3.1 Navigating the 2026 NEC: Article 90, Code Structure & Article 100 Definitions
Key Takeaways
Minnesota Rules part 1315.0200 incorporates the 2026 NEC (NFPA 70-2026) by reference, and DLI states that it became effective August 17, 2026, and is the edition used for exam questions.
NEC 90.5 makes rules using "shall" or "shall not" mandatory, rules using "shall be permitted" or "shall not be required" permissive, and Informational Notes explanatory only.
In the 2026 NEC, branch-circuit, feeder, and service load calculations are in Article 120, not Article 220.
Article 100 defines a continuous load as one where the maximum current is expected to continue for 3 hours or more.
Minnesota Rules part 3801.3620 requires electrical equipment to be listed and labeled by a testing laboratory unless an approved alternative evaluation is accepted.
3.1 Navigating the 2026 NEC: Article 90, Code Structure & Article 100 Definitions
Quick Answer: The Minnesota exam is based on the 2026 NEC, and DLI provides a soft-cover copy at the test site. Learn Article 90's rules for reading the Code, know where the 2026 edition moved familiar material (load calculations are now Article 120), and master the Article 100 definitions that decide many questions.
How Minnesota adopts the NEC
Minnesota Rules part 1315.0200 requires all new electrical wiring, apparatus, and equipment to comply with the 2026 edition of the National Electrical Code (NFPA 70-2026), Minn. Stat. 326B.35, and the Minnesota State Building Code. The NEC is incorporated by reference and made part of the State Building Code. DLI's exam guide states that the 2026 NEC became effective August 17, 2026, and is the edition used for exam questions.
DLI's exam guide adds two practical points:
- The Code book provided at the exam is a soft-cover copy without tabs or other aids.
- The NEC now shows SI (metric) units first with inch-pound units in parentheses. Compliance with either value is compliance with the Code, but all exam questions and answers use inch-pound units.
Article 90: reading the Code correctly
| Section | What it says | Exam use |
|---|---|---|
| 90.1 Purpose | The practical safeguarding of persons and property from hazards arising from the use of electricity | The NEC is a minimum safety standard, not a design manual |
| 90.2 Scope | Covers installation and removal of conductors, equipment, raceways, signaling and communications systems, and optical fiber for public and private premises, yards, lots, carnivals, and similar sites | Utility generation, transmission, and distribution under exclusive utility control are not covered |
| 90.4 Enforcement | The authority having jurisdiction (AHJ) interprets the Code, approves equipment and materials, and may permit alternative methods where equivalent safety is achieved | In Minnesota the AHJ is the state electrical inspector or a local inspection program |
| 90.5 Language | "Shall" and "shall not" are mandatory; "shall be permitted" and "shall not be required" are permissive; Informational Notes are explanatory and not enforceable | Do not answer a question with an Informational Note as if it were a requirement |
| 90.9 Units | SI units are primary, inch-pound units follow in parentheses | DLI questions use inch-pound units |
Utility-owned office buildings, warehouses, garages, and similar buildings that are not an integral part of a generating plant, substation, or control center are covered by the NEC. Utility facilities used for the utility function are not. Minnesota mirrors this in Minn. Stat. 326B.36, which exempts utility facilities used for the utility function from inspection unless they are on the load side of the service point.
How the 2026 NEC is organized
The 2026 edition made large structural changes. Knowing where material now lives saves time on an open-book exam.
| Change in the 2026 NEC | What to know |
|---|---|
| Article 120 (new location) | Branch-circuit, feeder, and service load calculations moved here from Article 220 |
| Article 130 (new) | Energy management systems, including power control systems, moved from Article 750 |
| Article 206 (new) | General requirements for non-power-limited remote-control and signaling circuits |
| Article 406 (expanded) | Now covers "wiring devices": receptacles, cord connectors, attachment plugs, snap switches, dimmers, and electronic control switches; small switch-type devices moved here from Article 404 |
| Articles 245, 265, 266, 267, 268, 270, 305, 315, 495 | Over-1000 V ac (1500 V dc) overcurrent protection, branch circuits, feeders, outside circuits, services, grounding, wiring methods, MV cable, and equipment |
| Articles 720 to 723, 742, 750 | Consolidated general rules for limited-energy systems: wiring methods, power sources, cables, raceways and cable trays, overvoltage protection, and grounding and bonding |
| Article 772 | Fire-resistive cable systems (formerly Article 728) |
| Deleted articles | Article 235 (its material moved to Articles 265 to 268), Article 770 (optical fiber), and Article 805 (communications circuits) |
The Code also replaced "overcurrent protective device" with the acronym OCPD in many rules and added "ac" to rules that apply only to alternating-current systems.
Article 100 definitions that decide answers
All definitions are in Article 100, in one alphabetical list.
Access terms
| Term | Meaning | Example |
|---|---|---|
| Readily accessible | Capable of being reached quickly for operation, renewal, or inspection without having to use tools (other than keys), climb over or under, remove obstacles, or use portable ladders | Service disconnects and most OCPDs must be readily accessible |
| Accessible (equipment) | Admitting close approach; not guarded by locked doors, elevation, or other effective means | Equipment behind an unlocked door |
| Accessible (wiring methods) | Capable of being removed or exposed without damaging the building structure or finish | Junction boxes above lift-out ceiling panels |
| Concealed | Rendered inaccessible by the structure or finish of the building | Cable inside a finished wall; wiring in concealed raceways is considered concealed even if it becomes accessible by withdrawing it |
A box above a lay-in ceiling is accessible but not readily accessible, because reaching it requires a ladder.
Load and circuit terms
- Continuous load: maximum current expected to continue for 3 hours or more. Conductors and OCPDs for continuous loads are generally sized at 125% of the continuous load plus 100% of the noncontinuous load.
- Branch circuit: conductors between the final OCPD protecting the circuit and the outlets.
- Feeder: conductors between the service equipment, a separately derived system source, or another power supply source and the final branch-circuit OCPD.
- Service conductors: conductors from the service point to the service disconnecting means.
- Outlet: a point on the wiring system at which current is taken to supply utilization equipment. A receptacle outlet, lighting outlet, and a hard-wired water heater connection are all outlets.
Equipment approval terms
| Term | Article 100 meaning |
|---|---|
| Approved | Acceptable to the authority having jurisdiction |
| Listed | Included in a list published by an organization acceptable to the AHJ that evaluates products, maintains periodic inspection of production, and states that the item meets appropriate standards or has been tested and found suitable for a specified purpose |
| Labeled | Bearing a label, symbol, or other identifying mark of an organization acceptable to the AHJ that evaluates products and maintains periodic inspection, indicating compliance with appropriate standards |
| Identified | Recognizable as suitable for the specific purpose, function, use, environment, or application where described in a particular Code requirement |
Minnesota adds its own rule. Minnesota Rules part 3801.3620 requires all electrical equipment used in an installation to be listed and labeled by a testing laboratory, except where the department accepts an alternative, such as an evaluation by a testing laboratory or by an independent registered electrical engineer with a written report filed with DLI. Equipment that the NEC specifically requires to be listed cannot use the alternatives.
Grounding and bonding terms
| Term | Article 100 meaning |
|---|---|
| Grounded conductor | A system or circuit conductor that is intentionally grounded (usually the neutral) |
| Equipment grounding conductor (EGC) | The conductive path that provides a ground-fault current path and connects non-current-carrying metal parts of equipment together and to the system grounded conductor, the grounding electrode conductor, or both |
| Grounding electrode conductor (GEC) | The conductor that connects the system grounded conductor or the equipment to a grounding electrode or to a point on the grounding electrode system |
| Main bonding jumper | The connection between the grounded circuit conductor and the EGC, or the supply-side bonding jumper, or both, at the service |
| System bonding jumper | The same connection at a separately derived system |
| Effective ground-fault current path | An intentionally constructed, low-impedance path designed to carry ground-fault current to the source and allow OCPDs or ground-fault detectors to operate |
Worked example: continuous loads
A store feeder serves 40 A of sales-floor lighting that operates 14 hours a day and 12 A of stockroom lighting used intermittently. The sales-floor lighting is a continuous load, so the minimum feeder ampacity is A. Under 215.3, the feeder OCPD is sized the same way unless the assembly is listed for 100% continuous operation.
Under NEC 90.5, how should an Informational Note in the 2026 NEC be treated?
As explanatory material that is not an enforceable requirement
As a mandatory rule that the inspector must enforce
As a permissive rule that allows an alternative method
As a requirement that applies only to dwelling units
A junction box with splices is installed above a suspended ceiling with lift-out panels. Under Article 100, which term describes the box?
Readily accessible, as applied to equipment
Concealed, as applied to wiring methods
Not accessible, because a ladder is needed
Accessible, as applied to wiring methods
A candidate needs the dwelling unit standard load calculation in the 2026 NEC. Which article contains it?
Article 220
Article 120
Article 210
Article 230
Sections you finish are checked off in the contents.