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 ›The Texas Journeyman exam outline in one page: 20 subject areas across the NEC Knowledge and Calculations parts, scored questions per area, the score you need on each part, time…
Updated 2026-10-17 · Read the article ›Class 2 and Class 3 circuits, fire alarm cable types, plenum and riser ratings, keeping low-voltage cable away from power conductors, and how to support it, explained for apprentices preparing…
Updated 2026-10-12 · Read the article ›Why pools are bonded, what goes into the equipotential bonding grid, how bonding differs from grounding, GFCI for pool pumps, receptacle and luminaire clearances, and a pool pump branch-circuit example…
Updated 2026-10-12 · Read the article ›