2026 NEC 210.8 GFCI and 210.12 AFCI lookups: dwelling vs other locations, the 150 V, 50 A and 100 A limits, kitchens, garages and dormitories.
Updated 2026-10-12 · Read the article ›Look up the GEC in Table 250.66 and the EGC in Table 250.122: which input each table uses, parallel sets, upsized wire and worked exam-style answers.
Updated 2026-10-12 · Read the article ›How to calculate three-phase current, kVA and kW with the 1.732 factor, how line and phase values differ in wye and delta systems, and worked 208 V and 480 V…
Updated 2026-10-12 · Read the article ›Ohm's law and the power formulas explained for electrical apprentices, with worked series, parallel and heater-on-the-wrong-voltage examples and the mistakes that cost points on the Texas Journeyman exam.
Updated 2026-10-12 · Read the article ›How to tell emergency, legally required standby and optional standby systems apart in the 2026 NEC, what each requires for transfer equipment, wiring, testing and signs, and a worked battery…
Updated 2026-10-12 · Read the article ›Worked 2026 NEC Article 690 calculations for solar PV: maximum string voltage with Table 690.7(A) or the module coefficient, maximum circuit current, the 156.25% conductor check, inverter output breakers, and…
Updated 2026-10-12 · Read the article ›What Article 645 of the 2026 NEC covers for IT equipment rooms, why it is optional, how the continuous load rule sizes ITE branch circuits with a worked 208 V…
Updated 2026-10-12 · Read the article ›How the 2026 NEC sizes supply conductors and overcurrent protection for arc welders: the effective current, the Table 630.11(A) duty cycle multiplier, the group of welders rule, the 200% breaker…
Updated 2026-10-12 · Read the article ›How the 2026 NEC handles motor controllers and disconnecting means: the in sight rules, what a disconnect must open and show, horsepower ratings, when one switch can be both, and…
Updated 2026-10-12 · Read the article ›How the 2026 NEC 240.21 tap rules work: why conductors are normally protected where they get their supply, the 10-foot and 25-foot feeder taps, transformer secondary taps, and worked sizing…
Updated 2026-10-12 · Read the article ›