F.S.S.S.

CHARECTERISTICS OBSERVATION REMARKS 1.A) Initial conditions :- a) M.F.R. is in no trip condition.

b). I.D. Fans- A & B bkrs. are in test position. c) Both I.D.& F.D.Fans A & B are made ON

B) Operations performed:-

a) I.D.Fan - A / B OFF P.B. pressed. b) I.D. Fans- A & B both OFF P.Bs. pressed.

a) MFR does not trip. b) i) MFR trips. ii)All ID fans off indication lamp appears in First Cause

of Trip panel. iii)All ID fans off annunciation

appears.

a) F.D.Fan- A / B does not trip. b) Both F.D.Fans trip & annunciations appear.

2. A) Initial conditions:- a) M.F.R. is in no trip condition. b) I.D. Fans A & B bkrs are in test positions. c) I.D.& F.D.Fans- A / B is made ON.

B) Operations performed:- Either I.D. Fan - A / B (whichever is

running) Off P.B. pressed.

i) M.F.R. trips. ii) All I.D. Fans OFF indication lamp appears in First Cause of Trip panel iii) All I.D. Fans off annunciation appears

Running F.D.Fans trip and annunciations appear.

3. A) Initial conditions:- a) M.F.R. is in no trip condition. b) F.D. Fans-A & B bkrs. are in test mode. c) Both I.D.& F.D.Fans-A & B are made ON

B) Operations performed:- a) F.D. Fan A / B off P.B. pressed. b) Both F.D.Fans off P.Bs. pressed.

a) M.F.R. does not trip.

b) i) M.F.R trips. ii) All F.D.Fans off indication lamp appears in First Cause of Trip panel iii) All F.D.Fans off annunciation

appears

a) I.D. Fan A / B does not trip. b) Both I.D.Fans do

not trip.

4. A) Initial Conditions:- a) M.F.R. is in no trip condition.

b) F.D.Fans-A & B bkrs. are in test mode. c) F.D.Fan-A / B is made on. B) Operations performed:- Either F.D.Fan-A / B (whichever is running) Off P.B. pressed.

i) M.F.R. trips. ii) Both F.D.Fans off indication lamp appears in First Cause of Trip panel. iii) All F.D.Fans off annunciation appears.

CHARACTERISTICS OBSERVATION REMARKS 5.A) Initial Condition:- M.F.R. is in no tripcondition. B) Operations performed:- a) Emergency P.B.-1 / 2 is only pressed. b) Both emergency P.Bs.-1& 2 are pressed simultaneously

a) M.F.R. does not trip. b) i) M.F.R trips. ii) Emergency Trip indication lamp appears in First Cause of

Trip panel. iii) Emergency Trip annunciation appears

6.A) Initial Conditions:- a) M.F.R. is in no trip condition.

b) Drum level is normal. B) Operations Performed:- a) Drum level is increased to > + 125 mmwcl. b) Drum level is increased to > + 225 mmwcl.

c) Drum level is decreased to < - 125 mmwcl. d) Drum level is decreased to < - 225 mmwcl.

a) Drum level high annunciation appears. b) i) M.F.R. trips with a time delay of 10 secs. ii) Drum level very high indication lamp appears in First Cause of Trip panel. iii) Drum level very high annunciation appears. c) Drum level low annunciation appears. d) i) M.F.R. trips with a time delay of 5 secs. ii) Drum level very low indication lamp appears in First Cause of Trip panel. iii) Drum level very low annunciation appears.

b) Drum level very high annunciation resets at +200 mm wcl. d) Drum level very low annunciation resets at 200 mm wcl.

7.A) Initial Conditions:- a) M.F.R. is in no trip condition. b) Furnace draft is normal. c) All I.D. & F.D.Fan bkrs. are in test mode. B) Operation Performed: - Total air flow is decreased to < 252 T/hr.

i) M.F.R. trips. ii) Air flow 30% ( 264.4 T/hr). B) Operations Performed:- a) Furnace press. is increased to > + 150 mm. b) Furnace press.is decreased to < -175 mm.

a) i) M.F.R. trips. ii)Furnace press. very high indication lamp appears in First Cause of Trip panel. iii)Furnace press. very high annunciation appears. b) i) M.F.R. trips. ii)Furnace press. very low indication lamp appears in First Cause of Trip panel. iii)Furnace press. very low annunciation appears.

.CC

CHARACTERISTICS OBSERVATION REMARKS

9.A) Initial Condition:- M.F.R.is in no trip condition. B) Operations Performed:- a) Unit 220V DC supply is not available. b) 24V DC supply is not available at : i) MFT panel (By hardware tripping). ii) Oil / Coal panel(By individual equipment hardware tripping). c) Unit flame failure occurs when : Coal elevation is without oil support & corresponding elevation scanners 2 out of 4 F.B.s are not present. d) R/H protection operated when : [Any HPBP / LPBP v/v opening < 2% + Feeder on > 50 secs. + GCB open] OR [( Feeder on > 50 secs.) + {(HPBP & HPCVs closed) / (LPBP & IPCVs closed)}] with a time delay of 10 secs. e) Loss of all fuel occur when : No oil gun & coal feeder are in service.

a) i) M.F.R. trips with a time delay of 2 secs. ii) Loss of unit 220V DC >2secs. indication lamp appears in First Cause of Trip panel. iii) Loss of unit 220V DC >2secs.' annunciation appears. b) i) M.F.R. trips. ii)24V DC loss indication lamp appears in First Cause of Trip panel. iii)24V DC loss annunciation appears. c) i) M.F.R. trips. ii)Unit flame failure trip indication lamp appears in First Cause of Trip panel. d) i) M.F.R. trips. ii)R/H protection trip indication lamp appears in First Cause of Trip panel. e) i) M.F.R. trips. ii)Loss of all fuel trip indication lamp appears in First Cause of Trip panel.

10.A) Initial Conditions:- a) All H.O.& L.O. nozzle v/v-s are closed. b) H.O.T.V. & L.O.T.V. are closed. c) All P.A.Fans are off & H.A.Gs. are closed d) All feeders are off. e) No boiler trip is persisting. f) All scanners are showing no flame. g) Air flow is > 30% & < 40%. B) Operation Performed:- Push to Purge P.B. is pressed.

A) i) If anyone of these is not present, the two lamps mentioned first will get off. ii) No boiler trip lamp will not glow if any cause of M.F.T. presents. iii) When all conditions are satisfied, Purge Ready & Push to Purge lamps will glow. B) i) Purging lamp will glow for 300 secs. ii) After 300 secs.,Purge Complete lamp will glow& previous lamps will get off. iii) If any cause of M.F.T.occurs during the purging lamp glowing period, all the other lamps will get off.

CHARACTERISTICS OBSERVATION REMARKS 11.A) Initial Conditions:- a) M.F.R. is in no trip condition. b) T.L.R. is reset. c) Generator ckt.bkr. is closed. B) Operations Performed:- a) M.F.T. is operated. b) Generator class-A, group-1 is operated.

a) i) Turbine trips. ii) Generator low forward power relay 37G operates. iii) Generator class-B, group-2 operates. iv) Generator class-C, group-1 operates. v) Boiler S/H attemperation block v/v-s will close & indication lamps appear. b) i) M.F.R. trips. ii) Turbine trips. iii) Spare Trip indication lamp appears in First Cause of Trip panel.

12.A) Initial Conditions:- a) M.F.R. is in no trip condition. b)AC 110V is available in all fuel elevations. c) All coal feeders are in off condition. d) L.O.T.V. & H.O.T.V. are open. e) One pair of nozzle v/v-s are open. B) Operation Performed:- Simulate such that AC 110V is not available for the corresponding mill & nozzle v/vs.

i) M.F.R. trips with a time delay of 4 secs. ii) After M.F.R. trips, all running feeders get off and L.O.T.V. & H.O.T.V. get closed. iii)

TURBINE INTERLOCKS & PROTECTIONS

Annunciation Characteristics Alarm Value Trip Value

Process Remarks

1. 1.1) Control oil press low. 1.2) Control oil press.very low. 1.3) Control oil press. > 8 kg/cm2 & turbine speed 2950 rpm. 1.4) Trip oil press.low.

1.1) 5 kg/cm2. 1.2) 2 kg/cm2 Control oil press. low trip alarm. 1.4) 3 kg/cm2 Trip oil press.low alarm at CRT.

By draining press.switch line.

1.1) AC A.O.P. auto cut-in. 1.2) Turbine trip (T.L.R.= 86T1-T2 & 86TX1-TX2 operated). 1.3) AC A.O.P. auto cut-off. 1.4) Turbine trip (T.L.R.= 86T1-T2 & 86TX1-TX2 operated).

2. 2.1) AC A.O.P. trips / L.O.press.low. 2.2) AC power failure / AC E.O.P. trips / AC EOP fails to develop L.O.press.>1.1kg/cm2

2.1) 1 kg/cm2. 2.2)DC EOP auto startalarm.

By simulation.

2.1) AC E.O.P. auto start. 2.2) DC E.O.P. auto start

3. 3.1) Turbine speed = 500 rpm. 3.2) Turbine speed = 400 rpm. 3.3) AC power failure during AC J.O.P.running. 3.4) Jacking oil filter dp high. 3.5) Jacking oil press. low.

3.3)DC JOP auto startalarm.

3.4) 1 kg/cm2 3.5) 150 kg/cm2 J.O.press.low alarm.

~DO~

3.1) AC J.O.P.auto cut-off during turbine speed raising. 3.2) AC J.O.P.auto start during turbine speed lowering. 3.3) DC J.O.P.auto start.

4. Turbine L.O.press.very low.

0.8 kg/cm2 L.O.press.low trip alarm.

~DO~

Turbine trip & vacuum breaker open (T.L.R.= 86T1-T2 & 86TX1-TX2 operated).

5. 5.1) Turbine speed = 403 rpm during speed rising. 5.2) Turbine speed = 302 rpm during speed decreasing.

5.1) Turing oil supply valve closes. 5.2) Turning oil supply valve opens.

6. T.P.R. system heavy fault

6. Turbine trip alarm.

6. By making point contact.

6. Turbine trips (T.L.R.= 86T1-T2 & 86TX1-TX2 operated).

Annunciations Characteristics Alarm Value Trip Value

Process Remarks

7. 7.1) Turbine trip from back-up panel. 7.2) Turbine trip by emergency trip device at governing rack.

7.1)Emergency turbine trip on P.B.alarm. 7.2) Turbine trip & Emergency hand trip device operated alarms.

7.1) By pressing P.B.at back-up panel.

7.2) By pressing lever.

7.1) Turbine trips, MSVs.& RSVs. close (T.L.R.= 86T1-T2 &86TX1- TX2 operated). 7.2) ~DO~

8. 8.1) Axial thrust high (mechanical). 8.2) Axial thrust high (electrical).

8.3) Axial thrust very high ( mechanical). 8.4) Axial thrust very high (electrical).

8.1) + 0.51 mm. - 0.53 mm. 8.2) + 0.49 mm. - 0.53 mm.

8.3) + 0.98 mm. - 1.03 mm. Thrust failure protection device operated & Condenser vacuum breaker openalarms 8.4) + 1.00 mm. - 1.01 mm. Electrical thrust failure trip & Condenser vacuum breaker openalarms

8.3) By operating lever for thrust failure device near brg. no.- 2. 8.4) By

simulation.

8.3) Turbine trips& vacuum breaker opens (T.L.R.= 86T1-T2 & 86TX1-TX2 operated). 8.4) ~DO~

9. 9.1) Turbine overspeed (mechanical). 9.2) Turbine overspeed (electrical).

9.1) 111% O.S. i.e. 3260 rpm. Emergency governor 1/ 2 operated at 111% O.S.alarm. 9.2) 112 % O.S. i.e. 3360 rpm. Elect.O.S.tripalarm.

9.1) By operating 1st & then 2nd lever of emergency governor. 9.2) By

simulation.

9.1) Turbine trips (T.L.R.= 86T1-T2 & 86TX1-TX2 operated ). 9.2) ~DO~

Annunciations Characteristics Alarm Value Trip Value

Process Remarks

10. 10.1) Shaft vibration high. 10.2) Shaft vibration very high.

10.1) 125 micron.

10.2) 250 micron Shaft vibration high trip alarm.

10.2) By simulating high signal to any brg. & very high signal to its consecutive brg.

10.2) Turbine trips & vacuum breaker opens (T.L.R.= 86T1-T2 & 86TX1-TX2 operated).

11. 11.1) Brg. pedestal vibration high. 11.2) Brg. pedestal vibration very high.

11.1) 62 micron Brg.pedestal vibration highalarm.

11.2) 125 micron Brg. pedestal vibration very high tripalarm.

11.2) By

simulation.

12. Turbine eccentricity high. 12. 75 micron Turbine eccentricity highalarm.

13. 13.1) Condenser vacuum low. 13.2) Condenser vacuum very low.

13.1) 608 mmHg Condenser vacuum low alarm.

13.2) 532mmHg. Condenser vacuum very low trip alarm.

13.1) By simulation. 13.2) By actual.

13.2) Turbine trips (T.L.R.= 86T1-T2 & 86TX1-TX2 operated).

14. 14.1) Seal oil temp.after duplex filter high. 14.2) Seal oil temp.after duplex filter very high.

14.1) 500 C. Seal oil temp. after duplex filter high alarm.

14.2) 550 C. Seal oil temp.after duplex filter very high& Turbine tripalarms.

14.2) By simulation

14.2) Turbine trips (T.L.R.= 86T1-T2 & 86TX1-TX2 operated ). Generator mechanical protection relay operated.

Annunciations Characteristics Alarm Value Trip Value

Process Remarks

15. 15.1) Differential expansion high: a) H.P.T. b) I.P.T. c) L.P.T. 15.2) Differential expansion very high: a) H.P.T. b) I.P.T. c) L.P.T. 15.3) Turbine casing expansion high.

15.1) a) + 4.75 mm. - 3.02 mm. b) + 7.6 mm. - 2.0 mm. c) + 18.5 mm. - 3.0 mm. Differential

expansion high alarm. 15.3) 36 mm. Turbine casing expansion high alarm.

15.2) a) + 5.69 mm. - 3.96 mm. b) + 8.4 mm. - 2.9 mm. c) +19.2 mm. - 3.8 mm. Differential expansion very high trip alarm.

15.2) By

simulation.

15.2) Turbine trips (T.L.R.=86T1-T2 & 86TX1-TX2 operated)

16. Liquid in generator terminal bushing. 16. Liquid in generator high & Turbine tripalarms.

16. By making point contact.

16. Turbine trips (T.L.R. = 86 T1- T2 & 86TX1-TX2 operated). Generator mechanical protection relay operated.

17. 17.1) H.P.T. I/L steam press. low. 17.2) H.P.T. I/L steam press. very low.

17.1) 63.5 kg/cm2 H.P.T. I/L steam press. low alarm.

17.2) 60 kg/cm2 H.P.T. I/L steam press. very low tripalarm.

17.2) By simulation.

17.2) Turbine trips when turbine load > 40 % (T.L.R.= 86 T1- T2 & 86TX1-TX2 operated).

Annunciations Characteristics Alarm Value Trip Value

Process Remarks

18. 18.1) H.P.T. I/L temp. low. 18.2) H.P.T. I/L temp.very low. 18.3) H.P.T. I/L temp. high. 18.4) H.P.T. I/L temp.very high. 18.5) L.P.T.exhaust steam temp.high. 18.6) L.P.T.exhaust steam temp.very high 18.7) H.P.T./ I.P.T.casing I/L differential temp.high.

18.1) 4500 C H.P.T. I/L temp. lowalarm. 18.3) 5450 C H.P.T. I/L temp. highalarm. 18.5) T.E.= 90.60 C G.E.= 90.80 C L.P.T.exhaust steam temp. highalarm. 18.7) 300 C H.P.T./ I.P.T.casing I/L differential temp. highalarm.

18.2) 4300 C H.P.T. I/L temp.very low tripalarm. 18.4) 5650 C H.P.T. I/L temp.very high trip alarm. 18.6) T.E.=1100 C G.E.=1110 C L.P.T.exhaust steam temp. very high trip alarm.

18.2) By simulation. 18.4) ~DO~ 18.6) By simulation.

18.2) Turbine trip (T.L.R.=86T1-T2 & 86TX1-TX2 operated). 18.4) ~DO~ 18.5) L.P.T.exhaust spray v/v opens. 18.5) Turbine trip (T.L.R=86T1-T2 & 86TX1-TX2 operated).

19. 19.1) T.O.cooler O/L oil temp.high. 19.2) Brg. L.O drain temp. high. 19.3) Brg. metal temp. high. 19.4) Brg. metal temp.very high.

19.1) 550 C Oil cooler O/L oil temp. high alarm. 19.2) 750 C Brg. L.O. drain temp.high alarm. 19.3) Brg.no.-1 = 1000 C Brg.no.-2 = 900 C Brg.no.-3 & 4=1050 C Brg.metal temp.highalarm

19.4) 1200 C. Brg. metal temp.very high. trip alarm.

19.4) By simulation.

20. U-ring broken (MCV:1-4 drain temp.high) 20. 1000 C U-ring broken (MCV:1-4 drain temp.high)alarm.

TILPARA INTAKE PUMP 1.Annunciations: - 1.1) Sump level high = 62.39 M. 1.2) Sump level low = 60.20 M. 1.3) Sump level very low = 59.70 M. 1.4) Pump discharge header press.low = 7 kg/cm2. 1.5) Pump discharge header press.high = 11 kg/cm2. 1.6) Motor brg.( D.E. / N.D.E.) temp.high = 70 0 C. 1.7) Motor brg.( D.E. / N.D.E.) temp.very high = 80 0 C. 1.8) Motor winding temp.high = 100 0 C. 1.9) Motor winding temp.very high = 110 0 C. 2. Start Permissives: - 2.1) Sump level not low. 2.2) Motor brg. & winding temps.not high. 2.3) Discharge butterfly v/v fully closed. 2.4) No auto stand-by selection. 2.5) No switchgear disturbance persisting. 2.6) L.O.S. released, bkr.in service & D.C.P. selector switch innormalposition. 2.7) Bus under-voltage relay(86M) not operated. 2.8) Lock out relay(86A) not operated. 2.9) Interlock AC supply not failed at DCP. 2.10) Trip ckt.relay(95C) in reset condition, i.e. DC control on. 3. Interlocks & Protection Trips:- 3.1) Sump level very low. 3.2) Motor brg. temp.very high. 3.3) Motor winding temp.very high. 3.4) Bus under-voltage relay(86M) operated. 3.5) Lock out relay(86A) operated. 3.6) Off-command from local / DCP. 3.7) Discharge butterfly v/v will close after pump trips / made off. 3.8) Auto stand-by pump starts if running pump trips. 3.9) Auto stand-by pump does not start if running pump is tripped manually from D.C.P. 3.10) Pump does not start if discharge butterfly v/v is not fully closed. 3.11) If all the three pumps in pipeline no.-1 are started, then preferential tripping of pump no.-3 will occur. Also,if all the three pumps in pipeline no.-2 are started,then preferential tripping of pump no.-6 will occur. 3.12) In running conditions of pumps,if power-pack v/v of any pipeline gets closed; then all the pumps in that line will trip.

Bakreswar Intake Pump 1. Status Indications & Audio Visual Indications At Drive Control Panel (D.C.P.): 1.1) On / Off / Trip indication lamp of each pump. 1.2) Pump failure audiovisual indication. 1.3) Pump discharge header press.low ( 1kg. /cm.2) audiovisual indication. 1.4) Pump discharge header press.high ( 3kg. /cm.2) audiovisual indication. 1.5) Motor winding temp.high(1000C.) audiovisual indication. 1.6) Motor winding temp.very high(1100C.) audiovisual indication. 1.7) Motor brg.temp.high(700C.) audiovisual indication. 1.8) Motor brg.temp.very high(800 C.) audiovisual indication. 1.9) Full closing / opening of discharge v/v audiovisual indication. 1.10) Pump suction press.low( 0.3 kg /cm.2 70.5 M) audiovisual indication. 2. Start Permissives: 2.1) Suction press.not low. 2.2) Pump discharge v/v fully closed. 2.3) Motor brg.& winding temps.not high. 2.4) L.O.S.released,bkr.in service & D.C.P.selector switch inman./ normalmode. 2.5) No switchgear disturbance persisting. 2.6) Bus under-voltage relay(86M) not operated. 2.7) Trip ckt.relay(95C) in reset condition, i.e. DC control on. 2.8) Lockout relay(86A) not operated. 2.9) Interlock AC supply not failed at DCP. 3. Interlocks & Protection Trips: 3.1) Motor winding temp.very high. 3.2) Motor brg.temp.very high (scanner / heat gauge). 3.3) Motor protection relay operated. 3.4) Motor trip through L.O.S. / from DCP. 3.5) Lockout relay(86A) operated. 3.6) Bus under-voltage relay(86M) operated. 3.7) Discharge v/v will close automatically after pump trips.

Raw Water Pump

1. Start Permissives: 1.1) R.W. sump level not low(> 67.25 M). 1.2) Brg.temp.not high(< 700 C). 1.3) Motor winding temp.not high(< 1100 C). 1.4) Discharge v/v fully closed. 1.5) No electrical trip persisting. 1.6) L.O.S.released,bkr.in service & D.C.P.selector switch inman/automode. 1.7) No switchgear disturbance persisting. 1.8) Bus under-voltage relay(86M) not operated. 1.9) 95C trip ckt.relay in reset condition, i.e. DC control on. 1.10) Interlock AC supply not failed at DCP. 1.11) Lockout relay(86A) not operated. 2. Annunciations: 2.1) R.W. sump level high = 75 M. 2.2) R.W. sump level low = 67.25 M. 2.3) R.W. sump level very low = 67 M. 2.4) R.W. discharge header press.high = 4.55 kg /cm.2 2.5) R.W. discharge header press.low = 2 kg /cm.2 2.6) Motor brg.temp.high = 700 C. 2.7) Motor brg.temp.very high = 800 C. 2.8) Motor winding temp.high = 1100 C. 2.9) Motor winding temp.very high = 1200 C. 3. Interlocks & Protection Trips: 3.1) R.W. sump level very low. 3.2) Motor brg.temp.very high. 3.3) Motor winding temp.very high. 3.4) Lock out relay(86) operated. 3.5) Bus under-voltage relay(86M) operated. 3.6) Off- command from local / DCP. 3.7) Discharge butterfly v/v will close if pump trips / made off. 3.8) In auto,stand-by pump will take start if running pump trips. 3.9) In auto,stand-by pump does not take start if running pump is tripped manually from D.C.P.

C.T.Make-Up Pump, A.H.P.Make-Up Pump & Service Water Pump 1. Start Permissives: 1.1) Sump level not very low (> 72 M). 1.2) Discharge v/v fully closed. 1.3) No electrical trip persisting. 1.4) L.O.S.released,bkr.in service & D.C.P. selector switch inman/ normal mode. 2. Annunciations: 2.1) Clear water sump level high = 77.25 M. 2.2) Clear water sump level low = 72.25 M. 2.3) Clear water sump level very low = 72 M. 2.4) C.T.M.U.Pump discharge header press.high = 5 kg /cm.2 2.5) C.T.M.U.Pump discharge header press.low = 2 kg /cm.2 2.6) A.H.PM.U.Pump discharge header press.high = 6.3 kg /cm.2 2.7) A.H.PM.U.Pump discharge header press.low = 3 kg /cm.2 2.8) S.W. Pump discharge header press.high = 16 kg /cm.2 2.9) S.W. Pump discharge header press.low = 10 kg /cm.2 3. Interlocks & Protection Trips: 3.1) Sump level very low. 3.2) In auto, stand-by pump will take start if running pump trips. 3.3) In auto, stand-by pump does not take start if running pump is tripped manually from D.C.P.

A.C.W.Pump 1. Start Permissives: 1.1) Bkr.is in service & selector switch is innormalmode. 1.2) L.O.S.of pump & its discharge v/v are in released condition. 1.3) Motor protection relay not operated & no trip command existing. 1.4) At local control panel(L.C.P.),selector switch is inman/automode. 1.5) Motor winding temp.not high(

3. Protection Trips: 3.1) Motor winding temp.very high(1300C). 3.2) Pump thrust brg.temp.very high(800C). 3.3) Pump/Motor brg.vibration very high(200microns). 3.4) Motor electrical protection operated. 3.5) Discharge v/v fails to open 30% with a time of 10 secs. 3.6) Sump level very low(71.1 M). 4. Auto Operation & Interlocks: 4.1) In auto, stand-by pump will take start (provided start permissives are fulfilled) at the following conditions:- a] Running pump trips. b] Common discharge header press.low(2.8 kg/cm2). 4.2) After pump starts,discharge v/v will open 30% automatically. 4.3) Discharge v/v will fully open when discharge header press.becomes adequate(>2 kg/cm2). 4.4) On issuestopcommand to pump other than trip,discharge v/v will close first & after full closing of the v/v,the pump will stop. 4.5) Due to 30% opening failure of discharge v/v,when a pump trips or when a pump trips for another reason,further start of the said pump & operation of its discharge v/v are protected unless reset is done by closing the L.O.S.of the pump & its discharge v/v. 5. Remote Feedback At U.C.R.: 5.1) Current of both pumps. 5.2) On,Off&Tripindications. 5.3) Discharge v/vopen&closeindications. 5.4) Discharge header press.lowalarm. 5.5) Alarm as group trouble of both pumps.

C.W.Pump 1. Start Permissive: 1.1) Bkr.is in service & no switchgear disturbance is persisting. 1.2) Motor protection relay not operated & no trip command existing. 1.3) At L.C.P.,selector switch is inman/automode. 1.4) Motor winding temp.not high(< 1000C). 1.5) Pump / Motor brg.temp.not high(< 700C). 1.6) Pump thrust brg.temp.not high(< 700C). 1.7) Sump level not low. 1.8) L.O.S.of pump & its discharge v/v are in released conditions. 1.9) Pump discharge v/v fully closed. 2.Alarms & Annunciations: 2.1) Sump level high. 2.2) Sump level low. 2.3) Sump level very low(71.1 M) 2.4) Motor winding temp.high(1000C). 2.5) Motor winding temp.very high(1200C). 2.6) Pump/Motor brg.vibration high(6.3mm/sec). 2.7) Pump/Motor brg.vibration very high(13mm/sec). 2.8) Pump/Motor brg.temp.high(700 C). 2.9) Pump/Motor brg.temp.very high(800C). 2.10) Pump thrust brg.temp.high(700C). 2.11) Pump thrust brg.temp.very high(800C). *2.12) Common discharge header press.low(1.3 kg/cm2 for #1 and 1.4 kg/cm2 for #2 & #3). Alarm reset value = 1.5 kg/cm2 for #1 and 1.6 kg/cm2 for #2 & #3. 2.13) Motor protection operated (indication lamp only). 2.14) Pump trip. 2.15) Discharge butterfly v/v 100 opening failure. 2.16) Discharge butterfly v/v 900 opening failure. 2.17) Discharge butterfly v/v 900 closing failure. 2.18) C.W.dp.across condenser (L/R) high(0.6 kg/cm2).

3. Protection Trips: 3.1) Motor electrical protection operated (earth fault, short ckt.,stalling,-ve phase sequence & overcurrent). 3.2) Motor winding temp.very high (1300C). 3.3) Bus under voltage (86M). 3.4) BTS trip command. 3.5) Lock out relay(86) operated (multiplier at DCP). 3.6) Trip command from LCP. 3.7) Off- command from LCP / local. 3.8) Pump/Motor brg.temp.very high(800C). 3.9) Pump/Motor brg.vibration very high. 3.10) Pump thrust brg.oil temp.very high(800C). 3.11) Discharge v/v fails to open 100 with a time delay of 12 secs. 3.12) Sump level very low(71.1 M). 4. Auto Operation & Interlocks:~ 4.1) In auto,stand-by pump will take start (provided start permissives are fulfilled) at the following conditions: a] Any other pump trips. b] Common discharge header press.low(1.2 kg/cm2). 4.2) After pump starts,discharge v/v will open 100 automatically. 4.3) Discharge v/v will fully open when discharge header press.becomes adequate(>1.1 kg/cm2). 4.4) Discharge v/v closes fully with pump off / trip. 4.5) Due to 100 opening failure of discharge v/v,when a pump trips or when a pump trips for another reason,further start of the said pump & operation of its discharge v/v are protected unless reset is done by closing the L.O.S.of the pump & its discharge v/v. 5. Remote Feedback At U.C.R.: 5.1) Current of both pumps. 5.2) On, Off&Tripindications.On feedbacks of C.W.PPs. which were earlier from aux.contactor at C.W.local panel are modified & presently taken from individual pump breaker to avoid tripping problem originating from panel. 5.3) Discharge v/vopen&closeindications. 5.4) Discharge header press.lowalarm. 5.5) Alarm as group trouble of all pumps.

C.W.Chlorination System 1. Annunciations: 1.1) Expansion tank I/L press.high(2.5 kg/cm2). 1.2) Liquid CL2 press.low(1.5 kg/cm2). 1.3) Liquid CL2 press.high(18 kg/cm2). 1.4) Safety relief v/v I/L press.high(>1.5-2.5 kg/cm2). 1.5) Evaporator gas line press.high(>15 kg/cm2). 1.6) Press. regulating v/v d/s press.high(3.5 kg/cm2). 1.7) Evaporator water level high. 1.8) Booster pump discharge header press.high(9.6 kg/cm2). 1.9) Booster pump discharge header press.low(3.5 kg/cm2). 1.10) Booster pump overloaded. 1.11) Evaporator water temp.low(900C). 1.13) Vacuum in chlorinator high(>25of WC). 1.14) Vacuum in chlorinator low(1ppm) 1.18) CL2 leak high LD-2(>1ppm) 1.19) Booster pump suction press.low(1.2 kg/cm2). 2 Interlocks & Protections: 2.1) Gas CL2 v/v(CL-34) opens when vacuum is normal(between 5&25of WC). 2.2) CL-34 v/v closes when vacuum is high(>25of WC)or low(700C. 2.4) CL-34 v/v closes when evaporator water temp.850C. 2.6) Heater will cut-in automatically at evaporator water temp.

C.T.Fan 1. Start Permissives: 1.1) Gearbox oil level is normal. 1.2) Nooverload trip&vibration high tripis persisting. 1.3) Control fuse O.K. & L.O.S. released. 1.4) D.C.P. control supply,control transformer-A/B & 415v 1PC bus-A/B normal. 2. Power Source: 2.1) In general:~ a] Control transformer-A415v 1PC bus-AGroup-A C.T.fans (Fan nos.-1 to 5). b] Control transformer-B415v 1PC bus-BGroup-B C.T.fans (Fan nos.-6 to 10). 2.2) In case of shut-down / emergency:~ Control transformer-A / B 415v 1PC bus-A & B or 415v 1PC bus-A / B Group-A & B C.T.Fans. 3. Indications, Annunciations & Protection Trips: 3.1) On&Offindications of each C.T.fan in C.R.T. 3.2) Any C.T.fan tripannunciation at U.C.P. 3.3) Any C.T.fan tripannunciation at U.C.P.will appear for the following protection trips:~ a] If anyone or more running C.T.fans in Gr.-A / B trip because of overload/control fuse blown/vibration high/oil level low. b] If all the running C.T.fans in Gr.-A / B trip because of 415v 1PC bus-A / B dead/control transformer-A /B fail. c] If all the running C.T.fans in Gr.-A & B trip because of 415v 1PC bus-A & B dead/control supply of D.C.P.fail.

Compressor 1. Start Permissives: 1.1) L.O.S.normal. 1.2) Bkr.is in service. 1.3) Cooling flow adequate(>300 lit/min). 1.4) L.O.press.O.K.(>2.5 kg/cm2). 1.5) H.P.cylinder jacket cooling water temp.normal(< 470C). 1.6) L.O.temp.normal(< 600C). 1.7) L.P.cylinder O/L air temp.normal(< 1650C). 1.8) H.P.cylinder O/L air temp.normal(< 1750C). 2. Alarms & Interlocks: 2.1) Auto start of compressor at low common header press.through PS-3 press.switch < 7.2 kg/cm.2 2.2) H.P.cylinder discharge air press.lowalarm through PS-4 press.switch 7.8 kg/cm2. 2.3) H.P.cylinder discharge air press.highalarm through PS-5 press.switch 8.4 kg/cm2. 2.4) After cooler O/L air press.highalarm through PS-6 press.switch 7.3 kg/cm2. 2.5) Receiver air press.lowalarm through PS-7 press.switch 6.8 kg/cm2. 2.6) Receiver air press.highalarm through PS-8 press.switch 8.3 kg/cm2. 2.7) Cooling water header press.lowalarm through PS-11 press.switch 2 kg/cm2. 2.8) L.O.press.lowalarm through PS-12 press.switch 2.5 kg/cm2. 2.9) L.O.press.very lowalarm & compressor trip through PS-13 press.switch 2 kg/cm2. 2.10) L.P.cylinder O/L air temp.very highalarm & compressor trip through TS-1 temp.switch > 1650C. 2.11) H.P.cylinder suction air temp.highalarm through TS-2 temp.switch > 500C. 2.12) H.P.cylinder O/L air temp.very highalarm & compressor trip through TS-3 temp.switch > 1750C. 2.13) Aftercooler O/L air temp.highalarm through TS-4 temp.switch > 500C. 2.14) L.O.temp.highalarm through TS-5 temp.switch 600C. 2.15) L.O.temp.very highalarm & compressor trip through TS-6 temp.switch 650C. 2.16) H.P.cylinder jacket cooling water temp.highalarm through TS-7 temp.switch 470C. 2.17) H.P.cylinder jacket cooling water temp.very highalarm & compressor trip through TS-8 temp.switch 500C. 2.18) Compressor trip due to overloadalarm. 2.19) Cooling water flow lowalarm through FS-2 flow switch = 300 lit/min 2.5 kg/cm2. 2.20) Cooling water flow very lowalarm & compressor trip through FS-1 flow switch = 270 lit/min 1.8 kg/cm2. 2.21) 100% 50% loading unloading through PS-1 press.switch = 7.8 7.5 kg/cm.2 2.22) 100% 0% loading unloading through PS-2 press.switch = 8.1 kg/cm.2 2.23) Atomising air press.at operating floor lowalarm = 5 kg/cm.2 2.24) Atomising air press.at operating floor very lowalarm = 4.5 kg/cm.2 3. Compressor panel & its drier panel control power supplies which were initially from 240v AC control power,have been changed & presently taken from UPS & 24v DCDB respectively to avoid tripping of all compressors due to power supply failure.

Fuel Oil Pumps

1. L.D.O. & H.F.O. Pumps:~ 1.1) Start Permissives: a] L.D.O./H.F.O. storage tank level not very low ( 0.8 M). b] M.C.C. selected normal,power isolator on & L.O.S. released. c] L.C.P. selected in manual mode. 1.2) Auto-start Interlocks: In auto,stand-by pump will take start at the following conditions: a] Any running pump trips or fails to start. b] F.O.header press.becomes low( 13 kg/cm2 for L.D.O./H.F.O.) at a definite time delay. 1.3) Indications & Remote Operations: At L.C.P. & U.C.R. pumpon,off,M.C.C.disturbance,normal power supply&alternate power supply healthyindications should be found O.K. Remote operation of H.F.O.pump no.-1 from U.C.R.-1,H.F.O.pump no.-2 from U.C.R- 2,H.F.O.pump no.-3 from U.C.R.-3,H.F.O.pump no.-4 from all U.C.Rs. & L.D.O.pumps from L.C.P.should be checked & found O.K. L.D.O. / H.F.O. tank I/L or O/L v/vopenindications,L.D.O./ H.F.O.tank level high / low,H.F.O.tank oil temp.high / low,H.F.O. tank stage heater temp.low,D.O.T. level high / low&H.F.O. / L.D.O. pump suction strainer dp highannunciations are to be found O K. After H.F.O.C.V.-HO33A1,H.F.O.press.lowalarm = 3.5 kg/cm2. After H.F.O.C.V.-HO33A1,H.F.O.temp.lowalarm = 1150C. DP across H.F.O.discharge strainer highalarm 0.7 kg/cm2. H.O.T.V./L.O.T.V. trip at very low oil press. 3 kg/cm2. 2. L.D.O. & H.F.O. Unloading Pumps:~ 2.1) Start Permissives: a] Either L.D.O. tank-1 / 2 & H.F.O. tank-1 / 2 levels are normal. b] Either I/L v/vs of L.D.O. tank-1 / 2 & H.F.O. tank-1 / 2 are open. 2.2) Protection Trippings: a] Either L.D.O. tank-1 / 2 level becomes high = 9.35 M. b] Either H.F.O. tank-1 / 2 level becomes high = 10.45 M. 3. Drain Oil Pump, Oil Recovery Pump, Oil / Water Separator Pump & Sump Pump:~ 3.1) Start Permissives: For D.O.pump & O.R.pump,selector switches are to be put in1for starting of pump no.-1 & vice versa. Nothing is provided for O / W.S.pump. 3.2) Protection Tripping: Tank level low.

C.S.T.-D.M.S.W.Pump-C.T.P. 1. Alarms, Annunciations & Feedback Indications:~ 1.1) L.C.P. alarms & annunciations: a] C.S.T. level high = 8.15 M. b] C.S.T. level low = 1.15 M. c] C.S.T. level very low = 0.65 M. d] D.M. make-up tank level high. e] D.M. make-up tank level low. f] D.M.S.W.pump discharge press.lowalarm appear = 3 kg/cm2. g] D.M.S.W.pump discharge press.lowalarm reset = 3.5kg/cm2. h] Suction dp highof D.M.S.W.pump & C.T.P. 0.6 kg/cm2. I] D.M.S.W.pump & C.T.P.trip. j] Stand-by D.M.S.W.pump & C.T.P.start. 1.2) U.C.R. alarms & annunciations: a] C.S.T. level high,low & very low. b] D.M.S.W.pump trip. 1.3) U.C.R. feedback indications: a] On,Off,Trip&Remoteindications of D.M.S.W.pumps & C.T.Ps. b] Operation of D.M.S.W.pump from back-up panel. 2. Start Permissives For C.T.P.& D.M.S.W.Pump:~ 2.1) C.S.T.level not very low. 2.2) M.C.C.selected for L.C.P.,L.O.S. released,module switch on,no M.C.C.disturbance or trip exists. 2.3) L.C.P.selected local/U.C.B.for L.C.P./U.C.B.operation respectively.

3. Auto-start Interlocks:~ 3.1) D.M.S.W.Pump: a] C.S.T. level not very low. b] Pump selected auto at L.C.P. & not running,discharge press.low and any of the other two running pumps tripped. 3.2) C.T.P.: a] C.S.T. level not very low. b] Pump selected auto at L.C.P.& not running and if the other running pump trips. 4. Protection Trip:~ C.S.T. level very low. 5. Local & Auto Operation Of The Following V/vs:~

Valves Manual Auto Closing Auto Opening Status 5.1) D.M.- 4 / 5 5.1) O.K. 5.1) C.S.T. level high. 5.1) C.S.T. level low / very low. 5.1) O.K. 5.2) D.M. 6 / 7 5.2) O.K. 5.2) C.S.T. level very low. 5.2) C.S.T. level not low. 5.2) O.K. 5.3) D.M. 63 / 64 5.3) O.K. 5.3) C.S.T. level very low. 5.3) C.S.T. level not low. 5.3) O.K. 5.4) D.M.C.W. 40 5.4) O.K. 5.4) D.M. make-up tank level high 5.4) D.M. make-up tank level low. 5.4) O.K.

D.M.C.W.( Boiler ) & D.M.C.W.( Turbine ) Pumps 1. Suction press.lowalarm 1.5 kg/cm2. 2. Suction press.lowalarm reset & pump start permissive 1.8 kg/cm2. 3. Discharge header press.lowalarm 3.5 kg/cm2.[D.M.C.W.(B)] / 3.2 kg/cm2.[D.M.C.W.(T)]. 4. Discharge header press.lowalarm reset 4.4 kg/cm2.[D.M.C.W.(B)] / 4.5kg/cm2.[D.M.C.W.(T)]. 5.Stand-by pump auto-start interlock checking procedure: 5.1) Pump M.C.C.power & position = Normal. 5.2) Pump L.O.S.condition = Released. 5.3) Pump selector switch condition = Auto. 5.4) Pumpsuction press.lowalarm = Reset. 5.5) After satisfying point nos.- 5.1 to 5.4,the stand-by pump should take start in auto when discharge header press.of the running pump becomes low[ 3.5 kg/cm2.{D.M.C.W.(B)}/3.2 kg/cm2.{D.M.C.W.(T)}]or get tripped electrically. For D.M.C.W.(T) system,this auto- start interlock logic is applicable for the third stand-by pump when two pumps are already in running condition as well as for the first pump when the remaining two pumps areoff. 6. All annunciation & indication lamps at L.C.P.,U.C.R.& C.R.T.should be found O.K.Onfeedbacks of D.M.C.W.(T)PPs.which were earlier from aux.contactor at local panel,are modified & presently taken from individual pump MCC to avoid tripping of all DMCW(T)PPs & thereby C.E.PPs.due to power supply failure at local panel.

C.E.Pump 1.Start Permissives:~ 1.1) Suction v/v = Open. 1.2) Recirculation v/v open 80%. 1.3) Vent v/v = Open. 1.4) Discharge v/v = Close. 1.5) Hotwell level = Adequate ( 0 mm). 2. Alarms & Interlocks:~ 2.1) Hotwell level very lowalarm & pump trip with alarm = - 800 mm. 2.2) Hotwell level lowalarm = - 400 mm. 2.3) Hotwell level + 150mm.alarm = 150 mm. 2.4) Hotwell level highalarm = 260 mm. 2.5) Hotwell level very highalarm = 300 mm. 2.6) DP across suction strainer highalarm 0.05 kg./cm2. 2.7) Discharge press.lowalarm 16 kg/cm2. 2.8) Discharge press. very lowalarm & pump trip with alarm with a time delay of 20 secs.14 kg/cm2. 2.9) After first pump starts,discharge v/v will open when discharge press.18 kg/cm2. In case of S.G.C.,discharge v/v of stand-by pump will open if common discharge header press.16 kg/cm2. 2.10) Discharge v/v will close after pump off. 2.11) Pumps will trip if all DMCW(T)Ps.off feedback comes. 2.12) Vent v/v will close after 2 mins.of pumpon. 2.13) Vent v/v will open after pump stop / trip. 2.14) Motor winding temp.highalarm 1250C. 2.15) Motor winding temp.very highalarm at C.R.T.1300C. 2.16) Pump thrust pad temp.highalarm at C.R.T.850C. 2.17) Pump journal brg.temp.highalarm at C.R.T.850C. 3. S.L.C. Auto-start Permissives:~ Out of three pumps,one no.,selected asmain(say pump-A),is started & between the remaining two pumps-B & C;anyone,say pump-C is kept in stand-by mode and thereafter SLC is madeon.In this condition,the logics are as follows: 3.1) If mainpump-A runs single, pump-B will start inautowhen m/c load is > 50%. 3.2) If single running mainpump-A trips or its discharge header press.becomes < 16.5 kg/cm2 when m/c load is > 50%, then pump-B will start in auto.If m/c load is < 50%,then stand-by pump-C will start in auto instead of pump-B when discharge header press. becomes < 16.5 kg./cm2.Stand-by pump-C will also take start in autowhen common discharge header press.becomes < 16.5kg/cm2 in case both pumps-A & B are running. 3.3) Discharge v/v of stand-bypump-C will open when common discharge header press. 16 kg/cm2. 3.4) If M.S.flow & L.P.B.P.CV position are > 60% each,then one or two pumps which are not running, all will take start. 3.5) If mainpump-A or pump-B trips & the reason for tripping is withdrawn then the tripped pump will start instantaneously irrespective of stand-by pump-C is running or not.

Boiler Feed Pump 1. Start Permissives: 1.1) Suction & recirculation v/vs open. 1.2) Deaerator level adequate(> 0 mm). 1.3) Deaerator level not very low(> -1835 mmwc). 1.4) Motor winding temp.not high( 2 kg./cm2.). 1.7) No electrical trip. 1.8) Bkr.in service & selector switch innormalcondition. 2. Alarms: 2.1) L.O.press.low(1.2 kg/cm2). 2.2) Motor brg.temp.high( 850C). 2.3) Motor winding temp.high(1250C). 2.4) Pump brg.temp.high(900C). 2.5) Working oil cooler oil I/L temp.high(1100C). 2.6) L.O.cooler oil I/L temp.high(650C)at LCP. 2.7) L.O.cooler oil O/L temp.high(550C)at LCP. 2.8) L.O.suction strainer dp high at LCP. 2.9) Pump discharge press.low(50 kg/cm2). 2.10) Common discharge header press.low(75 kg/cm2). 2.11) Suction strainer dp high(0.6 kg/cm2). 2.12) Deaerator level low(-500 mm). 2.13) Deaerator level high(150 mm). 2.14) Deaerator level high +100(250 mm). 2.15) Deaerator level very high(465 mm). 3. Protection Trips With Alarms: 3.1) Motor brg.temp.very high(900C). 3.2) Motor winding temp.very high(1300C). 3.3) Working oil cooler oil I/L temp.very high(1300C). 3.4) L.O.common header press.very low (1 kg/cm2). 3.5) Suction v/v close with a time delay of 1.5secs. The previous instantaneous tripping logic has been modified & a time delay is introduced to avoid pump tripping & thereby system instability causing from momentary malfunctioning of limit switch. 3.6) Deaerator level very low(-1835mmwc).

4. Interlocks: 4.1) Pumpongives auto open command to D.M.C.W.- 63 v/v. 4.2) Pumpoffgives auto close command to D.M.C.W.- 63 v/v. 4.3) Pumpoff& L.O.press.< 1.5 kg/cm2 = A.O.P. cut-in. 4.4) Pumpon& L.O.press. > 2.8 kg/cm2 for 30 secs = A.O.P. cut-out. 4.5) When either one/two pumps are running & the selected pump is put into stand-by mode,the discharge v/v of the stand-by pump will open in auto after 30 secs. 4.6) DT across pump discharge / suction very high (150C) = Manual action to be taken. 4.7) Recirculation v/v of a running pump will close in auto when its flow is >220T/hr & open at 2 kg/cm2. c] Pumps discharge v/v alongwith its I.B.V.close. d] Recirculation v/v opens. e] Scoop position becomes minimum. 5.3) Step-03 = a] Pump takes start. b] D.M.C.W. I/L v/v opens. 5.4) Step-04 = a] Pump scoop changes over frommantoautomode. b] Scoop position matches as per demand. 6. Auto Shut-down Sequences: 6.1) Step-51 = Shut-down-selected pump stop command. 6.2) Step-52 = a] A.O.P.takes start. b] D.M.C.W. I/L v/v closes. c] Recirculation v/v opens. 6.3) Step-53 = I.B.V.of discharge v/v alongwith the discharge v/v get closed.

I.D.Fan 1. L.O.press.adequate & fan start permissive 0.8 ata. 2. L.O.press.lowalarm & L.O.pump auto change-over when fan is on 0.6 ata. 3. L.O.press.very low alarm & fan trip with a time delay of 10 secs 0.4 ata. 4. DP.across L.O.filter highalarm 0.6 ata. 5. Hydraulic Coupling troublealarm for the followings: 5.1) Before cooler W.O.temp.highalarm 1000C. 5.2) Before cooler W.O.temp.very highalarm & fan trip 1100C. 5.3) After cooler W.O.temp.highalarm 800C. 5.4) After cooler W.O.temp.very highalarm & fan trip 900C. 5.5) H.C. DP across L.O.filter highalarm 0.4 bar. 5.6) H.C. DP across L.O.filter very highalarm & fan trip with a time delay of 20 secs 0.6 ata. 5.7) H.C. L.O. I/L press.> 0.8 bar within 20 secs.after fan starts,otherwise fan will trip. 5.8) H.C. L.O. I/L press.lowalarm 0.8 bar. 5.9) H.C. L.O. I/L press. very lowalarm & fan trip 0.6 ata.with a time delay of 20 secs. 6. Fan DE/NDE brg.temp.highalarm 770C. 7. Fan DE/NDE brg.temp.very highalarm & fan trip 820C. 8. Motor DE/NDE brg. temp.highalarm 850C. 9. Motor DE/NDE brg. temp. very highalarm & motor trip 900C. 10. Motor winding temp.highalarm 1250C. 11. Motor winding temp. very highalarm & motor trip 1300C. 12. All I.D.Fan offannunciation at U.C.P. 13. Fan brg.vibration highalarm 9 mm/sec. 14. Fan brg.vibration very highalarm & fan trip with a time delay of 5 secs 18 mm/sec. 15. S.G.C. Start-up: 15.1) Permissive (Release for step 01):~ a] Fan A / B motor brg./ winding temp. = Not high. b] Any F.D.Fanon& I.D.Fanon/off = True. c] I.D.Fan A / B status = Off & not tripped. d] I.D.Fan A / B selector switch = Normal. e] I.D.Fan A / B bkr. = Spring charged & DC on. 15.3) Step 01 = I.D.Fan A / B L.O.PP. SLC on& discharge gate bloweronif inauto. 15.4) Release for step 02 = I.D.Fan A / B any L.O.PP.on& L.O.press.> 0.8 ata. 15.5) Step 02 = I.D.Fan A / B I/L gate(GD-5A/5B) & O/L gate(GD-7A/7B) close & scoop position minimum. 15.6) Release for step 03 = Step 02. 15.7) Step 03 = I.D.Fan A / B start. 15.8) Release for step 04 = Step 03. 15.9) Step 04 = I.D.Fan A / B I/L gate(GD-5A/5B) & O/L gate(GD-7A/7B) opens. 15.10) Release for step 05 = Step 04. 15.11) Step 05 (I.D.Fan-A status on) = Monitoring status upto Step - 04 15.12) Release for step 06 = Step 05. 15.13) Step 06 = Monitor I.D.Fan B on/If I.D.Fan B drive statusoff,then I.D.Fan B I/L & O/L gates(GD-5B & 7B) close & scoop position minimum. 15.14) Step 07 = I.D.Fan A scoop controlauto.

F.D.Fan 1.Start Permissives: 1.1) L.O.press.O.K.( 0.8 ata). 1.2) Control oil press.O.K.( 8 ata). 1.3) Fan brg.temp.not high( 950C). 1.4) Motor brg.temp.not high( 850C). 1.5) Motor winding temp.not high(1250C). 1.6) I.D.Fanon. 1.7) Pitch control damper position min.(

T.A.S. & B.A.S. Controls & Interlocks:~ 1.Auxiliary steam header press.is sensed by press.transmitters-LBG10,CP101&CP102(for T.A.S.) & LBG20,CP101&CP102(for B.A.S.) in 1 out 2logic & HC-PRV(AS-22 for T.A.S. & AS-46 for B.A.S.) or LC-PRV(AS-32 for T.A.S. & AS-56 for B.A.S.)[depending upon the v/v selected for operation] is modulated to maintain constant press.of 11kg/cm2 in the auxiliary steam header. If both HC-PRV & LC-PRV are in operation,HC-PRV is modulated to maintain constant header press. 2. Auxiliary steam header temp.is sensed by temp.elements- LBG10,CT101 & CT102(for T.A.S.) & LBG20,CT101 & CT102 (for B.A.S.) in 1 out 2logic & HC-PRV(CD-65 for T.A.S. & CD-77 for B.A.S.) or LC-PRV(CD-71 for T.A.S. & CD-83 for B.A.S.) is modulated. If both HC-PRV & LC-PRV are in operation,spray water temp.control v/v of HC-PRV is modulated to maintain constant temp.LC stream spray water temp.control v/v remains open corresponding to LC-PRV position. 3. When HC-PRV(AS-22 for T.A.S. & AS-46 for B.A.S.) opens > 2%,the following actions will be initiated: 3.1] The u/s M/O isolating v/v(AS-21 for T.A.S. & AS-45 for B.A.S.) will open automatically. 3.2] Spray water control v/v(CD-65 for T.A.S. & CD-77 for B.A.S.) is to be in operation automatically. 3.3] The M/O isolating v/v(CD-64 for T.A.S. & CD-76 for B.A.S.) in spray water line will open automatically. 3.4] AS-32/AS-56 will changeover fromautotoman. 4. When HC-PRV opening is < 2%,the following interlocks will be initiated: 4.1) AS-21/AS-45 v/v will close. 4.2) CD-65/CD-77 v/v will close. 4.3) CD-64/CD-76 v/v will close. 4.4) AS-32/AS-56 will open. 5. When HC-PRV opening is < 2% & M.S.flow is 5T/hr,the following actions will be initiated: AS-22/AS-46 will changeover fromautotoman. 6.When LC-PRV(AS-32 for T.A.S. & AS-56 for B.A.S.) opens > 2%,the following actions will be initiated: 6.1) AS-31/AS-55 will open automatically. 6.2) CD-71/CD-83 is to be in operation automatically. 6.3) CD-70/CD-82 will open automatically.

7. When LC-PRV(AS-32 for T.A.S. & AS-56 for B.A.S.) opening is < 2%,the following interlocks will be initiated: 7.1) AS-31/AS-55 v/v will close. 7.2) CD-71/CD-83 v/v will close. 7.3) CD-70/CD-82 v/v will close. 8. Auto-changeover from LC-PRV to HC-PRV: 8.1) When aux.steam header press.comes down to 10 kg /cm2. 8.2) Continues to be 10 kg/cm2 for 0 10 secs. 8.3) When LC-PRV opening is > 95% or M.S.flow is > 5T/hr. 9. Forced-closing of both LC-PRV & HC-PRV: 9.1) AS-22 & 32 will close when TPRDS temp.becomes very high(3000C). 9.2) AS-46 & 56 will close when BPRDS temp.becomes very high (2400C). 10. Alarms: 10.1) TAS temp.lowalarm is 2200C. 10.2) TAS temp.highalarm is 2800C. 10.3) BAS temp.lowalarm is 2100C. 10.4) BAS temp.highalarm is 2250C. 10.5) TAS/BAS header press.lowalarm is When HC-PRV opens automatically,controls will be transferred to HC-PRV,both on steam as well as spray water side. LC stream spray temp.control v/v remains open corresponding to LC-PRV position.To avoid undesirable prolonged & repeated operation of control v/vs at very low opening,LC-PRV is to be closed manually when HC-PRV is operating at low lift condition.

Air Evacuation System 1. Auto Sequential Vacuum Pulling: 1.1) Step-00 = S.G.C.of condensate & air evacuation system is madeon. 1.2) Step-01= S.L.C.of C.E.PP.is madeon. 1.3) Step-02 = a] Turbine drain v/v master is put intoauto. b] Gland steam exhauster A/B is madeon. 1.4) Step-03 = a] L.P.exhaust hood spray v/v is put intoauto. b] Gland steam press.controller is inmanmode. c] Condensate header press.is > 18 kg/cm2. d] Gland steam CV-1 is closed. e] Gland steam supply header press.> 5.5 kg/cm2. 1.5) Step-04 = Starting ejector steam I/L v/v opens. 1.6) Step-05 = a] Starting ejector air I/L v/v opens. b] After 2 mins,vacuum bkr.is put intoauto& it becomes closed. 1.7) Step-06 = a] As per selection,main ejector A/B steam I/L v/v opens. b] Main ejector A/B air I/L v/v opens. c] Second main ejector steam I/L v/v opens. d] Second main ejector air I/L v/v opens. 1.8) Step-07 = a] Turbine speed > 15 rpm. b] Condenser vacuum > 133 mm of Hg or Condenser press.< 0.85kg/cm2. 1.9) Step-08 = a] Gland steam press.controller is inauto. b] Gland steam press.< 200 mmwc. c] Gland steam press.> 1900 mmwc. d] As per selection,gland steam exhauster A/B takes start. 1.10) Step-09 = Condenser vacuum > 568 mm of Hg or Condenser press.< 0.26 kg/cm2. 1.11) Step-10 = Starting ejector air I/L v/v closes. 1.12) Step-11 = Starting ejector steam I/L v/v closes. 1.13) Step-12 = a] Condenser vacuum > 672 mm of Hg or Condenser press.< 0.12 kg/cm2. b] Generator load > 5%. 1.14) Step-13 =As per selection of main ejector,the stand-by ejectors steam I/L & then air I/L v/vs get closed.

2. Auto Sequential Vacuum Breaking: 2.1) Step-00 = S.G.C.condensate & evacuation shut-down is madeon. 2.2) Step-01 = a] Main ejector-A steam I/L v/v closes. b] Main ejector-A air I/L v/v closes. c] Main ejector-B steam I/L v/v closes. d] Main ejector-B air I/L v/v closes. 2.3) Step-02 = a] Vacuum bkr.opens. b] Starting ejector air I/L v/v closes. 2.4) Step-03 = a] Turbine drain v/v master is inauto. b] Gland steam press.controller is inmanmode. c] Gland steam supply controller closes. 2.5) Step-04= Gland steam exhauster A & Boff.

3. Vacuum Breaker :-

3.1) Auto open logic : (a) When gen.ckt.bkr.not close. (b) T.G.in tripped condition.

+

(a) Axial shift very high [1(M)/1.1(E)mm]

(b) Turbine L.O. press.low(0.8kg/cm2) (c) Shaft vibration very high(250)

Or

(a) Turbine speed < 200 rpm (b) Boiler is in tripped condition (c) H.P.B.P. & L.P.B.P.are closed

3.2) Auto close logic : During open command / feedback of Starting Ejector air v/v with a time delay of 2mins. 4. Auxiliary steam press. to main ejector low alarm = 7.5 kg/cm2.

Steam Extraction Check Valves 1. Steam Extraction Check Valve No.-2: Under the following satisfied conditions,this will open otherwise it will trip or not open: ~ 1.1) L.P.H.-2 drip level not very high(< 300 mmwc). 1.2) Secondary oil press.is not low(> 2.8 kg/cm2). 1.3) I.P.T.steam I/L press.> 2.73 kg/cm2. 1.4) Turbine not tripped. 2. Steam Extraction Check Valve No.-3: Under the following satisfied conditions,this will open otherwise it will trip or not open: ~ 2.1) L.P.H.-3 drip level not very high(< 260 mmwc). 2.2) Secondary oil press.is not low(> 2.8 kg/cm2). 2.3) I.P.T.steam I/L press.> 2.73 kg/cm2. 2.4) Turbine not tripped. 3. Steam Extraction Check Valve No.-4: Under the following satisfied conditions,this will open otherwise it will trip or not open: ~ 3.1) Deaerator level not very high(< 465 mmwc). 3.2) Secondary oil press.is not low (> 2.8 kg/cm2). 3.3) Check v/v dp high(> 60% i.e. 6 kg/cm2) with a time delay of 2 mins. 3.4) I.P.T.steam I/L press.> 2.73 kg/cm2. 3.5) Turbine not tripped. 4. Steam Extraction Check Valve Nos.- 5 & 6: Under the following satisfied conditions,this will open otherwise it will trip or not open: ~ 4.1) H.P.H.-5/6 drip level not very high(< 400 mmwc). 4.2) Secondary oil press.is not low(> 2.8 kg/cm2 & > 1.8 kg/cm2 for steam extraction check v/v nos.- 5 & 6 respectively). 4.3) I.P.T.steam I/L press.> 2.73 kg/cm2 for steam extraction check v/v no.- 5 & H.P.T.chamber I/L press.> 23 kg/cm2 for steam extraction check v/v no.- 6. 4.4) Turbine not tripped. 5. Reheater Check Valve: Under the following satisfied conditions,this will open otherwise it will trip or not open: ~ 5.1) Secondary oil press.is not low(> 1.8 kg/cm2). 5.2) Turbine not tripped. 5.3) H.P.turbine steam I/L press.< 23.6 kg/cm2.

L.P.Heater 1. L.P.H. 1: 1.1) Drip level very high alarm appear = 300 mmwc. 1.2) Drip level very high alarm reset = 250 mmwc. 1.3) Drip level high alarm appear = 150 mmwc. 1.4) Drip level high alarm reset = 110 mmwc. At drip level very high: a] Auto close command = EX-17,CD-29 & 30 and DR-25. b] Auto open command = CD-31. 2. L.P.H. 2: 2.1) Drip level very high alarm appear = 300 mmwc. 2.2) Drip level very high alarm reset = 280 mmwc. 2.3) Drip level high alarm appear = 150 mmwc. 2.4) Drip level high alarm reset = 110 mmwc. 2.5) Drip level low alarm appear = - 50 mmwc. 2.6) Drip level low alarm reset > - 50 mmwc. At drip level very high: a] Auto close command = EX-9,CD-32 & 33 and DR-19. b] Auto open command = CD-34,EX-128 & 133. c] Protection open command = DR-28. 3. L.P.H. 3: 3.1) Drip level very high alarm appear = 300 mmwc. 3.2) Drip level very high alarm reset = 250 mmwc. 3.3) Drip level high alarm appear = 150 mmwc. 3.4) Drip level high alarm reset = 110 mmwc. 3.5) Drip level low alarm appear = - 50 mmwc. 3.6) Drip level low alarm reset > - 50 mmwc. At drip level very high: a] Auto close command = EX-10,CD-35 & 36. b] Auto open command = CD-37,EX-126 & 132. c] Protection open command = DR-22. 4. 4.1) Protection open command of EX-126,128,132 & 133 during turbine trip. 4.2) Protection close command of EX-17 during turbine trip or close signal of CD-29 / 30. 4.3) Protection close command of EX-9 during turbine trip or close signal of CD-32 / 33 4.4) Protection close command of EX-10 during turbine trip or close signal of CD-35 / 36.

H.P.Heaters 1. Alarms: 1.1) H.P.H. 5 / 6 drip level low alarm = - 200 mmwc. 1.2) H.P.H. 5 / 6 drip level high alarm = 200 mmwc. 1.3) H.P.H. 5 / 6 drip level very high alarm = 400 mmwc. 2. Protection Interlocks: 2.1) At H.P.H. 5 drip level very high: ~ a] Auto close command = FD-7,7A,9,9A; EX-12 & DR-2. b] Auto open command = FD-8A, EX-104 & DR-16. c] Protection open command = FD-8. 2.2) At H.P.H. 6 drip level very high: ~ a] Auto close command = FD-10,10A,12,12A; EX-13 & DR-2. b] Auto open command = FD-11A, EX-131 & DR-9. c] Protection open command = FD-11 2.3) At deaerator level very high (465 mmwc): Auto close command = DR-6 & 13. 2.4) (a) At turbine trip / close signal of FD7 / 9 = Protection close command of EX-12. (b) At turbine trip / close signal of EX12 = Protection open command of EX-104. (c) At turbine trip / close signal of FD10 / 12 = Protection close command of EX-13. (d) At turbine trip / close signal of EX-13 = Protection open command of EX-131.

P.A.Fan 1. Start Permissives:~ 1.1) No M.F.T. 1.2) P.A.fan general shut off damper closed. 1.3) C.A.D.< 5% open. 1.4) P.A.fan discharge damper in minimum position. 1.5) P.A.fan L.O.system healthy(L.O.press.> 0.8 kg/cm2) 1.6) P.A.fan bkr.in service & no switchgear disturbance persisting. 1.7) P.A.fan ready permissive (one F.D.fan must run for three P.A.fans only). 1.8) Seal air system healthy [S.A.fanon,seal air dampers open & seal air to hot P.A.dp O.K.(> 100mm)]. 1.9) Followingno pulveriser tripconditions: (a) H.A.G. & C.A.G. open. (b) Feeder I/L & O/L gates open. (c) Mill discharge v/vs open. (d) Mill O/L temp. not high(< 1100C). (e) Mill L.O.(L.O.press.> 0.9kg/cm2 & L.O.flow > 40lit/min) and gas (N2-gas press. > 41kg/cm2) systems healthy. (f) Burner manual isolating v/vs open. 2. Protection Trippings:~ 2.1) M.F.T. 2.2) F.D.fan trip (when one out of two running F.D.fans trips,the topmost 4th P.A.fan will trip). 2.3) L.O.system failure[L.O.press.very low ( 0.4 kg./cm2) or *tripping of both L.O.PPs.] with a time delay of 60 secs. *2.4) Discharge press. very low( 500mmwc). 2.5) P.A.fan brg.vibration very high( 10 mm/sec) with a time delay of 60secs. 2.6) P.A.fan motor winding temp.very high(1300C). 2.7) P.A.fan / fan motor brg.temp.very high(900C). 2.8) Followingpulveriser tripconditions:

(a) *Burner manual isolating v/vs closed. (b) Ignition permit not available within 3mins.from feederontoofforofftoonstatus. (c) HAG,CAG,feeder I/L & O/L gates closed. (d) Anyone mill discharge v/v closed with a time delay of 3secs. (e) Mill O/L temp.high(1100C). (f) Mill gas press.very low( 22 kg./cm2). (g) Mill L.O.press. very low( 0.6 kg./cm2) with a time delay of 3secs. & L.O.flow very low( 40lit/min) with a time delay of 5secs. (h) Millon& seal air system failed [seal air to hot PA dp low(100mm) with a time delay of 70secs. & S.A.fan off with a time delay of 60secs].

3. Alarms:~ 3.1) P.A.fan brg.temp.high = 850C. 3.2) P.A.fan motor winding temp.high = 1250C. 3.3) P.A.fan brg.vibration high = 8 mm/sec. *3.4) P.A.fan discharge press.low = 350 mmwc. 4. L.O.PP. Auto Changeover:~ Stand-by L.O.PP.(MCC & L.O.S.being normal) will take start in auto if L.O.press. becomes low (0.6 kg/cm2) or running L.O.PP.is made off / trips when P.A.fan is on.

Pulveriser 1. Start Permissives: 1.1) Seal air system healthy[S.A.fanon,seal air dampers open & seal air to hot P.A.dp O.K.(>100mm)]. 1.2) P.A.fan on >20 secs. 1.3) P.A.fan general shut off damper open. 1.4) Mill L.O.S.released,bkr.in service & no switchgear disturbance is persisting. 1.5) Mill L.O.(L.O.press.>1.1 kg/cm2 & L.O.flow > 40 lit/min) and gas (N2-gas press.> 41kg/cm2) systems healthy. 1.6) Mill O/L temp.not low(> 650C). 1.7) Pulveriser / Feeder start permissive (burner-tilt position horizontal & total airflow < 40% MCR in case of 1st mill / feeder). 1.8) Pulveriser ignition permit available. 1.9) Nopulveriser tripcondition persisting. 2. Protection Trippings: 2.1) M.F.T. 2.2) No burner isolating v/v.is open. 2.3) S.A.fan off > 60 secs. 2.4) Seal air to hot P.A.dp low(70 secs. 2.5) P.A.fan off. 2.6) H.A.G. & C.A.G. closed. *2.7) Mill gearbox brg.vibration very high( 4.5 mm/sec). 2.8) Mill gearbox brg.temp.very high(900C). 2.9) Mill motor winding temp.very high(1300C). 2.10) Mill motor brg.temp.very high(900C). 2.11) Mill L.O.press.very low( 0.6 kg./cm2) > 3secs. 2.12) Mill L.O.flow low(< 40lit/min) > 5secs. 2.13) Mill loading gas press.very low( 22 kg./cm2). 2.14) Any mill-discharge-gatenot openfeedback > 3secs. *2.15) Feeder I/L & O/L gates closed. 2.16) (a) With feederon,if mill O/L temp.becomes high(1100C). After mill tripping,H.A.G.will close with a time delay of 30secs;if high mill O/L temp.does not reset within that period. (b) With feederoff,if mill O/L temp.becomes high(1100C),H.A.G.will close first with a time delay of 30secs.& then the mill trips. 2.17) If ignition permit is not available within 3mins.from feeder on to off or off to on status. 3. L.O.PP. Auto Changeover: Stand-by L.O.PP.(MCC & L.O.S.being normal) will take start in auto if L.O.press. becomes low(0.9 kg/cm2) or running L.O.PP.is made off / trips when pulveriser is on. 4. Auto Start-up Sequence Of Mill Group: 4.1) Step-1= Oil elevation starts provided ignition permit is available. 4.2) Step-2= a] Seal air fan starts. b] S.A.fan O/L damper opens with a time delay of 40 secs. c] Seal air to pulveriser I/L damper opens. d] Seal air to hot P.A.dp becomes O.K. 4.3) Step-3= Mill L.O.PP.-Astarts. If not,L.O.PP.-B will start with a time delay of 5secs. Mill L.O.press. & L.O.flow to mill become O.K. 4.4) Step-4=Pulveriser discharge v/vs. open. 4.5) Step-5= a] P.A.fan starts. b] P.A.fan general shut off damper opens. 4.6) Step-6=Pulveriser starts if P.A.D.minimum signal is not present. 4.7) Step-7=Coal feeder starts with minimum feeding with a time delay of 60 secs. 5. Auto Shut-down Sequence Of Mill Group: 5.1) Step-1= Oil elevation starts provided ignition permit is available. 5.2) Step-2= Running feeder speed becomes minimum. 5.3) Step-3= Coal feeder becomes off. 5.4) Step-4= Pulveriser becomes off. 5.5) Step-5= P.A.Fan becomes off. 5.6) Step-6= P.A.fan general shut off damper closes. 5.7) Step-7= S.A.Fan becomes off & its discharge damper closes.

Seal Oil System

Characteristics Observation 1. Auto start of stand-by A.C.S.O.P.(provided, pump L.O.S.released, M.C.C.power available,seletor switch in normal& pump is in auto mode)

1.a) Running A.C.S.O.P.trips. b) Running A.C.S.O.P.fails to develop discharge press.>8.5 kg/cm2 c) A.C.S.O.P.auto on annunciation appears.

2. Auto start of D.C.S.O.P.(fulfilling start permissives). 2.a) Running A.C.S.O.P.- 1 / 2 trips & stand-by A.C.S.O.P.fails to start / develop discharge press.>8.5 kg/cm2. b) A.C.power failure. c) When both A.C.S.O.Ps fail to develop discharge press.> 8.5 kg/cm2. d) D.C.S.O.P.auto on annunciation appears.

3. Remote operation of A.C.S.O.P.- 1 / 2 (fulfilling start permissives) 3.a) On& Offindication lamps appear as per command. b) Locally pump normal discharge press.= 9.5 kg/cm2.

4. Seal oil tank level high.

4.a) Vacuum tank oil level high annunciation appears. b) Running seal oil vacuum pump trips.

5. Seal oil tank level low.

5.a) Vacuum tank oil level low annunciation appears. b) Running A.C.S.O.P.trips & D.C.S.O.P.takes auto start.

6.a) Seal oil temp.after duplex filter high alarm. b) Seal oil temp.after duplex filter very high alarm.

6.a) 500 C. b) 550 C. & turbine trips.

7.a) Seal oil to H2 differential press. low / high alarms. b) Seal oil press. to seals low alarm.

7.a) 0.9 / 1.7 kg/cm2. b) 2 kg/cm2.

8. Brg.chamber extraction blower vacuum low alarm. 8. > 0.3 bar. 9. CO2 flash evaporator temp.high alarm. 9. 1500 C. 10. Temp.of air side to H2 side seal oil drain temp.high alarm. 10. 700 C. 11. H2 purity in generator casing low alarm. 11. 95%. 12. H2 press. in generator casing low / high alarms. 12. 1.8 / 2.2 kg/cm2. 13. Brg.chamber extraction blower overload alarm. 13. Blower trips. 14.a) Liquid in generator casing(T.E.) high alarm. b) Liquid in generator casing(G.E.) high alarm. c) Liquid in generator casing(E.E.) high alarm. d) Liquid in terminal bushing(both ends) high alarm. e) Oil level in prechamber(E.E.) high alarm.

14. Liquid in generator high group alarm.

15. I.O.T. level low alarm.

H.P.Bypass System

A. Interlocks:-

Characteristics Observation 1. Remote(from C.R.T.& back-up panel) open& closeoperation of BP1& BP2v/vs. 1. Operation as well as feed back positions are to be found accurate. 2. BP1& BP2v/vs 2% open. 2.a) BPE1& BPE2change from man to auto mode.

b) BD v/v opens. 3. BP1& BP2v/vs < 2% open or closing of BP1& BP2v/vs. 3.a) BPE1& BPE2close & remain in auto.

b) BD v/v. closes. 4. Oil press. of oil unit very low(90 kg/cm2). 4. BP1& BP2 stuck-up position. 5. O.S.U.- 1 / 2 auto start. 5. At oil press.110 kg/cm2 & 115 kg/cm2 respectively. 6. O.S.U.- 1 / 2 auto stop. 6. At oil press.145 kg/cm2 & 155 kg/cm2 respectively. 7.a) Condenser vacuum low ( 308 mm.of Hg.) b) Downstream temp.very high (3800 C.) c) Turbine L.O.press.very low (0.8 kg/cm2.). d) Axial shift very high ( 1 mm.) or thrust failure trip. e) Shaft vibration very high ( 249 micron)

7.a) H.P.bypass trip. BP1,BP2& BDv/vs.close.BPE1& BPE2 also close & change fromautotoman. b) Downstream temp.very highalarm appears at 3800 C.

B. Operating Conditions:- 1. H.P.B.P.spray temp.should be at least 1400C.for M.S.temp.> 4600C.For this,the deaerator should be pegged well at 3.5 kg/cm2 press. either from T.A.S.header or from C.R.H. 2. H.P.B.P. M/O warm-up regulating glove v/vs should always be opened & regulated to have a H.P.B.P.v/v u/s temp.of 4500C during normal operation. 3. H.P.B.P. d/s set point should be maintained to around 3300C during normal operation of unit.This set point should be manipulated during house-load operation to keep C.R.H.temp.within limits.During start-up,it should be manipulated to get required R/H O/L temp. 4. Condenser press.should be < 0.6 ata before H.P.B.P.is opened. 5. H.P.B.P.warm-up line drain v/vs are to be kept opened till H.P.B.P.v/vs are taken into service. 6. H.P.B.P. set-point: 6.1)Fixed set-point: a] When m/c is running on C.M.C.,H.P.B.P.set-point = Set-point from C.M.C.+ x% where x = parameter set. b] When m/c is not running on C.M.C.,the set-point will follow the following logics: i) As soon as boiler fire is on,set-point = 24 kg/cm2.It can be increased manually (keeping set-point in auto mode only) upto 120 kg/cm2 @ 50 kg/min. ii) After M.S.press.crosses this set-point,H.P.B.P.v/vs start opening. iii) After H.P.B.P.v/vs are 10% open,set-point tracks actual press.Thus H.P.B.P.position does not change till M.S.press.is 70 kg/cm2. iv) Once M.S.press.> 70 kg/cm2,set-point is fixed at 70 kg/cm2.After this,it can be increased manually upto 120 kg/cm2 @ 50 kg/min. 6.2) Variable set-point: a] Once m/c.load > 70 MW & H.R.H.press.> 11 kg/cm2,the variable set-point circuit allows the M.S.press.to rise @ 2kg/cm2max.with set-point as = M.S.press.+ 2 kg/cm2. b] If after that,any of the above conditions(i.e.>70 MW or.>11kg/cm2) does not hold true,then set-point (M.S.press + 2 kg/cm2) remains at last value. c] If turbine trips,set-point remains at last value.However,if M.S.press.decreases,set-point also decreases. 7. H.P.B.P.opening limitations:

7.1) 0 MW = 100%. 7.2) 110 MW = 67%. 7.3) 130 MW = 54%. 7.4) 150 MW = 40%. 7.5) 170 MW = 40%. 7.6) 190 MW = 15%. 7.7) 210 MW = 5%. H.P.B.P.max.set-point = 153 kg/cm2. 8. Once m/c.load > 70 MW & H.R.H.press.> 11 kg/cm2 is achieved & afterthat if any condition disappears,then minimum opening = 10%. 9. When both H.P.B.P.v/vs are in auto,the position of both the v/vs will try to be very close to each other (tracking of position of other v/v by way of changing effective set-point). C. Valve Fast Opening Command:- During large load rejections,H.P.B.P.v/vs shall open in about 3 secs.after initiation of no priority closingsignals from the followings: i)Generator bkr.open, ii)Turbine trip & iii)Turbine load shedding relay operate. Rapid opening of H.P.B.P.v/vs under the above conditions is achieved by activating a fast opening device which is incorporated in the bypass v/v actuators. a] In case of fast opening,both BPE1 & BPE2 positions will track BP1 & BP2 positions respectively for 10 secs.& then switch over to auto. b] If M.S.press.< 130 kg/cm2 & m/c load < 50 MW or M.F.T.operated,then no fast opening occurs;only H.P.B.P.v/vs are forced to auto. c] Fast opening time varies depending on the load & press.at the point of initiation of fast open. Load (0 to 120 MW) = Fast opening time (0.3 to 3 secs). M.S.press.(130 to 140 kg/cm2) = Fast opening time is (80 to 100%) the average mean time being derived from load. d] Whenever fast open & H.P.B.P.system is forced to auto,the H.P.B.P.press.set-point is matched momentarily to actual M.S.press.

L.P.Bypass System A. Operation Procedure: 1) Step-1 = Put L.P.B.P.spray controller on auto. 2) Step-2 = Check initial set-point of L.P.B.P.to be at 3 kg. 3) Step-3 = Open L.P.B.P.CV manually to around 5%. 4) Step-4 = Open H.P.B.P. 5) Step-5 = Check H.R.H.press.When H.R.H.press.is > 4 kg., put L.P.B.P.CV on auto. B. Controller Logic: At the first step,L.P.B.P.controller set-point is fixed at 3 kg. As H.R.H.press.increases,L.P.B.P.CV opens. When L.P.B.P. CV opens 25%,the CV is fixed at 25% & the set-point tracks the H.R.H.press.upto 11 kg. Then the L.P.B.P.CV maintains constant 11 kg. press.in the H.R.H.line. At this condition,the turbine is rolled & the H.P.chamber press.increases. At certain load,the H.P.chamber press. becomes > 11 kg.& at that time the max.selector in the control circuit selects the H.P.chamber press.as its set-point. As this set-point is more than H.R.H.press.,the CV starts closing & under normal operation the CV remains closed. The H.P.chamber press.set-point is limited to 41 kg. So H.R.H.press.cannot go beyond 41 kg. Emergency open of L.P.B.P.CV occurs when load shedding relay operates. C. L.P.B.P.CV Opening Condition: No emergency close command is existing. D. L.P.B.P. Stop V/v. Emergency Auto Open Condition:

1)Load shedding relay operated for 2secs. +

2) L.P.B.P.spray flow > 17%. Or (L.P.B.P.CV > 1% open). + 3) Emergency stop command not existing. E. L.P.B.P. Stop V/v. Emergency Close Conditions: 1) Hotwell level high ( 260 mm). An annunciation of hotwell level = + 150mm is introduced to get an early alarm of level tending to higher value for taking precautionary measure to avoid tripping of LPBP through high hotwell level,occasionally occurring during unit start-up. 2) Condenser vacuum very low ( 308 mm.of Hg.). 3) Condenser temp.very high ( 900 C.). 4) L.P.B.P.spray flow deviation very high (> 13.3%). 5) No C.W.pump is running. 6) Turbine thrust failure trip.

F. Protection & Interlocks: Test Item Condition Action Confirmation

1. Output signal for CV. 2. Stop v/v operation command ( Open Close ). 3.L.P.B.P.CV operation command (Open Close). 4. FCV auto operation command. 5. Attemperation spray flow EMG close. 6. Condenser level high ( 260mm) EMG close. 7. Condenser vacuum low(304mmof Hg.) EMG close. 8. Condenser temp.high ( 900C). EMG close.

Simulate the condition as follows: a) Cable short: MAG11CT001A & MAG11CT002A b) Cable lift: MAG11CP205 c) Make contact C.W.pump run d) Spray flow > 20%. TCP manual mode. e) Simulate the H.R.H.press.50%.

C.E.PP. running.

C.E.PP. running.

1.a) Output signal = 0,25,50,75& 100%. b) ~DO~ c) ~DO~ d) ~DO~ 2.a) Stop v/v open P.B.on. b) Stop v/v close P.B.on. 3.a) L.P.B.P.CV manual operation (open). b) L.P.B.P.CV manual operation (close). c) L.P.B.P.CV auto operation (open / close). 4. FCV auto operation (open). 5.a) A & B Spray flows simulated to 0%. 5.b) A & B - Spray flows simulated to 22% keeping L.P.B.P.CVs.in auto. 5.c) Simulate A & B spray control deviation > 10% 5.d) Simulate A & B spray control deviation to 0% keeping L.P.B.P.CVs in auto. 6.a) Make the contact of condenser level very high switch at local. 6.b) Return the contact of level switch to normal keeping L.P.B.P.CVs.in auto. 7.a) Make the contact of condenser vacuum low press. switch at local. 7.b) Return the contact of level switch to normal keeping L.P.B.P.CVs.in auto. 8.a) Make the contact of condenser temp.high switch at local. 8.b) Return the contact of temp.switch to normal keeping L.P.B.P.CVs.in auto.

1.a) A-CV position indicator 0 to 100%. b) B-CV position indicator 0 to 100%. c) A-FCV position indicator 0 to 100% d) B-FCV position indicator 0 to 100% 2.a) A & B Stop v/v open lamp on. b) A & B Stop v/v close lamp on. 3.a) A & B Stop v/vs open lamp on. b) A & B Stop v/vs close lamp on. c) A & B Stop v/vs open /close lamp on. 4.a) A & B L.P.B.P.CV 100% b) A & B FCV 100%. 5.a).i] A & B Stop v/vs close lamps on. ii] A & B L.P.B.P.CVs.0%. iii] A & B FCVs.x% where x% = any % depending on control demand. L.P.B.P.CVs. press. controls force to manual. 5.b).i] A & B Stop v/vs open lamps on. ii] A & B L.P.B.P.CVs.100%. iii] A & B FCVs. x%. 5.c).i] A & B Stop v/vs close lamps on. ii] A & B L.P.B.P.CVs. 0%. iii] A & B FCVs. x%. (After 5 secs.from deviation low) 5.d).i] A & B Stop v/vs open lamps on. ii] A & B L.P.B.P.CVs.100%. iii] A & B FCVs. x%. 6.a).i] A & B Stop v/vs close lamps on. ii] A & B L.P.B.P.CVs. 0%. iii] A & B FCVs. x%. 6.b).i] A & B Stop v/vs open lamps on. ii] A & B L.P.B.P.CVs.100%. iii] A & B FCVs. x% . 7.a).i] A & B Stop v/vs close lamps on. ii] A & B L.P.B.P.CVs. 0%. iii] A & B FCVs. x% . 7.b).i] A & B Stop v/vs open lamps on. ii] A & B L.P.B.P.CVs.100%. iii] A & B FCVs. x% . 8.a).i] A & B Stop v/vs close lamps on. ii] A & B L.P.B.P.CVs. 0%. iii] A & B FCVs. x% . 8.b).i] A & B Stop v/vs open lamps on. ii] A & B L.P.B.P.CVs.100%. iii] A & B FCVs. x%.

Test Item Condition Action Confirmation

9. C.W.PP. stop. EMG close. 10. EMG open.

10.Simulate the condition as follows: a) Cable short: MAG11CT001A&MAG11CT002Ab) Cable lift: MAG11CP205 c) Make contact: C.W.pump run d) Spray flow > 20%. e) Simulate H.R.H.press. to 0%.

9.a) Make the contact of C.W.PP.stopat M.C.C. 9.b) Return the contact of C.W.PP.run keeping L.P.B.P.CVs.in auto. 10.a) Make contact load shedding relay by EHG. 10.b) After 6 secs.from load shedding relay on. 10.c) Simulate the spray water flow to 0%. Make contact the load shedding relay by EHG.

9.a).i] A & B Stop v/vs close lamps on. ii] A & B L.P.B.P.CVs. 0%. iii] A & B FCVs. x% . 9.b).i] A & B Stop v/vs open lamps on. ii] A & B L.P.B.P.CVs.100%. iii] A & B FCVs. x% . 10.a).i] A & B Stop v/vs open lamps on. ii] A & B L.P.B.P.CVs.100%. iii] A & B FCVs. x%. (EMG open command is 6 secs.on by DCS). b).i] A & B Stop v/vs open lamps on. ii] A & B L.P.B.P.CVs.0%. iii] A & B FCVs. 0%. c).i] A & B Stop v/vs close lamps on ii] A & B L.P.B.P.CVs.0%. iii] A & B FCVs.100%.

G. Oil Supply Unit: O.S.U.PP.no.- 1 or 2 will always remain in opn.as per pump selection if the control is in auto,no fault is present and both pumps power supply & LOS are on.Normal system press.will remain between120 kg/cm2&160 kg/cm2. Filter pump will also start in auto as soon as any O.S.U.PP.gets start.Filter pump can only be made off from MCC, if reqd. Cooling fan takes start when oil temp.becomes high(500 C) & vice versa. During initial starting,i.e.,at zero press.condition,both O.S.U.PPs.will take start throughoil press.lowalarm(

Generator-Turbine-Boiler Alarms-Interlocks-Protections

Characteristics Annunciations Process Remarks 1.a) Cold gas temp.after H2- coolers high. b) Cold gas temp.after H2- coolers very high. c) Hot gas temp before H2- coolers high. d) Cold gas temp. controller

1.a) 500 C. b) 550 C. Cold gas temp.after H2- coolers very high trip & Turbine trip. c) 750 C.

1.a) By simulation. b) ~DO~ c) ~DO~ d) By power failure

1.b) Turbine trips, T.L.R.= 86 T1- T2 & TX1-TX2 operated and Generator mech.protection relay operated. 1.d) V/v will open during power failure. The old, v/v close logic is changed to avoid manual opening opn. delay during panel power failure for eliminating unit tripping

2.a) Cold air temp.to main excitor high. b) Hot air temp.after rectifier wheel high. c) Hot air temp.after main excitor high. d) Hot air temp.after main excitor very high.

2.a) 450 C. [ ] [ Air temp.of ] b) 650 C. [ excitor / rectifier] [ wheel high ] c) 700 C. [ ] d) 800 C. Turbine trip& Air temp.of excitor / rectifier wheel high

2.a) By simulation. b) ~DO~ c) ~DO~ d) ~DO~

2.d) Turbine trips, T.L.R.= 86 T1- T2 & TX1-TX2 operated and Generator mech. protection relay operated.

3.a) Stator winding temp.high. b) Stator core temp.high.

3.a) 1050 C. b) 1000 C.

3.a) By simulation. b) ~DO~

4. Rotor temp.high. 4. 1100 C. 4. By simulation. 5.a) Generator brg.temp.high. b) Gen.brg.temp.very high.

5.a) 900 C. b) 1200 C.

5.a) By simulation. b) ~DO~

6.a) Gen. brg. vibration high. b) Gen. brg. vibr.very high.

6.a) 250 micron. b) 400 micron.

6. By simulation.

7. Load shedding relay operates.

7. Gland steam press.abnormal.

7. By simulating gland steam temp >2350C & then operating the load shedding relay.

7. Gland steam supply controller opens fully.Gland steam exhaust controller closes. Gland steam set press.tracks actual gland steam press.& then I/L controller position changes as per actual.

Characteristics Annunciations Process Remarks 8.Generator casing H2-gas press. 8.a) Low alarm = 1.8 kg./ cm2.

b) High alarm = 2.2 kg./ cm2.

9.Generator casing H2-gas purity 9. Low alarm = 95%. 10. Boiler M.F.R. trip. 10.M.F.R.trip,Turbine trip,

T.L.R.=86T1-T2 & 86TX1-TX2 operated,Low forward power relay operated,Gen.class-B, Gr.-1,86B11B12B13 operated& Gen.class-C,Gr.-1,86C11C13 operated.

10.By pressing M.F.R.trip P.B. 10.M.F.R.,turbine & generator trip,main ckt.bkr.opens & gen field bkr.becomes off.

11.a) Gen.class-A,Gr.-1 operated. b) Gen.class-A,Gr.-2 operated.

11.a)M.F.R.trip,Turbine trip, T.L.R.=86T1-T2 & 86TX1- TX2 operated,&Gen.class-A Gr.-1,86A11A12A13 operated. b)M.F.R.trip,Turbine trip, T.L.R.= 86T1-T2 & 86TX1- TX2 operated,Gen.class-A, Gr.-2,86A21A22A23operated & alarm of the simulated relay appear.

11.a) By pressing emergency P.B b) By simulation.

11.a)M.F.R., turbine & generator trip,main ckt.bkr.opens & gen field bkr.becomes off. b) ~DO~

12.Gen.class-B,Gr.-1 operated.

12.Turbine trip,T.L.R.= 86T1-T2 & 86TX1- TX2 operated,Gen. class-B,Gr.-1,86B11B12B13 operated& alarm of the simulated relay appear.

12. By simulation. 12. No M.F.R.trip.Only turbine trips, main ckt. bkr.opens & generator field bkr.becomes off.

13.a) Gen.class-C,Gr.-1 opera