Recent

  • Show all results for ""

🎧 New: AI-Generated Podcasts Turn your study notes into engaging audio conversations. Learn more

Untitled Quiz
37 Questions
0 Views

Untitled Quiz

Created by
@CorrectPeachTree

Podcast Beta

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the primary function of a differential protective relay?

  • To regulate voltage and current levels
  • To operate based on a quantitative difference of electrical quantities (correct)
  • To disconnect load in a power circuit
  • To trip a circuit breaker automatically

    • Which device is used to regulate various electrical quantities within certain limits?

  • Line switch
  • Tripping relay
  • Voltage directional relay
  • Regulating device (correct)

    • What does a voltage and power directional relay do when the power flow exceeds a predetermined value in the opposite direction?

  • Permits connection of circuits
  • Disconnects the two circuits from each other (correct)
  • Regulates voltage levels
  • Increases field excitation

    • What is the function of a field changing contactor?

    <p>To increase or decrease field excitation in one step</p> Signup and view all the answers

    How does a tripping or trip-free relay operate?

    <p>It prevents immediate reclosure of a circuit interrupter</p> Signup and view all the answers

    What is the primary function of the time-delay starting relay?

    <p>To give a desired amount of time delay in a switching sequence.</p> Signup and view all the answers

    Which device serves to make and break the necessary control circuits under desired conditions?

    <p>Master contactor</p> Signup and view all the answers

    What is the main purpose of the checking or interlocking relay?

    <p>To provide feedback on conditions of other devices.</p> Signup and view all the answers

    What kind of device is used primarily to shut down equipment and keep it out of operation?

    <p>Stopping device</p> Signup and view all the answers

    How does the anode circuit breaker function within a power rectifier?

    <p>To interrupt the rectifier circuit in case of an arc-back.</p> Signup and view all the answers

    Which device is responsible for connecting and disconnecting the source of power to equipment?

    <p>Control power disconnecting device</p> Signup and view all the answers

    What function does a reversing device provide?

    <p>It reverses a machine field or operation.</p> Signup and view all the answers

    Which device is reserved for future application?

    <p>Device Number 11</p> Signup and view all the answers

    What function does an undervoltage relay serve?

    <p>It functions on a given value of undervoltage.</p> Signup and view all the answers

    Which device disconnects one circuit from another for emergency purposes?

    <p>Isolating contactor</p> Signup and view all the answers

    What is the primary purpose of a flame detector?

    <p>To monitor the presence of flame in combustion processes.</p> Signup and view all the answers

    What type of relay functions based on power flow direction?

    <p>Directional power relay</p> Signup and view all the answers

    What is a master sequence device primarily used for?

    <p>To control the operating sequence of major devices.</p> Signup and view all the answers

    The main function of a thermal device apparatus is to respond to which of the following conditions?

    <p>Temperature exceeding or falling below a predetermined value.</p> Signup and view all the answers

    Which device is specifically designed to provide a visual indication of protective device function?

    <p>Annunciator relay</p> Signup and view all the answers

    What does a position switch do?

    <p>It makes or breaks contact based on apparatus positioning.</p> Signup and view all the answers

    What function does a machine thermal relay serve?

    <p>It operates based on the temperature of the machine components.</p> Signup and view all the answers

    Which relay type is specifically designed to indicate a fault through excessive current?

    <p>AC time overcurrent relay</p> Signup and view all the answers

    What is the primary role of an AC circuit breaker?

    <p>To interrupt and close an AC circuit during normal and fault conditions.</p> Signup and view all the answers

    The power factor relay operates based on what criteria?

    <p>Power factor deviations from a predetermined value.</p> Signup and view all the answers

    What triggers a rectification failure relay to act?

    <p>Failure of a diode to conduct or block properly.</p> Signup and view all the answers

    Which type of relay is focused on controlling field excitation in an AC motor?

    <p>Field application relay</p> Signup and view all the answers

    What action does an overvoltage relay perform?

    <p>Functions when voltage exceeds a specified value.</p> Signup and view all the answers

    Which device is designed to execute a shutdown after a time delay?

    <p>Time-delay stopping relay</p> Signup and view all the answers

    What is the primary function of a ground protective relay?

    <p>To detect insulation failure of equipment to ground</p> Signup and view all the answers

    How does a governor aid in operating machinery?

    <p>By regulating the flow of operational mediums like water or steam</p> Signup and view all the answers

    What does a notching or jogging device primarily control?

    <p>The timing of operation for equipment</p> Signup and view all the answers

    What does an AC directional overcurrent relay respond to?

    <p>AC overcurrent flowing in a specific direction</p> Signup and view all the answers

    What feature does a blocking relay provide?

    <p>Initiates a pilot signal for blocking external faults</p> Signup and view all the answers

    What is a permissive control device used for?

    <p>To allow or prevent equipment operation via manual control</p> Signup and view all the answers

    Which of the following best describes a rheostat?

    <p>A variable resistance device in electric circuits</p> Signup and view all the answers

    What does a level switch operate based on?

    <p>Given values or rate of change of level</p> Signup and view all the answers

    Study Notes

    Device Definitions and Functions

    • Master Element (Device 1): Initiates equipment operation (e.g., control switch, voltage relay, float switch).
    • Time-Delay Relay (Device 2): Introduces a delay before or after a switching operation. 
    • Checking/Interlocking Relay (Device 3): Monitors the position of other devices or conditions to ensure safe and correct equipment operation. 
    • Master Contactor (Device 4): Switches equipment on and off under specific conditions, controlled by the Master Element and other protective/permissive devices.
    • Stopping Device (Device 5): Shuts down equipment and holds it out of operation, excluding electrical lockout.
    • Starting Circuit Breaker (Device 6): Connects a machine to its starting voltage.
    • Anode Circuit Breaker (Device 7): Interrupts the circuit of a power rectifier if an arc-back occurs. 
    • Control Power Disconnecting Device (Device 8): Connects and disconnects the power supply to the control bus or equipment. 
    • Reversing Device (Device 9): Changes the direction of a machine’s field or performs other reversing functions.
    • Unit Sequence Switch (Device 10): Modifies the order in which units are placed in or out of service in multi-unit equipment.
    • Apparatus Thermal Device (Device 26): Monitors the temperature of equipment components (e.g., windings, coolers, rectifiers) and activates when exceeding or falling below a set value.
    • Undervoltage Relay (Device 27): Activates when the voltage drops below a predetermined level. 
    • Flame Detector (Device 28): Monitors the presence of pilot or main flames in equipment like gas turbines or boilers.   
    • Isolating Contactor (Device 29): Disconnects one circuit from another for maintenance, testing, or emergency operation. 
    • Annunciator Relay (Device 30): Provides visual indications of protective device operation and can perform a lockout function.
    • Separate Excitation Device (Device 31): Provides separate excitation during starting for circuits like synchronous converter shunt fields or power rectifier ignition circuits. 
    • Directional Power Relay (Device 32): Functions based on the direction of power flow, detecting reverse power during arc-back in rectifiers. 
    • Position Switch (Device 33): Makes or breaks contact when the main device reaches a specific position. 
    • Master Sequence Device (Device 34): Controls the operating sequence of major equipment devices during starting, stopping, or other switching operations (e.g., motor-operated switch, computer).
    • Brush-Operating Device (Device 35): Used to raise, lower, or shift brushes on a machine, short-circuit slip rings, or engage/disengage mechanical rectifier contacts.
    • Polarity/Polarizing Voltage Device (Device 36): Operates based on a predetermined polarity or verifies the presence of a polarizing voltage. 
    • Undercurrent/Underpower Relay (Device 37): Activates when the current or power flow falls below a predetermined level. 
    • Machine/Transformer Thermal Relay (Device 49): Functions when the temperature of a machine armature, other winding, or power rectifier/transformer exceeds a set value.
    • Instantaneous Overcurrent Relay (Device 50): Activates immediately on excessive current or current rise rate, indicating a fault. 
    • AC Time Overcurrent Relay (Device 51): Activates on excessive current or current rise rate, with a time delay, indicating a fault.
    • AC Circuit Breaker (Device 52): Opens and closes AC power circuits under normal conditions and interrupts them during faults or emergencies.
    • Exciter/DC Generator Relay (Device 53): Forces DC machine field excitation buildup during starting and operates when the machine voltage reaches a specific value.
    • Power Factor Relay (Device 55): Activates when the power factor in an AC circuit exceeds or falls below a predetermined level. 
    • Field Application Relay (Device 56): Automatically controls the application of field excitation to an AC motor at a specific slip cycle point.
    • Short-Circuiting/Grounding Device (Device 57): Short-circuits or grounds a circuit in response to manual or automatic triggers.
    • Rectification Failure Relay (Device 58): Activates if one or more anodes of a power rectifier fail to fire, detect arc-back, or malfunction.
    • Overvoltage Relay (Device 59): Functions when the voltage exceeds a predetermined value. 
    • Voltage/Current Balance Relay (Device 60): Operates based on discrepancies in voltage or current between two circuits.
    • Time-Delay Stopping Relay (Device 62): Delays shutdown or opening operations in conjunction with the initiating device in an automatic sequence.
    • Pressure Switch (Device 63): Activates based on pressure values or rate of change.
    • Ground Protective Relay (Device 64): Detects insulation failure to ground or flash-overs in machines, transformers, or other apparatus.
    • Governor (Device 65): Regulates the flow of fluids (e.g., water, steam) to the prime mover for starting, speed/load control, or stopping. 
    • Notching/Jogging Device (Device 66): Controls the number of operations of a device or equipment within a specified time, allowing intermittent acceleration or mechanical positioning at low speeds.
    • AC Directional Overcurrent Relay (Device 67): Activates when AC overcurrent flows in a predetermined direction above a set value.
    • Blocking Relay (Device 68): Initiates a pilot signal to prevent tripping on external faults (e.g., transmission lines) under specific conditions or blocks reclosing during out-of-step or power swing events. 
    • Permissive Control Device (Device 69): A two-position switch that either permits or prevents the operation of a circuit breaker or equipment based on its position.
    • Rheostat (Device 70): A variable resistance device used in an electric circuit, with electrical operation or auxiliary switches.
    • Level Switch (Device 71): Activates based on fluid level values or rates of change.
    • Load Resistor Contractor (Device 72): Opens and closes a DC power circuit for normal operation and interrupts it during faults or emergencies. 
    • Load Resistor Contact (Device 73): Shunts or inserts resistance into a power circuit for load limiting, shifting, indicating, space heating, or switching lights in regenerative load resistors. 
    • Differential Protective Relay (Device 87): Detects faults by comparing two currents or other electrical quantities based on percentage, phase angle, or other quantitative differences. 
    • Auxiliary Motor (Device 88): Operates auxiliary equipment (e.g., pumps, blowers, exciters).
    • Line Switch (Device 89): A disconnecting load-interrupter or isolating switch in AC or DC power circuits, with electrical operation or auxiliary features (e.g., magnetic lock). 
    • Regulating Device (Device 90): Controls quantities like voltage, current, power, speed, frequency, temperature, and load within set limits. 
    • Voltage Directional Relay (Device 91): Activates when the voltage across an open circuit breaker or contractor exceeds a given value in a particular direction.
    • Voltage and Power Directional Relay (Device 92): Connects two circuits if the voltage difference exceeds a set value in a specific direction and disconnects them if power flow exceeds a threshold in the opposite direction. 
    • Field Changing Contactor (Device 93): Increases or decreases the field excitation on a machine in one step.
    • Tripping/Trip-Free Relay (Device 94): Triggers a trip of a circuit breaker, contactor, or equipment, preventing immediate reclosure after automatic opening.
    • Devices 95-98: Reserved for specific applications where standard functions 1-94 are not suitable. 

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Related Documents

    Device Definition And Function PDF

    More Quizzes Like This

    Untitled Quiz
    6 questions

    Untitled Quiz

    AdoredHealing avatar
    AdoredHealing
    Untitled Quiz
    37 questions

    Untitled Quiz

    WellReceivedSquirrel7948 avatar
    WellReceivedSquirrel7948
    Untitled Quiz
    19 questions

    Untitled Quiz

    TalentedFantasy1640 avatar
    TalentedFantasy1640
    Untitled Quiz
    36 questions

    Untitled Quiz

    PatriLavender avatar
    PatriLavender
    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser