Apprentice to Master · 2020 & 2023 NEC
It is timed, and every question you have to hunt for costs you two more you never reach. This is a focused study companion for the navigation and calculations covered here, built for candidates who want honest practice against tables that have not moved in years.
Read a scenario, name the article, before you open anything. Article 310 or 240. Chapter 9 or the raceway article. The navigation drill nobody else builds.
Derating, breaker sizing, conduit fill, box fill, voltage drop, grounding conductors, motor circuits, the full dwelling service calculation. Pure calculations, so they are generated rather than shipped as the same fifty questions reshuffled.
Every distractor is the number one specific mistake produces. Pick one and you learn which mistake you made, not just that you missed.
Miss a calculation and you get numbered steps. Almost nobody fails these on arithmetic. They fail on one skipped step, and a paragraph hides which one.
Code Basics, Conductors & Ampacity and Installation Rules, including the article navigation drills, the ampacity quizzes, and the working space, burial depth, support spacing and receptacle placement numbers you look up on site. All eight field calculators are free too.
Six rooms cover code-book navigation, conductors and ampacity, the installation rules, worked calculations, dwelling service and load calculations, and grounding with motors. Ten calculation shapes generate fresh problems. Special occupancies, hazardous locations and the low-voltage chapters are not covered yet.
Built on the 2023 NEC, and every table the app computes from is unchanged across the 2020 and 2023 cycles, so the arithmetic is the same arithmetic your paper asks for. What does move between editions is coverage: GFCI and AFCI scope, surge protection, equipment disconnects. Those are taught as rules to confirm in your own book rather than as numbers to memorise, and the app has a screen listing exactly which tables are stable and which areas are not.
Unlocks Worked Calculations, Service & Load Calc and Grounding & Motors, extra sets in every covered room, endless generated practice, the timed challenge, and Code Minute, one shared five-question challenge a day.
A study aid, not a code book. Not affiliated with, endorsed by, or connected to the NFPA. Concepts and calculations are written in original wording with article numbers cited so you can verify each one yourself. Requirements vary by the code edition your jurisdiction has adopted and by local amendments, so always check the code in force where you work.