Maintenance Generations
➢ First Generation 1940 – 1955
• Fix it when it broke
• Basic and Routine maintenance
• Corrective maintenance
➢ Second Generation 1955 – 1975
• Planned Preventitive maintenance
• Time-based maintenance
• System for planning and controlling work
Maintenance Generations
➢Third Generation 1975 – 2000
• Condition based maintenance
• Reliability-centered maintenance
• Workforce multi-skilling and team working
• Proactive and strategic thinking
Maintenance Generations
• Current Generation 2000 +
• Risk-based inspection
• Risk-based Maintenance
• Risk-based life assessment
• Reliability-centered maintenance
• Condition based monitoring
• Computer aided maintenance management and information system
What is preventive maintenance (PM)?.
Preventive maintenance is maintenance that is regularly performed on a piece of equipment to lessen the likelihood of it failing. It is performed while the equipment is still working so that it does not break down unexpectedly
HOW TO PREPARED PREVENTIVE MAINTENANCE SCHEDULE ?
First Identified the equipment Services for prepared PM schedule.
➢types of machine (static/ rotating)➢ Types of Operation cycle (continuous
Running/ interval)➢ Types of function
(continuous process one depend on other)➢Types of important of particular machine
involved in the whole process.
Classified the Equipment Base on Operation
• ROTATING MACHINE
• STATIC MACHINE
• ROTATING & STATIC COMBINE MACHINE
MAINTENANCE OF ROTATING EQUIPMENT again classified base on installation
• ROTATING Equipment Installed at fix location (PUMP –MOTOR Set)
• ROTATING Equipment Installed on Moving Vehicle (i.e. DG SET On Vehicle)
• ROTATING Equipment Installed on Frame and frame moving with Equipment from one location to other ( i.e DG SET fix on frame)
MAINTENANCE OF STATIC EQUIPMENT again classified base on installation
• STATIC Equipment Installed at fix location ( i.e Big Transformer on foundation)
• STATIC Equipment Installed on Moving vehical( Small Transformer fix on vehicle)
PREPARATION of PREVENTIVE MAINTENANCE SCHEDULE
Sr.No.
Activity Condition Periodicity
1 Checking of Bearing Temp And Record
With out shut down
Hourly
2 Checking and Record Electrical parameter of Machine
3 Checking of Winding Temp And RecordHourly
4 Checking of Cooling System work or not Hourly5 Checking of Water Cooling System Inlet And Outlet
Water & Hot Cold Air Temp and record for water cool motor.
Hourly
6 Checking of Vibration By Hand FeelingEach Shift
7 Checking For Unusual Internal / External NoisesEach Shift
8 Greasing To Be Done In Running Condition Three Monthly9 Half Yearly Maint of machine (minor work)
With shut down
Half Yearly
10 Yearly Maint of machine (cleaning and inspection) AOH
11 O/H of major machine (During COH every five to six year or Running 40000 hours )
COH
For Rotating Machine (Motor)
PREPARATION of PREVENTIVE MAINTENANCE SCHEDULE
Sr.No.
Activity Condition Periodicity
1 Checking Of Bearing Temp And Record With out shut down
Hourly
2 Checking and Record Electrical parameter of Machine
3 Checking of inlet & out let Oil Temp And Record Hourly4 Checking of Cooling System . Hourly5 Checking of Water Cooling System Inlet And Outlet
Water & Hot Cold Air Temp and recordHourly
6 Checking of Vibration By Hand FeelingEach Shift
7 Checking For Unusual Internal / External NoisesEach Shift
8 Greasing To Be Done In Running Condition Three Monthly9 Half Yearly Maint of machine (minor work)
with shut down activity
Half Yearly
10 Yearly Maint of machine (cleaning and inspection) AOH
11 O/H of major machine (During COH every five to six year or Running 40000 hours )
COH
For Rotating Machine (Pump)
Sr.No.
Activity Condition Periodicity
1. Checking of Ambient temperature
With out shut down
Hourly2. Checking of oil temperature Hourly3. Checking of winding temperature Hourly4. Checking of load – amperes. Hourly5. Checking of load voltage. Hourly 6. Checking of oil level in conservator. Hourly 7. Checking of oil level in Dis connecting chamber Hourly 8. Checking of pressure relief explosion vent
diaphragm for cracks.Daily
9. Checking condition of silica gel in Dehydrating breather. Daily
10. Checking up the oil level of the oil seal of Dehydrating breather (to be upto the level marked in the cup) .
Daily
11. Checking up of pipe work and accessories for leakages. Daily
12. Checking for unusual internal noises. Each shift
PREPARATION of PREVENTIVE MAINTENANCE SCHEDULE
For Static Machine (TANSFORMER)
13. Checking of oil level in Conservator
With out shut down
Monthly14. Checking of oil level in Buchholz relay Monthly15. Checking condition of silica gel in Dehydrating breather (Replace if colour
changes from blue to pink say about 50% of the total quantity).Monthly
16. Checking up the oil level of oil seal of Dehydrating breather (to be upto the level marked in the cup) and ensuring air passages are free.
Monthly
17. Checking the diaphragm for cracks. Monthly 18. Checking of oil leaks Monthly 19. Checking of all connections on the transformer for tightness such as tank earth
connections, neutral earth connection etc.Half Yearly
20. Oil testing for BDV Half yearly
21. Thermovision scanning of all terminal connectors, tank, radiator ,cable box etc Half yearly
22 Check oil in the WTI & OTI pockets. With shut down
Yearly23 Calibration of oil and winding temperature indicator. Yearly
24 Checking operation of gauge on conservator Yearly
PREPARATION of PREVENTIVE MAINTENANCE SCHEDULE
For Static Machine (TANSFORMER)
PREPARATION of PREVENTIVE MAINTENANCE SCHEDULE
25 Marshalling Box :(i) Cleaning and vermin proofing of Marshalling Boxes of transformer. (ii) Tightness of terminations. (iii) Checking of contactors, space heaters
Illumination etc.
With shut down
Yearly
26 External cleaning of complete Transformer and Radiators. Yearly
27 Checking IR of protection cables for Buchholz,,WTI,OTI, Oil Level etc Yearly
28 (i) Checking of alarm & tripping by actual operation of Buchholz relay (by draining of oil) ,WTI,OTI, oil level etc.
(ii) Checking / replacement of the gaskets of the terminal box.
Yearly
29 Measuring insulation resistance of Power cable. YearlyCheck for proper sealing of compound filling holes and check for cracks in the compound (if used).
Yearly
30 Measuring IR of Core Yearly31. Tests :-
a) Measuring insulation resistance of windingsb) Measurement of DC winding resistance.
c) Measurement of core balance test voltages at low voltage at tap in service.
d) Measurement of magnetising current at low Voltage at tap in service. e) Measurement of Voltage Ratio error at tap in service. f) Short circuit Test at low voltage at tap in service.
Yearly
For Static Machine (TANSFORMER)
PREPARATION of PREVENTIVE MAINTENANCE SCHEDULE
32. Check earth resistance.
With shut down
Yearly
33. Checking of Buchholz relay for any gas collection and testing the gas collected.
During fault
34 Acidity test of oil 5 yearly
35. Filtration / Degassing of tank oil. SOS
36 Check for rusting & paint SOS
37. General Overhaul :(a) Core tightening. (b) De-sludging/washing of windings. (c) Inspection of core and windings. (d) Replacement of all gaskets. (e) Check core bolt insulation.
10 Years
For Static Machine (TANSFORMER)
PREPARATION of PREVENTIVE MAINTENANCE SCHEDULE
For Static Machine (VC BREAKER & Panel )
Sr.No.
Activity Condition Periodicity
1. Clean the Breaker from out side. S/D Quarterly2 Clean the Phase Separators, Shrouds, support insulators etc. and Check
for damage, cracks, proper fitmentS/D Quarterly
3. Clean the Jaw contacts ,Arm and Check for pitting, over heat, flexibility, looseness
S/D Quarterly
4. Clean the Vacuum Bottles and Check the bottle for physical damage and Visual Checking of contact wear by observing wipe mark in breaker closed position.
S/D Quarterly
5. Check the Insulating coupler rod for any crack, deformation or damage. S/D Quarterly
6. Clean the Oil or Grease from bottom surface S/D Quarterly
7. Check for proper racking of breaker in to SERVICE position and locking. S/D Quarterly
8. Cleaning of complete operating mechanism S/D Half Yearly
9. Check the closing and tripping coil for over heat S/D Half Yearly
10. Check for tightness of fix end side connection of jaws, arm, Vacuum bottle and flexible copper strap connection.
S/D Half Yearly
11. Checking of tightness of control wiring terminations of Auxiliary switches , Limit switches , sliding contacts / multipin plug , counter etc.
S/D Half Yearly
12. Check condition and intactness of all clips and pins S/D Half Yearly
PREPARATION of PREVENTIVE MAINTENANCE SCHEDULE
For Static Machine (VACUUM CIRCUIT BREAKER )
13 Check the operation of Breaker Mechanism i.e Spring Charge mechanism, Limit switch , Auxiliary switches ,sliding contacts etc.
S/D Half Yearly
14. Check the functioning of plunger and lever of trip coil and close coil S/D Half Yearly
15 Check the close and Open operation of breaker by charging the closing spring manually
S/D Half Yearly
16. Check for tightness of phase and earth side connection of surge suppressor
S/D Half Yearly
17. Checking and tightening of all the Screws, Nut Bolts of mechanism, frame, supports, rollers etc. Of the breaker.
S/D Yearly
18. Lubrication of breaker mechanism parts with lubricant recommended by manufacturer
S/D Yearly
19. Checking of Spring charge motor carbon brush wear and replacing if required.
S/D Yearly
20. checking of oil leakage from surge suppressor , Cracks in bushing , body etc. and ensuring healthiness of surge suppressor
S/D Yearly
21. Check earth connection of breaker S/D Yearly
PREPARATION of PREVENTIVE MAINTENANCE SCHEDULE
For Static Machine (VACUUM CIRCUIT BREAKER )
22. TESTS S/D Yearly(1) Measurement of IR value of(a) Each pole in open condition(b) Phase to Phase in close condition(c) Phase to Earth (body) in close condition(1) Resistance Measurement
(a) Spring Charge Motor(b) Closing coil(c) Tripping coil
(3) Contact Resistance Measurement of each pole in breaker closed condition.
(4)Vacuum Integrity i) High voltage test of Vacuum chamber in breaker open conditionii) Checking of vacuum by detaching the insulator coupler and moving of contact by hand
(5)Measurement of wipe(6)Breaker operating time
23. Replacement of Vacuum bottle S/D Depending on breaker operation suggested by
OEM
24. Complete Circuit breaker Over hauling SOS As suggested by OEM
PMS For