National Electrical Code (NFPA 70) and Chapter 120 Electrical Installation Standards
What this domain tests
This domain covers how Maine applies NFPA 70 and the Board's Chapter 120 Electrical Installation Standards. Questions ask you to locate the controlling article, apply Article 100 definitions, and recognize where a Maine amendment, permit rule, or inspection requirement changes the result. The NEC is the minimum installation standard; Chapter 120 adopts it by reference and adds state-specific requirements, so the stricter applicable rule controls for work in Maine.
Core rules
- Article 90 gives scope and enforcement. Article 100 definitions are testable: listed, labeled, identified, approved, accessible, and readily accessible.
- Chapters 1-4 are general; 5 special occupancies; 6 special equipment; 7 special conditions; 8 communications; Chapter 9 tables. Annexes are informative unless the Code or adopting rule makes them mandatory.
- Chapter 120 can amend NEC text. Do not quote an NEC section without checking the Maine amendment.
- Local permits and inspections are separate from licensing. Concealed work must be inspected before cover.
Worked example
A 12 ft dwelling kitchen wall counter has no breaks. Under NEC 210.52(C)(1), receptacle outlets must be installed so no point along the wall line is more than 24 in. from an outlet. With a 2 ft allowance at each end, place outlets at 2 ft, 6 ft, and 10 ft: three outlets. Reasoning: maximum spacing is 4 ft; the first outlet must be within 2 ft of the end; the last must be within 2 ft of the other end.
Traps
Treating informative annexes as mandatory; using an outdated edition; missing a Chapter 120 amendment; confusing listed with approved; forgetting GFCI/AFCI expansion; assuming a local inspector cannot be stricter.