MT, MG, CE (Stator), Isophase

Question 1

Which of the following Main Generator components is NOT cooled by Stator Cooling Water System?

A. Connection Ring
B. Collector Housing
C. Excitation Rectifiers
D. Terminal Bushings

Answer 1

B. Collector Housing

Question 2

Identify the electrical source that supplies power to the Air Stator Cooling Water Pump.

A. NGN-L15
B. NHN-M09
C. NKN-M46
D. NBN-S01

Answer 2

A. NGN-L15

Question 3

The following alarm has annunciated in the control room.  Which of the following is true?
Gen Stator
Clg Wtr
Lo Press
Hi Temp
Trip

A. The turbine will trip after a short time delay (70 seconds) if the initiating condition is not corrected.
B. The turbine should have tripped simultaneously with this alarm.
C. The turbine will trip if trends worsen but no parameter trip set point has yet been reached.
D. The turbine will not automatically trip on either of these parameters.

Answer 3

A. The turbine will trip after a short time delay (70 second) if the initiating condition is not corrected.

Question 4

Which one of the following will generate a main turbine trip? Stator Cooling water:

A. Conductivity HI-HI
B. Rectifier return flow Low.
C. Rectifier temperature HI-HI (2/3)
D. Pump discharge pressure HI

Answer 4

B. Rectifier return flow Low.

Question 5

Stator Cooling is in a normal lineup
CEN-P01 A running
CEN-P01 B in standby
CEN-P01 A trips unexpectedly. CEN-P01 B does not auto start.
The Operator turns the hand switch for CEN-P01B to the start position with no success.
Which of the following could have caused this condition?

A. CEN-P01A has tripped on low discharge pressure
B. Generator Reverse Power Trip
C. Low Stator cooling water tank level tripped both pumps
D. The Generator has tripped on Unit Differential Lockout

Answer 5

D. The Generator has tripped on Unit Differential Lockout

Question 6

When the CEN-HS-29B (Standby Stator Cooling test valve HV-29) is pressed, the:

A. Standby pump will start and then stop after the pushbutton is released
B. Running pump trips causing an auto-start of the standby pump
C. Standby pump will start and continue to run until secured manually
D. Standby pump starts causing an auto-trip of the running pump

Answer 6

C. Standby pump will start and continue to run until secured manually

Question 7

Which of the following is true of the Stator Cooling Water Heat Exchangers?

A. The tube side of the heat exchanger can be isolated at 100% power provided it is less than 24 hours
B. The shell side of one heat exchanger can be isolated, however the generator’s output must be lowered to 80%
C. The tube side of one heat exchanger can be isolated, however the generator’s output must be lowered to 80%
D. The heat exchangers cannot be isolated at power

Answer 7

C. The tube side of one heat exchanger can be isolated, however the generator’s output must be lowered to 80%

Question 8

Which of the following would be a consequence of the loss of Instrument Air to the Stator Cooling Water System?

A. The generator will trip on Low inlet water pressure
B. The generator will trip on High outlet temperature
C. Both stator cooling water pumps will trip on low suction pressure
D. This loss will not result in a generator or pump trip

Answer 8

D. This loss will not result in a generator or pump trip

Question 9

How many Isophase bus duct coolers are normally running?

A. 0
B. 1
C. 2
D. 3

Answer 9

C. 2

Question 10

Isophase bus duct cooling is supplied to the ____ phase and returns to the inlet via the ____ phase.

A. A and C; B
B. B; A and C
C. A; C
D. A, B and C; A, B and C

Answer 10

B. B; A and C