Non Class Electrical Flashcards
What are the loads on NBN-S01?
Turbine Cooling Pump A Plant Cooling Water Pump A Nuclear Cooling Water Pump A Heater Drain Pump B Normal Chiller B Condensate Pump A Condensate Pump B
State the possible characters for the second position in the electrical distribution system nomenclature. example: PBA-S03
A - 13.8 KV B - 4.16 KV G - 480 VAC LC H - 480 VAC MCC K - 125 VDC N - 120 VAC INST E - 4.16 KV DG Q - 120 VAC UPS
State the possible characters for the third position in the electrical distribution system nomenclature. example: PBA-S03
A - Train A B - Train B C - Train C D - Train D N - Non Train
State the possible characters for the fourth position in the electrical distribution system nomenclature. example: PBA-S03
D - Distribution Panel
M - Motor Control Center (Bus - generally < 50 HP loads)
L - Load Center (generally > 50 HP loads)
S - Switchgear
State the possible characters for the last two positions in the electrical distribution system nomenclature. example: PBA-S03
The last two numbers are particular to the equipment.
What is the Normal and Alternate Control Power Supply to NAN-S06?
NKN-M46 (Norm)
NKN-M45 (Alt)
On 13.8kV and 4160V Switchgear, the RED light indicates ….
Breaker CLOSED
Continuity through breaker Trip Coil
NOTE: If the RED light is NOT lit, the trip ckt may NOT function
On 13.8kV and 4160V Switchgear, the Bright GREEN light indicates ….
Breaker TRIPPED on fault or breaker racked to the TEST position.
A 480 VAC Load Center breaker has just been CLOSED, what is the status of the closing spring?
Discharged
After the bkr has been CLOSED, the closing spring remains discharged
When does the tripping spring charge for 13.8 kV and 4160V bkrs?
As the bkr closes, the tripping spring is charged.
Once the bkr contacts reach the full CLOSED position, the bkr latches in this position with the tripping spring fully charged and ready to OPEN the contacts.
What two functions does the 13.8kV and 4160V anti-pumping relay provide?
- Ensures that the bkr only attempts to close ONCE per control switch operation
- Prevents a bkr closure attempt with an uncharged spring
On U1 Control Panel B01, what do the two digital meters located on the vertical section of the control board indicate?
East and West bus voltages in the SRP Switchyard
List the transmission lines connected to the “ring bus”?
Westwing #1 Westwing #2 Rudd Hassayampa #1 Hassayampa #2 Hassayampa #3 Colorado River
What is the electrical capacity of one Startup Transformer (i.e. NAN-X01, X02 or X03)?
1/2 the non-Class 1E loads of one Unit and 2 trains of ESF loads, one of which is from another Unit, during Unit trips or during startup/shutdown operation.
Startup Transformer temperature is < 70C, what is the cooling mode?
Cooling is accomplished by natural circulation of the oil. Fans are NOT operating.
One pump and a bank of fans have just started on a Startup Transformer (i.e. NAN-X01, X02 or X03), what is the temperature of the transformer?
70C
At 70C, a thermal control device automatically turns on one oil pump and bank of fans
Temperature on the Startup Transformer is >75C, what is the cooling mode?
A second oil pump and bank of fans are energized, and operate in conjunction with the first pump and bank of fans to cool the Startup Transformer.
List the 4 Startup Transformer protective relays that detect a fault and isolate the transformer.
Differential Current
Neutral Ground Fault
Overcurrent
Sudden Pressure
The intermediate buses (NAN-S05 and S06) associated with Unit 1 supply the …
Water Reclamation Facility (WRF)
Startup Switchyard 480V LCs (NGN-L43 & L44)
525kV Switchyard - NAN-S05 powers SRP Swyd & Batt Chgrs
NAN-S03 & S04 receive control power from …
NKN-D41 (Non-Class 125 VDC) and NKN-D42 (Non-Class 125VDC) respectively
In order for an automatic FAST BUS Transfer to occur on NAN-S01 and NAN-S02, what conditions must be satisfied?
The BUS XFR SWITCH must be in AUTO
Generator trip must have occurred or UAT trip
Early ‘b’ contact on NAN-S01 norm supply bkr closed
Sync Check relay must be satisfied
NO bus lockout
Voltage must be available on NAN-S03 and NAN-S04
The Unit is shutting down and a transfer of in-house loads on NAN-S01 & S02 to off-site power is required. As the RO, you are directed to accomplish this via a Manual Bus Transfer, what conditions must first be met before in-house loads can be transferred?
Sync Switch must be ON
If NAN-S01 and S02 are energized, Sync Check relay must be satisfied
NO bus lockout
Voltage must be available on NAN-S03 and NAN-S04
NAN-S01 and S02 Normal Supply Bkrs (from UAT) trip under the following conditions …
Generator trip (initiates a fast bus transfer) Bus overcurrent During a manual bus transfer, when the alt supply bkr switch is returned to normal
What is a “Coastdown Trip”?
On a LOOP (loss of off-site power) and generator trip, S01 & S02 busses are load shed except for RCP bkrs. NAN-S01 & S02 normal supply bkrs are kept CLOSED for 20 seconds OR until voltage drops to 80%, whichever occurs FIRST. After this time, S01 & S02 de-energize and the RCPs stop.
What is the cooling mode of the NSF (NBN-X01 or X02) if temperature at the winding “hot spot” is 70C?
The transformers are of the Forced Air/Oil Air type. Fans operate based on temperature of the winding hot spot. When “hot spot” temperature reaches 70C, the fans start (if in AUTO).
What is the protection scheme for NBN-X01 and X02?
Sudden Pressure Relay
Transformer differential current
Phase and ground overcurrent
What is the purpose of the “Kirk Key” interlock?
A device installed to ensure that the B2 breaker is opened before the load interrupter switch (upstream of the transformer) can be OPENED. This prevents operating this switch under load which would damage the disconnect.
(ANNUNCIATOR) 4.16KV UNIT 1 SWGR S01 TRBL
Alarm received when: Supply bkr lockout UV (3675V), Negative sequence or 125VDC loss UV load shed (3255V) Cooling fan trouble
(ANNUNCIATOR) NORM SERV XFMR X01 PROT TRIP/ TRBL
Annunciator indicates a trip or problem with the transformer. A trip will result in a fast transfer of NBN-S01 to S02.
(ANNUNCIATOR) 480 VOLT LC L## TRBL
Each LC has its own annunciator. This indicates the following conditions:
LC transformer high temperature
Bus UV
Main Feeder bkr lockout
What is required for NAN-S01 and NAN-S02 Fast Bus Transfer to NAN-S03 and NAN-S04?
1) The ‘BUS XFR SWITCH’ must be in AUTO. 2) Generator trip must have occurred. 3) Early ‘b’ contact on NAN-S01 normal supply breaker must be closed. 4) Synch Check relay must be satisfied. 5) No bus lockout on either bus (86 lockout)
What is the Normal and Alternate Control Power Supply to NAN-S05?
NKN-M45 (Norm)
NKN-M46 (Alt)
Unit 2 was at 100% power with all systems in a normal alignment when the main turbine tripped.
After the turbine trip, startup transformer NAN-X03 trips on sudden pressure.
NBN-S01 is ___(1)___ and ___(2)___ Reactor Coolant Pumps are running.
A. (1) energized; (2) two
B. (1) energized; (2) four
C. (1) de-energized; (2) two
D. (1) de-energized; (2) four
A
Unit 3 was at 100% power with all systems in a normal alignment when the main turbine tripped.
After the turbine trip, startup transformer NAN-X03 trips on sudden pressure.
NBN-S01 is ___(1)___ and ___(2)___ Reactor Coolant Pumps are running.
A. (1) energized; (2) two
B. (1) energized; (2) four
C. (1) de-energized; (2) two
D. (1) de-energized; (2) four
B
What are the entry conditions for the Loss of Offsite Power (LOOP) EOP?
NAN-S01 and NAN-S02 are de-energized.
(ANNUNCIATOR) 525KV SWYD VOLT TRBL/ WRF TRIP PERM
Annunciator indicates a potential T.S. issue concerning off-site power capability. Action must be taken to evaluate and prevent double sequencing of SI equipment.
State the possible characters for the first position in the electrical distribution system nomenclature. example: PBA-S03
N - Non-Class
P - Class
To transfer MAN-PL922, PL942 and PL992 bkr control from TGD control to plant control, switch _________ is operated?
MAN-HS-942A (525kV line bkrs Control Transfer Switch)
To transfer MAN-PL912, PL932 and PL982 bkr control from TGD control to plant control, switch _________ is operated?
MAN-HS-932A (525kV line bkrs Control Transfer Switch)
(ANNUNCIATOR) 525KV SWYD BKR TRIP
Alarm indicates that a 525kV bkr has tripped.
Impact to the plant will depend on which bkr, and how many, tripped.
(ANNUNCIATOR) 13.8KV UNIT 1 SWGR S05 TRBL
Alarm caused by a lockout, UV/negative sequence,or loss of control power on the bus
(ANNUNCIATOR) SU XFMR X01/2/3 525KV BKR FAIL BKUP TRIP
Alarm is received when a 525 kV bkr trips.
Contact SRP to correct the problem, after problem corrected power can be restored to intermediate buses (NAN-S05/S06)
(ANNUNCIATOR) SU XFMR X01 125VDC PROT TRIP SPLY FAIL
Indicates a loss of 125VDC control power to the Startup transformer protection ckts. This transformer will NOT trip on a fault and poses a serious problem. AO should be sent to NKN-M45 and M46 to investigate. IF power cannot be restored, transfer loads OFF this transformer.
(ANNUNCIATOR) 13.8KV UNIT 1 SWGR S01 TRBL
Alarm received when: NAN-S01 load shed UV (12.6 kV), Negative Sequence or 125 VDC loss 480 VAC LC transformer supply bkr trip Cooling fan failure or loss of power
(ANNUNCIATOR) SU XFMR OSCG OPERATED/ TRBL
Investigate the Digital Fault Recorder
(ANNUNCIATOR) 13.8KV PWR SOURCES PARALLELED
Annunciator indicates when 13.8kV bkrs are in parallel.
(ANNUNCIATOR)
LAST
UNIT
ON-LINE
Annunciator indicates a potential T.S. issue concerning off-site power capability. Action must be taken to evaluate and prevent double sequencing of SI equipment.
(ANNUNCIATOR)
4.16KV
PWR
SOURCES PARALLELED
Indicates 4.16kV bkrs are in parallel
NBN-S02 receives Control Power from …
NKN-D42 (Non-Class 125 VDC)
NBN-S01 receives Control Power from …
NKN-D41 (Non-Class 125 VDC)
What conditions are required to MANUAL Bus Transfer NBN-S01(S02) to NBN-S02(S01)?
Sync Switch Aligned in the S01(S02) XFR position
NBN-X02(X01) is not locked out
No lockout on either NBN-S01 or S02
What are the required conditions for FAST Bus Transfer of NBN-S01(S02)?
B01 Bus Transfer Switch in AUTO NSF NBN-X01 (X02) Fault NBN-S01 (S02) Supply Breaker OPEN Voltage Sensed on NBN-S02 (S01) Sync Check Relay satisfied No Lockout on either bus
What are the loads on NBN-S02?
Turbine Cooling Water Pump B Plant Cooling Water Pump B Nuclear Cooling Water Pump B Heater Drain Pump A Normal Chiller C Small Normal Chiller E02 Condensate Pump C
