ROLLING PROCEDURE

INITIAL CHECK UP

1. CHECK WHETHER ALL TURBINE AUXILIARY EQUIPMENTS ARE IN SERVICE.

2. INFORM THE ROLLING PARAMETERS AFTER VERIFYING MAXIMUM METAL

TEMPERATURE.

3. CONFIRM WHETHER ALL DRAINS TO IBD/FB INCLUDING MAL DRAINS AND ITS

RESPECTIVE GATE VALVES ARE IN OPEN CONDITION.

4. OPEN HP B/P ATMOSPHERIC DRAINS.

5. CHECK WHETHER LUBE OIL TCV IS IN AUTO AND THE TEMPERATURE SETTING IS

AT 45 0 C.

6. STEAM TO SEALS CAN BE FED FROM AST PREFERABLY FROM STAGE I FOR ITS

LOWER TEMPERATURE.

7. CHECK WHETHER THERE IS SUFFICIENT VACUUM IN THE CONDENSER.

8. CHECK WHETHER ALL TEST VALVES OF STOP VALVES ARE IN OPEN CONDITION.

9. CHECK CUT OUT VALVES FOR EHC AND CRH PILOT VALVE ARE IN OPEN CONDITION.

10. RECORD ALL SUPERVISORY READINGS.

11. CHECK WHETHER POWER SUPPLY FOR K 101 & 201 IS AVAILABLE.

12. CHECK FOR ANY ABNORMAL ALARMS IN ANNUNCIATION PANEL.

13. CHECK WHETHER ALL INSTRUMENTS REQUIRED FOR ROLLING ARE HEALTHY.

14. ENSURE THAT THERE ARE NO TRIP SIGNALS PRESENT.

ROLLING THROUGH EHC

SPEEDER GEAR SHOULD BE IN THE MAXIMUM POSITION.

CHECK THE EHC CONTROL DESK FOR THE FOLLOWING:

LP MODE SELECTION

NO FAULT IN EHC

SPEED CONTROL ACTIVE DISPLAY

TRACKING DEVICE OFF

SPEED SET POINT ZERO.

HEALTHINESS OF STARTING DEVICE AND SPEEDER GEAR MOTOR.

LOAD CONTROLLER ON

LOAD SET POINT APPROXIMATELY TO 30 MW IN PR LIMITER.

LOAD GRADIENT ON AND LOADING RATE SET AT 4 MW/MIN.

1. AS SOON AS THE PARAMETERS FOR OPENING STOP VALVES IS OBTAINED, BRING

DOWN THE STARTING DEVICE TO 0 % TO OPEN THE STOP VALVES

2. STEAM TEMPERATURE SHOULD BE 50OC MORE THAN CONTROL VALVE BODY

TEMPERATURE AND SHOULD BE IN SUPER HEATED REGION WITH RESPECT TO MS

PRESSURE.

3. INFORM GENERATOR BOARD TO RESET THE PROTECTION RELAYS IN GRP.

4. AFTER RESETTING, OBSERVE TRIP OIL PRESS RISE & RESETTING OF ‘TURBINE

TRIPPED’ ALARM.

5. IF THE TRIP OIL PRESS IS LESS, ROTATE THE SELF CLEANING FILTERS IN THE

GOVERNING RACK

6. RISE THE STARTING AND LOAD LIMITER SLOWLY AND CHECK FOR OPENING OF

STOP VALVES AFTER OBSERVING START UP OIL PRESSURE.

7. MS 25, 26, HR 47, 48(15, 16) CAN BE CHOCKED AFTER ENSURING FLOW THROUGH

RESPECTIVE MAL DRAINS.

8. RAISE THE STARTING AND LOAD LIMITER TO MAXIMUM POSITION.

9. SPEEDER GEAR SHOULD BE AT MAXIMUM POSITION IF ROLLING HAS TO BE DONE

THROUGH EHC.

10. SLOWLY RAISE SPEED SET POINT IN EHC TO 600 RPM.

11. OBSERVE THE SPEED RISE AND VIBRATION.

12. HOLD IT AT 600 RPM FOR ABOUT 10 MINUTES & RECORD THE SIP READINGS

INCLUDING BEARING METAL TEMPS

13. OBSERVE TSE MARGINS FOR CONTROL VALVES

14. AGAIN RAISE THE SPEED SET POINT WITHOUT ANY INTERRUPTION TILL THE SET

POINT REACHES 3000 RPM.

15. RECORD THE SPEEDS AT WHICH GATE VALE GEARING CLOSES AND JOP A STOPS.

16. RECORD THE SPEED AT WHICH MAXIMUM SHAFT AND PEDESTAL VIBRATIONS

OCCUR.

17. AFTER REACHING 3000 RPM INFORM GENERATOR BOARD FOR SYNCHRONIZING.

18. IF THE HOLDING TIME IS MORE THAN 15 MINS, HPT EXHAUST TEMPERATURE IS

TO BE MONITORED.

19. UNIT IS TO BE SYNCHRONIZED PREFERABLY THROUGH AUTO SYNCHRONIZER AND

SYNCHRONSCOPE INDICATION SHOULD BE IN THE CLOCKWISE DIRECTION.

(TURBINE SPEED GREATER THAN GRID SPEED)

20. ENSURE CLOSING (CLOSE INDICATION OF GENERATOR BREAKER) DURING

SYNCHRONIZING AND ‘AUTO’ RISE IN SPEED SET POINT FOR BLOCK LOAD. IF

SPEED SET POINT NOT RISES ON AUTO, THEN ADDITIONAL 10 RPM SETTING CAN

BE RAISED TO PREVENT UNIT TRIPPING ON REVERSE POWER PROTECTION.

21. AFTER ENSURING LOAD CONTROL LOOP TAKING OVER, LOAD SHOULD BE RAISED

ONLY THROUGH LOAD LOOP. IN CASE OF ANY SPEED/LOAD LOOP CHANGER OVER

NOTICED SET POINT TO BE RAISED PREFERABLY IN LOAD LOOP (PR).

ROLLING THROUGH MHG

1. CLOSE THE EHC CUT OUT VALVES.

2. BRING DOWN THE SPEEDER GEAR TO MINIMUM POSITION.

3. EHC SPEED SET POINT CAN BE RAISED TO MAXIMUM.

4. OPEN STOP VALVES AS MENTIONED EARLIER.

5. SLOWLY RAISE THE STARTING DEVICE; AT APPROXIMATELY 60% THE CONTROL

VALVES BEGIN TO OPEN.

6. WAIT FOR THE SPEED TO SETTLE AT APPROXIMATELY 600 RPM.

7. AFTER OBSERVING SIP READINGS SLOWLY RAISE STARTING DEVICE AND AT

APPROXIMATELY 2400RPM SPEEDER GEAR WILL TAKE OVER FROM STARTING

DEVICE AND STARTING DEVICE CAN BE WITHDRAWN.

8. THEN RAISE THE SPEED THROUGH SPEEDER GEAR AND AT APPROXIMATELY AT

50% POSITION OF SPEEDER GEAR, 3000 RPM WILL BE REACHED

9. SYNCHRONIZE THE UNIT AND BLOCK LOAD TO BE RAISED IN SPEEDER GEAR

MANUALLY.

LOAD RISING:

1. SLOWLY RAISE THE LOAD AND TEMPERATURE ADHERING TO ABT SCHEDULE AND

TSE.

2. ALWAYS STRESS MARGIN HAS TO BE CHASED WHILE RAISING THE LOAD.