Practice Test Geeks(EETC) Electrical Technician Certification Practice Test
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Power Distribution Flashcards

7 cards from real EETC practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.

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  1. In power distribution, 'load factor' is defined as:

    Answer: Average load divided by peak demand over a given period

    Load factor = average load / peak load over a period, indicating how efficiently the system capacity is utilized; a higher load factor means more uniform loading.

  2. What is the typical voltage range for 'primary distribution' circuits in the United States?

    Answer: 2.4 kV to 35 kV

    Primary distribution operates at medium voltages, typically 2.4 kV to 35 kV (most commonly 4, 13.2, 13.8, or 25 kV), between the substation and distribution transformers.

  3. Which type of fault produces the highest fault current on a three-phase power system?

    Answer: Bolted three-phase fault

    A bolted (zero impedance) three-phase symmetrical fault produces the highest fault current because all three phases are involved symmetrically with no fault impedance.

  4. A distribution recloser is set for a '2 fast, 2 delayed' sequence. What does this mean?

    Answer: It opens twice quickly, then twice after a time delay, and locks out after the 4th operation

    The '2 fast, 2 delayed' sequence means the recloser trips twice on a fast (instantaneous) curve, then twice on a slower time-delay curve before locking out after the fourth operation if the fault persists.

  5. Underground residential distribution (URD) cables most commonly use which insulation material?

    Answer: Cross-linked polyethylene (XLPE) or EPR

    Modern URD cables use XLPE or EPR insulation for their superior electrical properties, moisture resistance, and long service life compared to older materials.

  6. What is the primary cause of 'ferroresonance' in distribution systems?

    Answer: Interaction between transformer magnetizing inductance and system capacitance under light or no-load conditions

    Ferroresonance occurs when the nonlinear magnetizing inductance of an unloaded or lightly loaded transformer resonates with cable or capacitor charging capacitance, producing overvoltages.

  7. According to the NESC, what minimum vertical clearance above ground is required for a 13.8 kV overhead distribution conductor crossing a public roadway (open country)?

    Answer: 18 feet

    The NESC requires 18 feet of vertical clearance for conductors operating at 15 kV or less crossing roads accessible to truck traffic in open country.