Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

LOIT > Non-Class Elec Dist. (NA, NB, NG, NH) COPY > Flashcards

Non-Class Elec Dist. (NA, NB, NG, NH) COPY Flashcards

1
Q

What is the electrical flow path from the Startup Yard to the WRF NB system for the Cooling Tower Make Up and Blowdown (TB) system?

Do these NB busses have cross tie capability?

A

NAN-S05/S06 -> NBN-X05/X06 -> NBN-S05/S06

Yes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

On a 13.8 kV (NA) breaker, what does the red light mean?

A

Breaker closed

continuity through trip coil

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

On a 13.8 kV (NA) breaker, what does the Green light mean?

A

Breaker Open

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

On a 13.8 kV (NA) breaker, what does the bright green light mean?

A

Breaker tripped on fault

breaker racked to test

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

On a 13.8 kV (NA) breaker, what does the white light mean?

A

status of lockout relay

if light is ON, relay is reset and continuity through it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

On a 13.8 kV (NA) breaker, what does the clear light mean?

A

closing springs are charged

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the control room indications for a breaker?

A

Red light - breaker closed & continuity through trip coil
green light - breaker open
bright green light - breaker tripped on fault or racked to test

voltmeter on B01
ammeter on B01

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the Startup Oscillograh for?

A

Multi-channel transient recorder (Digital Fault Recorder) that detects and automatically records power system abnormalities in analog and on-off event form.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

When do the closing springs recharge for big breakers?

A

immediately after discharging to close the breaker

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

When do 480 VAC LC breaker closing springs recharge?

A

when the breaker reopens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the purpose of Anti-pumping protection?

A

to ensure that the breaker only attempts to close ONCE per control switch operation

prevents closure attempt with an uncharged spring

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

When would you have to locally manually operate big breakers?

A

loss of control power

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Can we parallel power supplies locally electrically on non-class busses?

A

No

there are interlocks that prevent multiple supply breakers from closing at the same time when operating the breaker locally electrically

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the purpose of the synch switch in the control room in relation to operating breakers?

A

enables closure of multiple supply breakers in parallel

energizes synch indications on B01

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the purpose of the Line Breakers Control Transfer Switches regarding the 525kV SRP Switch Yard breakers?

A

Provides permissives to operate the SRP breakers from the Unit 1 control room

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are the two positions for the 525kV line breaker Control Transfer Switches?

A

PDO - SRP Control only

CON RM1 / PDO - allows Control Room control

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What indications are available for voltage on the EAST and West Busses in the SRP Switchyard?

A

two digital meters on U1 B01

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What alarm window indicates degraded or loss of voltage on the East/West busses in the SRP Switchyard?

A

EAST/WEST 525 KV SWYD LO/LO-LO VOLTS

(1B06B)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is a “ring bus” regarding the SRP Switchyard?

A

the East/West Busses that are connected to each other in 8 locations

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Regarding SRP Switchyard design, why is the ‘breaker and half scheme’ important?

A

transmission lines, startup transformers and main transformers connect between 525kV breakers. This ensures two paths that current can take in the switchyard.

prevents huge impact from a single fault (breaker failing open)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What voltage does the AE-ZYN-X05 transformer step down to from 525 kV?

A

12.47 kV

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is each Start-up transformer secondary winding designed to have the capability of doing?

A

Start and carry half the auxiliary loads of one unit while feeding one train of ESF loads of one of the two other units

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

How are the control and indication signals sent to/received from NAN-S05/S06?

A

Controls are hardwired and indications are multiplexed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What are the requirements for fastbus transfer on NAN-S01/S02 busses?

A

Bus XFR switch in AUTO.
Generator trip or MT trip (Zero VARs signal)
Early ‘b’ contact on S01 normal supply breaker must be closed
Synch check relay satisfied
NO bus lockouts
Voltage available on NAN-S03/04

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
When do the cooling fans start on the normal service transformer?
When “hot spot” temperature reaches 70C, if in AUTO
26
Where can we reset lockouts on non-class breakers (NA, NB, NG, NH)?
Locally ONLY
27
Where do MCC’s get control power from?
The magnetic starters get control power from downstream of circuit breaker
28
what features are lost when a Non-Class breaker loses control power?
remote breaker operation electrical protection trips
29
How do you manually charge closing springs on high voltage breakers?
5/8" ratchet attached to the end of a charging motor
30
What two 86 lockout relays are featured on 480 VAC LC breakers?
Bell alarm Ground fault (50G)
31
what is the bell alarm on the 480 VAC LC breakers?
White reset button provides local indication of: overcurrent trip breaker rack out interlock
32
Why are start up transformers physically and electrically separated from each other?
minimize the possibility of a single failure affecting more than one transformer
33
What are the isolation boundaries for the startup transformers?
two 525kV breakers 13.8 kV breakers on switchgear motor operated disconnects (MOD)
34
What are the startup transformer stages of cooling?
<70C - Natural circ of oil, no fans 70C - first stage of cooling fans, forced circ of oil >70C - second stage of cooling fans added to first stage, forced circ of oil
35
How does the Open Phase Detection system work for Startup Transformers?
trip function disabled CR alarm when open phase is detected
36
Where are all the NAN-S05/S06 supply breakers controlled from? Where are the load breakers controlled from?
Unit 1 can control ALL of the supply breakers, U2 and U3 can only control their respective supply breakers load breakers are controlled from their respective units
37
What protective relays are available for the Startup transformers?
Differential Current Neutral Ground Fault Overcurrent Sudden Pressure Open Phase Detection
38
When will the supply breakers to WRF open automatically?
SIAS or CSAS and switchyard reaches low voltage setpoint
39
Which bus supplies power to the SRP Switchyard for smaller loads?
NAN-S05
40
Where does NAN-S05/S06 receive control power from? How is it aligned?
NKN-M45/M46 through NKN-U45/U46 transfer switches
41
Where do NAN-S03/S04 get control power from?
NKN-D41/D42
42
Where do NAN-S01/S02 get control power from?
NKN-D41/D42
43
What happens in the plant if the Main Generator fails to trip on reverse power?
Zero VARs signal is generated to promptly initiate a fast bus transfer this prevents the Rx from tripping on low DNBR on the loss of RCPs
44
Requirements for NAN-S01/S02 manual transfer
Synch switch ON if NAN-S01/S02 energized, synch check satisfied NO bus lockouts voltage available on NAN-S03 and NAN-S04
45
NAN-S01/S02 normal supply breaker trips?
Generator trip bus overcurrent during manual bus transfer, when alt supply breaker handswitch returns to normal after closing
46
What is a coast down trip?
Generator trip concurrent with LOOP (loss of voltage on NAN-S03/S04) NAN-S01/S02 remain aligned to UAT all breakers except RCPs open on NA busses RCPs maintain flow through the core as they coastdown for 20 seconds or until <80% voltage (whichever comes first)
47
What electrical protection does the NAN-S01/S02 busses have?
overcurrent undervoltage & negative phase alarm in CR undervoltage relay for motor breakers and LC breakers undervoltage relay for coastdown trip
48
Big picture, how do we remove an NAN-S01/S02 bus from service
not an outage for other bus verify app. for loads lost remove loads from bus Unit in MODE 5, 6, or defueled secure CW pumps secure RCPs transfer NB bus to other NB bus make sure both supply breakers are open
49
What kind of cooling do the Normal Service Transformers have?
Forced Air/Oil (air is blown across the cooling fins filled with oil)
50
On the Normal service transformers, what is the purpose of the Auto-Throwover switch?
auto transfers control cabinet power supply to the alternate on a loss of the normal supply must be manually reset
51
What powers the Normal Service Transformer control cabinets?
NH
52
What protection does the normal service transformer have?
sudden pressure fault relay differential current phase and ground over current
53
what does the synch switch do for NBN-S01/S02 busses?
closes the tie breaker opens to associated normal supply breaker when the control switch is returned to normal
54
what are the requirements for NB auto bus transfer?
B01 Bus Transfer Switch in AUTO Normal Service Transformer NBN-X01 FAULT NBN-S01 Normal Supply breaker OPEN (early “b” contact) Voltage sensed on NBN-S02 Synch Check relay satisfied No lockout on either bus
55
manual NB bus transfer requirements what happens if you take the handswitch to the wrong position?
synch switch aligned NBN-X01/X02 NOT locked out no lockout on either NB bus the wrong breaker will trip (dont overshoot, either)
56
Where do NBN-S01/S02 get control power from?
NKN-D41/D42 individual control power breakers (RRC) inside the breaker cubicle
57
Purpose of the kirk key interlock?
prevent opening the mechanical disconnect under load
58
What indications are available for LCs in the control room?
breaker position voltage
59
Where are LC main feeder breakers normally operated from?
B01 can be locally also
60
Where are MCC breakers operated from?
locally ONLY
61
where do MCC breakers get control power from?
itself, downstream of the breaker
62
What could bring in this alarm window?
generator lockout fault on the UAT
63
What could bring in this alarm window?
startup transformer lockout
64
What could bring in this alarm window?
525kV breaker(s) tripped
65
What could bring in this alarm window?
undervoltage/negative sequence on the bus. UNIT 1 ONLY
66
What could bring in this alarm window?
525kV startup transformer supply breaker tripped
67
What could bring in this alarm window?
loss of control power to the SU Transformer protection circuits Unit 1 ONLY alarm
68
What could bring in this alarm window?
undervoltage negative sequence loss of control power cooling fan failure
69
What could bring in this alarm window?
issue with digital fault recorder UNIT 1 ONLY
70
What could bring in this alarm window?
when 13.8 kV breakers are paralleled
71
What could bring in this alarm window?
supply breaker lockout undervoltage negative sequence loss of control power undervoltage load shed cooling fan trouble
72
What could bring in this alarm window?
4.16 kV breakers in parallel
73
What could bring in this alarm window?
trip or problem with transformer must be investigated by AO if not a trip
74
What could bring in this alarm window?
transformer high temp bus undervoltage main feeder breaker lockout each LC has its own window
75
What could bring in this alarm window?
potential Tech Spec issue concerning off-site power capability
76
What could bring in this alarm window?
low switchyard bus voltage excessive load on the metering circuitry (sync switch on) loss of power to WRF trip permissive relays (NKN-D4303) loss of power to voltage metering (NNN-D1116)
77
What could bring in this alarm window?
issue with transformer AO must investigate UNIT 1 ONLY
78
Describe the response of the Non-Class Distribution system to a failure of power NA - NB -
complicates operation of the plant loss of RCPs - Rx trip loss of CDPs and EDPs - FWP trip on low suction psi and have to feed S/Gs with AF

LOIT (32 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions