Practice Test Geeks(CET) Certified Elevator Technician Practice Test
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Electrical & Control Systems Flashcards

7 cards from real CET 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. What is the primary function of a phase-loss relay in a three-phase elevator motor circuit?

    Answer: Disconnect the motor if one phase is lost

    A phase-loss relay monitors all three phases and disconnects the motor if any single phase is lost, preventing single-phasing damage.

  2. In an elevator control circuit, what does a 'slowdown' switch typically do?

    Answer: Signals the controller to begin deceleration before reaching a landing

    A slowdown switch triggers the controller to initiate deceleration so the car arrives at a landing at proper leveling speed.

  3. Which type of relay is commonly used in elevator circuits to provide a time delay before re-acceleration after a brief power interruption?

    Answer: Time-delay relay (TDR)

    A time-delay relay (TDR) holds the circuit open for a preset period, preventing immediate re-acceleration that could cause passenger discomfort or mechanical stress.

  4. What is the purpose of a 'door zone' signal in a microprocessor elevator controller?

    Answer: Triggers the door open command only when the car is within ±3 inches of a landing

    The door zone signal confirms the car is within approximately ±3 inches of a landing, enabling the door operator to open safely.

  5. In a variable-frequency drive (VFD) controlled elevator, what determines the motor's rotational speed?

    Answer: The output frequency supplied by the VFD

    Motor speed in a VFD system is directly proportional to the output frequency, allowing smooth acceleration and deceleration profiles.

  6. What is 'regenerative braking' in an elevator VFD system?

    Answer: Converting kinetic energy back to electrical energy during deceleration or descent of a loaded car

    Regenerative braking converts the motor's kinetic or gravitational energy back into electricity that is fed back to the power grid or a resistor bank.

  7. Which ASME A17.1 code requirement applies to the elevator car lighting circuit?

    Answer: Must be supplied from a dedicated circuit separate from the driving machine circuit

    ASME A17.1 requires the car lighting circuit to be on a dedicated branch circuit independent of the driving machine to ensure lighting remains on during motor faults.