1. FORT CHURCHILL GENERATION CURTAILMENT REMEDIAL ACTION SCHEME (RAS)
Status Logic Modification
November 15, 2017

2. ONE-LINE DIAGRAM

3. RAS CLASSIFICATION
This scheme was presented at the April 2016 RASRS meeting and approved as a Local Area Protection Scheme (LAPS).
During testing unrelated to the RAS, we experienced an accidental trip at the McGinness plant which resulted in a RAS Trip indication to the EMS
The present concern is only with the RAS trip indication provided to EMS
Informational presentation
No scheme operational logic changes are required
Supervise the “returned” breaker trip signal to the RAS controller with the “RAS Trip” sent from the controller to indicate an actual RAS operation
Modify logic for both Anaconda Moly and McGinness indications
s Scheme remains a LAPS

4. RAS DESIGN: RAS sensing, actions, and outputs to the end-devices
Primary and backup systems operate identically

5. RAS DESIGN – LOGIC

6. RAS DESIGN – TESTING
SEL-2506 Inputs and Outputs
OUT101 – provides trip for RAS overload conditions
IN101 – provides indication of “Received Trip” (i.e. breaker trip circuit was energized)
OUT102 – provides isolation of the breaker trip circuit during testing
IN102 – provides indication of “Received Trip” during testing
OUT105 and IN105 – provides “Test Mode” status to Ft. Churchill
OUT105 and OUT102 are set with same logic
All circuit breaker trips are monitored by the RAS
Original “RAS Trip” status at Ft Churchill just monitored the MB from IN101 to indicate a RAS operation
This allowed a false “RAS” indication for any breaker trip – whether real, normal protection, or accidental!

7. RAS TRIP INDICATIONS
RAS Trip
RAS Trip
ANM or McG Breaker Trip
FTC RAS Controller
Ft Chur RAS Monitor
Breaker Trip
RMB3A
EMS RAS Trip
Indication
Breaker Trip
Breaker Trip
Breaker Trip
RMB3A
RAS Trip
SV02T
NOTE: RMB2A and SV01T provide Anaconda Moly data
RMB3A and SV02T provide McGinness data
Existing (to be modified) and modified logic to provide “RAS Trip” indications to the EMS

8. CONCLUSION
Modify the RAS Trip indication provided by the RAS controller from the received “breaker trip” to include a logical “AND” between the “RAS Trip” sent and the received “breaker trip”

9. QUESTIONS?