Using the 2017 NEC on Exam Day
Key Takeaways
NABCEP provides the 2017 NEC at the PVIP exam, so answers follow 2017 section numbers even though most jurisdictions now enforce the 2020 or 2023 edition.
Key 2017 locations: the 120% rule is 705.12(B)(2)(3)(b), supply-side connections are 705.12(A) with OCPD within 10 feet under 705.31, and dc circuits inside buildings are 690.31(G).
The 2017 ampacity tables are numbered 310.15(B)(16), 310.15(B)(2)(a), and 310.15(B)(3)(a); the rooftop adder is 310.15(B)(3)(c).
Common traps from other editions include the 2014 rapid shutdown limits (240 VA within 10 seconds), the 2014 manual-restart AFCI rule, and the 2020 6 AWG supply-side minimum.
Using the 2017 NEC on Exam Day
NABCEP provides the 2017 National Electrical Code during the PVIP exam, but most jurisdictions now enforce the 2020, 2023, or 2026 edition. Section numbers moved between editions, and several PV rules changed in substance. Answers on the exam follow the 2017 code book in front of you, so this guide cites 2017 section numbers first and notes the later numbers where they differ. Use this section as a map before you start the technical chapters.
1. How Article 690 Is Organized (2017 NEC)
| Part | Topic | Key Sections |
|---|---|---|
| I. General | Scope, definitions, equipment listing, ac modules | 690.1, 690.2, 690.4, 690.6 |
| II. Circuit Requirements | Maximum voltage, circuit sizing, overcurrent, stand-alone systems, arc-fault protection, rapid shutdown | 690.7, 690.8, 690.9, 690.10, 690.11, 690.12 |
| III. Disconnecting Means | PV system disconnect; equipment isolation | 690.13, 690.15 |
| IV. Wiring Methods | Methods permitted, component interconnections, connectors, access to boxes | 690.31, 690.32, 690.33, 690.34 |
| V. Grounding and Bonding | System grounding and ground-fault protection, equipment grounding, EGC size, grounding electrode system | 690.41, 690.42, 690.43, 690.45, 690.46, 690.47 |
| VI. Marking | Module marking, dc power source label, interconnection marking, ESS polarity, identification of power sources | 690.51–690.56 |
| VII. Connection to Other Sources | Refers to Article 705 | 690.59 |
| VIII. Energy Storage Systems | Refers to Article 706; self-regulated charge control | 690.71, 690.72 |
| IX. Systems Over 1000 Volts | Additional requirements for high-voltage systems | 690.80, 690.85 |
Related articles you will use constantly: Article 705 (interconnected power production sources), Article 706 (energy storage systems, new in 2017), Article 710 (stand-alone systems), Article 691 (large-scale PV of 5 MW or more), Article 250 (grounding and bonding), Article 310 (conductor ampacity), and Article 110 (general requirements such as working space and terminal torque).
2. Code Edition Crosswalk for High-Use PV Rules
| Topic | 2017 NEC (exam) | 2020 NEC | 2023 NEC |
|---|---|---|---|
| Maximum PV system voltage; Table 690.7(A) | 690.7, 690.7(A) | 690.7, 690.7(A) | 690.7(A); voltage label in 690.7(D) |
| PV source circuit current (125% of Isc) | 690.8(A)(1) | 690.8(A)(1)(a) | 690.8(A)(1)(a) |
| Conductor ampacity (125%) | 690.8(B) | 690.8(B) | 690.8(B) |
| Overcurrent device rating (125%) | 690.9(B) | 690.9(B) | 690.9(B) |
| DC arc-fault protection | 690.11 | 690.11 | 690.11 |
| Rapid shutdown | 690.12 | 690.12 | 690.12 |
| PV system disconnect | 690.13 | 690.13 | 690.13 |
| Equipment disconnects and isolating devices | 690.15 | 690.15 | 690.15 |
| PV wire and USE-2 single conductors | 690.31(C)(1) | 690.31(C)(1) | 690.31(C)(1) |
| DC circuits inside buildings; raceway labels | 690.31(G) | 690.31(D) | 690.31(D) |
| Mating connectors | 690.33 | 690.33 | 690.33 |
| System grounding configurations; ground-fault protection | 690.41(A), 690.41(B) | 690.41(A), 690.41(B) | 690.41(A), 690.41(B) |
| EGC size for PV circuits | 690.45 | 690.45 | 690.45 |
| Grounding electrode system | 690.47 | 690.47 | 690.47 |
| DC PV power source label | 690.53 | 690.53 (maximum voltage only) | 690.7(D) |
| Rapid shutdown labels | 690.56(C) | 690.56(C) | 690.56(C) |
| Supply-side connection | 705.12(A); OCPD location 705.31 | 705.11 | 705.11 |
| Load-side 100% busbar method | 705.12(B)(2)(3)(a) | 705.12(B)(3)(1) | 705.12(B)(1) |
| Load-side 120% busbar method | 705.12(B)(2)(3)(b) | 705.12(B)(3)(2) | 705.12(B)(2) |
| ESS disconnecting means | 706.7 | 706.15 | 706.15 |
| ESS circuit sizing; overcurrent protection | 706.20; 706.21 | 706.30; 706.31 | 706.30; 706.31 |
| Ampacity table | Table 310.15(B)(16) | Table 310.16 | Table 310.16 |
| Ambient temperature correction | Table 310.15(B)(2)(a) | Table 310.15(B)(1) | Table 310.15(B)(1)(1) |
| More than three current-carrying conductors | Table 310.15(B)(3)(a) | Table 310.15(C)(1) | Table 310.15(C)(1) |
| Rooftop temperature adder (7/8 in rule) | 310.15(B)(3)(c) | 310.15(B)(2) | 310.15(B)(2) |
| Terminal torque; lockable disconnects; working space | 110.14(D); 110.25; 110.26 | Same | Same |
3. Rules That Changed in Substance (Common Traps)
Many textbooks, online articles, and older practice questions were written for the 2014 NEC or for later editions. These changes come up again and again:
| Rule | Older or Newer Version | 2017 NEC (Exam) Version |
|---|---|---|
| Rapid shutdown limits | 2014: 30 V and 240 VA within 10 seconds, controlled beyond 10 ft from the array or 5 ft inside a building | 30 V within 30 seconds outside a 1-ft array boundary; 80 V inside it (effective January 1, 2019); no VA limit |
| Rapid shutdown labels | 2014: a single white-on-red "PHOTOVOLTAIC SYSTEM EQUIPPED WITH RAPID SHUTDOWN" plaque | Two label types: black-on-yellow title (array shut down) or white-on-red title (only conductors leaving the array shut down) |
| Maximum voltage method | 2014: manufacturer coefficients required when supplied | Coefficients, Table 690.7(A), or (100 kW and up) a PE-stamped method are alternatives |
| Arc-fault protection | 2014: annunciator and manual restart required | 80 V or more between any two conductors; manual-restart wording removed |
| Ungrounded arrays | 2014: 690.35 required PV wire and two-pole protection | 690.35 deleted; arrays are functionally grounded or ungrounded per 690.41(A); USE-2 or PV wire allowed |
| Wiring below roof decks | 2014: 10-inch clearance from decking | Clearance rule deleted; metal raceway or MC to the first readily accessible disconnect (690.31(G)) |
| DC power source label | 2014: also listed maximum power-point current and voltage | Maximum voltage, maximum circuit current, converter or charge controller output current |
| EGC and voltage drop | General rule 250.122(B) requires proportional upsizing | 690.45: no EGC upsizing required for voltage drop in PV circuits |
| Equipment disconnect location | 2020: lockable alternative; 2023: within sight and readily accessible | Within the equipment, or within sight and within 10 ft, or remotely operable from within 10 ft; lockable per 110.25 |
| Connector intermating | 2020: explicit listing rule added to 690.33(C) | Follows from listing and 110.3(B) |
| Supply-side conductor minimum | 2020: 6 AWG copper or 4 AWG aluminum in 705.11(B) | No explicit minimum in Article 705 |
| Backfed breaker label | 2014: "INVERTER OUTPUT CONNECTION" | "POWER SOURCE OUTPUT CONNECTION — DO NOT RELOCATE THIS OVERCURRENT DEVICE" |
| Rooftop conduit adder | 2014: tiered adders by height up to 36 in | 33°C adder only when less than 7/8 in above the roof; XHHW-2 exempt |
4. Code-Lookup Strategy for Exam Day
- Use the article, then the section. Most PV questions live in 690, 705, 706, 250, 310, and 110. Going straight to the right article is faster than the index.
- Read the whole subsection. Exceptions and the "one of the following" lists (690.7(A), 690.15(C), 705.12(B)(2)(3)) often decide the answer.
- Check units and conditions in tables. Table 690.7(A) uses ambient temperature bands; the ampacity table assumes 30°C ambient; the adjustment table counts only current-carrying conductors.
- Do not over-rely on memory of newer editions. If you work under the 2020 or 2023 NEC every day, expect numbering to differ; the substance usually matches, but the exceptions in Section 3 above do not.
- Budget lookups. Save code searches for questions that need exact values (correction factors, Table 250.122 or 250.66 sizes, label wording). Answer concept questions from understanding.
In the 2017 NEC provided at the exam, where is the load-side "120% rule" for busbars?
705.12(B)(2)(3)(b)
705.12(B)(3)(2)
705.11(B)
705.12(D)(2)(3)(b)
Under the 2017 NEC, which statement about rapid shutdown limits is correct?
Outside the 1-ft array boundary, 30 V within 30 seconds; inside it, 80 V within 30 seconds
Outside the array boundary, controlled conductors must reach 30 V and 240 VA within 10 seconds
Inside the array boundary, controlled conductors must reach 30 V within 10 seconds
Rapid shutdown applies only to ground-mounted systems that enter a building
A candidate who works under the 2023 NEC looks for the ampacity adjustment factors for more than three current-carrying conductors. Which table in the 2017 NEC holds them?
Table 310.16
Table 310.15(C)(1)
Table 310.15(B)(3)(a)
Table 310.15(B)(1)(1)
Sections you finish are checked off in the contents.