Term
4KV
Describe the windings on 2R and 1R. |
|
Definition
-X windings supplies buses 11 and 12.
-Y windings supplies buses 13 and 14. |
|
|
Term
4KV
Describe power supply to bus 17 & 18. |
|
Definition
-Bus 17 normally from 1ARS transformer.
-Bus 18 normally from #6 transformer. |
|
|
Term
4KV
Describe what powers buses 15 & 16. |
|
Definition
-15 normally powered from 13 bus.
-Alternate supply from 1AR and 11 EDG.
-16 normally powered from 14 bus.
-Alternate supply from 1AR and 12 EDG. |
|
|
Term
4KV
Describe bus control power. |
|
Definition
-11,13,15 buses are div I (11 battery).
-12,14,16 are div II (12 battery).
-15,16 can be cross-connected.
-If 17 bus is energized then supplies both 17 and 18 bus control power.
-Loss of 17 bus transfers to 18 bus.
-ABT is normal seeking. |
|
|
Term
|
Definition
-Normal source for 4KV.
-Powered from 2RS.
-Control power is 480VAC (MCC-131/121 normal seeking).
-Sudden pressure rise in oil tank causes lockout and alarm |
|
|
Term
|
Definition
-Backup power to buses 11-16.
-Fan cooled based on amps powered from MCC-121. |
|
|
Term
|
Definition
-Normal power from 10 bank.
-Alternate feed from 1ARS. |
|
|
Term
4KV
Describe transformers 7 and 8. |
|
Definition
-Powers discharge structure buses.
-Interlock prevents both breakers being closed based on B disconnects. |
|
|
Term
4KV
Describe the automatic station power transfer. |
|
Definition
-Break before make.
-Transfers from 2R to 1R but not back.
-No time delays.
-Caused by anything that secures power to 2R.
-First trips both recirc pump drive motors and both CW pump motor breakers.
-If a recirc MG drive motor breaker fails to trip open, the 1R source breaker to associated bus (11 or 12) will not close.
-Then 2R breakers open then 1R breakers close.
-Buses 11,13,&14 auto transfer to 1R when bus voltage is <25% normal voltage.
-Bus 12 does not normally transfer, but will transfer if bus 11 is locked out or #11RFP breaker is open and 12 bus voltage < 25% rated. |
|
|
Term
4KV
Describe the loss of normal supply essential bus transfer. |
|
Definition
| -If both source breakers to a given bus open for > 5 seconds then the associated tie breaker trips and loss of voltage initiates. |
|
|
Term
4KV
Describe loss of essential bus voltage transfer. |
|
Definition
-Setpoint is 2625volts.
-4 sensing relays (1 out of 2 twice).
-Loss of voltage sensed then:
-Degraded bus voltage is disabled.
-5 second time delay and 10 second time delay initiated.
-Associated EDG starts immediately.
-After 5 seconds the bus tie breaker trips and transfer to 1AR.
-If 10 seconds pass w/out voltage then tie breaker trips and 1AR trips and transfer to associated EDG. |
|
|
Term
4KV
Describe the degraded essential bus voltage transfer. |
|
Definition
-3 sensing relays (2 of 3).
-Setpoint 3920volts.
-Sense for 9 seconds then tie breaker trips and transfer to 1AR and associated EDG starts.
-If now that on 1AR and still sees degraded voltage for 5 more seconds then 1AR breaker trips and transfer to the EDG. |
|
|
Term
4KV
Describe load shed for the essential bus transfer. |
|
Definition
-Shed of all essential bus loads except the associated 480VAC load center.
-Shed of all non essential MCCs.
-Trip of associated tie breaker. |
|
|
Term
4KV
Describe in detail the load shed on essential bus transfer. |
|
Definition
Division I/II
-11,13/12,14 RHR pumps.
-11/12 core spray pumps.
-11/12 CRD pumps.
-11,13/12,14 RHRSW pumps.
-MCC-131,132/141,142B.
-LC-103 tie to 104/ LC-104 tie to 103.
-Turbine aux oil pump (div I) |
|
|
Term
4KV
Describe normal ECCS load shedding. |
|
Definition
If 2R or 1R supplying:
-Drywell cooling recirc fans.
-RHRSW pumps. |
|
|
Term
4KV
Describe ECCS load shedding if on 1AR or EDG. |
|
Definition
-11/12 CRD pump.
-11,13/12,14 RHRSW pumps.
-VRF-1,3/2,4 drywell cooling fans.
-11/12 fuel pool cooling pumps.
-11/12 RBCCW pumps.
-12 service water pump (div II). |
|
|
Term
4KV
Describe ASDS transfer load shedding. |
|
Definition
-12,14 RHR pumps.
-12,14 RHRSW pumps.
-12 CRD pump.
-12 core spray pump.
-MCC-141,142B.
-LC-104 tie to LC-103.
(Same as Div II ECCS shed). |
|
|
