B3 8.1

  1. Tap changers are used to regulate the                 voltage of the bank
    load side
  2. What are the two types of Tap Changers
    • No Load Tap Changers
    • Load Tap Changers
  3. What Tap Changers are most commonly used on distributing
    station banks
    No Load Tap Changers
  4. True/False

    No Load Tap Changers require that the bank be cleared up and grounded to change the taps.
  5. True/False

    These tap changers require that the bank be cleared up
    to change the taps.
  6. True/False

    LRC (Load Ratio Control) banks are used in place of voltage regulators on the feeders
  7. What are three major components to a tap changer
    • Motor Drive Mechanism
    • Tap Changer Assembly
    • Tap Connections to the Bank Winding
  8. The tap changer assembly consists of a:
    • Tap Selector
    • Contactor
    • Vacuum Interrupter
  9. Control power for the Tap Changer Assembly system is supplied from                 
    station service
  10. Regarding LTCs, the                    simulates the
    impedance of the circuit
    line-drop compensator
  11. True/False

    In LTCs, the simulated line-drop from the compensator is subtracted from the potential transformer secondary voltage, the results are applied to the voltage sensor
  12. The Operator Control Panel typically contains
    • Circuit breaker for the drive power
    • Tap indicator with drag hands
    • Auto/Manual switch
    • Raise/Lower switch
    • Remote/Local switch
  13. How does the indicator receive tap position information
    from the drive motor
  14.                   assure that the drive motor does not travel past
    predetermined limits
    Limit switches
  15. True/False

    Tap changers can be operated automatically, manually as a group (all three phases of the transformer), or manually at each individual phase
  16. The bandwidths used are between                volts on a 120-volt scale.
    1.5 and 3.0
  17. The time delay is adjustable from 10 through 90 seconds. The time delay is typically set for           
    30 seconds
  18. What do you do if a loss-of-vacuum alarm occurs
    • De-energize the power transformer
    • Check the tap changer for obvious problems
    • Report to the Load Dispatcher
Card Set
B3 8.1
Bank Tap Changers