whole article.
3. Go to the section, then read its heading. Confirm the heading matches your question before you read the rule. If it does not, go back to the index rather than reading onward and hoping.
4. Read the whole rule, including the exceptions. Then check the question. In Texas, for example, the bulletin tells candidates not to apply exceptions or optional calculation methods unless the question says to.

4. Tabs, highlighting and notes

The rules depend on your state and exam vendor, so read your candidate bulletin first. For example, Texas (PSI) allows:

• Highlighting, underlining and notes written in the book before the exam, but not during it.
• Permanent index tabs made or supplied by the NEC book publisher. Homemade or third-party tabs are not allowed.
• Soft-bound books only. Spiral, ring-bound or loose-leaf copies are not allowed, and neither is the NEC Handbook or any loose paper.

Where marking is allowed, less is more. Useful habits:

• Tab articles, not pages. One tab per article you use often is enough. A book with a tab on every page is as slow as one with none.
• Highlight the numbers you look up often, such as the 125% for continuous loads, and the table headings you hunt for.
• Use one color for values and another for exceptions, so a glance tells you whether you are looking at the rule or a way out of it.
• Write cross-references in the margin where one rule sends you to another. For example, next to a conductor ampacity table, note where the adjustment and correction factors are.

5. The lookups every calculation uses

Calculation questions look different but walk the same path through the book. Learn the path once and each problem becomes a series of familiar lookups. The section numbers below are NEC 2026. If your exam uses an older edition, confirm each one in your own book.

Sizing a branch circuit or feeder

1. Find the load. Article 120 (Article 220 before 2026). Small-appliance and laundry circuits are 1,500 VA each (120.52). Dryers are at least 5,000 VA (120.54). Four or more fixed appliances take a 75% demand factor (120.53). Ranges use the demand table in 120.55. General lighting loads are in 120.42 and lighting demand factors in 120.45.
2. Account for continuous loads. Conductors and overcurrent devices are sized at 125% of the continuous load plus 100% of the noncontinuous load (210.19 and 210.20 for branch circuits).
3. Pick the conductor. Allowable ampacities are in Table 310.16. Apply ambient temperature correction and adjustment for more than three current-carrying conductors from 310.15.
4. Pick the overcurrent device. Standard ratings are listed in 240.6. Check the small-conductor limits in 240.4.
5. Size the grounding. Equipment grounding conductors from Table 250.122. Grounding electrode conductors from Table 250.66.

Motor circuits

1. Use the table current, not the nameplate, for conductors and short-circuit protection: full-load current tables in 430.247 to 430.250.
2. Conductors: 125% of the table full-load current for a single motor (430.22). For several motors, 125% of the largest plus the rest (430.24).
3. Overload protection is the exception to the table rule: it is based on the nameplate full-load amps (430.32).
4. Branch-circuit short-circuit and ground-fault protection: Table 430.52.

Conduit fill

Percent fill and raceway dimensions come from the Chapter 9 tables (Table 1 for percent fill, Table 4 for raceway areas, Table 5 for conductor areas). For conductor resistance, used in voltage-drop problems, see Chapter 9 Table 8.

Nameplate or table? Mixing up motor nameplate current and table current is one of the most common calculation errors. Tab the motor tables, and write "table FLC" next to 430.22 and "nameplate FLA" next to 430.32 before test day if your rules allow notes.

6. What moved in NEC 2026

If your exam is on NEC 2026 (Texas moved to it for exams on or after September 1, 2026), these are the moves most likely to cost you time:

Most of the Article 220 load-calculation sections kept their numbers when they moved (220.55 became 120.55, for example), but the three shown above did not. Watch out for 230.2. It still exists in NEC 2026, but it is now a different rule (Listing Requirements), so an old reference leads you to a real section that does not answer your question.

7. Speed drills that work

Looking things up quickly is a skill, and it improves with timed practice like any other skill.

1. The 20-term drill. Write 20 terms from past practice questions on cards (for example bathroom receptacles, service drop clearance, motor overloads). Draw one, find the governing section and write down the number. Time the whole set. Repeat every few days with new cards.
2. Set a target. A useful rule of thumb is that a lookup should take no more than half your per-question time. On an exam at 2.2 minutes a question, that is about a minute to find the rule, leaving time to read it and answer.
3. Drill the calculation chain from section 5 until you turn to Table 310.16, 240.6 and Table 250.122 without the index.
4. Practice with the book you will take in, tabbed and marked the way it will be on the day. Page positions become muscle memory, and that only helps if it is the same book.

8. On the day: a two-pass method

1. First pass: answer everything you know without the book. Flag anything that needs a lookup.
2. Second pass: go back to the flagged questions and use the book. You now know exactly how much time you have left to share between them.
3. Cap each lookup. If you have not found the rule within your time cap, make your best answer, flag it and move on. One stubborn question should not cost you three easy ones.
4. Never leave a blank. Guess on anything unanswered before time runs out.

Frequently asked questions

Can I use tabs in my NEC book on the electrician exam?

It depends on your state and exam vendor, so check your candidate bulletin. In Texas, PSI allows permanent index tabs made or supplied by the NEC book publisher and does not allow homemade tabs. Books that break the rules can mean testing without your book or forfeiting your exam fee.

Can I highlight and write notes in my code book?

In Texas, yes, as long as you do it before the exam. You cannot write in or mark the book during the exam. Other states set their own rules, so check your bulletin.

How much time do I get per question on an open-book electrician exam?

It varies by exam, from about 2.0 minutes per question at the tightest. On the Texas journeyman exam it is about 2.2 minutes per question on the knowledge portion and 4.2 on calculations. That is not enough time to look up every answer, so you need to know the book.

Where are load calculations in the 2026 NEC?

In Article 120, in Chapter 1. They were in Article 220 in the 2023 and earlier editions. The key values did not change: small-appliance and laundry circuits are still 1,500 VA, the dryer minimum is still 5,000 VA, and fixed appliances still take a 75% demand factor at four or more.

Should I use the index or the table of contents?

Use the index for specific questions. Look up the main noun in the question, such as the equipment or location, and go straight to the section it points to. The table of contents is faster only when you already know which article you need.

Can I bring the NEC Handbook?

Not in Texas: the PSI bulletin excludes the NEC Handbook. Most open-book exams allow only the Code itself, so bring the standard edition your exam is referenced to.

Sources

• NFPA 70, National Electrical Code, 2026 edition (section locations and the 2023 to 2026 changes)
• TDLR, Electrician examination information (read September 2026)
• PSI, Electrician Candidate Information Bulletin (Texas book rules). Check for the newest version before you test.
• Exam lengths and code editions: the official bulletins linked from each TradePass state exam page