ROLE AND RESPONSIBILITIES DURING BLACK OUT

A.  Possible Causes for Total Station Power Failure.

√ Tripping of both transmission lines (400 kV Line-1 & 2).

√ If unit trips /under shut down and charged transformers (both GT & ST) also trip at same time. 

B. Main objectives to be achieved during total power failure.

1. To protect turbine from oil starvation. 

2. To prevent the H2 from escaping through generator seals by maintaining adequate Seal Oil-H2 differential pressure.

3. In case of total collapse of seal oil system, to purge out the Ha with CO.

4. To prevent turbine rotor from damage & sagging. 

5. To save LP Turbine diaphragm (Rupture disc). 

6. To protect the flame scanners from damage due to excessive heat. 

7. To prevent deformation of air pre heaters due to uneven heating of segments. 

8. To provide Illumination at various working areas (DC Lights & later emergency AC lighting system). 9. To be ready for firefighting, whenever & wherever necessary

10. To maintain healthiness of protection and 400 KV breaker operation. 

11. To maintain healthiness of 220V main plant battery bank (2 No's), 220V switchyard battery bank (2 No's) switchyard PLCC, Switchyard 48 V battery bank, CWPH Battery charger & UPS, Fire water pump House Battery charger & UPS, DM Plant Battery charger & UPS, IDCT Battery Charger & UPS. 

12. To make Startup power available as early as possible and restart the Unit. 

13. To ensure availability of all control systems, panels, monitors for effective monitoring and control. 

C. Work Responsibilities (ln Order of Work Priority)

 1) Responsibilities of Electrical Operator / Switchyard Operator/Shift Engineer (BOP/ Elec.) 

I.  Quickly ascertain causes or reason leading to total station power failure.

II.  Switch ON emergency light.

III. Not down the relays operated ( do not reset any relay without the clearance from EMD).

IV. Communicate the problem to SCE / ASCE. 

V.  Check that all 400 KV breakers are opened.

VI. Send message to WRLDC Control Room informing the failure as well as nearest NPS.

VII. Yard visit should be done for visual survey of isolators and breaker status.

VIII. Charging plan for Line -1 & 2, and 400KV switchyard. 

            a) Ensure AC & DC supply is available for Isolator and Circuit breaker. 

            b) Ensure Line #1 & Line #2 zero voltage shown in SCADA measurement screen. 

            c) Ensure all the Isolators are in closed position. 

            d) Ensure all the Earth switches are open condition. 

            e) Check protection relays in BCU / switchyard CRP for type of fault. 

            f) Ask the details of fault to NPS (Power Grid) end relay & note down for future reference). 

           g) Communicate details of fault to Power Grid & WRLDC control room. 

           h) PLCC counter reading to be noted down & check the carrier received/sent. 

            i) Before charging, ensure that Line to be charged is free from fault (Le. faulted line shall not be charged). 

            j) Before charging ensure that communication is available between both end and all protection are in service (no protection must be in by-passed condition). 

           k) Start process for back charging of Line #1& Line #2. Take consent from New Polling Station NPS, (Power Grid). 

            l) Apply charging code from WRLDC control room. (Via Telephone & Email).

          m) After received the charging code, Line #1 and Line #2 to be back charged one by one from NPS, and end) 

           n) Before Charging Main Breakers (403 CB, 409 CB) and Tie Breakers (402, 408) following breakers should be open (401 CB, 404 CB, 405 CB & 406CB) 

           o) After charging Line #1 & Line #2. first charge the Bus reactor bay (406 CB & 406 CB) to maintain Bus Voltage. 

           p) After Charging Line #1 & Line #2, note down the Bus-1 & Bus-2 voltage & Frequency.

IX.  After Charging, Inform SCE / ASCE about line #1 & #2 charging status. 

X. Power Restoration Procedure.

         a) 11KV Standby switchboard: Ensure that I/C Breaker & all other Breaker are open condition 

         b) 11KV Unit Switchboard 1A & 18: Ensure Tie Breaker 1/2 and all other breaker are open condition. 

         c) Charge station transformer (ST), by closing 404 CB, as per procedure. 

                     (Note: GT to be charged from Generator side only before unit synchronization). 

         d) 11KV Standby switchboard: Close Incomer (from ST) Breaker and reset under voltage. 

         e) 11KV Unit Switchboard 1A & 18: Close The Breaker 1 & 2 of 11KV Standby switchboard & 11KV Unit switchboard 1A & 18. Reset Under Voltage. 

         f) After availability Power in 11 KV Unit Switchboard 1A & 1B, charge following switchboards.                  a. 3.3KV unit aux board & station aux boards, 

                b. Unit service switchboard (415V) & station service switchboard (415V) 

                c. Turbine MCC & Boiler MCC. 

g) Charge the emergency MCC by synchronizing emergency MCC with both side incomer & DG supply. DG breaker will trip in auto after supply from incomer (Just after emergency bus synchronization). 

h) DG set 1 kept in standby (auto pick up) if any case emergency board power supply interrupted then DG set 1 will auto pickup and emergency board will be charged. 

i) Charge Boiler Valve & Damper DB and Turbine Valve ACDB after emergency switchboard gets charged from normal source (grid supply)

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2. Responsibilities of Turbine Operator. 

I. Check that Main TG DC EOP & later AC AOP & JOP have started, if both JOP failed to start, start hand barring of main turbine, to prevent rotor stoppage, (Ensuring any of EOP / LOPS is running). 

II. Check that TDBFP-A& B DC-EOP have started, If JOP failed to start, start hand barring, to prevent rotor stoppage. (Ensuring any of EOPLOPS is running). 

III. If seal oil pressure is found to be dropping and it is not available from any the above source, immediately inform the SCE/ASCE &TG Desk Engineer and after consultation & clearance from CR (SCE/ ASCE TG Desk), open H2 purging line vent and start charging CO2 to purge out H2. 

IV. After ensuring vacuum breaker of both condensers are open and vacuum is killed, put wooden wedge in both vacuum breaking valves to avoid unwanted closure of vacuum breaking valves (in case of compressed air unavailability during extended/ longer duration blackout condition). 

V. All effort must be taken to save/avoid breakage of rupture disk of Turbines diaphragm. For this following valves must be manually dosed, if it is found open. 

         a) Close all CRH/ HRH/ MS/ Drip & drains isolating valves and motorized valves manually, if open. 

         b) Close main isolation valve for turbine/gland sealing. 

         c) Isolate hot well make-up line from make-up station. Ensure lube oll is not draining / leaking from centrifuge. 

VI. Open APRDS line drains to atmosphere.

VII. Inform turbine desk engineer about status of equipment mentioned above. 

VIII Line up CW, ACW & Instrument air compressor as soon as possible. 

3. Responsibilities of Boiler (Field) Operator.

(i) Check that both APH are rotating by air motor and if not then do hand, barring with the support of boiler maintenance team. 

(ii) Check that the DC scanner air fan has started & emergency (atmospheric) inlet damper is in open condition.

(iii) Ensure that Isolation of main steam, re-heater & APRDS spray lines are isolated. 

(iv) Check that HOTV / LOTV are closed and close their manual isolating valves.

(iv) Retract all wall blowers & soot blowers to home position and isolate steam supply to soot-blowers (v) Manually close CBD/ IBD valves if found open. 

(vi) Isolate the boiler sample lines to sampling coolers and SWAS panel.

(vii) As soon as Emergency MCC power supply is restored through DG set, check rotation of APH through electric motor, LOPS of Fans APH & Mills. 

(ix) Re vigilant, so that no fire hazard can take place near the mill and other boiler area. 

(x) Inform SCE / ASCE, for any abnormality noticed. 

4. Responsibilities of DG Operator (This will be the responsibility of Electrical Operator in absence/ unavailability of DG operator).

(i) Rush to DG set and check that DG set has started on auto otherwise contact Desk Engineer for its starting permission and with his (or SCE/ASCE) instruction/ permission, start the DG set from local 

(ii) Check diesel oil level in the DG set oil storage tank. 

(iii) Check battery terminal voltage. 

(iv) Check voltage generated by the DG set. 

(v) Check emergency MCC is charged or not .

(vi) In case any abnormality is noticed in above conditions, seek advice of desk engineer. Also inform him for ita (vi) detailed status. 

5) Responsibilities of Fuel OIL Pump House Operator.

(i) Switch ON emergency lights. 

(ii) Remain vigilant that no oil spillage/ leakage take place.

(iii) Inform CCR regarding tripping of LDO pumps. 

(iv) After restoration of power supply line up LDO pumps and start it after getting instruction from desk engineer 

6. Responsibility of IDCT/ CW pump house operator. 

(i) Inform CCR regarding tripping of both CW pumps. 

(ii) Ensure Discharge valves of CW pump-1& 2 are closed, otherwise close from Local Panel 

(iii) Note down the alarms/annunciation appearing in control panel of both CW pumps. 

(iv) Check CW pumps bearing temperature, discharge valves position. 

Check control supply of HOPD valves. Check UPS battery Voltage. 

(v) Switch ON emergency lights. 

(vi) Line-up and keep the CW pumps in ready condition for start-up. 

(vii) Ensure all IDCT Fan breakers are open. 

(viii) Adjust Cooling tower riser MIVs as per single pump operation. 

7. Responsibility of ESP operator. 

(i) Switch-off power supply all ESP fields. 

(ii) As soon as power is available, charge hopper heater, support & shaft insulator heaters and put rapping system in service. 

8. Responsibility of Fire Water Pump House operator.

(i) Inform CCR regarding tripping of fire water AC pumps.

(ii) Ensure that Diesel hydrant pump has taken start on auto, otherwise start manually/ locally Check healthiness of diesel engine and adequate header pressure (>9.0 kg/cm). 

(iii) Switch ON emergency lights, 

(iv) Check diesel oil level in the oil tank. 

(v) Check engine lube oil level.

(vi) Check battery terminal voltage.