Electric Distribution

  1. Which of the following is NOT a function of the Main Power Distribution System?
    Transmits and steps down generator output for distribution
  2. What does ESF stand for?
    Engineered Safeguard Features
  3. All electrical systems and components vital to plant safety, including the emergency diesel generators, are designed so that their integrity is not impaired by the maximum potential earthquake, wind storms, floods, or disturbances on the external electrical systems. These components are known as?
    Class 1E / Safety Related.
  4. Name a concept that is NOT a major consideration in the Electrical System's design
    Ensuring that all electrical trains are tied together through bus tie breakers in order to maintain an electrical network for optimum reliability.
  5. Which switchyard bus is used to supply the unit #3 startup transformer
    NE 240KV Bus
  6. What is the normal feed breaker to the 3D 4KV Bus
  7. How many secondary windings are on the unit 3 auxiliary transformer?
    two 4KV windings
  8. How many 4KV busses and 480 Volt Load Centers are on unit #3?
    four 4KV busses (A,B,C,D) and eight 480 Volt Load Centers (A(01),B(02),C(03),D(04),E(41),F(14),G(15),H(50))
  9. What is the purpose of the station blackout tie breaker?
    ties unit 3 and unit 4 4160 'D' busses together
  10. Which 480 volt load center is known as the swing load center
    3H 480 Volt Load Center
  11. What is the purpose of the SF-6 gas in the 240KV switchyard circuit breakers?
    SF-6 is used to absorb heat and to extinguish the arc of the breaker contacts
  12. What is the purpose of the G switchyard switches?
    They are operated only on circuits with no current flow for isolation
  13. What is the purpose of the X switchyard switches?
    They are normally open and can be used to ground a line when closed.
  14. What component is NOT found inside the switchyard switch house?
    Main Generator 240KV Breaker Control Handles
  15. Of the eight transmission lines, which one shares the switchyard bay #7 with the Main Transformer #3 240KV breakers?
    The Davis #3 240KV Line
  16. What is the purpose of the Isophase bus?
    22KV bus that connects the generator output to the main and aux transformers
  17. What type of cooling is used for the Isophase buse?
    Air circulated through the Isophase bus work. Air cooled by TPCW.
  18. Name a component that is NOT used to protect the main transformer
    The Anti-motoring reverse power relay
  19. What is the purpose of the main transformer bladder located on top of the conservator oil tank?
    Prevents oxygen and moisture from mixing with the transformer oil
  20. Which transformer's fault pressure relay does NOT trip its respective lockout relay and provides an alarm only?
    Startup Transformer
  21. Which transformers require pumps and fans running to prevent overheating?
    Main and Auxiliary Transformers
  22. What are the vital 4KV buses
    A, B, D
  23. What is NOT fed from a vital 4KV bus?
    3A Charging Pump
  24. Which 4KV bus feeds the 3B Steam Generator Feed Pump
  25. What power ratings are pumps fed from the 4KV buses
    >300 HP
  26. What are the 3A 4KV bus breaker numbers for Unit 3 Aux transformer,_____, Unit 3 Startup Transformer, _____ , Unit 4 startup Transformer, _____, 3A EDG, ______?
    • 3AA02 - Aux
    • 3AA05 - Startup
    • 3AA22 - Unit 4 Startup
    • 3AA20 - EDG
  27. What is the location of the 3D 4KV bus?
    in the Unit 4 EDG building
  28. In order to assure a dead bus manual on the 3D 4KV bus what sequence must take place?
    If feeding from the 3A bus, 3AD01 must be closed first with 3AD06 and 3AA17 open. Then 3AA17 can be closed to energize the bus.
  29. Under what conditions will a permissive blue light come on for the 3AD07 station blackout breaker assuming that the 4AD07 breaker is open and the 3A bus is to be used to power the 3D bus?
    Loss of offsite power, with 3A and 3D buses cleared and 3A and 3B EDGs unavailable.
  30. What power rating are loads fed from the 480 Volt Load Centers
    between 100 and 300 HP
  31. What power ratings are loads fed from the 480 Volt Motor Control Center
    <100 HP
  32. What is the purpose of the 4 safety related EDGs
    Provide 4KV power to the A and B 4KV buses following a loss of offsite power.
  33. What is the purpose of the reactor coil on the 4KV bus?
    The reactor coil's impedance limits the amount of short circuit current
  34. What breaker number is the 3A 4KV breaker tie to the 3A 480v Load Center
  35. What breaker number is the 4B 4KV EDG breaker
  36. In which section of the control room are the 3A, 3B, 3C, 3D 480 volt load center voltmeters along with thee switchyard voltmeter located
    Vertical Panel A (VPA)
  37. In what part of the control room are the 3A & 3B EDG watt and volt meters located?
  38. In which section of the control room are the 3E, 3F, and 3G 480 volt load center voltmeters located
  39. With PTN unit 3 at 100% power, following a main generator lockout relay trip for a main transformer failure, how would the 3A 4KV bus react
    The tripped lockout relay would open the auxiliary transformer breaker 3AA02 then it would automatically close the startup transformer breaker 3AA05
  40. What is the normal source of power for the 3D 4KV bus?
    3B 4KV Bus Breaker 3AB19
  41. Which devices activating result in an automatic closure of the low-side startup transformer 4KV breakers and tripping of the auxiliary transformer 4KV breakers
    A SI trip or a Generator Lockout trip
  42. When the unit is on-line the _______, normally supplies the A and B 4KV buses. With the unit off-line the ______, normally supplies the A and B 4KV buses
    Aux Transformer, Startup Transformer
  43. After the unit 3 RO closes in the 3AA02 auxiliary transformer 4KV breaker what should happen next?
    After the circuitry senses the 3AA02 closed the 3AA05 startup breaker will open as soon as the operator releases the breaker control handle
  44. Which of the following conditions will result in the 3B EDG starting and energizing the 3B 4KV?
    A sustained undervoltage condition exists on the 3D 480 Volt Load Center
  45. What is the purpose of the emergency load sequencer
    Provides sequential bus stripping, EDG start and critical loading
  46. With unit 4 in Mode 4 which of the following equipment is required to be in-service in order to satisfy the Electrical Power Systems Technical Specifications
    EDGs (4A, 4B, and 3A or 3B), Unit 3 & 4 Startup transformers, 4A and 4B train 4KV buses, Vital 480 load Centers 4A, 4B, 4C, 4D, 4H and MCCs 4A, 4B, 4C, 4D
  47. With unit 4 in Mode 5 which of the following equipment is required to be in-service in order to satisfy the Electrical Power Systems Technical Specifications
    Unit 3 or 4 Startup transformer, 4A or 4B train 4KV buses, and one train of vital 480 volt Load Centers and MCCs
  48. What is NOT a lesson learned from the SEN 282 HB Robinson Event
    Normal operating procedure guidance are always appropriate for the conditions created by damage from the event and must be followed
  49. What is NOT a condition for Entry into Main Transformer 3-ONOP-92.1
    Main Generator Lockout due to generator underfrequency
  50. What is the first thing that should be done when responding to a transformer alarm?
    Verify that the gas detector gauge is reading <200 cc gas from a distance of at least 100 feet away from the transformer
  51. What would result in a unit trip?
    Main transformer fault pressure relay as part of a 2 part AND gate logic
  52. When a 4KV breaker is open its ______ light will be lit, when it is closed the _____ light is lit, the _______ light indicated that DC power is available for tripping, and the ______ light verifies that the breaker charging power is available.
    Green, Red, Blue, White
  53. Who has possession of the transformer ONOPs and is in charge of the procedure during its evolution
    The unit 3 Reactor Operator in the control room.
  54. As part of the major action categories for the 3-ONOP-004.2 after a loss of the 3A 4KV bus if the 3A EDG is unavailable what is the order of sources of power that are used to try and re-energize the bus?
    #3 Startup, #4 Startup, Blackout Tie, 3C bus
  55. Which ONOP includes major action to verify that the turbine runback is not in progress
    3-ONOP-004.4 loss of 3C 4KV Bus
  56. In restoring the 4KV bus following a loss of off-site power what is the entry condition into the 3-ONOP-004.1
    A call from the the System Dispatcher indicating that the startup transformer is energized and the system is stable
  57. The load rating of individual components connected to a 480 volt Motor Control Center (MCC) is
    <100 HP
  58. What load is supplied by the 3D 4.16 KV bus?
    3C CCW pump
  59. Given the following plant conditions
    Reactor power is at 100% with NORMAL line-ups
    Describe the system response to an overcurrent trip on the LC 3H NORMAL supply breaker
    is automatically reenergized from the Load Center 3C
  60. Given the following conditions
    Unit 4 is in normal electrical lineup
    4C ICW pump is running (supplied by 4D bus)
    Describe the expected system response if a loss of offsite power occurs?
    4AB19 and 4AD06 would remain closed and the 4C ICW pump breaker would open
  61. Given Units 3 & 4 are in Mode 1 in normal electrical lineups. A loss of offsite power occurs and Unit 3 and Unit 4 trip with only the 4A EDG energizing the associated bus.
    Determine the correct power lineup
    It would be possible to re-energize the 3B 4KV Bus by opening 4AB19 and 4AD06, closing 4AD01 and 4AA17, and then closing 3AD07 and 4AD07
  62. To transfer 3D Bus from 3A bus to 3B bus, the interlock for the 3D 4KV Bus supply breaker requires that
    3D Bus must be de-energized
  63. When energizing the 3D 4KV bus from the 3B 4KV Bus, which correctly describes the interlock between 4KV Tie Breaker 3AB19 and the 4KV Tie Breaker 3AD06.
    3AD06 must be closed first. 3AB19 will trip if 3AD06 is opened
  64. Operators are attempting to energize 3D 4KV bus from the 3B 4KV bus.
    Describe the interlock between 3D 4KV bus feeder breakers 3AB19 and 3AD06
    3AD06 must be closed first. 3AB19 will trip if 3AD06 is opened
  65. The plant is aligned for normal 100% power operations. A reactor trip is experienced on Unit 3 with offsite power available. What is the expected final alignment of the Unit 3 electrical power distribution system, assuming all systems function normally and no operator actions are taken?
    The unit 3A and 3B 4KV buses will be supplied by the Unit 3 Startup. The Unit 3C 4KV bus will be supplied by the unit 3C transformer
Card Set
Electric Distribution
Electric System 1