NEC Code Reference — Plain-Language Guide to Every Article
The National Electrical Code (NFPA 70) is the foundation of every electrical install in the United States. These plain-language guides cover the highest-traffic articles. Every page links to the relevant NEC citation so you can verify in the official codebook.
Featured NEC Articles
We’ve published deep-dive guides for 18 of the most-searched NEC articles. More are being added regularly. For specific questions not covered, use the AI chat or download the Sparky AI app.
NEC 210
Branch Circuits
NEC Article 210 covers the requirements for branch circuits — the wiring from the final overcurrent device pro…
NEC 210.12
AFCI Protection
NEC 210.12 requires arc-fault circuit-interrupter (AFCI) protection on most 120-volt, single-phase, 15- and 20…
NEC 250
Grounding & Bonding
NEC Article 250 covers grounding and bonding — the requirements that limit voltage to ground, stabilize voltag…
NEC 310
Conductors
NEC Article 310 covers the general requirements for conductors and their type designations, insulations, marki…
NEC 310.15
Ampacity Calculations
NEC 310.15 contains the ampacity tables and the correction and adjustment factors that you apply to those tabl…
NEC 314
Boxes
NEC Article 314 covers the installation and use of outlet boxes, device boxes, pull boxes, and junction boxes.…
NEC 314.16
Box Fill Calculations
NEC 314.16 is the box fill calculation rule. It tells you how many cubic inches of capacity a box needs based …
NEC 408
Panelboards
NEC Article 408 covers switchboards, switchgear, and panelboards — the equipment that distributes branch-circu…
NEC 410
Luminaires
NEC Article 410 covers luminaires (lighting fixtures), lampholders, and lamps. It specifies wet, damp, and dry…
NEC 430
Motors
NEC Article 430 covers motors, motor circuits, controllers, and motor disconnects. Motor circuit sizing uses d…
NEC 440
HVAC
NEC Article 440 covers air-conditioning and refrigerating equipment. It is a specialized supplement to Article…
NEC 500
Hazardous Locations
NEC Article 500 introduces the classification system for hazardous locations — Class I (gases/vapors), Class I…
NEC 625
EV Chargers
NEC Article 625 covers electric vehicle (EV) supply equipment (EVSE) — the chargers used to charge EVs. As EV …
NEC 680
Pools & Spas
NEC Article 680 covers swimming pools, spas, hot tubs, fountains, and similar installations. It is one of the …
NEC 690
Solar PV
NEC Article 690 covers solar photovoltaic (PV) systems — the installation requirements for grid-tied and stand…
NEC 700
Emergency Systems
NEC Article 700 covers emergency systems — electrical systems essential for safety to human life that are requ…
NEC 702
Standby Generators
NEC Article 702 covers optional standby systems — generator and similar systems installed at the owner's optio…
NEC 720
Low Voltage
NEC Article 720 covers installations operating at less than 50 volts — landscape lighting, doorbells, intercom…
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Michael started in the IBEW at 18 and made foreman as a 3rd-year apprentice. Thirteen years in, he’s a Local 134 journeyman, a licensed electrical contractor, a licensed Illinois teacher, and OSHA 30 and EPA 608 certified. He teaches a federally recognized pre-apprenticeship on the south side of Chicago — where he’s helped 100+ students get into the IBEW. He built Sparky AI around exactly what the NJATC exam tests and what trips people up. Prep with this and you walk in ready.