Open Book Is Not the Advantage It Sounds
The California General Electrician exam gives you the 2023 National Electrical Code as an on-screen reference, along with NFPA 70E and the Cal/OSHA pocket guide. It also gives you 100 questions in four and a half hours — 2.7 minutes each — and about half of first-time candidates fail. The two facts are connected. A candidate who reads a question and then searches the code for the answer spends five minutes on it; a candidate who reads the question, knows it lives in 430.52, opens the article and confirms the percentage spends forty seconds. The exam is passed by people who know the map.
This guide is the map: how the NEC is organised, what an article number tells you before you open it, the internal pattern every article follows, the tables that settle most questions, and the forty sections that produce the bulk of exam items. Pair it with the worked problems in our calculations guide and the reference values in the California exam guide, then time yourself on our free electrician questions.
The Numbers
| Item | Value |
|---|---|
| Questions and time | 100 scored questions (plus up to 10 unscored) in 4 h 30 min — 2.7 minutes each |
| Passing score | 70% |
| References on screen | NFPA 70 (NEC) 2023 · NFPA 70E 2024 · Cal/OSHA Pocket Guide for the Construction Industry |
| Your own book, tabs, notes | Not allowed |
| NEC chapters | 9, plus informative annexes; Chapters 1–4 apply generally, 5–7 modify them, 8 stands alone, 9 is tables |
| Articles the exam draws on most | About 20 of the roughly 150 in the code |
| First-time pass rate | About 51% (DLSE, 2023) |
| Look-up budget that works | No more than 30 look-ups in the whole exam — confirmations, not searches |
The Nine Chapters and What They Are For
| Chapter | Subject | Articles the exam uses |
|---|---|---|
| 1 — General | Definitions and the rules for everything: working space, terminations, identification | 100 (definitions), 110 (110.14 terminations, 110.26 working space) |
| 2 — Wiring and Protection | Circuits, calculations, services, overcurrent protection, grounding and bonding | 200, 210, 215, 220, 225, 230, 240, 250 |
| 3 — Wiring Methods and Materials | Conductors, cables, raceways, boxes | 300, 310, 312, 314, 320–362 (each cable and raceway type), 392, 400, 402, 404, 406, 408 |
| 4 — Equipment for General Use | Lighting, appliances, motors, transformers, capacitors, storage | 410, 422, 424, 430, 440, 450, 480 |
| 5 — Special Occupancies | Hazardous locations, health care, assembly, agricultural, marinas | 500–517, 547, 555 |
| 6 — Special Equipment | Signs, elevators, welders, data centres, pools, solar, EV charging | 600, 625, 680, 690, 700-series interplay |
| 7 — Special Conditions | Emergency, standby, Class 1–3 circuits, fire alarm, optical fibre | 700, 701, 702, 725, 760 |
| 8 — Communications Systems | Stands alone — Chapters 1–7 apply only where Chapter 8 says so (90.3) | 800, 805, 810 |
| 9 — Tables | Conduit fill, conductor dimensions, resistance, plus the informative annexes | Tables 1, 4, 5, 8; Annex C conduit-fill counts; Annex D calculation examples |
Section 90.3 is the rule that makes the map work: Chapters 1 through 4 apply generally; Chapters 5, 6 and 7 supplement or modify them for special situations; Chapter 8 is independent; Chapter 9 tables apply where referenced. So a question about a motor in a hazardous location starts in Article 430 and is then modified by Article 500-series rules, never the other way around.
What the Number Tells You Before You Open It
The first digit is the chapter. 250 is in Chapter 2 (grounding), 430 in Chapter 4 (motors), 680 in Chapter 6 (pools). Within Chapter 3 the cable and raceway articles run in a predictable order — cables in the 320s and 330s (NM is 334, MC is 330, AC is 320), then conduits and tubing in the 340s and 350s (RMC 344, IMC 342, PVC 352, EMT 358, FMC 348, LFMC 350), then other raceways (wireways 376, cable tray 392). If you know a cable type you can guess its article to within ten.
Inside an article, the second part of the number follows a pattern that the 2020 and 2023 editions made consistent for the Chapter 3 wiring-method articles and that most other articles already followed:
| Section suffix | Always about | Example |
|---|---|---|
| .1 | Scope — what the article covers | 430.1 |
| .2 | Definitions specific to the article (many moved to Article 100 in 2023) | 250.2 |
| .6 | Listing requirements (wiring-method articles) | 334.6 |
| .10 | Uses permitted | 334.10, 358.10 |
| .12 | Uses not permitted | 334.12, 358.12 |
| .14 | Dissimilar metals | 358.14 |
| .20 | Size | 358.20 |
| .22 | Number of conductors (fill) | 358.22 |
| .24 | Bends — how made | 358.24 |
| .26 | Bends — number (360° between pull points) | 358.26 |
| .30 | Securing and supporting | 334.30, 358.30 |
| .80 | Ampacity | 334.80 |
| .100 and up | Construction specifications | 334.104 |
So "how far apart must EMT be supported?" is 358.30 before you open the book, and "can I run NM cable in a wet location?" is 334.12. Practise this until the number arrives before the search box does.
The 40 Sections That Decide Most Questions
General and circuits
- 110.14(C) — termination temperature ratings: why the 75 °C column is the working column.
- 110.26(A) — working space: 3 ft minimum depth (Table 110.26(A)(1)), 30 in wide, 6½ ft high; Condition 1, 2, 3 by voltage.
- 210.8 — GFCI locations: dwelling bathrooms, garages, outdoors, crawl spaces, basements, kitchens, sinks, laundry, and the non-dwelling list in 210.8(B).
- 210.12 — AFCI: dwelling-unit 120 V, 15 and 20 A circuits in the listed rooms.
- 210.19(A) and 210.20(A) — 125% for continuous loads.
- 210.23 — permissible loads on 15/20/30 A branch circuits; cord-and-plug equipment at 80%.
- 210.52 — dwelling receptacle spacing: 6 ft/12 ft wall rule, countertops, bathrooms, outdoors, laundry, garages.
- 210.70 — required lighting outlets.
- 215.2(A) — feeder sizing; the 3%/5% voltage-drop notes.
Calculations, services and overcurrent
- 220.41, 220.45, 220.52–220.55, 220.60, 220.82 — the dwelling calculation, standard and optional.
- 230.42, 230.79, 230.70, 230.71 — service conductor sizing, the 100 A minimum, disconnect location and the number of disconnects.
- 240.4(B) and (D) — next-size-up rule and the small-conductor limits.
- 240.6(A) — standard ampere ratings.
- 240.21(B) — feeder tap rules: 10 ft, 25 ft, and the 100 ft high-bay rule.
- 240.24 — where overcurrent devices may and may not be located (not in bathrooms, not over stairs).
Grounding and bonding
- 250.24 and 250.28 — the main bonding jumper and where the neutral is bonded.
- 250.32 — separate buildings and structures: grounding electrode required, no neutral-ground bond downstream.
- 250.50 and 250.52 — the grounding electrode system; which electrodes must be used if present.
- 250.53(A)(2) — a single rod must be supplemented unless it measures 25 Ω or less.
- 250.66 and Table 250.66 — grounding electrode conductor size; the 6 AWG rod limit.
- 250.104 — bonding water piping and structural steel.
- 250.118 and 250.122 — what counts as an equipment grounding conductor and how big it is; (B) for upsized circuits.
Wiring methods
- 300.4 — protection against physical damage: the 1¼ in setback, nail plates.
- 300.5 and Table 300.5 — burial depths: 24 in direct burial, 18 in PVC, 6 in RMC/IMC, 12 in for residential 120 V GFCI-protected 20 A circuits.
- 310.15(B) and (C) and Table 310.16 — temperature correction, bundling adjustment, ampacities.
- 312.6 — wire-bending space in cabinets.
- 314.16 and Table 314.16(A)/(B) — box fill.
- 314.28 — pull and junction boxes: 8× for straight pulls, 6× plus other entries for angle pulls.
- 334.10/.12/.30/.80 — NM cable uses, support (4½ ft, 12 in from boxes) and the 60 °C ampacity rule.
- 358.22/.26/.30 — EMT fill, bends and support (10 ft, 3 ft from boxes).
- 400.12 — where flexible cords may not be used (as a substitute for fixed wiring).
- 404.2(C) — a grounded conductor at switch locations.
- 406.4(D) — replacement receptacles: GFCI, AFCI, tamper-resistant where required.
Equipment
- 410.16 — luminaires in clothes closets.
- 422.11 and 422.13 — appliance overcurrent; water heaters as continuous loads (125%).
- 430.6, 430.22, 430.24, 430.32, 430.52, 430.62, 430.102, 430.110 and Tables 430.248/430.250 — the whole motor chain: which current to use, conductors, feeders, overloads, short-circuit protection, disconnect location and rating.
- 440.22 — air-conditioning branch-circuit protection (175%, up to 225%).
- 450.3(B) — transformer overcurrent protection for 1,000 V and below (125% primary only, or 250% primary with secondary protection at 125%).
- 680.22, 680.26 — pool receptacle distances and equipotential bonding.
- Chapter 9 Tables 1, 4, 5, 8; Annex C — conduit fill and conductor properties.
A Look-Up Drill
Do this with an electronic copy of the code — a PDF on a laptop, not a tabbed paper book, because that is what the exam gives you. Set a timer for 60 seconds per item and write the section number before you open the file.
- Maximum distance between supports for 1 in EMT. (358.30 — 10 ft)
- Minimum burial depth for PVC conduit under a residential driveway. (Table 300.5 — 18 in)
- Overload setting for a motor with a 1.0 service factor. (430.32(A)(1) — 115%)
- Volume allowance for a 10 AWG conductor in a box. (Table 314.16(B)(1) — 2.50 in³)
- Maximum fill for three conductors in a raceway. (Chapter 9 Table 1 — 40%)
- Minimum working-space depth in front of a 480 V panel with grounded concrete behind you. (Table 110.26(A)(1), Condition 2 — 3½ ft)
- Size of the copper GEC for a service with 3/0 copper conductors. (Table 250.66 — 4 AWG)
- Which dwelling receptacles need GFCI protection within 6 ft of a sink. (210.8(A)(7))
- Maximum number of quarter bends between pull points in a raceway. (358.26, and the same section number in every raceway article — 360°)
- Demand for one 12 kW range. (Table 220.55, Column C — 8 kW)
When you can name eight of ten sections cold, the exam's look-ups become confirmations, and the time you save goes to the calculation questions that need it.
Reading Traps in the Code Itself
- Exceptions live after the rule. Read to the end of the section before answering; the exam loves the exception (the 6 AWG rod limit in 250.66(A), the 400% breaker allowance in 430.52).
- Informational Notes are not requirements. The 3% voltage drop is a note; a question asking what the NEC requires has a different answer from one asking what it recommends.
- "Shall be permitted" is optional; "shall" is mandatory. Distractors are built by swapping them.
- Table headings carry conditions. Table 310.16 is for not more than three current-carrying conductors at 30 °C; Table 250.122 is by overcurrent device, Table 250.66 by conductor size.
- The 2023 edition renumbered things. Dwelling lighting is 220.41 (was 220.12); Table 310.16 (was 310.15(B)(16) before 2020); many article-specific definitions moved into Article 100. Older study material sends you to the wrong place — the on-screen code is the 2023 edition.
Frequently Asked Questions
Is the California electrician exam open book?
Yes, with the 2023 NEC, NFPA 70E (2024) and the Cal/OSHA construction pocket guide provided on screen at the testing centre. You cannot bring your own code book, tabs, notes or calculator; an online calculator is provided.
How is the NEC organised?
Nine chapters: 1 general, 2 wiring and protection, 3 wiring methods and materials, 4 equipment for general use, 5 special occupancies, 6 special equipment, 7 special conditions, 8 communications, 9 tables — plus informative annexes. Under 90.3, Chapters 1–4 apply generally, 5–7 modify them, 8 stands alone.
What does the article number tell me?
The first digit is the chapter, and within the wiring-method articles the section suffix is standardised: .10 uses permitted, .12 uses not permitted, .22 number of conductors, .26 bends, .30 securing and supporting, .80 ampacity. 358.30 is EMT support; 334.30 is NM cable support.
Which NEC articles are most tested on the journeyman exam?
Articles 210, 220, 230, 240, 250, 300, 310, 314, 334, 358, 430 and the Chapter 9 tables account for the large majority of questions; Articles 110, 404, 406, 422, 440, 450 and 680 make up most of the rest.
How long should a look-up take?
Under a minute, and only to confirm a value you already expect. With 2.7 minutes a question, a budget of about 30 look-ups across the whole exam leaves enough time for the calculation items; searching the PDF for a topic you cannot place costs five minutes each.
Sources
- NFPA 70, National Electrical Code, 2023 edition — Article 90 (90.3 code arrangement), the chapter and article structure, and every section cited above.
- California DLSE Electrician Certification Unit — examination information — format, open-book references, pass mark and retest rules.
- The section values quoted in the drill are summaries for orientation; the on-screen 2023 code governs on exam day, and no NEC text is reproduced here.
