This package prepares candidates for Japan's First-Class Electric Chief Engineer Examination (第一種電気主任技術者試験), a national licensing examination under the Electricity Business Act. The primary stage comprises four mark-sheet multiple-choice subjects—Theory, Power, Machinery, and Law—while the secondary stage is descriptive in Power and Management and Machinery and Control. The 20-question set here checks supporting knowledge and calculation technique; it is not a simulation of either the primary A/B multiple-choice paper or the descriptive secondary examination. Always confirm current procedural and legal requirements with the issuing body. Build a four-subject foundation, drill units and models, practice written justification, and verify current legal material against current official material. The MCQ set checks supporting knowledge only and does not predict a result.
1. Scope, jurisdiction, and assessment map
This is a Japanese national licensing examination with a four-subject multiple-choice primary stage and a two-subject descriptive secondary stage.
This package is for the Japanese First-Class Electric Chief Engineer Examination, not a generic electrical engineering test. The official overview identifies it as a national examination under the Electricity Business Act, administered by the Electrical Engineer Examination Center as designated by the Minister of Economy, Trade and Industry. The license is a chief engineer qualification for business electrical facilities. The same official material states that a first-class licensee may be selected for any electrical facility without the voltage-range limit applied to second-class licensees, who are limited to facilities below 170,000 V. Those facts are context; always read the current official application instructions for procedural details.
The primary examination has four subjects: Theory; Power; Machinery; Law. The official overview says each is answered by mark-sheet multiple choice. The secondary examination has two descriptive subjects: Power and Management; Machinery and Control. The R8 application guide states that secondary answers are written and presents selection counts of 4 of 6 in Power and Management and 2 of 4 in Machinery and Control. Treat those counts as specific to the R8 application guide, not an eternal rule. The four topic areas in this guide are study organizers; no official topic weighting, pass mark, or question-by-question blueprint is asserted here.
The 20 MCQs at the end check supporting knowledge for primary-style content and some law-management concepts. They are not a simulation of either the primary A/B multiple-choice format or the descriptive secondary examination and do not cover the whole syllabus. A representative open written task appears later. Use official texts for current legal or procedural statements, and use this guide for mechanism practice, error diagnosis, and study design.
2. The tested skills: model, calculate, justify
Success depends on correct modeling, unit discipline, and the ability to explain assumptions and operational consequences.
The primary examination rewards multi-step calculation with clean units, approximations, and interpretation. In Theory, expect phasor representation, impedance, complex power, resonance, three-phase relationships, and transient reasoning. In Power, expect per-unit modeling, fault calculations, voltage regulation, stability, reactive-power compensation, and protective-relay reasoning. In Machinery, expect equivalent circuits from tests, transformer performance, induction-machine slip and torque, synchronous-machine excitation and power angle, and motor starting or speed control. In Law, the source places safety-related electrical regulations and electrical facility management, including technical standards interpretation, within the subject; this demands structured application rather than isolated trivia.
The secondary examination adds written justification. A good answer states assumptions, draws or describes the model, derives the result, keeps units visible, comments on limiting cases, and links the calculation to operation or safety management. Because no official pass mark is supplied here, do not invent one. Self-check against correctness, completeness, and clarity rather than a fabricated score threshold.
3. Preparation priorities without invented weightings
Prioritize dependency order: theory foundations, then power and machinery models, then law-management application, with written practice throughout.
No official topic weighting is supplied, so use dependency order. Start with phasors, complex power, three-phase relations, and per-unit conversion because these support both Power and Machinery. Then build transformer and machine equivalent circuits from no-load and short-circuit tests, followed by induction-machine slip-torque reasoning and synchronous-machine power-angle relationships. In Power, add fault modeling, voltage regulation, stability, and reactive compensation. In Law and management, learn the structure of duties, maintenance control, inspection records, and grounding concepts, while verifying current legal details in official material.
Keep a formula sheet that records conditions, not just equations: line versus phase quantities, per-unit base definitions, referred impedance, rms versus peak, and whether a machine is motoring or generating. Diagnose errors by type—model, algebra, unit, sign, or interpretation—rather than by topic alone. This prevents repetitive practice from merely rehearsing the same mistake.
4. Mechanisms with original worked scenarios
Short original calculations show how exam-level reasoning connects a model to a numerical result.
Series RLC and phase sign. A series circuit has R = 6 Ω, inductive reactance 10 Ω, and capacitive reactance 2 Ω. The net reactance is +8 Ω, so the impedance magnitude is sqrt(6² + 8²) = 10 Ω. With 100 V at 0°, the current is 10 A at about −53.1°, meaning it lags the voltage. The sign of net reactance, not the mere presence of a capacitor, determines lead or lag. For resonance, a 100 mH inductor and 10 µF capacitor give f0 = 1/(2π√(LC)) ≈ 159 Hz; at resonance the net reactance is zero, but inductor and capacitor voltages can exceed the supply voltage, so do not conclude that every component voltage is small.
Three-phase power. A balanced Y load has a 400 V line voltage and a per-phase impedance of 20 Ω at 0.866 lagging power factor. The phase voltage is 400/√3 ≈ 231 V, so phase current is about 11.55 A. Total active power is √3 × 400 × 11.55 × 0.866 ≈ 6.93 kW. Mixing phase voltage with line current, or omitting the power factor, produces a plausible but wrong answer. For a fault study, use the correct base: with 100 MVA and 66 kV, the base impedance is 66²/100 = 43.56 Ω, so an 8.712 Ω reactance is 0.20 pu. If a 10 kV bus has a 2 Ω per-phase Thevenin reactance and resistance is neglected, the three-phase fault current is (10,000/√3)/2 ≈ 2.89 kA; using 10 kV directly as a phase voltage is a common error.
Transformer tests and machine speed. A 50 kVA, 2400/240 V transformer has a rated high-voltage current of 50,000/2400 ≈ 20.83 A. If the short-circuit test from the high-voltage side gives 120 V, 20.83 A, and 400 W, then the equivalent impedance referred to the high-voltage side is 120/20.83 ≈ 5.76 Ω, resistance is 400/20.83² ≈ 0.922 Ω, and reactance is sqrt(5.76² − 0.922²) ≈ 5.69 Ω. For a 4-pole, 60 Hz induction motor, synchronous speed is 120f/p = 1800 rpm. At 4% slip, rotor speed is 1800(1 − 0.04) = 1728 rpm. Starting torque varies approximately with voltage squared, so reducing terminal voltage to 80% gives about 0.64 times the rated-voltage starting torque, not 0.80 times.
5. Common errors and how to catch them
Most lost marks come from predictable modeling and communication faults rather than exotic theory.
Watch for line/phase confusion in three-phase circuits, rad/s versus Hz, per-unit base changes, and impedance referred to the wrong side of a transformer. In AC circuits, check whether net reactance is inductive or capacitive before stating lead or lag. In fault work, distinguish prefault voltage from phase voltage and do not ignore the chosen MVA and kV bases. In machines, do not treat rotor speed as synchronous speed, do not make induction-motor torque linear in voltage, and do not confuse field excitation with mechanical speed in a synchronous machine. In written answers, missing assumptions, absent units, and an unexplained final sentence are substantive errors. In law-management answers, avoid memorized numbers without checking the current official text; explain the duty, the risk, the control, and the record.
6. Integrated practice task and self-check rubric
Use a compact per-unit and management task to integrate calculation with written justification.
Practice task. A 100 MVA base is chosen at 66 kV. A 66/6.6 kV transformer is rated 20 MVA with 0.10 pu leakage reactance on its own base. A 66 kV line has 0.25 pu reactance on the 100 MVA, 66 kV base. A 2 MVA load at 0.9 lagging power factor is connected to the 6.6 kV bus. First, convert the transformer reactance to the 100 MVA base. Second, estimate the three-phase fault current at the 6.6 kV bus for a 1.0 pu prefault source, neglecting resistance. Third, calculate the load current and approximate active and reactive power. Fourth, write a 250-word secondary-style answer explaining the model, assumptions, result, one protection or voltage-control implication, and two safety-management actions such as isolation verification and record-keeping.
Worked check. The transformer becomes 0.10 × (100/20) = 0.50 pu; total series reactance is 0.50 + 0.25 = 0.75 pu. The 6.6 kV base current is 100,000 kVA/(√3 × 6.6 kV) ≈ 8.75 kA, so the fault current is (1/0.75) × 8.75 ≈ 11.7 kA. The 2 MVA load current is 2,000/(√3 × 6.6) ≈ 175 A; active power is about 1.8 MW and reactive power about 0.872 Mvar. These values are approximate teaching values, not a claim about a real facility.
Self-check rubric. Score each criterion 0–2: (1) correct base conversion and single-line model; (2) numerical accuracy and units; (3) stated assumptions and limiting conditions; (4) operational interpretation of fault and load results; (5) safety-management language and records; (6) clear structure and readable derivation. A total of 0–7 indicates revisiting the model; 8–9 is usable but needs refinement; 10–12 is strong for this exercise. This rubric is a study aid, not an official scoring rule.
7. A practical study sequence
Use a twelve-week cycle that alternates calculation drills, mixed sets, and written explanation.
Weeks 1–2: rebuild Theory with daily short problems on phasors, complex power, three-phase circuits, resonance, and transients; begin a one-page formula sheet. Weeks 3–4: study Power systems using per-unit diagrams, fault calculations, voltage regulation, stability, and reactive compensation. Weeks 5–6: cover Machinery through transformer tests, induction-motor slip and torque, synchronous-machine excitation and power angle, and DC-machine basics. Week 7: build Law and management scenario cards around duties, maintenance control, inspection records, and grounding concepts, checking current official material. Week 8: take mixed timed sets and maintain an error log by error type. Weeks 9–10: write two secondary-style answers per week under time, choosing problems and stating assumptions. Week 11: run two timed mock sessions and review every error; practice only permitted basic arithmetic and square-root calculator operations. Week 12: consolidate the formula sheet, revisit high-value errors, and use short daily retrieval practice. This is a preparation heuristic, not an official weighting or score forecast.
8. Frequently asked questions
Short answers clarify the exam map and the limits of this preview.
FAQ answers are shown below.
FAQs
The following questions address common planning and assessment questions.
10. Official verification points
Use the official overview and R8 application guide for current identity, subjects, format, and procedural statements.
The official overview provides the subject map, assessment methods, primary subject-pass outline, and broad license context. The R8 application guide provides the application-stage schedule and format statements used here, including the secondary descriptive character and selection counts. Where a detail is procedural or legal, rely on the current official text rather than this independent guide.
References and further reading
Use these references to explore the concepts and check the latest information from the relevant organizations.