Free Practice Questions for BM Électricien

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Key Facts: BM Électricien Exam

Niveau 5

French national qualification level (Bac+2 / EQF Level 5)

France Compétences (RNCP37531)

Maître Artisan

Official title accessible to BM holders with two years of practice

CMA France — Chambre de Métiers et de l'Artisanat

RNCP37531

Official national registry code for the BM Installateur en Équipements Électriques

France Compétences

10.0 / 20

Minimum score required to validate each modular competency unit

Règlement d'examen CMA France

100 MCQs

Comprehensive practice questions authored in this OpenExamPrep subject bank

OpenExamPrep Practice Curriculum

The BM Installateur en Équipements Électriques is France's premier artisanal qualification (Level 5 / Bac+2) for master electricians, awarded by CMA France. Evaluating both general business administration and complex electrical engineering (NF C 15-100, TT/TN/IT earthing schemes, short-circuit current calculations, KNX automation, IRVE charging, and NF C 18-510 safety), candidates must achieve at least 10/20 in each module. This 100-item practice bank delivers targeted mastery of technical calculations, installation standards, and artisanal management.

Sample BM Électricien Practice Questions

Try these sample questions to review concepts for the BM Électricien exam. Each question includes a detailed explanation. Start the interactive quiz above for the full 100+ question experience with AI tutoring.

1A master electrician is sizing the supply line for a three-phase 400 V induction motor with a mechanical power rating of 15 kW, a power factor (cos φ) of 0.85, and an efficiency (η) of 0.90. What is the design operating current (Ib) of the circuit?

A.21.6 A

B.26.8 A

C.31.2 A

D.37.5 A

Explanation: The electrical active power absorbed by the motor is P_elec = P_mech / η = 15,000 W / 0.90 = 16,667 W. The three-phase design current is calculated as Ib = P_elec / (√3 × U × cos φ) = 16,667 / (1.732 × 400 × 0.85) ≈ 26.8 A. Sizing the protective switchgear and cable cross-section must be based on this full-load operating current.

2Under French standard NF C 15-100, what are the maximum permissible voltage drops (chute de tension) between the origin of an installation connected directly to the public low-voltage distribution network (Tarif Bleu / Tarif Jaune) and any point of utilization?

A.1% for lighting and 3% for all other uses.

B.3% for lighting circuits and 5% for other uses (heating, power, sockets).

C.5% for lighting circuits and 8% for other uses.

D.6% for lighting circuits and 10% for motor circuits.

Explanation: NF C 15-100 Part 5-52 specifies that when an installation is supplied directly from the public low-voltage distribution grid, the maximum voltage drop between the connection point (point de livraison) and the load terminals must not exceed 3% for lighting circuits and 5% for other applications such as heating and power socket circuits.

3In an industrial facility equipped with a private medium-voltage/low-voltage (HTA/BT) transformer substation, what are the maximum permissible voltage drops under NF C 15-100 from the transformer secondary terminals to the equipment terminals?

A.3% for lighting and 5% for other uses.

B.4% for lighting and 6% for other uses.

C.6% for lighting circuits and 8% for other uses (motive power, heating).

D.8% for lighting circuits and 12% for motor starting transients.

Explanation: Under NF C 15-100 (Table 52N), when an electrical installation is fed from an on-site private HTA/BT transformer, the maximum allowable steady-state voltage drop is expanded to 6% for lighting circuits and 8% for other uses (such as motive power and heating), because the entire distribution chain from the transformer is under the owner's engineering control.

4A master electrician routes four three-phase multicore XLPE cables laid touching in a single horizontal layer on a perforated cable tray (chemin de câbles perforé). According to UTE C 15-105 / NF C 15-100 grouping tables, which grouping correction factor (f1) must be applied to determine the admissible current (Iz)?

A.0.80

B.0.75

C.0.65

D.0.50

Explanation: According to the grouping correction tables in NF C 15-100 (Table 52-E1 / UTE C 15-105), four multicore circuits routed touching each other on a single horizontal perforated cable tray require a grouping de-rating factor f1 of 0.75. The admissible continuous current capacity Iz of each cable is reduced by 25% due to mutual thermal proximity heating.

5An XLPE-insulated (PR) power cable is routed through an industrial boiler room where the ambient air temperature consistently reaches 45°C. Given that the normative reference temperature is 30°C and XLPE max operating temperature is 90°C, what thermal de-rating factor (f2) applies according to UTE C 15-105?

A.0.71

B.0.79

C.0.87

D.0.94

Explanation: The temperature correction factor is calculated using the formula f2 = √((θ_max - θ_ambient) / (θ_max - θ_reference)). For XLPE insulation, θ_max = 90°C and θ_reference = 30°C. With θ_ambient = 45°C: f2 = √((90 - 45) / (90 - 30)) = √(45 / 60) = √0.75 ≈ 0.866 (0.87). This reduces the cable's current-carrying capacity by approximately 13%.

6When designing a commercial distribution switchboard where the prospective symmetrical three-phase short-circuit current (Ik3) at the busbar is calculated at 22 kA, what condition must the ultimate breaking capacity (Icu) of the incoming circuit breaker satisfy under NF EN 60947-2?

A.Icu must be greater than or equal to 22 kA.

B.Icu can be 10 kA provided that service breaking capacity (Ics) is 100%.

C.Icu must be at least twice the prospective current (Icu >= 44 kA).

D.Icu is irrelevant; only the thermal trip threshold (Ir) governs switchboard protection.

Explanation: Under standard electrical engineering rules and NF EN 60947-2, every protective circuit breaker installed without an upstream limiting device must have an ultimate breaking capacity (Icu) at least equal to the maximum prospective short-circuit current (Ik max) at its installation terminals. Therefore, the breaker must have Icu >= 22 kA at 400 V.

7A 630 kVA, 20 kV / 400 V three-phase distribution transformer has a short-circuit impedance voltage (Usc) of 4.0%. Neglecting upstream grid impedance, what is the maximum prospective three-phase short-circuit current (Ik3 max) at the transformer low-voltage secondary terminals?

A.11.4 kA

B.15.8 kA

C.22.7 kA

D.32.5 kA

Explanation: First, calculate the nominal secondary current: In2 = S_tr / (√3 × U20) = 630,000 / (1.732 × 400) ≈ 909.3 A (or 885 A at 410 V no-load). The prospective three-phase short-circuit current is Ik3 = In2 / (Usc / 100) = 909.3 / 0.04 ≈ 22,733 A (22.7 kA). This benchmark value is essential for sizing the main low-voltage switchboard (TGBT) breaking capacity.

8According to the adiabatic thermal stress equation k²S² >= I²t under NF C 15-100, what is the normative value of constant k for a copper conductor insulated with cross-linked polyethylene (XLPE / PR)?

A.76

B.115

C.143

D.176

Explanation: Under NF C 15-100 / IEC 60364-5-54, the thermodynamic constant k represents conductor material and insulation thermal withstand. For copper conductors with XLPE (PR) or EPR insulation (operating up to 90°C and 250°C during short-circuit), k = 143. For copper with PVC insulation (70°C to 160°C), k = 115. For aluminum with XLPE, k = 94.

9In electrical switchboard engineering, what is the principle of 'cascading' (technique de filiation) between an upstream and a downstream circuit breaker?

A.Installing circuit breakers in series with identical rated currents to double the trip response time.

B.Utilizing the current-limiting capacity of an upstream circuit breaker to allow a downstream breaker with a lower nominal breaking capacity to safely interrupt prospective short-circuit currents.

C.Coordinating circuit breaker trip curves solely by ensuring the upstream thermal threshold is smaller than the downstream threshold.

D.Connecting multiple circuit breakers in parallel to divide high fault currents equally across branches.

Explanation: Cascading (filiation under NF C 15-100 / IEC 60947-2 Annex A) takes advantage of an upstream current-limiting circuit breaker's rapid arc choke capability during a fault. This reduces the peak current and let-through energy downstream, allowing downstream circuit breakers to be selected with a breaking capacity (Icu) below the local prospective short-circuit current, verified via manufacturer coordination tables.

10To achieve total current-based selectivity (sélectivité ampéremétrique) between two standard miniature circuit breakers (MCBs) of the same trip curve (e.g., Curve C) in series, what is the general rule of thumb regarding their rated currents?

A.The upstream rating must be at least 1.1 times the downstream rating.

B.The upstream rating must be at least 1.6 to 2 times the downstream rating, though full selectivity is limited to overload and low fault currents.

C.Current selectivity cannot be established between breakers with identical curves under any circumstances.

D.The downstream rating must be at least 3 times greater than the upstream rating.

Explanation: Current-based selectivity relies on separating the instantaneous magnetic tripping thresholds. For standard MCBs sharing the same curve family (e.g. Type C), a rating ratio of at least 1.6:1 (preferably 2:1, such as 32 A upstream and 16 A downstream) ensures overload selectivity; however, for high short-circuit currents exceeding the upstream magnetic threshold, selectivity becomes partial unless energy-based limiting coordination is verified.

About the BM Électricien Exam

The Brevet de Maîtrise Installateur en Équipements Électriques (BM Électricien, RNCP37531, Level 5 / Bac+2) is the prestigious master-craft qualification delivered by the French Chambers of Trades and Crafts (CMA France). It entitles successful graduates to apply for the esteemed professional distinction of Maître Artisan. Designed for ambitious electrical technicians, site managers, and prospective enterprise founders, the credential validates advanced technical engineering in commercial, industrial, and smart residential electrical infrastructure under French standard NF C 15-100, alongside comprehensive enterprise leadership: costing and bidding (devis déboursé sec), human resources, apprentice mentoring, and renewable energy integration (photovoltaics, IRVE electric vehicle charging infrastructure, GTB building management). OpenExamPrep provides a rigorous 100-question practice bank formatted in English with authentic French technical standards to support master-level revision.

Exam sponsor: Chambre de Métiers et de l'Artisanat (CMA France). The requirements and fees below concern the certification or admission exam, separate from our free practice resources.

Assessment

The Brevet de Maîtrise Installateur en Équipements Électriques (RNCP37531, Level 5 / Bac+2, certified by CMA France) is organized into modular competency units divided between General Enterprise Modules (Module G: G1 Business Creation/Takeover and Management, G2 Commercial Development, G3 Human Resource Management, and G4 Apprentice Tutoring / Maître d'apprentissage) and Professional Technical Modules (Module P: P1 Complex Technical Studies & Electrical Installation Design under NF C 15-100, P2 Site Organization and Commissioning, and P3 Technical Viva Voce & Professional Dossier Defense before an expert industry jury). Technical evaluations involve creating complete distribution schematics, calculating cable cross-sections and fault levels, selecting switchgear, planning smart building networks (KNX, DALI, IRVE), and validating electrical safety pursuant to NF C 18-510.

Time Limit

General units: ~10h total | Technical design and oral defense: 6h

Passing Score

Minimum 10.0/20 in each module (general and professional)

Exam / Certification Fees

Varies by regional CMA (typically 800 €–1,500 € for full cycle or funded via CPF/OPCO)

Exam sponsor website

Fees, eligibility, and exam policies can change. Confirm them with the exam sponsor before applying or paying.

Official sources

Our practice resources: topics covered

We aim to reflect publicly available exam outlines and topic information in our study resources. Coverage, format, and difficulty may differ from the actual exam, and we cannot guarantee that every detail is accurate or current. Confirm exam requirements, fees, and policies with the official exam sponsor.

25 of 100 questions

Electrical Installation Design & Sizing (NF C 15-100)

Conductor sizing methodologies, installation method correction factors, permissible voltage drop limits (3%, 5%, 6%, 8%), prospective maximum and minimum short-circuit currents (Ik3, Ik min), thermal stress validation (k²S² >= I²t), circuit breaker breaking capacities, cascading, selectivity, and power factor compensation.

20 of 100 questions

Earthing Systems & Protection Schemes (TT, TN, IT)

Comparative analysis and operational rules for TT, TN-C, TN-S, and IT neutral regimes (schémas de liaison à la terre); touch voltage calculation; residual current devices (DDR) and tripping thresholds; permanent insulation monitoring (CPI) in IT networks; and surge arrester (parafoudre) integration.

20 of 100 questions

Smart Systems, Automation & Energy Transition

KNX building automation architecture, line couplers, and ETS commissioning; DALI/DALI-2 digital lighting protocols; electric vehicle supply equipment (IRVE) compliance under Décret 2017-26; grid-tied photovoltaic design under UTE C 15-712-1; and commercial building management systems (BACS / GTB).

15 of 100 questions

Electrical Safety, Compliance & Commissioning (NF C 18-510)

NF C 18-510 safety authorizations (B1V, B2V, BC, BR, BS); the strict 5-stage de-energization and lockout protocol (consignation); absence of voltage testing (VAT); mandatory initial verification tests (insulation, loop impedance, RCD trip curves); and Consuel compliance attestations.

20 of 100 questions

Artisanal Business Management, Devis & Apprentice Tutoring

Price study principles (déboursé sec, frais de chantier, frais généraux, coefficient de vente K, hourly labor rate), working capital (BFR) and cash flow budgeting, decennial liability (assurance décennale), public procurement subcontracting rights, and pedagogical coaching of apprentices.

Preparing for the BM Électricien Exam

What You Need to Know

Passing score: Minimum 10.0/20 in each module (general and professional)
Assessment: The Brevet de Maîtrise Installateur en Équipements Électriques (RNCP37531, Level 5 / Bac+2, certified by CMA France) is organized into modular competency units divided between General Enterprise Modules (Module G: G1 Business Creation/Takeover and Management, G2 Commercial Development, G3 Human Resource Management, and G4 Apprentice Tutoring / Maître d'apprentissage) and Professional Technical Modules (Module P: P1 Complex Technical Studies & Electrical Installation Design under NF C 15-100, P2 Site Organization and Commissioning, and P3 Technical Viva Voce & Professional Dossier Defense before an expert industry jury). Technical evaluations involve creating complete distribution schematics, calculating cable cross-sections and fault levels, selecting switchgear, planning smart building networks (KNX, DALI, IRVE), and validating electrical safety pursuant to NF C 18-510.
Time limit: General units: ~10h total | Technical design and oral defense: 6h
Exam / certification fees: Varies by regional CMA (typically 800 €–1,500 € for full cycle or funded via CPF/OPCO) Official sources

Using Our Practice Resources

Work through all 100 available questions
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BM Électricien: Suggested Study Strategy

1Master conductor sizing formulas under UTE C 15-105: calculate the fictitious current I'b by dividing the circuit design current Ib by all applicable environmental de-rating factors (k1 for grouping, k2 for ambient temperature, k3 for soil/duct conditions), then verify that the cable's admissible current Iz exceeds I'b.

2Thoroughly analyze earthing systems (SLT): memorize the fundamental differences between TT (mandatory 300/500 mA head RCD and 30 mA branch RCDs), TN (fast overcurrent disconnection within Table 41A times where Id = 0.8 * U0 / Z_loop), and IT (continuous operation on first fault with CPI alarm, instantaneous trip on second fault).

3Calculate prospective short-circuit currents: compute transformer maximum Ik3 at switchboard terminals using Ik3 = (S_tr / (√3 * U20)) / (Usc% / 100), and ensure all upstream protective devices possess breaking capacity (Icu/Icn) greater than or equal to this value.

4Review the NF C 18-510 electrical safety standard: memorize the 5 sequential steps of the consignation protocol (Séparation, Condamnation, Identification, Vérification d'Absence de Tension - VAT, and Mise à la Terre / Court-Circuit - MALT/CC).

5Practice artisanal cost estimation (devis déboursé sec): understand how to calculate direct material and labor costs, apply general overhead rates (frais généraux), determine the coefficient de vente K (PVHT / DS), and calculate required working capital (BFR) for multi-month contracting projects.

Frequently Asked Questions

What is the Brevet de Maîtrise (BM) Électricien and what qualification level does it represent?

The Brevet de Maîtrise Installateur en Équipements Électriques is a Level 5 state-recognized professional title (Bac+2 / EQF Level 5), registered under code RNCP37531. Delivered by the regional Chambers of Trades and Crafts (CMA France), it represents the pinnacle of artisanal electrical qualifications in France, certifying both advanced technical engineering and comprehensive business management.

How does the Brevet de Maîtrise lead to the title of Maître Artisan?

Graduates who hold the Brevet de Maîtrise in their trade and can demonstrate at least two years of professional electrical management experience are eligible to apply to the CMA for the official legal title of Maître Artisan (Master Craftsman), the highest honorary and professional title awarded in the French craft sector.

What is the difference between a BP Électricien, BTS Électrotechnique, and the BM Électricien?

While the BP (Brevet Professionnel) is a Level 4 qualification focused on site execution, and the BTS is an academic technical diploma, the BM Électricien uniquely pairs Level 5 advanced technical design (NF C 15-100, industrial schematics, KNX, IRVE) with entrepreneurial leadership, financial costing (devis déboursé sec), legal administration, and the certified pedagogy required to train apprentices as a Maître d'apprentissage.

What qualifications are required to install commercial EV charging stations (IRVE) in France?

Under French Décret n° 2017-26, any charging infrastructure with a power output exceeding 3.7 kW must be installed by a certified professional holding an IRVE qualification issued by an accredited body such as Qualifelec or AFNOR Certification. Training levels range from Level 1 (basic AC up to 22 kW without power management) to Level 2 (smart AC charging with dynamic load shedding) and Level 3 (fast DC charging up to high power).

Why is this OpenExamPrep practice bank presented in English?

This practice test bank is an English-language adaptation developed by OpenExamPrep to assist bilingual apprentices, foreign engineers, and international tradespeople seeking to master the rigorous technical French standards (NF C 15-100, NF C 18-510, UTE guides) and French artisanal management principles required by CMA France.