EDG Electrical Flashcards
Discuss 86B relay
Protective Lock out relay for E-Bus
Trips EDG BKR, UAT/RAT BKRs
-EDG keeps rolling
Discuss 86DP relay
Primary Protective relay
Differential phase relay
-Trips EDG and BKR
Discuss 86DB relay
DG backup relay
- trips DG on Reverse power, Overcurrent, Loss of Field
- blocked Via the RLA relay on an SI
Discuss RA relay
- Strips Containment Structure Cooling fans
- allows for more loading during a SI
- Can reset once UAT or RAT BKR is closed
Discuss RLA relay
- energized on an SI signal, stays locked in until SI reset
- Blocks 86DB relay
- Bypasses High lube oil temp trip and High Coolant temp trip
Discuss EPS
Sequences loads
- 5 seconds each step
- 9 Steps
- Activated on LOP condition
Discuss RMO Relay
- Trips UAT and RAT BKRs
- Prevents Starting large load from the MCB
- Prevents reclosure until RMO has been bypassed (Two Handed Operation)
- This prevents overloading EDG when paralleled with the grid
Discuss PR1 relay
Auto starts EDG
energized by EPS
Discuss PR1X relay
DG BKR permissive
- Closes DG BKR when EDG is at rated speed and voltage
Discuss R2X relay
Step 0 of EPS
Starts Running CCP
Starts Control Room Ventilation
List major loads sequenced on EPS
STEP 0: CCP, CR Make up fan STEP 1: SI STEP 2: RHR STEP 3: CBS STEP 4: PCCW STEP 6: MDEFW pump STEP 8: SW/CBS STEP 9: Battery Chargers
Describe 94 Relay on E-bus
Strips bus on LOP
- Doesn’t strip US breakers
- Doesn’t strip charging pump
Discuss Loss of DC power to EDG
PP-111A/B will lose EPS, SU and SD solenoids
DC Bus 11A/B will lose local and remote breaker ops
When can EDG manual Voltage control be used
When sync exists between UAT/RAT and EDG and 1 BKR is closed, Shifts EDG to Droop mode
List EDG BKR trips
Paralleled with grid when SI occurs
86DP, 86DP without SI, or 86B
Paralleled with grid and UAT/RAT BKR opens
DG Shut down signal
