UNIT:

UNIT:

DATE:

Interlock & protection checklist for MILL-

PERMISSIVES:

1. Pulveriser start permit

2. Mill discharge valve open (simulated)

3. Mill outlet temperature less than 95 Deg C

4. Feeder in remote

5. Cold air gate open (simulated)

6. Tramp iron hopper valve open (simulated)

7. No pulveriser unsuccessful start

8. Bunker outlet gate open (simulated)

9. Lube oil permit

10. No pulveriser trip

11. PA permit

12. Elevation AC supply (110 V) available

Mill start when

1. Pulveriser off

2. Pulveriser ready

3. Ignition permit available

4. Start push button command

5. Seal air header to bowl mill DP adequate (+150 mmwcl ()

LOP INTERLOCK:

1. When LOP-B trips, LOP-A starts and vice versa.

2. Running LOP trips after 30 min when pulveriser made OFF

3. Running LOP trips after 10 sec on Mill sump oil level very low (LS7310).

4. Running LOP trips after 10 sec if lube oil press. less than 2.0 KSc (PS7332)

PROTECTIONS:

1. Lube oil pressure very low (2.0 KSc ()

2. Pulveriser ON and seal air to bowl DP very low (+125 mmwcl () for 1 minute

3. Mill sump oil level very low for 10 sec.(LS7310)

4. Loss of primary air

5. Loss of one PA fan (trip elevation D, E, F only)

6. Loss of both PA fans

7. MFT

8. Loss of unit power 24 V DC

ELECTRICAL PROTECTIONS:

1. Overload 1

2. Overload 2

3. Sensitive earth fault

4. Over current

5. EPB (SER only)

ALARMS:

1. Lube oil pressure low

2. Lube oil system trouble

3. Mill tripped

4. Pulveriser to seal air DP low

5. Motor overload

6. Lube oil pump A/B tripped

7. Mill lube oil filter dirty

OPERATIONO&M/C&I

SIGNATURE

NAME

UNIT:

DATE:

Interlock & protection checklist for RAPH-A

MOTOR INTERLOCK:

1. When electrical motor-A trips, electrical motor-B starts and vice-versa.2. If running electrical motor trips and standby electrical motor remains OFF for more than 2 sec and air pressure before solenoid valve more than 2.5 KSc, air motor starts.LOP INTERLOCK:

1. When guide bearing LOP-A trips, guide bearing LOP-B starts and vice-versa.2. When support bearing LOP-A trips, support bearing LOP-B starts and vice-versa.3. If any guide bearing LOP is ON and guide bearing lube oil flow (FS7311) is low for more than 10 sec, standby guide bearing LOP will ON.4. If any support bearing LOP is ON and support bearing lube oil flow (FS7313) is low for more than 10 sec, standby support bearing LOP will ON.DAMPER INTERLOCK:

1. When RAPH-A starts, flue gas inlet & outlet dampers (FGD8001 & FGD8003) and secondary inlet & outlet dampers (SAD7705 & SAD7707) open.2. If any PA fan motor is ON and RAPH-A starts, primary air inlet & outlet dampers (PAD7607 & PAD7609) open.3. If RAPH-B is ON and RAPH-A remains OFF for more than 2 min, flue gas inlet & outlet dampers and secondary inlet & outlet dampers and primary air inlet & outlet dampers close.ALARMS:

1. RAPH-A electric motor A/B tripped2. RAPH-A guide bearing LOP-A/B tripped3. RAPH-A support bearing LOP-A/B tripped4. RAPH-A guide bearing temp high5. RAPH-A support bearing temp high6. RAPH-A guide bearing flow low7. RAPH-A support bearing flow lowOPERATIONO&M/C&I

SIGNATURE

NAME

UNIT:

DATE:

Interlock & protection checklist for RAPH-B

MOTOR INTERLOCK:

1. When electrical motor-A trips, electrical motor-B starts and vice-versa.2. If running electrical motor trips and standby electrical motor remains OFF for more than 2 sec and air pressure before solenoid valve more than 2.5 KSc, air motor starts.LOP INTERLOCK:

1. When guide bearing LOP-A trips, guide bearing LOP-B starts and vice-versa.2. When support bearing LOP-A trips, support bearing LOP-B starts and vice-versa.3. If any guide bearing LOP is ON and guide bearing lube oil flow (FS7312) is low for more than 10 sec, standby guide bearing LOP will ON.4. If any support bearing LOP is ON and support bearing lube oil flow (FS7314) is low for more than 10 sec, standby support bearing LOP will ON.DAMPER INTERLOCK:

1. When RAPH-B starts, flue gas inlet & outlet dampers (FGD8002 & FGD8004) and secondary inlet & outlet dampers (SAD7706 & SAD7708) open.2. If any PA fan motor is ON and RAPH-B starts, primary air inlet & outlet dampers (PAD7608 & PAD7610) open.3. If RAPH-A is ON and RAPH-B remains OFF for more than 2 min, flue gas inlet & outlet dampers and secondary inlet & outlet dampers and primary air inlet & outlet dampers close.ALARMS:

1. RAPH-B electric motor A/B tripped2. RAPH-B guide bearing LOP-A/B tripped3. RAPH-B support bearing LOP-A/B tripped4. RAPH-B guide bearing temp high5. RAPH-B support bearing temp high6. RAPH-B guide bearing flow low7. RAPH-B support bearing flow lowOPERATIONO&M/C&I

SIGNATURE

NAME

UNIT:

DATE:

BOILER Interlock & protection checklist

PURGE PERMISSIVES:

1. LOTV closed

2. HOTV closed

3. All LONV closed

4. All HONV closed

5. Drum level not high (drum level less than +125 mmwcl)

6. Drum level not low (drum level more than -125 mmwcl)

7. No boiler trip condition

8. All scanners showing no flame

9. Air flow less than 40%

10. Aux. air damper modulating

11. Wind box to furnace DP not very high (wind box to furnace DP less than +225mmwcl)

12. All PA fans off

13. All hot air gate closed

14. All pulverisers off

15. All feeders off

Following purge sequence were checked and found OK:

1. Purge ready (all purge permissives are satisfied)

2. Purging (2 minute cycle)

3. Second stage purging

4. Purge complete

MASTER FUEL TRIP CONDITIONS:

Alarm

Trip1. Both ID fans off

2. Both FD fans off

3. Both RAPH off

4. Furnace pressure very high (2/3 logic)

+100 mmwcl+180 mmwcl

5. Furnace pressure very low (2/3 logic)

-100 mmwcl-150 mmwcl

6. Drum level very high for more than 10 sec

+125 mmwcl+225 mmwcl

7. Drum level very low for more than 5 sec

-125 mmwcl-225 mmwcl

8. Emergency trip

9. Loss of 220 V DC for more than 2 sec

10. Air flow less than 30%

11. Reheater protection

12. Loss of all fuel trip

13. All BFPs trip

14. All of unit critical power +24 V DC

OPERATIONO&M/C&I

SIGNATURE

NAME

UNIT:

DATE:

Interlock & protection checklist for FD FAN - APERMISSIVES:

Criteria no1. FD fan lube oil pressure more than 0.9 bar (PS 7307)

50

2. FD fan control oil pressure more than 9.0 bar (PS 7305)

51

3. FD fan lube oil tank level adequate (LS7301)

52

4. FD fan bearing temp less than 90 Deg C

53

5. ID fan A/B motor ON

54

6. FD fan lube oil cooler outlet temp less than 45 Deg C (TS7305)

55

7. FD fan blade pitch minimum

56

8. FD fan discharge damper closed

57

9. FD fan any LOP ON

58

LOP INTERLOCK:

1. When LOP-B trips, LOP-A starts and vice- versa.

2. If any LOP is ON and lube oil pressure goes less than 0.9 KSc, standby LOP start. (PS 7307)

3. If any LOP is ON and control oil pressure goes less than 8.0 KSc, standby LOP start. (PS 7305)

4. Running LOP trips after 30 min when FD fan made OFF

DAMPER INTERLOCK:

1. When FD fan motor starts, discharge damper open.

2. When FD fan motor stops, discharge damper gets close provided other FD fan is ON.

PROTECTIONS:

1. Lube oil pressure very low (0.5 KSc () for more than 1.0 sec

2. FD fan motor bearing temp very high (110 Deg C () for more than 1 min

3. FD fan bearing temp very high (110 Deg C () for more than 1 min

4. FD fan bearing vibration very high (9.0 mm/s ()

5. FD fan discharge damper closed for more than 1 min

6. Both ID fans off

7. Both ID & FD fans are ON and corresponding ID fan trips

ELECTRICAL PROTECTIONS:

1. Overload 1

2. Overload 2

3. Sensitive earth fault

4. Over current

5. EPB (SER only)

ALARMS:

1. Lube oil/control oil pressure low

2. Bearing vibration high (4.5 mm/s ()

3. Bearing temp high (90 Deg C ()

4. Winding temp high (120 Deg C ()

5. FD fan A/B tripped

6. Lube oil pump A/B tripped

7. Motor overload

8. FD fan running and discharge damper not opening for more than 30 sec

9. FD fan lube oil system trouble

OPERATIONO&M/C&I

SIGNATURE

NAME

UNIT:

DATE:

Interlock & protection checklist for FD FAN - BPERMISSIVES:

Criteria no1. FD fan lube oil pressure more than 0.9 bar (PS 7308)

50

2. FD fan control oil pressure more than 9.0 bar (PS 7306)

51

3. FD fan lube oil tank level adequate (LS7302)

52

4. FD fan bearing temp less than 90 Deg C

53

5. ID fan A/B motor ON

54

6. FD fan lube oil cooler outlet temp less than 45 Deg C (TS7306)

55

7. FD fan blade pitch minimum

56

8. FD fan discharge damper closed

57

9. FD fan any LOP ON

58

LOP INTERLOCK:

1. When LOP-B trips, LOP-A starts and vice- versa.

2. If any LOP is ON and lube oil pressure goes less than 0.9 KSc, standby LOP start. (PS 7308)

3. If any LOP is ON and control oil pressure goes less than 8.0 KSc, standby LOP start. (PS 7306)

4. Running LOP trips after 30 min when FD fan made OFF

DAMPER INTERLOCK:

1. When FD fan motor starts, discharge damper open.

2. When FD fan motor stops, discharge damper gets close provided other FD fan is ON.

PROTECTIONS:

1. Lube oil pressure very low (0.5 KSc () for more than 1.0 sec

2. FD fan motor bearing temp very high (110 Deg C () for more than 1 min

3. FD fan bearing temp very high (110 Deg C () for more than 1 min

4. FD fan bearing vibration very high (9.0 mm/s ()

5. FD fan discharge damper closed for more than 1 min

6. Both ID fans off

7. Both ID & FD fans are ON and corresponding ID fan trips

ELECTRICAL PROTECTIONS:

1. Overload 1

2. Overload 2

3. Sensitive earth fault

4. Over current

5. EPB (SER only)

ALARMS:

1. Lube oil/control oil pressure low

2. Bearing vibration high (4.5 mm/s ()

3. Bearing temp high (90 Deg C ()

4. Winding temp high (120 Deg C ()

5. FD fan A/B tripped

6. Lube oil pump A/B tripped

7. Motor overload

8. FD fan running and discharge damper not opening for more than 30 sec

9. FD fan lube oil system trouble

OPERATIONO&M/C&I

SIGNATURE

NAME

UNIT:

DATE:

Interlock & protection checklist for PA FAN - APERMISSIVES:

Criteria no1. PA fan and motor bearing temp less than 80 Deg C

50

2. PA fan hydraulic coupling bearing temp less than 100 Deg C

51

3. PA fan lube oil cooler outlet temp less than 45 Deg C (TS7317)

52

& hydraulic cplg cooler outlet temp less than 70 Deg C (TS7353)

4. PA fan lube oil pressure more than 1.2 bar (PS 7317)

53

& hydraulic cplg oil pressure more than 1.0 bar (PS 7353)

5. PA fan lube oil/hydraulic cplg tank level adequate (LS7305/LS7351)

54

6. Either FD fan ON

55

7. Start permit from FSSS available

56

8. PA fan inlet & outlet gate closed

57

9. PA fan regulating vane & scoop tube minimum

58

10. PA fan any LOP ON

59

11. PA fan any AOP ON

60

12. PA fan oil flow at cooler outlet more than 75% (FS7305)

61

LOP INTERLOCK:

1. When LOP-B trips, LOP-A starts and vice- versa.

2. If any LOP is ON and lube oil pressure goes less than 0.9 KSc, standby LOP start. (PS 7319)

3. Running LOP trips after 30 min when PA fan made OFF

AOP INTERLOCK:

1. When AOP-B trips, AOP-A starts and vice- versa.

2. If any AOP or PA fan motor is ON and hydraulic coupling oil pressure goes less than 0.8 KSc, standby AOP start. (PS 7355)

3. If PA fan motor is ON and main oil pump pressure goes more than 2.0 KSc, running AOP will OFF after 30 sec. (PS7351)

4. Running AOP trips after 30 min when PA fan made OFF

GATE INTERLOCK:

1. When PA fan motor starts, inlet and outlet gates open.

2. When PA fan motor stops, inlet and outlet gates close.

PROTECTIONS:

1. Lube oil pressure very low (0.4 KSc () for more than 10 sec

2. Hydraulic cplg oil pressure very low (0.6 KSc ()

3. PA fan motor or fan bearing temp very high (90 Deg C () for more than 1 min

4. PA fan hydraulic cplg bearing temp very high (110 Deg C () for more than 1 min

5. PA fan bearing vibration very high (9.0 mm/s ()

6. PA fan inlet or outlet gate closed for more than 1 min

7. Hydraulic coupling return oil temp very high (120 Deg C ()

8. MFT

9. Both FD fans OFF

ELECTRICAL PROTECTIONS:

1. Overload 1

2. Overload 2

3. Sensitive earth fault

4. Over current

5. EPB (SER only)

ALARMS:

1. Lube oil pressure low

2. Hydraulic coupling oil pressure low

3. Bearing vibration high (4.5 mm/s ()

4. Bearing temp high (80 Deg C ()

5. Hydraulic coupling bearing temp high (100 Deg C ()

6. Winding temp high (120 Deg C ()

7. PA fan A/B tripped

8. Lube oil pump A/B tripped

9. Hydraulic coupling oil pump A/B tripped

10. Motor overload

11. PA fan running and inlet or outlet gate not opening for more than 30 sec

12. PA fan lube oil system trouble

13. Hydraulic coupling oil filter dirty

OPERATIONO&M/C&I

SIGNATURE

NAME

UNIT:

DATE:

Interlock & protection checklist for PA FAN - BPERMISSIVES:

Criteria no1. PA fan and motor bearing temp less than 80 Deg C

50

2. PA fan hydraulic coupling bearing temp less than 100 Deg C

51

3. PA fan lube oil cooler outlet temp less than 45 Deg C (TS7318)

52

& hydraulic cplg cooler outlet temp less than 70 Deg C (TS7354)

4. PA fan lube oil pressure more than 1.2 bar (PS 7318)

53

& hydraulic cplg oil pressure more than 1.0 bar (PS 7354)

5. PA fan lube oil/hydraulic cplg tank level adequate (LS7306/LS7352)

54

6. Either FD fan ON

55

7. Start permit from FSSS available

56

8. PA fan inlet & outlet gate closed

57

9. PA fan regulating vane & scoop tube minimum

58

10. PA fan any LOP ON

59

11. PA fan any AOP ON

60

12. PA fan oil flow at cooler outlet more than 75% (FS7306)

61

LOP INTERLOCK:

1. When LOP-B trips, LOP-A starts and vice- versa.

2. If any LOP is ON and lube oil pressure goes less than 0.9 KSc, standby LOP start. (PS 7320)

3. Running LOP trips after 30 min when PA fan made OFF

AOP INTERLOCK:

1. When AOP-B trips, AOP-A starts and vice- versa.

2. If any AOP or PA fan motor is ON and hydraulic coupling oil pressure goes less than 0.8 KSc, standby AOP start. (PS 7356)

3. If PA fan motor is ON and main oil pump pressure goes more than 2.0 KSc, running AOP will OFF after 30 sec. (PS7352)

4. Running AOP trips after 30 min when PA fan made OFF

GATE INTERLOCK:

1. When PA fan motor starts, inlet and outlet gates open.

2. When PA fan motor stops, inlet and outlet gates close.

PROTECTIONS:

1. Lube oil pressure very low (0.4 KSc () for more than 10 sec

2. Hydraulic cplg oil pressure very low (0.6 KSc ()

3. PA fan motor or fan bearing temp very high (90 Deg C () for more than 1 min

4. PA fan hydraulic cplg bearing temp very high (110 Deg C () for more than 1 min

5. PA fan bearing vibration very high (9.0 mm/s ()

6. PA fan inlet or outlet gate closed for more than 1 min

7. Hydraulic coupling return oil temp very high (120 Deg C ()

8. MFT

9. Both FD fans OFF

ELECTRICAL PROTECTIONS:

1. Overload 1

2. Overload 2

3. Sensitive earth fault

4. Over current

5. EPB (SER only)

ALARMS:

1. Lube oil pressure low

2. Hydraulic coupling oil pressure low

3. Bearing vibration high (4.5 mm/s ()

4. Bearing temp high (80 Deg C ()

5. Hydraulic coupling bearing temp high (100 Deg C ()

6. Winding temp high (120 Deg C ()

7. PA fan A/B tripped

8. Lube oil pump A/B tripped

9. Hydraulic coupling oil pump A/B tripped

10. Motor overload

11. PA fan running and inlet or outlet gate not opening for more than 30 sec

12. PA fan lube oil system trouble

13. Hydraulic coupling oil filter dirty

OPERATIONO&M/C&I

SIGNATURE

NAME

UNIT:

DATE:

Interlock & protection checklist for ID FAN - APERMISSIVES:

Criteria no1. ID fan and motor bearing temp less than 80 Deg C

50

2. ID fan hydraulic coupling bearing temp less than 100 Deg C

51

3. Air preheater running condition available

52

4. ID fan any LOP ON

53

5. ID fan any AOP ON

54

6. ID fan lube oil cooler outlet temp less than 45 Deg C (TS7311)

55

7. ID fan hydraulic cplg cooler outlet temp less than 70 Deg C (TS7343)

56

8. ID fan stack path available

57

9. ID fan lube oil tank level adequate (LS7303)

58

10. ID fan hydraulic cplg tank level adequate (LS7341)

59

11. ID fan lube oil pressure more than 1.2 bar (PS 7311)

60

12. ID fan hydraulic cplg oil pressure more than 1.0 bar (PS 7343)

61

13. ID fan inlet gate closed

62

14. ID fan outlet gate closed

63

15. ID fan regulating vane minimum

64

16. ID fan scoop tube minimum

65

LOP INTERLOCK:

1. When LOP-B trips, LOP-A starts and vice- versa.

2. If any LOP is ON and lube oil pressure goes less than 0.9 KSc, standby LOP start. (PS 7313)

3. Running LOP trips after 30 min when ID fan made OFF

AOP INTERLOCK:

1. When AOP-B trips, AOP-A starts and vice- versa.

2. If any AOP or ID fan motor is ON and hydraulic coupling oil pressure goes less than 1.0 KSc, standby AOP start. (PS 7345)

3. If ID fan motor is ON and main oil pump pressure goes more than 2.0 KSc, running AOP will OFF after 30 sec. (PS7341)

4. Running AOP trips after 30 min when ID fan made OFF

GATE INTERLOCK:

1. When ID fan motor stops, inlet and outlet gates close provided other ID fan is ON.

2. When both ID fan motors stop, inlet and outlet gates open.

PROTECTIONS:

1. Lube oil pressure very low (0.4 KSc ()

2. Hydraulic cplg oil pressure very low (0.6 KSc ()

3. ID fan motor or fan bearing temp very high (90 Deg C () for more than 1 min

4. ID fan hydraulic cplg bearing temp very high (110 Deg C () for more than 1 min

5. ID fan bearing vibration very high (9.0 mm/s ()

6. ID fan inlet or outlet gate closed for more than 1 min

7. Hydraulic coupling return oil temp very high (120 Deg C ()

8. IF ID fan B is ON and FD fan A trips then ID fan A tripped

ELECTRICAL PROTECTIONS:

1. Overload 1

2. Overload 2

3. Sensitive earth fault

4. Over current

5. EPB (SER only)

ALARMS:

1. Lube oil pressure low

2. Hydraulic coupling oil pressure low

3. Bearing vibration high (4.5 mm/s ()

4. Bearing temp high (80 Deg C ()

5. Hydraulic coupling bearing temp high (100 Deg C ()

6. Winding temp high (120 Deg C ()

7. ID fan A/B tripped

8. Lube oil pump A/B tripped

9. Hydraulic coupling oil pump A/B tripped

10. Motor overload

11. ID fan running and inlet or outlet gate not opening for more than 30 sec

12. ID fan lube oil system trouble

13. Hydraulic coupling oil filter dirty

OPERATIONO&M/C&I

SIGNATURE

NAME

UNIT:

DATE:

Interlock & protection checklist for ID FAN - BPERMISSIVES:

Criteria no1. ID fan and motor bearing temp less than 80 Deg C

50

2. ID fan hydraulic coupling bearing temp less than 100 Deg C

51

3. Air preheater running condition available

52

4. ID fan any LOP ON

53

5. ID fan any AOP ON

54

6. ID fan lube oil cooler outlet temp less than 45 Deg C (TS7312)

55

7. ID fan hydraulic cplg cooler outlet temp less than 70 Deg C (TS7344)

56

8. ID fan stack path available

57

9. ID fan lube oil tank level adequate (LS7304)

58

10. ID fan hydraulic cplg tank level adequate (LS7342)

59

11. ID fan lube oil pressure more than 1.2 bar (PS 7312)

60

12. ID fan hydraulic cplg oil pressure more than 1.0 bar (PS 7344)

61

13. ID fan inlet gate closed

62

14. ID fan outlet gate closed

63

15. ID fan regulating vane minimum

64

16. ID fan scoop tube minimum

65

LOP INTERLOCK:

1. When LOP-B trips, LOP-A starts and vice- versa.

2. If any LOP is ON and lube oil pressure goes less than 0.9 KSc, standby LOP start. (PS 7314)

3. Running LOP trips after 30 min when ID fan made OFF

AOP INTERLOCK:

1. When AOP-B trips, AOP-A starts and vice- versa.

2. If any AOP or ID fan motor is ON and hydraulic coupling oil pressure goes less than 1.0 KSc, standby AOP start. (PS 7346)

3. If ID fan motor is ON and main oil pump pressure goes more than 2.0 KSc, running AOP will OFF after 30 sec. (PS7342)

4. Running AOP trips after 30 min when ID fan made OFF

GATE INTERLOCK:

1. When ID fan motor stops, inlet and outlet gates close provided other ID fan is ON.

2. When both ID fan motors stop, inlet and outlet gates open.

PROTECTIONS:

1. Lube oil pressure very low (0.4 KSc ()

2. Hydraulic cplg oil pressure very low (0.6 KSc ()

3. ID fan motor or fan bearing temp very high (90 Deg C () for more than 1 min

4. ID fan hydraulic cplg bearing temp very high (110 Deg C () for more than 1 min

5. ID fan bearing vibration very high (9.0 mm/s ()

6. ID fan inlet or outlet gate closed for more than 1 min

7. Hydraulic coupling return oil temp very high (120 Deg C ()

8. IF ID fan B is ON and FD fan A trips then ID fan A tripped

ELECTRICAL PROTECTIONS:

1. Overload 1

2. Overload 2

3. Sensitive earth fault

4. Over current

5. EPB (SER only)

ALARMS:

1. Lube oil pressure low

2. Hydraulic coupling oil pressure low

3. Bearing vibration high (4.5 mm/s ()

4. Bearing temp high (80 Deg C ()

5. Hydraulic coupling bearing temp high (100 Deg C ()

6. Winding temp high (120 Deg C ()

7. ID fan A/B tripped

8. Lube oil pump A/B tripped

9. Hydraulic coupling oil pump A/B tripped

10. Motor overload

11. ID fan running and inlet or outlet gate not opening for more than 30 sec

12. ID fan lube oil system trouble

13. Hydraulic coupling oil filter dirty

OPERATIONO&M/C&I

SIGNATURE

NAME