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Month: October 2026

NEC 210.8 GFCI and 210.12 AFCI for the Journeyman Exam: How to Read the Voltage, Amp and Location Limits

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 ›

NEC Table 250.66 and Table 250.122 for the Journeyman Exam: How to Look Up GEC and EGC Sizes Step by Step

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 ›

Three-Phase Power Calculations for Apprentices: Where 1.732 Comes From, kVA to Amps and Wye vs Delta

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, Power and Series-Parallel Circuits for Apprentices: The Four Formulas and How Exam Questions Use Them

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 ›

NEC 700, 701 and 702 for Apprentices: Emergency, Legally Required and Optional Standby Systems and Their Transfer Switches

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 ›

NEC 690 PV Calculations for Apprentices: Cold-Weather String Voltage, the 125% Current Factors and Rapid Shutdown Limits

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 ›

NEC 645 Information Technology Equipment for Apprentices: When the Article Applies, the 125% Rule and Where Communications Wiring Fits

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 ›

NEC 630 Electric Welders for Apprentices: Duty Cycle, Branch Circuit Ampacity and Overcurrent Protection With Worked Examples

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 ›

NEC 430 Motor Disconnects and Controllers: In Sight Rules, Horsepower Ratings and One Switch for Several Motors

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 ›

NEC 240.21 Feeder Tap Rules for Apprentices: The 10-Foot, 25-Foot and Transformer Secondary Taps With Worked Sizing

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 ›
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Not a licensed Professional Engineer in Texas or any U.S. state. Does not offer engineering services. Exam-prep education only.