1. START PERMISSIVE
August 9, 2015 1
 Boiler Feed Pump:
 Boiler feed pump suction valve open Feed
Back
 Dearator level Normal.
Recirculation Line valve open feed back

2.  Condensate Extraction pump:
 Pump Feeder Healthy .
 No pump trip signal.
 Level greater than set point.
August 9, 2015 2

3.  ID FANS:
 ID Fan O/L Damper close feed back .
 ID Fan I/L Damper close feed back.
 Guillotine damper open.
 ID Fan MCC no trouble.
August 9, 2015 3

4.  Boiler trip:
 SH#1 Metal temperature Hi-Hi.
 SH#2 Metal temperature Hi-Hi.
 Drum level less than Low-Low.
 Drum Level Greater than Hi-Hi.
 Both ID fan Trip/ Stop feedback.
TRIP CONDITION
August 9, 2015 4

5.  Turbine trip:
 Main steam temperature Low-Low( 480 °c).
 Temp. of Turbine thrust pads & bearing liners
Hi-Hi (100 ° C), common.
 Return Oil temp. of bearing Hi-Hi (70 °C),
common.
 Condenser pressure Hi-Hi(-0.4 kg/cm²).
 Main steam pressure Low-Low (60.95 kg/cm²).
Hot well Level Low-Low (20%).
Lube oil pressure Low-Low ((0.3 kg/cm²).
August 9, 2015 5

6. Protection Oil pressure Low-Low (8 kg/cm²).
Tur. Rotor Axial displacement Hi-Hi(±1.5 mm).
Differential Expansion Hi-Hi(±1.5 mm).
Turbine front shaft vibration Hi-Hi( 0.07 mm).
Turbine rear shaft vibration Hi-Hi( 0.07 mm).
Generator front shaft vibration Hi-Hi( 0.07 mm).
Generator rear shaft vibration Hi-Hi( 0.07 mm).
August 9, 2015 6

7.  Turbine speed Hi-Hi (3360 RPM).
 Emergency Shutdown.
 Turbine emergency Stop (PB).
 Mechanical over speed trip.
 Turbine reset Push Button.
August 9, 2015 7

8. Generator Trip:
 Differential Protection (5%).
 Generator Rotor Earth Protection(1 stage-
alarm/2nd
stage- trip).
 Stator Frame Temperature Operated (80 °c
alarm /100°c trip)
 Emergency Trip Push Button Operated .
 Reverse Power Protection (0.5%) .
 Generator Winding Temperature Operated
(100°C –alarm/110 °C trip).
 Backup Impedence Protection.

Incase of air cooler tube leakage.?
August 9, 2015 8

9. Turbine Trip Solenoid:
 Low forward power Protection (05%).
 Loss of Excitation Protection.
 Under voltage protection (Drop out 70%)
 Gen. over current protection with time delay
unit (105%, 10 sec.)
 PT fuse failure relay (Met-A, Port- Gen. Ckt
closed).
 Gen. negative phase sequency protection
(1st=7.5%,
-Alarm , 12t= 10- Trip) .
August 9, 2015 9

10.  Over / under frequency port ( 1st
=2 sec-Alarm,
2nd
=2 sec-Trip.
 All devices connected for Turbine.
 Gen. over current voltage restraint port.
 Gen. over voltage protection (105%=0.3 sec.-
Alarm, 110%=2 sec.- Trip.
 Under voltage protection (80%= 3 sec- Trip.).
August 9, 2015 10

11.  TIE CIRCUIT BREAKER TRIP:
 Over /under Frequency (1st
- Alarm+ Trip)
Negative Phase sequence ( 1st
- Alarm+ Trip).
Over voltage / under voltage protection (1st
-
Alarm+ Trip).
 Vector surge protection (1st
- Alarm + Trip).
August 9, 2015 11