NEC Article For Wiring Methods: Article 300 Explained (2026)

The NEC article for wiring methods is Article 300, General Requirements for Wiring Methods and Materials, the first article in Chapter 3 of the National Electrical Code (NFPA 70). It sets the rules that apply to every cable and raceway you install: how to route, protect, secure, splice and bury conductors. Once you know this NEC article for wiring methods, the individual articles for EMT, PVC, MC and NM cable make far more sense.

In this guide I walk through the Article 300 sections inspectors check most often, the Table 300.5 burial depths, and how Articles 310, 430 and 725 connect to it. It is part of our NEC articles list series, so use that page when you need a different article.

NEC article for wiring methods: Article 300 rules explained. Placement: after the second intro paragraph.

Quick answer: Article 300 is the general article for wiring methods in Chapter 3. It covers protection from damage (300.4), underground cover (300.5), securing (300.11), free conductor length (300.14) and conductor fill (300.17). Each wiring method then has its own article, such as 358 for EMT and 334 for NM cable.

What Is the NEC Article for Wiring Methods?

Article 300 is the general article that applies to all wiring methods in Chapter 3 unless a specific article modifies it. Section 300.1 gives the scope, and Section 300.3 says which conductors may share a raceway. Think of it as the foundation: Article 358 tells you how to install EMT, while Article 300 tells you what applies to every raceway, including protection, securing and corrosion.

Check Section 90.3 for how Article 300 applies to communications circuits in the edition your inspector enforces, because the 2026 code changed how Chapter 8 fits in.

NEC Chapter 3 Wiring Methods and Materials: Article Map

Chapter 3 is titled Wiring Methods and Materials. Use it in this order: start with the NEC article for wiring methods, Article 300, then open the article for your wiring method, then check the Chapter 9 tables if fill is involved.

Article 300: general requirements for wiring methods and materials.
Article 310: conductors for general wiring.
Articles 312 and 314: cabinets and boxes. See our NEC article for box fill and junction box sizing guides.
Articles 320, 330 and 334: armored cable (AC), metal-clad cable (MC) and nonmetallic-sheathed cable (NM).
Articles 344, 350, 352 and 358: RMC, liquidtight flexible metal conduit, PVC conduit and EMT.
Articles 376 and 392: wireways and cable trays.

NEC Article 300 section map showing 300.3, 300.4, 300.5, 300.11, 300.14 and 300.17

Key Sections in the NEC Article for Wiring Methods

These sections come up on almost every inspection. Numbers below follow the 2023 code, and the 2026 edition re-lettered some subsections, so confirm against your adopted edition.

300.3: keep all conductors of one circuit together in the same raceway or cable.
300.4: protect wiring from physical damage.
300.11: support the wiring method itself, never from ceiling grid support wires.
300.13: make splices only in boxes, and never let neutral continuity depend on a device.
300.14: leave at least 6 in. of free conductor in a box, with at least 3 in. outside the opening where the opening is under 8 in.
300.17: keep the number and size of conductors within what the raceway can dissipate and allow you to pull. Our conduit fill calculator applies the Chapter 9 tables for you.
300.20: group all phase conductors and the neutral together in ferrous raceways to avoid induced heating.

NEC 300.3(C)(1): AC and DC Conductors in One Raceway

Under 300.3(C)(1), conductors of AC and DC circuits rated 1,000 V or less may share a raceway, cable or enclosure. Every conductor must have insulation rated for at least the highest circuit voltage present.

NEC Article 300.4: Protection Against Physical Damage

Where cable or raceway passes through a wood stud or joist, bore the hole at least 1-1/4 in. from the nearest edge. If you cannot keep that distance, or you cut a notch, add a steel plate at least 1/16 in. thick. Cables running parallel to framing members follow the same 1-1/4 in. rule. Through metal studs, use bushings or grommets to protect the cable from sharp edges.

NEC 300.4 diagram showing a bored hole and a notch protected with a 1/16 inch steel plate in a wood stud

What Is Article 300.5 of the NEC Code? Minimum Burial Depth

Within the NEC article for wiring methods, Section 300.5 covers underground installations rated 1,000 V or less, and Table 300.5 sets minimum cover. In open ground the common values are 24 in. for direct-buried cable, 18 in. for PVC conduit, 6 in. for RMC or IMC, and 12 in. for 120 V, 20 A GFCI-protected residential circuits. Roads and alleys need 24 in.

Cover is measured from the top of the raceway or cable to finished grade. Underground raceways are wet locations, so conductors need a wet-location rating such as THWN-2. That is also why Romex is not allowed underground, even in conduit. For the full chart and exceptions, read our NEC code for underground conduit depth guide and the NEC code for buried electrical wires.

NEC Table 300.5 minimum burial depth chart for cable, PVC, RMC and GFCI circuits.

NEC Article 310: Conductors for General Wiring

Article 300, the NEC article for wiring methods, tells you how to install conductors. Article 310 tells you which conductors to use and how much current they carry. Table 310.16 gives allowable ampacities for up to three current-carrying conductors at 30 C (86 F) ambient in the 60 C, 75 C and 90 C columns. Apply correction for ambient temperature and adjustment for bundling when they apply.

Insulation types such as THWN-2 are listed for wet locations, which connects Article 310 straight back to 300.5(B). To size a run, use our AC cable size calculator or the DC cable size calculator, and convert sizes with the AWG to mm² chart.

What Is Article 430 in the NEC?

Article 430 covers motors, motor circuits and controllers. The wiring method still comes from the NEC article for wiring methods, but conductor sizing, overload protection and disconnecting means come from Article 430. Motor branch-circuit conductors are generally sized at 125 percent of the full-load current in Table 430.250 for three-phase motors (430.22), while overload protection under 430.32 is based on the motor nameplate current.

Use our overload relay setting calculator, the wire sizing for motors guide and the motor overload setting table when you apply it.

What Is Article 725 of the NEC?

Article 725 covers Class 2 and Class 3 power-limited circuits, such as thermostat, doorbell and low-voltage control wiring. Class 1 power-limited circuits moved to Article 724 in the 2023 code, and the 2026 code added Article 206 for non-power-limited remote-control and signaling circuits.

For wiring methods, the key rule is separation: Class 2 and Class 3 conductors must be kept apart from power conductors under 725.136 (2023 numbering), unless the section allows otherwise. The general rules of the NEC article for wiring methods still apply unless Article 725 modifies them.

NEC Articles 300, 310, 430 and 725 comparison chart.

What Changed in the NEC Article for Wiring Methods in 2026

The 2026 edition tightened several Article 300 rules:

300.4(C): conductors and wiring methods damaged by overheating, fire, corrosion or water must be replaced, not left in place.
300.6(E): roof deck protection now covers all roof decking types, with an exception for wiring encased in 2 in. of concrete.
300.11(B): raceways in indoor wet locations must provide drainage.
300.13(E): cable ties used to secure and support wiring must be listed.
300.24: the 360-degree bend limit applies even when you transition between different raceway types.

2026 NEC Article 300 changes to 300.4(C), 300.6(E), 300.11(B), 300.13(E) and 300.24.

NEC Article for Wiring Methods PDF and Free Download

Many people search for an NEC article for wiring methods PDF, an NEC article 300 PDF or an NEC Table 300.5 PDF. NFPA copyrights the NEC, so there is no legal free PDF of the full code. NFPA offers free read-only access to NFPA 70 on nfpa.org after you register, and it sells print and PDF copies. Unofficial PDFs are often an older edition.

For a free field reference, save the section map and Table 300.5 chart on this page, then read the exact wording in NFPA’s online copy.

NEC Article for Wiring Methods Quizlet: Practice Questions

If you searched for an NEC article for wiring methods Quizlet set, build your own cards from these questions. Writing them yourself beats copying a stranger’s set that may use an old edition.

Which article is the general NEC article for wiring methods? Article 300.
How far from a stud edge must a bored hole be? At least 1-1/4 in., or use a 1/16 in. steel plate.
What is the minimum cover for PVC conduit in open ground? 18 in. under Table 300.5.
How much free conductor is required at a box? At least 6 in., with 3 in. outside the opening.
Can Type NM cable be buried? No.
Which article gives conductor ampacity? Article 310, Table 310.16.

NEC Code Questions and Answers

Reading the code is one skill, and answering exam questions is another. Our upcoming guide to NEC code questions and answers will collect practice questions on definitions, grounding, branch circuits and wiring methods, each with the article and section that gives the answer.

What Article Can You Find NEC Definitions

Article 100 holds the NEC definitions, and Article 90 explains how to use them. Terms like “raceway,” “branch circuit” and “wet location” are defined there, and Article 300 assumes you know them. Our upcoming guide on what article you can find NEC definitions will cover the most-searched terms.

NEC Code Year by State

The NEC applies only where a state or city adopts it, often with amendments, so one state can enforce the 2020 NEC while its neighbor enforces the 2023 or 2026 edition. Our upcoming NEC code year by state guide will list the adopted edition by state. Check it before you cite an Article 300 section number.

Tools and Guides That Support the NEC Article for Wiring Methods

FAQs About the NEC Article for Wiring Methods

Which NEC article covers wiring methods?

Article 300 is the general article, and Chapter 3 holds the articles for each specific wiring method.

What is Article 300 in the NEC?

It is General Requirements for Wiring Methods and Materials, covering protection, securing, underground cover and conductor fill.

What is the minimum burial depth under Article 300?

Table 300.5 sets it by wiring method, from 6 in. for RMC to 24 in. for direct-buried cable.

Is Article 310 part of wiring methods?

Yes. Article 310 is in Chapter 3 and gives conductor ampacity and insulation types.

Conclusion

The NEC article for wiring methods is Article 300, and it is the first place to look before you open any specific raceway or cable article. Learn the key sections, apply Table 300.5 for burial depth, size conductors from Article 310, and confirm your edition and local amendments before you inspect or install. Then return to the NEC articles list for the next article you need.

Disclaimer: This article is for educational use and does not replace the NEC, local amendments or your AHJ. Electrical work should be done by qualified persons.

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NEC Article for Wiring Methods: Article 300 Rules Explained (2026)