EO1 B2 MAIN GEN Flashcards
During a Turbine/Generator startup, which ONE of the following actions should be taken AFTER
increasing generator output voltage to 25 KV?
A. CLOSE the Exciter Field Breaker
B. CLOSE the Main Generator Field Breaker
C. Raise Main Generator loading to 50 MWE.
D. CLOSE the Main Generator Output Breakers (34560/34561)
D
Per the Generator and Exciter Operating procedure, generator output breakers 34560 and 34561 should
be re-closed within one hour of being opened to
A. minimize pressure on seal components in the operating mechanism
B. minimize the potential for inadvertent main generator reenergization
C. avoid having to start an RCS cooldown within one hour
D. avoid reliance on disconnect switches for isolation
A
The following plant conditions exist:
- The plant is operating at 100% power
- Switchyard voltage is 365 Kv
- Main Generator MVars is O
The load dispatcher requests us to lower voltage. What actions should be taken?
A. Inform the Load Dispatcher that we are at minimum MVars and cannot lower voltage.
B. Inform the Load Dispatcher we are operating within the requirements of the voltage schedule and
maintain our current voltage.
C. Lower voltage as requested to the maximum Mvars IN allowed by the generator capability curve or
the voltage requirements of C1/D1 Busses.
D. Lower voltage to the maximum MVars OUT allowed by the generator capability curve or the voltage
limits of the C1/D1 Buses.
C
If reverse power of 5.2 MW is detected on the Main Generator, it will trip
A. immediately
B. after 2-3 seconds
C. after 25-30 seconds
D. only if the turbine stop valves are closed
C
The plant is at 100% power.
The following event occurs:
- Annunciator 16-4-B, VOLTAGE REG TRBL, is in alarm
- Generator Field Volts = O
- Generator Field Bkr Control Switch green light is ON
- Exciter Field Bkr control switch red light is ON
Assuming NO AUTOMATIC or OPERATOR actions occur, which ONE of the following conditions will result?
A. The Main Generator will fall out of synchronization with the Grid, resulting in slipping a pole.
B. An unbalanced loading between the three phase windings of the Main Generator.
C. An underfrequency condition, resulting in excessive temperatures being generated in the last
stages of the Low Pressure Turbines.
D. Oscillating current flows through the stator windings of the Main Generator resulting in
insulation breakdown.
A
The following plant conditions exist:
- The plant has commenced a power reduction.
- Main Generator loading is 800 MWe.
- Both isophase bus fans have tripped on overcurrent.
- Zone II operator reports local isophase bus temperatures are 106 °C and rising.
Which one of the following is the maximum Main Generator stator amperage limit imposed?
A. 24600 amps
B. 18200 amps
C. 12400 amps
D. 6600 amps
B
Given the following conditions for the Main Turbine/ Main Generator:
- 700 MWe
- 60 Hz
- 1800 Rpm
- EHC is in MANUAL
Describe the effect on the Main Generator if the EHC INCREASE LOAD pushbutton is depressed, with no
operator action.
A. MVARs rise
B. MWe rise
C. Excitation Voltage lowers
D. Frequency rises
B
The following plant conditions exist:
- 700 MWe
- 60 Hz@ 1800 RPM
- EHC in MANUAL
The AUTO VOLTAGE REGULATOR is turned in the LOWER direction. What are the effects on the Main
Generator?
A. KVARs will LOWER or go towards LEADING pf
B. KVARs will NOT change
C. KVARs will INCREASE or more lagging pf
A
5 MC The Main Generator is being paralleled and connected to the grid with the following
conditions:
* Generator Frequency 60.1 Hz
- Grid Frequency: 59.9 Hz
- Generator voltage: 345.5 KV
- Grid Voltage: 344.8 KV
When the Main Generator output breaker is closed, the generator will:
A. acquire real load and reactive load
B. acquire real load, but become a reactive load to the grid
C. become a real load to the grid, but acquire reactive load
D. become a real load and a reactive load to the grid
A
6 MC The Main Generator is being paralleled to the grid.
- Generator voltage and grid voltage are matched.
- Generator frequency is 60.1 Hz.
- Grid frequency is 60.0 Hz.
Closing the generator output breaker will
A. cause the generator to immediately pick up load
B. cause generator voltage to rise
C. cause a reverse power trip
D. cause the turbine to overspeed
A
Which ONE of the following is NOT a purpose of the Main Generator Exciter System?
A. To control Main Generator Terminal Voltage during Turbine Generator startup.
B. To control megawatt output of the main generator.
C. To control reactive loading on the Main Generator.
D. To supply DC current to the Main Generator Rotor.
B
2 MC The purpose of the Main Generator is to
A. Ensure power to C1 and D1 during a loss of offsite power
B. Control reactor power during plant operations
C. Convert mechanical energy of the turbine to electrical energy
D. Prevent the Main Turbine from overspeeding during a partial loss of load
C
4 MC The Main Generator converts the energy of the Main Turbine to energy for commercial sales.
A. thermal; rotational
B. mechanical; electrical
C. chemical; thermal
D. hydraulic; electrical
B
4 MC The Main Generator converts the energy of the Main Turbine to energy for commercial sales.
A. thermal; rotational
B. mechanical; electrical
C. chemical; thermal
D. hydraulic; electrical
B
Which ONE of the following describes the purpose of the Main Generator Under-excited Reactive
Ampere Limiter (URAL)?
A. Establishes a MINIMUM megawatt output (loading) for the main generator to prevent a reverse
power condition.
B. Establishes a MINIMUM LAGGING Power Factor to maintain grid stability.
C. Prevents voltage Regulator output from RAISING to a level which would cause excessive armature
heating.
D. Prevents the Voltage Regulator output from LOWERING to a level which could cause the Main
Generator to drop out of synchronization with the grid.
D
Which ONE of the following will cause the Main Generator Voltage Regulator to transfer from
AUTO to MANUAL?
A. Stator Coolant flow LOWERS
B. Generator Field Breaker OPENS
C. Main Generator Hydrogen pressure LOWERS
D. Main Generator Output Breakers (34560 & 34561) OPEN.
B
Which ONE of the following is an indication that the Main Generator Under- excited Reactive Ampere Limiter (URAL) is affecting voltage regulation control?
A. Excitation current cannot be increased manually.
B. The voltage regulator is not responsive to commands to lower excitation (both manual and
automatic).
C. In AUTO outgoing VAR load cannot be changed (increased or decreased).
D. The Voltage Regulator transfers from auto to manual.
B
Which ONE of the following describes the effect of the URAL circuit on the voltage regulator if the voltage regulator is in MANUAL?
A. In MANUAL control the URAL has NO EFFECT
B. Main Generator MVAR loading cannot be changed (increased or decreased)
C. Attempts to increase incoming MVARs become less effective
D. The voltage regulator will automatically transfer to AUTO control.
C
Which ONE of the following Main Generator components is the one into which terminal voltage is
induced?
A. Rotor windings
B. Stator Bars
C. Isolated phase bus
D. High voltage bushing
B
9 MC Which ONE of the following could be utilized to determine the stator winding temperatures of
the Main Generator?
A. Temperature meter in the Control Room.
B. Temperature readout located in “A” Switchgear Room.
C. Temperature readout located on Generator skirt.
D. Temperature readout located near Auxiliary Boiler.
D
11 MC Which ONE of the following describes the function of the Main Generator Stator?
A. Supplies the magnetic field
B. Has the output voltage induced into it
C. Cools the Main Generator Core
D. Connects the Main Generator to the Auxiliary Transformer
B
Which ONE of the following describes the FUNCTION of the Main Generator Rotor?
A. Supplies the magnetic field
B. Has the output voltage induced onto it
C. Contains stator cooling slots for cooling
D. Converts thermal energy to rotational motion
A
Which ONE of the following indicates the normal speed at full power of the Main Generator Exciter?
A. 900 RPM
B. 1200 RPM
C. 1800 RPM
D. 3600 RPM
C
Which ONE of the following is the function of the Main Generator Exciter Rectifiers?
A. Convert the Exciter DC to AC for the Main Generator Field.
B. Convert the Exciter AC to DC for the Main Generator Field.
C. Convert Main Generator field AC for use in the Exciter.
D. Couple Exciter AC and Main Generator Field to maintain 60 Hz.
B
Which ONE of the following describes the location of the Alternator Exciter Field Breaker?
A. Exciter house, 623’ elev.
B. 13.8 KVA “A” bus, 585’ elev.
C. Control Room cabinet area, 623’ elev.
D. Voltage regulator cabinet, 603’ elev.
D
Which ONE of the following describes the location of the Alternator Exciter Rectifier disconnects?
A. Exciter housing, 623’
B. 13.8 KVA “A” bus, 585’
C. Control Room cabinet area
D. Voltage regulator cabinet, 603’
D
Which ONE of the following components applies the Direct Current directly to the Main Generator Field Windings?
A. brushes and collector rings
B. high voltage bushings
C. exciter field rectifiers
D. rotor retaining rings
A
In accordance with OB-OP-06301, which of the following values is the maximum value that can
be applied to the Generator Field?
A. 500 VAC
B. 400 VAC
E. 250 VAC
D. 120 VAC
A
4 MC Which ONE of the following combinations describes the field current of the Main Generator?
The current passes through the field breaker, then is supplied to the Main Generator
field windings via exciter brushes.
A. DC; generator
B. DC; exciter
C. AC; generator
D. AC; exciter
A
ONE purpose of the lsophase Bus Cooling System is to cool the
A. Main Generator rotor
B. Main Generator stator
C. Power Rectifier cabinets
D. Main Generator High Voltage bushings
D
Which ONE of the following sequences describes the flow path of air through the lsophase Bus
Cooling System?
A. fan, B phase duct, A and C phase ducts, cooling coil, fan
B. fan, cooling coil, B phase duct, A and C phase ducts, fan
C. fan, cooling coil, B phase duct, A and C phase ducts, outside air damper
D. fan, A phase duct, B phase duct, C phase duct, cooling coil, fan
A
Which ONE of the following combinations correctly arranges the Isolated Phase Bus Cooling System flowpath starting at the fan?
- Cooling coils
- De-ionizing
- “B” phased
- “A” and “C”
A. 1, 4, 3, 2
B. 2,3, 1, 4
C. 3, 2,4, 1
D. 4,3,2, 1
C
Which ONE of the following conditions is indicated if the Main Generator Core Monitor alarms?
A. Stator winding overheating
B. Power Rectifiers overheating
C. Exciter Rectifiers overheating
D. Rotor winding overheating
A