OSER for Utilities

OPERATIONAL SKILL ENRICHMENT REPORT FOR

UTILITIES

Document No. : UTY/PRD-00Revision No. : 00Issue No. : 01Effective Date: 01-Dec-13Shift Morning

Type of Incident DG#2/4 tripping due to load fluctuation of STG-401

Report ID OSER # 1

Date of Incident 02-Dec-13

Time 1239 hrs.

Title Tripping of DG#2 & 4

Details of Incident

DG-2 & DG-4 were in service at 550 KW load (each) & running in synchronization with STG-401 at 1000 KW load. During checking of Governor 505 E for LP extraction by HTC TA (Mr. Cao JJ), load suddenly increased on STG-401 to 2100 KW. Due to low load, DG-2 & 4 tripped. Electrical team was called in & emergency was efficiently handled by the combined efforts of Utilities & Electrical maintenance team without any electrical or production loss of plant.

Root Cause

1. Due to sudden load decrease on DG-2 & DG-4 system voltage decreased.(360 Volts, normal range is 400-415)

2. Along with voltage decrease generators tripped on Reverse Power which was indicated on DG-2/4 digital modules.

Recommendations

1. Manual PF panels should be functional on Auto Mode to manage power factor (Mill/CDP/Utility) to prevent DGs tripping on Reverse Power.

2. SOP should be developed for load management, emergency handling, better communication between all interfaces (Production, Uty & E&I) to turn On/Off loads during the shift.

Responsibility1. E&I2. Production + Utility + E&I3. E&I + Maintenance

Target Date 05-Dec-13

Filled By MAB

Approved By Utility Manager


UTILITIES

Document No. : UTY/PRD-00Revision No. : 00Issue No. : 01Effective Date: 01-Dec-13Shift: Night

Type of IncidentAll tractors (blades, buckets) were stopped can cause steam failure/ST-401 tripping due to husk shortage

Report ID OSER # 2


Time 0245 hrs.

Title Husk Shortage

Details of Incident

HP Boiler and ST-401 were in service at 0245hrs, AM Utilities was on round and found:

1. Husk feeding blade tractors were stopped2. Husk supervisor was not there3. Husk was not coming out from return4. Husk feeding pit was empty.

Observer asked to drivers for feeding husk, and as result our system was not affected.

Root Cause

Post-3 FC sent Husk yard supervisor to start deep well turbine during this activity, no one was there on supervision of drivers due to which they stopped tractors operation, while FC did not accept his duties regarding operation of water turbine. Water turbine operation is the responsibility of FC Post-3 not husk yard supervisor.

Recommendations1. Husk yard supervisor should always be present in husk yard and should be vigilant.2. Coaching of every boardman, FC and 3po staff to be done for acceptance of their

JD`s.

Responsibility UTY TL,s, FC,s, Husk yard supervisor

Target Date To onwards

Filled By MMA



UTILITIES

Document No. : UTY/PRD-00Revision No. : 00Issue No. : 01Effective Date: 01-Dec-13Shift: Morning

Type of Incident Water Spillage

Report ID OSER # 3


Time 1630 hrs.

Title Raw water tank (T-100) overflow

Details of Incident 1. Area operator operated the P-101-B at 1500hrs when its level was 21 feet.2. T-100 over flow after maintaining its maximum level.

Root CauseArea operator went to attend polisher operational training without informing to any other area FC. Posts 3 FC also forget that water turbine was in service which cause over -flow..

RecommendationsDuring operation, area FC must have complete focus in his responsibilities and in case of another activities, charge must be hand over to other FC/TL.

Responsibility UTY TL,s, FC,s, Husk yard supervisor


Filled By MA



UTILITIES


Type of Incident Iron bar found stuck in Rice Husk Feeder #1

Report ID OSER # 4


Time 0216 hrs.

Title SG-321 steam drum Pressure decreased from 44 to 40 bar (g)

Details of Incident

RHF#1 motor tripped on overload due to iron bar (Diameter =10mm & length= 400mm Approximately) stuck in feeder causing decrease in boiler steam drum pressure. Furthermore, this iron bar can damaged the husk carrier which leads to shutdown of the SG-321 & STG-401 operation.

Root Cause

1. Pre-filtration/screening system (vibrating sieves) to be provided.2. Efficient Supervision during duty time. Husk yard supervisor should always be

present in husk yard and should be vigilant.3. Good house-keeping of the area.4. Proper inspection of husk carrier and its PM plan.

RecommendationsDuring operation, area FC must have complete focus in his responsibilities and in case of another activities, charge must be hand over to other FC/TL.

Responsibility Projects, Utilities, Maintenance


Filled By SS/HMA



UTILITIES


Type of Incident Feed water pump A of SG-321 front gland packing pusher damaged

Report ID OSER # 5

Date of Incident 02-Jan-14

Time 1115 hrs.

Title Gland Pusher of BFW Pump-A

Details of Incident

SG-321 BFW Pump-B was in service, leakage was observed from its front side gland, informed to maintenance team and cold work permit was handed over for gland leakage removal. Maintenance team person tightened the gland pusher and after completion of job, permit closing activity was in progress, suddenly, during this period, gland pusher damaged into two pieces, one piece shoot away (approx.. 15 m) to ash water pit side and warm water leaked from gland packing. Fortunately no person was standing b/w this area.

Root Cause1. Unbalance tightening of gland pusher.2. Continuous long term vibration causes fatigue failure.3. Due to chemical reaction, iron became brittle.

Recommendations1. Use good quality material for gland pusher.2. Daily monitoring of mechanical machinery parts by operation & maintenance team.3. Spare parts must be available.

Responsibility Projects, Utilities, Maintenance

Target Date 05-Jan-14

Filled By MA



UTILITIES


Type of Incident Boiler Tripped at Low Water Level

Report ID OSER # 6


Time 1517 hrs.

Title BFW Pump-A pressure and flow dropped.

Details of IncidentBFW Pump A was in service, at 1517 hrs. boiler area FC opened common circulation valve FWP A & B, during this activity, BFW Pump-A pressure and flow dropped which caused the SG-321 boiler water level drop and tripped the boiler.

Root Cause1. Unawareness of area FC.2. Lack of awareness b/w AM, TL, BM & FC.3. Pump design/construction fault.

Recommendations

1. Refresher training about SG-321 field operation & proper communication in b/w team is required, Daily monitoring of mechanical machinery parts by operation & maintenance team.

2. Strictly cautions board required at designated place in area for working.3. Arrange proper pumps with specifications as compare with boiler specifications

according to ASME code.

Responsibility Utilities, Maintenance


Filled By MA



UTILITIES


Type of Incident SG-321 tripped due to LT-324 showing low water level.

Report ID OSER # 7


Time 2025 hrs.

Title SG-321 tripped due to low water indication at LT-324

Details of Incident At 2025hrs, when area FC tried to take left side GLG in service, LT-324 showed low water level which was less than 35%, which caused SG-321 tripping.

Root Cause4. Unawareness of area FC.5. Lack of awareness b/w AM, TL, BM & FC.6. Pump design/construction fault.

Recommendations

4. Refresher training about SG-321 field operation & proper communication in b/w team is required, Daily monitoring of mechanical machinery parts by operation & maintenance team.

5. Strictly cautions board required at designated place in area for working.6. Arrange proper pumps with specifications as compare with boiler specifications

according to ASME code.



Filled By MA



UTILITIES


Type of Incident Ash conveyer of SG-321 de tracked from its path.

Report ID OSER # 8


Time 2120 hrs.

Title Ash conveyer of SG-321 de tracked.

Details of Incident At 2120hrs, sudden abnormal sound create from ash conveyer of SG321 immediately stopped the conveyer and inform to maintenance team.

Root Cause1. Due to Ash continuous collecting in ash conveyer which caused minimizing the

upper and down plate distance, plates hit to each other and chain de-tracked.2. Due to continuous operation, chain loose and de-tracked.3. Miss-alignment.

Recommendations1. Proper cleaning of ash on daily basis.2. Daily checking by maintenance team in each shift.



Filled By MA



UTILITIES


Type of Incident Husk Elevator plate Broken

Report ID OSER # 9


Time 1015 hrs.

Title Husk Elevator plate Broken

Details of Incident

At around 1015hrs, field operator observed high magnitude of abnormal sound from the husk elevator. So to avoid any further damage, field operator abruptly stopped husk elevator and called maintenance team. During continuous inspection, it was observed that the plate installed between chains to move husk was separated from the chain and was stuck in the return duct outlet. So the plate was removed. Boiler Box up andST-401 safe shutdown at 1050hrs.

Root Cause

The bolts were opened from one side of the plate in the initial step. After sticking into the return discharge duct, the free end of the plate applied back force on the fix end. In the result of this force, the chain misaligned and broke the angle of the connection point installed over the chain link to mount plate on it.

Recommendations Preventive Maintenance


Target Date 05-Feb-14

Filled By MAB



UTILITIES



Report ID OSER # 10


Time 1045 hrs.


Details of Incident

At 1045 hrs. Main ash conveyer de-tracked due to plate missing and supports then after that chain loosed and miss alignment cause de tracking of ash conveyer. Our teams try to complete the Maintenance job in time but in vain at last we safe shut down the Steam turbine at 1324 hours and Safe shut down of Boiler at 1340. After that Boiler restart the SG-321 at 1650 hours and ST-401 on Electric load sync at 1840.

Root Cause No preventive maintenance

Recommendations Preventive maintenance



Filled By RM



UTILITIES


Type of Incident Air Compressor K-701 motor tripped due to over load

Report ID OSER # 11


Time 1350 hrs.

Title Air Compressor K-701 motor tripped due to over load

Details of Incident

Air compressor K-701 motor tripped due to over load. Immediately, K-702 was taken in service and informed to E&I team for rectification of problem of K-701. During this period, air supply cut from mill and CDP while supply continuous to utilities equipment after 15 minutes, K-701 took back in service when problem rectify by E&I team.

Root Cause1. Due to lack of PM of K-701 from E&I/Maintenance2. Improper Cleaning of Air Compressors3. Due to dirty surrounding area.

Recommendations1. Preventive maintenance2. Cleaning must be on daily, weekly & monthly basis.3. Should be compressor separate houses & avoid dirty environment.

Responsibility Utilities, Maintenance, Civil


Filled By MA



UTILITIES


Type of Incident Right side ID fan abnormal sound and vibration due to coupling bolts loses.

Report ID OSER # 12


Time 1350 hrs.

Title Right side ID fan abnormal sound and vibration due to coupling bolts loses.

Details of IncidentAt 1830 hrs. Abnormal sound observed & vibration in right side ID fan due to coupling bolts loosen. Area operator informed to board-man and left side ID fan took in service in the presence of TL & AM. Inform & problem discussed with maintenance team.

Root Cause1. Lack of SG-321 fans PM.2. Fans long time operation without changing with standby fan.3. Improper tightening of coupling bolts.

Recommendations1. PM of SG-321 fans periodically.2. During maintenance proper tightening of coupling bolts.3. Vibrations and Load must be checked in each shift.

Responsibility Utilities, Maintenance, Civil, E&I


Filled By MA



Document No. : UTY/PRD-00Revision No. : 00Issue No. : 01

UTILITIES

Effective Date: 01-Dec-13Shift: Morning

Type of Incident Raw Water Pumps (P-102A-C) Start up Problem

Report ID OSER # 13

Date of Incident 14-Feb-14

Time 1000 hrs.

Title Raw Water Pumps (P-102A-C) Start up Problem

Details of Incident

At around 10:00 a.m., field operator observed that raw water pumps (P-102A-C) were not meeting the pressure requirement. Mechanical team was called to check the pump. Their suction valves were checked, found ok. Also, their strainers cleaning were done but still the problem persists. Eventually, when the rotation of motor was checked it was found that pumps motor rotation was opposite (Clock-wise).

Root CauseMaintenance job was carried out on pumps breaker during plant shut down and at that time, due to insufficient load margin, checking of pumps rotation was not done at that time.

Recommendations1. Proper training session for troubleshooting.2. Pumps operational instructions to be placed in area.

Responsibility Utilities


Filled By MHH/AM



Document No. : UTY/PRD-00Revision No. : 00Issue No. : 01Effective Date: 01-Dec-13

UTILITIESShift: Morning

Type of Incident DG # 2 startup problem

Report ID OSER # 14


Time 0750 hrs.

Title DG # 2 Startup problem

Details of Incident

At around 7:30 am, field operator started DG#2 to warm up, after warming up shutdown DG#2 but its starting motor didn't stop. Operator stopped it manually from DG local control Key and informs E & I team. E&I team started DG#2 about 11:50AM but it fails to start, and starting motor started prior to DG. E&I team consult Allied team(CAT engine service provider) for the issue, they advised to disconnect DC power supply of EMC module and do cleaning of its contacts. After cleaning, DC power restored to EMC and DG#2 started again, DG#2 starts successfully. Issue has been resolved.

Root Cause EMC Malfunctioning

Recommendations1. Preventive Maintenance2. Monitoring of DC Battery system on daily basis.



Filled By IH



Document No. : UTY/PRD-00Revision No. : 00Issue No. : 01

UTILITIES

Effective Date: 01-Dec-13Shift: Morning

Type of Incident DG # 1 Load sharing problem with STG-401

Report ID OSER # 15


Time 0750 hrs.

Title DG # 1 Load Sharing issue

Details of Incident

At around 11:30 am, field operator started DG#1 and successfully synchronized with STG-401. After synchronization DG#1 share 1000KW load from STG-401 in 1 minute and tripped at overload protection. Field operator informed utility team. Utility team investigated the issue and found DG#1 no load rpm (1503~1504) little higher than rated rpm (1500rpm). Than utility team inform E&I team to rectify the rpm problem. E&I team adjust its rpm from governor module and synchronize DG#1 with STG-401 & DG#2 successfully with a base load of 300KW. DG#2 stopped to check DG#1 behavior with STG-401. DG#1 took compressor load during loading of compressor and didn't decrease it to base load (300KW). Issue communicated to E&I and they are working on it.

Root Cause DG # 1 load sharing problem

Recommendations1. Configuration of ComAp module w.r.t STG-4012. Communication link to be provided between ComAp and STG-401

Responsibility Utilities, Maintenance, Technical


Filled By IH


Document No. : UTY/PRD-00


UTILITIES

Revision No. : 00Issue No. : 01Effective Date: 01-Dec-13Shift: Morning

Type of Incident Driven sprocket & shaft welding crack of husk carrier.

Report ID OSER # 16


Time 1052 hrs.

TitleSG-321 steam drum Pressure decreased from 61 to 56 bar g while STG was in service at 600 Kwh

Details of Incident

Driven sprocket & shaft welding crack of husk carrier, stopped husk carrier and elevator at 1052 hrs. After filling husk bin to 100 %, also synch DGs with STG and this job completed at 1128 hrs. during this job once husk carrier started to fill again husk bin.

Root Cause

1. Solid particle come through husk which cause welding damage of sprocket and shaft.

2. Wear and tear on key and key way.3. Poor condition of sprocket, shaft, key way and key.

Recommendations1. Sprocket and shaft should be replaced.2. Proper size key should be inserted in key way.3. Proper inspection of husk carrier and its PM plan.


Target Date 05-Mar-14

Filled By RM/AR



UTILITIES

Document No. : UTY/PRD-00Revision No. : 00Issue No. : 01Effective Date: 01-Dec-13Shift: Evening

Type of Incident Boiler pressure dropped due to improper charge.

Report ID OSER # 17

Date of Incident 14-Mar-14

Time 1900 hrs.

Title Boiler pressure dropped due to improper charge.

Details of Incident

At 1900 hrs. Boiler pressure was dropped to 43 bar (g) despite increasing husk feeder motor rpm. On investigation, it was found that boiler assistant left the field without giving charge to incoming person, also his co-assistant left the field without giving charge, moreover, husk yard supervisor also showed negligence due to which husk feeding shortage occurred.

Root Cause

1. On investigation, it was found that boiler assistant left the field without giving charge to incoming person.

2. His co-assistant left the field without giving charge, he communicated wrong that he gave charge to incoming person at LP boiler but actually, he gave charge at gate.

3. Husk yard supervisor also showed negligence due to which husk feeding shortage occurred.

Recommendations1. Charge must be hand over at respective areas despite at other site.2. AM/TL to ensure the charges are handover/take over at respective areas.

Responsibility Utilities


Filled By MHH/KM



UTILITIES



Report ID OSER # 18


Time 0230 hrs.


Details of Incident

At 0230hrs, sudden abnormal sound create from ash conveyer of SG321& due to continuous collection of ash in ash conveyer, caused minimizing the upper and down plate distance as a result plates hit to each other and chain de-tracked. Immediately stopped the conveyer and called the maintenance team.

Root Cause1. Due to continuous collection of ash in ash conveyer, it caused minimizing the upper

and down plate distance, plates hit to each other and chain de-tracked.2. Due to continuous operation, chain loose and de-tracked.3. Miss-alignment.

Recommendations1. Proper cleaning of ash on daily basis.2. Daily checking by maintenance team in each shift.



Filled By MHH



UTILITIES



Report ID OSER # 19


Time 1115 hrs.


Details of Incident

At 1115 hrs. Main ash conveyer de-tracked due to plate missing and supports then after that chain loosed and miss alignment cause de tracking of ash conveyer. Maintenance team was called and after checking, they communicated that the rectification will be completed after 5 hours. So, safe shut down of Steam turbine done at 1130 hours after shifting load on DG`s and boiler was operated at low pressure till 1545 hrs. After that, boiler (SG-321) pressure was increased at 1600 hrs. Load on STG-401 was taken from DG`s at 1915 hrs.

Root Cause No preventive maintenance

Recommendations Preventive maintenance



Filled By MHH


OSER for Utilities

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