Electrical Motor

MAINTENANCE PROCEDURE R-3&4-EMP-50100-01

Rev. No. 0 - 1 - Feb. 2002

NUCLEAR POWER CORPORATION (A Govt. of India Enterprise)

RAJASTHAN ATOMIC POWER STATION – 3&4

ELECTRICAL MAINTENANCE UNIT

MAINTENANCE PROCEDURE FOR ELECTRICAL MOTORS

(PROCEDURE NO. R-3&4 – EMP–50100–01)

Prepared by :

(C.P. Sharma) SO/E (EM)

Checked by & Reviewed By : Approved by :

(Vivek Jain) (P.K.Datta) SME (E) MS

Revision

No. Date Prepared/Revised By

Reviewed By Approved By

Rev –0 March, 2002


Rev. No. 0 - 2 - Feb. 2002

INDEX

S No. TITLE PAGE No.

0.0 Title 4 1.0 Scope 4 1.1 Category of Equipment/Maintenance Criteria 5 1.2 General Description 5 1.2.1 General 5 1.2.2 Stator 6 1.2.3 Rotor & Bearings 6 1.2.4 Lubrications 7 1.2.5 Bearing replacement 7 1.2.6 Drying out 8 1.2.7 End shield 8 1.2.8 Fan & fan guards 9 1.2.9 Terminal box 9 1.3 Technical Details 9 1.3. 1 Applicable Standards 9 1.3.2 Quantity of Grease 9 1.3.3. Quantity of Grease 10 1.4 List of Equipment sub Assemblies 10 1.5 List of References and Drawing 11 2.0 Maintenance Procedure 11 2.1 Condition Monitoring 11 2.2 Preventive Maintenance 11 2.2.1 Frequency of Preventive Maintenance 11 2.2.2 Pre-requisite 11 2.2.3 Tools/Instruments Required 11 2.2.4 Consumable & spare requirement 12 2.2.5 Man Power Required 12 2.2.6 Expected time of completion 12 2.2.7 Initial observation before starting the job 12 2.2.8 Safety instruction and precautions 12 2.2.9 Dismantling procedure 12 2.2.10 Test on Equipment 13 2.2.11 Return to service 13 2.2.11.1 Re-assembly 13 2.2.11.2 No load run 13 2.3 Break down Maintenance 14 2.3.1 Frequency of over hauling 15 2.3.2 Pre-requisite 15


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S No. TITLE PAGE No.

2.3.3 Tools and special instrument 15 2.3.4 Man Power 15 2.3.5 Expected time of completion 15 2.3.6 Consumables and spare requirement 15 2.3.7 Initial observation before starting the job 15 2.3.8 Safety instruction and precautions 15 2.3.9 Dismantling procedure 15 2.3.10 Test on equipment 18 2.3.11 Return to serve 15 3.0 Trouble shooting 16

Annexure 18 Annexure-1 Preventive Maintenance Check list EMP-50100/01/PM/01 19 Annexure-2 Preventive Maintenance Check list EMP-50100/01/BM/02 23 Annexure-3 Preventive Maintenance Check list EMP-50100/01/PM/03 27 Annexure-4 Preventive Maintenance Check list EMP-50100/01/BM/04 30

4.0

Annexure-5 Preventive Maintenance Check list EMP-50100/01/BM/05 34


Rev. No. 0 - 4 - Feb. 2002

0.0 TITLE :

Maintenance procedure for Electrical Motors. 1.1 SCOPE:

Approximately 2000 Nos. of LT / HT motor are installed alongwith pumps & fans in various systems in the plant. They are fed from HT / LT switchgears and MCC’s, depending upon size of the motor and are reasonably protected against various ‘expected’ faults. In order to ensure smooth operation of motors and also to prevent development or propagation of any deficiencies in the motors, they are being given preventive maintenance regularly. Still, if some motor breakdown, then it get rewinded / repaired. The scope of this manual covers maintenance requirements and procedural aspects of preventive & breakdown maintenance checks to be performed on motors. Apart from this manual, specific references is to be made to the relevant maintenance instructions of the respective manufacturer. The following make & sizes of motors are installed at RAPS-3&4 :- i) HT (6.6 KV) Motors - M/s Kirloskar / NGEF / BHEL make of size above 200 KW to 2800 KW. ii) LT (415V) Motor - M/s Kirloskar / NGEF / SIEMENS/ GEC / BHARAT BIJLEE /

CROMPTON GREAVES / ABB of sizes from fractional KW to 200 KW Details of important loads is as follows :-

S.No. Description Make KW Volt No. of motors (both Unit)

1 Primary circulating pump motor NGEF 2800 6600 8 2 Boiler feed pump motor BHEL 1450 6600 6 3 Condense extraction pump motor KEC 720 6600 4 4 Active low pressure process water pump

motor NGEF 335 6600 6

5 Chiller motor NGEF 435 6600 3 6 Condenser cooling water pump motor KEC 965 6600 6 7 Primary feed pump motor NGEF 350 6600 4 8 Plant water pump motor KEC 720 6600 2 9 HP Aux. Oil pump motor BHEL 375 6600 2 10 Active HP process water pump motor NGEF 170 415 8 11 Moderator pump motor Crompton

Greaves 132 415 10

12 Shut down cooling pump motor Crompton Greaves

80 415 4

13 Fueling machine supply pump motor NGEF 93 415 4


Rev. No. 0 - 5 - Feb. 2002

S.No. Description Make KW Volt No. of motors

(both Unit) 14 Active process cooling water pump NGEF 160 415 8 15 Auxiliary boiler feed pump motor NGEF 130 415 4 16 Compressor motor KEC 140 415 6 17 Fire water pump motor NGEF 100 415 2 18 ECCS pump motor NGEF 130 415 8 19 Exhaust fan SFB, RAB, RB GEC Alstom 125 415 3

1.1 CATEGORY OF EQUIPMENT / MAINTENANCE CRITERIA:

Motors covered in this manual will fall under all categories of station equipment classification i.e. Category – A, B, C or D, depending upon the respective process system. Frequency of maintenance of these motors, depending upon their usage, application, availability of shutdown accessibility to location etc., shall be i) Preventive Maintenance : Yearly- for safety related loads ( Cat. A)

Two yearly- for non-safety related (Cat. B,C &D)

ii) Breakdown Maintenance : Need based The above suggestive schedules may have to be reviewed for better performance depending upon factors like Running Time of the motor, maintenance intervals and lubrications intervals etc., as recommended by the respective manufacturer.

1.2 GENERAL DESCRIPTION :

1.2.1 GENERAL

i) Ensure that the motor is isolated from the power supply source and physically confirm at the

switchgear / MCC end ii) Request MMU to take pre-maintenance alignment values, if required by them. iii) Inspect the power terminal box for any abnormality, like loose connections, loosening of cable

lugs, de-colorization of cables due to overheating or any other sign of overheating and disconnect the cable. Insulate the cable lugs with insulation tape. Note down the RYB sequence of terminal connections before disconnecting the cable. Do the disconnection of space heater, if provided, in a similar way,

iv) Ensure handling equipment / manpower are ready for shifting the motor to maintenance area. v) Request MMU to de-couple the load, vi) Loosen the foundation bolts of the motor and remove it away from the platform. If any

foundation packing material like copper shims or vibration arresting pads are provided, mark them with proper identification marks (which would help in relocationg them at the right place during reinstallation) and secure them at a safe place, vii) Shift the motor to the motor maintenance area or shop as required.

viii) Check pre-maintenance IR values of winding, ix) Record the pre-maintenance value of winding resistance / inductance. x) Record space heater resistance and IR values, if applicable. xi) Record the RTD / Thermistor values, if applicable. xii) Prior to dismantling, make match marking on the stator body and the end shields on both sides,

to avoid human error during reassembly, xiii) Remove the fan cover and subsequently the fan,


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xiv) Remove the coupling pully and secure it along with the key safely. xv) Loosen the end shield mounting bolts diagonally and gradually, xvi) Use suitable pullers, wooden block or mallet while dismantling or assembling. Avoid using

hammers in the process as these may damage end shield / motor body which are made of Cast Iron,

xvii) Remove both the end shields. For large motors, suitable support should be provided to the shaft (while the end shields are being dismantled) so as to protect the shaft from getting bent or deformed,

xvii) Separate the end shields, rotor and the stator bodies

1.2.2 STATOR i) Inspect the stator winding closely for any physical damage to the winding insulation / coils/

overhangs, ii) Examine the inner surface of the stator slots for any abrasive marks, damage to the wedges etc., iii) Ensure that winding overhangs are safely secured, iv) Ensure terminal connections of the windings are healthy and tight. Take care to tighten the

terminal stud nuts, lock nuts etc., and ensure flat and spring washers are positioned appropriately,

v) Clean the stator core, windings, frames etc., with a suitable , lint free cloth etc., vi) Measure resistance / inductance of the windings with the help of Motor checker and ensure

these are balanced. If severe non-uniformity is found, locate the faulty winding and the location of fault by using a Growler. Rectify the fault if possible locally. Otherwise the motor must be sent for repair / rewinding and a spare motor should be put on the system,

vii) Check connection tightness of space heater connections and measure the resistance and insulation values,

viii) Check RTD resistance, if applicable and record their values along with ambient temperature at the time of testing,

ix) ix) Measure insulation resistance value of the winding and ensure it is more than 5 M ohm (when the stator is cold),

x) If the insulation resistance is found to be below 2 M ohm, the motor should be dried out before returning to service. The methods of drying out are explained vide 1.2.6 of this manual.

xi) If “Rotation Arrow” plate is provided, ensure it is visible and clear and does not lead to any illusion.

1.2.3 ROTOR & BEARINGS

i) Remove the dirt, dust from rotor by using brush cloth etc., or by compressed air / vacuum cleaner. Subsequently clean it with kerosene thoroughly.

ii) Inspect the cage rotor bars for any cracks or slackening, iii) Ensure shorting rings at both the ends of the rotor are healthy and no sign of cracks is present. iv) Inspect the bearings carefully and ensure they are free from any defect (If found defective,

replace both the bearings as per procedure given in para 1.2.5). v) If the old grease is found to be dirty or deteriorated, greasing should be done afresh, as per the

procedure laid down in 1.2.4 of this manual. Do the lubrication just before reassembly. vi) Inspect the coupling key/ key way for any defect or damage, vii) Whenever bearings are replaced, ensure inners of bearings covers are in place before installing

new bearings on to the shaft. Follow procedures laid down in 1.2.5 of this manual during bearings replacement.


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1.2.4 LUBRICATION

Normally the original grease need not be removed unless it has become dirty or has deteriorated. The hands must be perfectly clean and smeared with good quality mineral oil before any bearing is handled. A small quantity of old grease will unavoidably be left in the bearings (when old grease is wiped out from the bearing) and if this is clean and in good condition it should be left rather than washed out with petrol. A good bearing can be ruined by rotating in the absence of lubricant. When washing out is essential, it should be carried out in a bath of clean benzene or petrol to which a small quantity of lubricating oil has been added. Before bearing is packed with grease, a few drops of clean lubricating oil should be introduced into the bearing. Never over-grease any bearing which may lead to overheating and spillage. Lithium based multipurpose grease conforming to grade 3 of IS-1002-1956 amended up to date is recommended for all rotating machines fitted with anti-friction bearings. The approved grease among others is Castrol Ball Bearings Grease AP-3. The safe operating temperature for the above grease is 25°C to 120°C (approx. value)

1.2.5 BEARING REPLACEMENT

1) Removal of Bearings

The bearings along with its housing should be removed from the shaft using bearing puller, otherwise the bearing may get damaged. The endshied and the external bearing cap must first be removed, and then the small retaining screw in the split locking collar must be loosened, after which the collar can be unscrewed. If any difficulty is experienced, widen the split in the locking collar with say a screw-driver. The tapped holes in the housing may be used for fixing the withdrawing gear, studs and equal pressure must be put on each nut, otherwise the internal bearing cap may be distorted and damaged. When dismantling the inner ring of a ball bearing from the shaft on no account must the bearing be knocked off the shaft by hitting the outer ring of the bearing. The housing and the bearing may then be separated without any difficulty as a push fit is employed.

2) Cleaning of Bearing

The bearing should be washed to remove all traces of old grease and dirt or foreign matter that may have crept in. The use of goods quality solvent or a mixture of eight parts of white spirit to one part of light grade machine oil is recommended for washing. Where a solvent is used for washing, all the parts should be dipped in good quality light machine oil after the washing is completed. If not immediately re-used, protect the bearing with grease paper wrapping.

3) Assembly of Bearing Ensure that all the parts are handled carefully to avoid entry of foreign particles. A bearing should not be removed from its housing until it is required for use. After cleaning the housing it should be smeared lightly with the specified grade of grease. In the case of roller bearing lay the housing flat on a clean level surface and insert the bearing outer ring by applying even pressure to the ring. Ensure that the bearing remains “Square” in the housing through out this operation. It may be necessary to tap the outer ring lightly into the housing in the final stage.


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Next slip the inner bearing cap correctly over the shaft after a small quantity of grease has been applied inside it. The inner ring of the bearing may now be fitted over the shaft by heating the bearing in a mineral oil to a temperature not exceeding 100°C to enable easy mounting. Fit the split locking collar correctly on the shaft to clamp the inner ring, close the split on the collar by a gently blow on the same, and tighten the remaining screw firmly. Re-lubricate all parts as detailed in Appendix-2. Assemble the endshield containing the outer ring of the bearing and fasten to the inner bearing cap. Rotate the bearing housing by hand in both directions to check if the running is smooth. If this is the case fit the outer bearing cap firmly to the bearing housing. A small gap MUST be visible between the flange of the external bearing cap and the housing this gap confirms that the outer ring of the bearings is firmly clamped to prevent its creep during operation.

1.2.6 DRYING OUT A convenient method of “Drying out” is to block the rotor so that it can’t rotate and apply a very low voltage of about 10% of the rated value to the stator terminals. The heat generated in the winding is not easily dissipated and one part of the winding may be exceedingly hot before another part had time to expel the moisture. This may be deviated to some extent by taking every precaution to exclude draughts for the exposed parts of the winding. Second method of drying out is to keep the motor in an electrical oven. But the temperature shall not be allowed to exceed 60°C. Other options are (i) blowing of hot air (ii) using electric radiators (iii) placing of carbon filament lamps inside the m/c. When placing hot bulb, care shall be taken that it is not in contact with the windings. If it is not possible to reach sufficient high temperature the ventilation may be reduced by covering the stator with a tarpaulin. Whichever of the above method of drying out is adopted the heating shall be continuous and shall be carefully monitored to ensure that it does not attain a temperature sufficiently high to damage the insulation. The maximum safe temperature of the windings measured by thermometer is 90°C. At the same time the temperature should not be allowed to fall too low as otherwise re-absorption of moisture would take place. The insulation resistance will be found to drop considerably as the motor warms up will reach the minimum and then remain constant for sometime depending upon the dampness of the machine and as the drying progresses the insulation resistance will gradually rise. The drying out shall be continued as long as the insulation resistance rises or until a sufficiently high value has been reached which should not be less than 2M ohm by 500 volts megger (for LT motors). During the drying out period, readings of temperature and insulation resistance shall be taken at least once an hour in order to see how the drying out is progressing. The temperature of the motor shall be kept as constant as possible, otherwise the insulation resistance readings may be misleading. After drying out, air drying varnish should be applied by brush on the winding surfaces only and this should be applied when winding is in hot condition to prevent absorption of moisture. The length of drying time depends on the amo unt of dampness but in any case it should be at least six hours.

1.2.7 END SHIELDS

i) Clean the end shields thoroughly ii) Inspect the bearing housings for any damage or any abrasive mark. The bearings should fit tight

in the housing.


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iii) If any grease- filling holes are provided, ensure these are clean and not choked. Clean them thoroughly

iv) Also ensure air gap inspection holes (closed with threaded metal plugs), if any provided are clean.

1.2.8 FAN & FAN GUARD

i) Clean the fan and fan guard thoroughly. ii) Ensure balancing weights, if any, provided on the fan are intact iii) Inspect the fan closely for any crack. iv) Ensure key/keyway/locking screw of the fan is healthy.

1.2.9 TERMINAL BOX

i) Clean the terminal box thoroughly, ii) Inspect the lugs for de-colorization, lug afresh, if conductor strand found burnt, iii) Inspect the lead coming out from stator, for any damage to the conductor, If so, it must be

repaired by strengthening insulation or by re-lugging (for LT motors only) iv) Check terminals to be intact, v) Check glanding to be perfect, vi) For HT motors, check condition of HT kit to be OK, vii) Check tightness of cable connections.

1.3 TECHNICAL DETAILS : 1.3.1 APPLICABLE STANDARDS

All the motor maintenance activities and post-maintenance testing shall conform to the following Indian standards as per the latest revision : i) Performance & Testing - IS : 325 ii) Insulation - IS : 1271 iii) Method of cooling - IS : 6362 iv) Type of construction & mounting - IS : 2253 v) Terminal markings - IS : 4728 vi) Vibration level & measurement - IS : 4729 vii) Noise level - IS : 6098 viii) Testing - IS : 4029

1.3.2 QUANTITY OF GREASE

Quantity of grease required per bearing and the re-greasing intervals for normal motor is as per the following table :

Type Amount of grease in cm3

To be injected after running hours

AM AJ 4,6,8, & 10 pole 2 pole 4 pole 6 & 8 pole

132 - 12

160 160 16 1500 1500 2000


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Type Amount of grease in cm3

To be injected after running hours

AM AJ 4,6,8, & 10 pole 2 pole 4 pole 6 & 8 pole

180 180 20

200 200 20

225 225 20 35

250 250 20 35

280 280 20 35

315 315 25 40

355 355 25 40

750 1200 1500

For motors used in chemical industries, refineries and other industries where acid, alkali and saline atmosphere are predominant and for motors with IP 55 protection the re-greasing interval should be reduced by 20%

1.3.3 QUANTITY OF GREASE

Re-greasing interval Bearing Size

Grease Qty. (in Grams) 3000 RPM 1500 RPM and below

6313 20 1500 4000 6314 25 1000 2500 6315 30 1000 2500 6316 35 - - 6318 35 1000 2500 6319 40 1000 -

N315 30 1000 2500 N316 30 1000 2500 N318 35 1000 2500 N319 40 - 2500 N221 40 1000 - N321 50 - 2500

NOTE : ALL TWO POLE MOTORS SHALL HAVE C-3 CLEARANCE BEARINGS. FOR VH

SERIES MOTORS, TOP BEARING SHALL HAVE SPHERICAL ROLLER THRUST BEARING, WHICH IS OIL LUBRICATED.

1.4 LIST OF EQUIPMENT SUB-ASSEMBLIES: This maintenance procedure shall be applicable to all the electrical motors in various systems, along with their

corresponding power cable. The following are various parts / sub-assembly of motor – i) Rotor ii) Stator iii) Bearings


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iv) End shield v) Terminal box vi) Pulley vii) Space heater (for motor of rating 30 KW & above) viii) Space heater terminal box (for motor of rating 30 KW & above) ix) Cable end alongwith gland and termination kit (for HT cable only) x) Cable supporting structure. xi) Fan & fan guard.

1.5 LIST OF REFERENCES AND DRAWINGS:

1) Load schedule 2) User hand book for induction motors (Kirloskar) - (EM-855) 3) MI for PHT motor – (EM –556) 4) MI for BFP motor – (EM –545) 5) MI for CEP motor – (EM –584) 6) MI for main chiller unit – (EM –194) 7) MI for plant water pump motor - (EM – 635) 8) MI for moderator pump motor - (EM – 444) 9) MI for S/D cooling pump motor - (EM – 672) 10) MI for Air compressor (Kirloskar) - (EM – 190) 11) MI for PFP motor - (MM - 1241) 12) MI for CCW motor - (Central Doc cell - 2748) 13) MI for NAPW motor - (MM - 351) 14) MI for Fire water motor - (MM - 691) 15) MI for moderator motor. - (EM-1208)

2.0 MAINTENANCE PROCEDURE: The objective of maintenance is to ensure smooth operation of all the electrical motors.

2.1 CONDITION MONITORING: Not Applicable

2.2 PREVENTIVE MAINTENANCE: 2.2.1 Frequency of Preventive Maintenance:

Yearly – for safety related equipment (Cat. A) Yearly – for non-safety related equipment (Cat B,C &D)

2.2.2 Pre-requisite: 1) Work permit should be taken. 2) Proper isolation has been provided. 3) Proper tools & equipment are available. 4) Consumable are available

2.2.3 Tools & Special Instruments:

a) Megger ( 500 V for LT motors & 5 KV for HT motors) b) Motor checker c) Screw Driver d) Spanner e) Wire brush


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2.2.4 Consumables and Spare Requirement:

i) Cleaning agent – CRC, OKS ii) Lubricant – Sentinel synthetic lubricant iii) Contact grease (Electrically conducting) – “ Servogem” contact gelly iv) Winding / Core cleaner – Lotoxane (Arnold make) v) Rust remover (Nut bolts) – Rustolene (M/s Hard Castle & Ward Mfg. Co.Ltd.) vi) Paint & varnish remover – Action 100 (M/s Gunjan Organics Pvt. Ltd.) vii) Varnish – “Crown”Red insulating varnish

(M/s Stanvac chemicals (I) Ltd.) viii) For pasting / sticking gasket – LOCTITE (M/s Loctite India Pvt. Ltd.) ix) Repairs of stator winding (Patch-up work) – Epoxy gelcoat (Red) (Dr. Beck+ co.)

2.2.5 Man Power:

Supervisor – 1 Technician – 2

2.2.6 Expected Time of Completion:

8 Hour.

2.2.7 Initial Observation Before Starting the Job:

1) Check the motor terminals & lugs for any over heating marks. 2) Check the motor internal leads and cable leads for any crack / damage of insulation. 3) Any abnormality in motor.

2.2.8 Safety Instruction and Precaution:

1) Avoid using slide wrench, Never use plier for opening a bolt / nut. 2) Put proper marking on TB cover plate before opening. The plate may be too heavy to be

handled by one person. 3) All nut-bolts should be kept at one place, duly segregated size wise. 4) Discharge cable before touching the terminals, as the same may be having static charge. 5) While pulling rotor out from the motor, no damage to starter core/ winding should be ensured.

2.2.9 Dismantling Procedure: The sequence of dismantling motors is given below : 1) Before dismantling any machine, obtain “permit to work” from authorities. 2) If required, arrange a crane of sufficient capacity and height to lift off the motor and taking to

maintenance shop, 3) Disconnect supply cables at the terminal box, detatch terminal box from cable spreading box and

support the latter against falling, 4) Uncouple the motor from the driven machine, 5) Unfasten the foundation bolts or nuts and lift the motor for removed to maintenance shop or

elsewhere for further disassembly. 6) Collect all the hardware like bolts/nuts, shims used below machine foot (for alignment) etc., and

keep them separately. Do not mix them with ordinary hardware. 7) Remove the grease extractors if fitted to bearings and remove all the old grease collected in it.


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8) The dowel pins used for location of motor should be removed carefully. The dowel pins should be stored more carefully as these are required to ensure correct repositioning of motor after overhauling.

9) Remove the external fan cover and fan where fitted. 10) Remove any cowls, canopies or other fitments fitted on the endshields. 11) In the case of slipring motor, remove the slipring cover and dismantle the brushgear carefully.

The slipring stud nuts are all the brass, store them carefully away from other steel hardware. 12) Remove the endshields after the removal of fastening bolts, making use of the endshields

removing screws provided. 13) For bigger size of motors remove the rotor with the help of a crane. Ensure that this is done very

carefully and that the rotor does not touch the stator winding overhand during this process to prevent damage to the windings.

14) Remove any accumulated dust or dirt with a dry soft brush or bellows. 15) Remove the outer bearing caps and the bearing housing at both ends and remove also all old

grease from bearings to expose them. Note : Where the bearings are oil lubricated, drain the oil before removing the bearing housing or

endshield.

2.2.10 Test on Equipment:

Preventive maintenance test are to be carried out as per the following check lists : 1) EMP/50100/01/PM/01 - PM of HT Motor 2) EMP/50100/01/BM/02 - BM of HT Motor 3) EMP/50100/01/PM/03 - PM of LT Motor 4) EMP/50100/01/BM/04 - BM of LT Motor

2.2.11 Return to Service: - 2.2.11.1 Re-assembly –

1. The procedure is practically the reverse of that followed for dismantling.

2. After the assembly is completed, check the concentricity of the air gap through the air gap

inspection holes, and close these with the plugs provided. Ensure that the rotor can rotate freely. Any difficulty in rotating the rotor or any unusual noise should be taken as sign of interference between stationary and mo ving parts. In such a case investigate and eliminate the cause of the trouble.

3. Check the insulation resistance again. 4. Realign the machine with the load but do not couple. 5. Reconnect the machine to the supply cable acording to the terminal connection diagram fixed

inside the terminal box cover. Ensure that the supply cable sockets make intimate contact with the motor cable sockets in the case of low voltage terminal box, there must be NO nut or washer of any kind between the sockets.

2.2.11.2 No load Run :

1) A transient kick start may be given to ascertain the direction of rotation. If it is incorrect, stop the motor and inter change the connections to any two phases in the terminal box. Re-start the motor and examine carefully for any evidence of unusual sound, vibration, electrical or mechanical fault conditions and undue temperature rise of the bearings. Run the motor in uncoupled


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conditions and check the vibration level. Vibration measured on no load must be within 25 microns (peak to peak). Then run the motor in uncoupled condition with half-coupling pulley mounted on the motor shaft extension and check the vibration level. This vibration shall also be within 25 microns (peak to peak). Measure the no load current, though out its No Load run at a fixed regular intervals. The No Load current should remain constant and as thumb rule would be equal or less than 40% of full load current of the motor. Record the observations as per PM check list. No Load run for big motor shall preferably to done for a period till its bearing temp. stop rising further. This period may be 4 to 8 Hrs.

2) Couple the motor with the driven machine. Check that the driven machine is not loaded but see

above point-1 for vertical high thrust motors. Start the motor and examine carefully for any evidence to unusual sound, vibration, electrical or mechanical fault. If no abnormality is observed, run the motor for a few hours. Check the bearing and the body temperatures.

3) Load the driven machine. As far as possible increase the loading gradually. Allow the motor to

run under full load conditions for a few hours, provided there is no indication of fault any where. During this period note the current drawn by the motor and the speed and check that the current does not exceed the rated value as stated on the motor name plate. If it does, reduce the load or stop the motor and determine the cause. It could be that the voltage is lower than that specified or the motor may have been overloaded. The motor should not be restarted until the cause of this problem has been eliminated. Check the vibration level in coupled condition on load. The increase in vibration level on load over that measured on no-load (in uncoupled condition) should not exceed the value given in the following table. Allowable increase in vibration amplitude (peak to peak in mm) when the motor is coupled to the load and tested over the vibration amplitude of motor tested in uncoupled condition.

Synchronour speed re/min Increase in vibration amplitude (peak to peak) microns

3600 5

3000 6

1800 9

1500 11

1200 12

1000 14

900 15

750 16

720 16

600 18

500 20

428 25

375 26

2.3 BREAK DOWN MAINTENANCE :

Despite all precautions and preventive maintenance, if the motor insulation fails, then the motor is taken out for breakdown maintenance.


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2.3.1 Frequency : As and when required.

2.3.2 Pre-requisites: 1) Work permit is available 2) Proper isolation has been provided 3) Proper tools and equipment are available 4) Consumables are available

2.3.3 Tools & Special Instrument: Winding machine, former, brazing tool, oven screw guage, motor checker, spanner set, screw driver set.

2.3.4 Man Power: Supervisor –1, Technician – 2

2.3.5 Expected Time of Completion:

Not Applicable

2.3.6 Consumables & Spare Requirement: Copper wire, insulating paper, binding wire, RTD, Lugs, varnish, PVC sleeve, bearings.

2.3.7 Initial Observation Before Starting the Job:

1) Check the repairability of the fault. 2) Efforts should be made to determine the root cause of failure of the motor. Any foreign material

if recovered inside motor, the same must be immediately reported.

2.3.8 Safety Instruction & Precautions:

1) Prior to start of rewinding, hot spot in stator, if any, must be removed, 2) RTDs should be inserted during rewinding, 3) Winding coils must be properly tagged

2.3.9 Dismantling Procedure:

As envisaged in para 1.2.1

2.3.10 Test on Equipment:

As per check list No. 1) EMP/50100/01/BM/02 - BM of HT motor 2) EMP/50100/01/BM/04 - BM of LT motor

2.3.11 Return to Service:

As per para 2.2.11


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3.0 TROUBLE SHOOTING:

S.No. Trouble Cause Remedy

Excessive belt pull Decrease belt tension Pulley too far away Move pulley closer to bearing Pulley dia too small Use larger pulley Misalignment Correct by realignment of drive

1. Hot Bearing (General)

Bearing running dry Re-grease the bearing Insufficient grease Maintain proper quantity of grease in

bearings Excess lubricant Reduce quantity of grease (Bearing

should not be filled more than half) Over loaded bearings Check alignment, side thrust and end

thrust

2. Hot Bearings – Ball or Roller

Broken ball or rough races Replace bearings No supply voltage One phase open Voltage too low

Check voltage on each phase

Motor may be over loaded Reduce load or try to start uncoupled from load

3. Motor connected but does not start

Control gear defective Examine each step of the control gear for bad contacts or open circuit.

Starting torque of load is too high

a) If of squirrel cage type and with auto transformer starting, change to higher tap,

b) If it is slipring type, lower the starting resistance

Rotor Defective Look for broken rings Brushes are not down due to sticking or worn brushes

Free brushes in holders, change worn brushes

Short circuit to earth Test with Megger

Fault in starters or star delta switch

Check contacts and connections.

Power failure Check for loose connections to line, to fuses and to control

4. Motor runs and then dies down

Over load a) Examine overload trips and see that they are set correctly to approx. 150% full load current

b) See that the dashpots are filled with correct quantity of oil

Not applied properly Consult factory for proper type

Voltage is too low at motor terminals because of line drop

-- “--

If wound rotor, improper operations of secondary resistance

--“--

Starting load torque too high

Check the load characteristic with motor speed torque

5. Motor starts sluggishly speed falls when load is put on

Broken rotor bars a) Look for crack near the ring. b) New rotor may be required as repairs

are usually temporary


Rev. No. 0 - 17 - Feb. 2002

S.No. Trouble Cause Remedy

Open primary circuit Locate fault with testing device and repair

Load too high Reduce load or use larger motor Supply voltage low Check supply line and cables to motor

6. Motor starts with difficulty on star connection or not at all Burning of contacts in star-

delta starter Overhaul starter

Stator wrongly connected Check connection Phase – Short Rewind

7. Stator heats up quickly and takes a large no-load current Multiple earth Short-Rewind

Overload Reduce load Motor may have one phase open

Check to make sure that all leads are well connected

Shorted stator coil Repair and then check watt meter reading

Faulty connection Correct the connections High voltage Low voltage

Check terminals of the motor with voltmeter

Rotor rubs stator bore Recondition the rotor, replace worn bearings

Foreign material in airgap Dismantle and remove obstruction

8. Motor overheats while running under load

Motor operated on load cycle not in accordance with the rating particulars indicated in the Name plate

Run the motor on duty for which it is designated

Motor mis -aligned Re-align. Maintain within 0.03mm

Weak foundation Strengthen base

Coupling out of balance Balance coupling Driven equipment un-balanced

Re-balance

Defective ball or roller bearings

Replace bearing

Bearings not in line Line up properly Balancing weights shifted Re-balance rotor Wound rotor coils replaced

9. Motor Vibrates after connections are made

Excessive end play Adjust bearings or add washer. Use proper shim for alignment. Use vibration mounts dampen external vibration

10 Scraping Noise Fan rubbing fan cover Remove interference Fan rubbing insulation Clean fan Loose on bed plate Tighten holding bolts 11. Magnetic noise Air gap not uniform Check and correct bracket fit or bearings Loose bearings Correct or renew bearings 12. Shaft end breaks or Stator

Rotor rubbing Excessive radial loads due to pulley drives

Give pulley drive details to factory and check its suitability

13. Heavy vibrations Rotor unbalance Re-balance


Rev. No. 0 - 18 - Feb. 2002

4.0 ANNEXURE.

1) Preventive Maintenance Check list of HT Motors – EMP/50100/01/PM/01 2) Breakdown Maintenance Check list of HT Motors – EMP/50100/01/BM/02 3) Preventive Maintenance Check List of LT Motors – EMP/50100/01/PM/03 4) Breakdown Maintenance Check list of LT Motors – EMP/50100/01/BM/04 5) Preventive Maintenance Check list of LT Motors – EMP/50100/01/BM/05


Rev. No. 0 - 19 - Feb. 2002

RAJASTHAN ATOMIC POWER STATION-3&4 ELECTRICAL MAINTENANCE UNIT

PREVENTIVE MAINTENANCE CHECK LIST OF HT MOTORS

Sheet 1 of 4 UNIT NO. : R3/R4/R-3&4 CHECK LIST NO : EMP/50100/01/PM/01 REVISION : 1 EQUIPMENT TAG NO.

: ISSUE DATE : DEC.’ 2002

CATEGORY : A/B/C/D PREPARED BY : C.P.SHARMA, SO/E

FREQUENCY : YEARLY/TWO YEARLY

APPROVED BY : VIVEK JAIN SME (E)

DATE :

RUN/SHUTDOWN CONDITION

:

CREW : SUPERVISOR-1 TECHNICIAN-2

TOOLS : MOTOR CHECKER, 5KV MEGGER, VACUUM CLEANER, SPANNER SET, SCREW DRIVER SET, WIRE BRUSH.

DURATION OF JOB

: 08 HOURS MATERIAL : INSULATION TAPE, CLEANING AGENT, MASKING TAPE, LUBRICANT

A) PREREQUISITES:

(i) Work permit is available ( No…. …………. Dt---------------) (ii) Proper isolation has been provided on CB - (iii) Proper tools & equipment are available. - (iv) Consumable are available. - (v) Inform RT lab and switchgear group for taking up PM of their area. - Note :Always stand on rubber mats while working on bus bars.

B) PM CHECKS:

Sl. No. DESCRIPTION

DESIGNED / EXPECTED

VALUE

AS FOUND AS LEFT REMARKS

GENERAL: i) Clean motor body, fan, earthing connection with vacuum cleaner / cloth and cleaning re-gent

Clean

ii) Check foundation bolt for tightness Tight

iii) Check healthiness of cooling fan No damage & Clean

1.0

iv) Check tightness of both the earthing connections Earth at both side


Rev. No. 0 - 20 - Feb. 2002


PREVENTIVE MAINTENANCE CHECK LIST OF HT MOTORS

Sheet 2 of 4 UNIT NO. : R-3/R-4 CHECK LIST NO. : EMP/50100/01/PM/01

Sl. No. DESCRIPTION DESIGNED / EXPECTED

VALUE

AS FOUND

AS LEFT REMARKS

2.0 Terminal Box (Phase side) a) Check general condition of the terminal

box/chambers.

Clean /

No damage

b) Check tightness of lugs Tight

c) Check HT kit for any abnormality

No deformity / damage / over

heating

d) Check cable lug for any overheating/ de-colourisation

No overheating

e) Check insulator, separator etc., for cracks and correct installation

No crack, Properly installed

f) Check gaskets of terminal box No wear & tear Properly installed

3.0 Terminal box ( Neutral side) (if outside the motor) a) Check general condition of the terminal

box

Clean

b) Check tightness of shorting links Tight

c) Check insulator/ separators etc. for cracks and correct installation

No crack

d) Check gasket of terminal box No wear & tear

4.0 Space Heater Check space heater cable glanding, connection- tightness & overheating

Properly glanded, all connection tight, No de-colourisation

5.0 CB end (Tightness of Cable) a) Check lugs for over heating sign

No overheating

b) Check tightness of lugs Tight

c) Check any abnormality in the HT termination kit

No deformity/ damage/

overheating

6.0 CB end (Relay) Check corresponding relay(s) is/are calibrated (By RT lab)

Calibrated


Rev. No. 0 - 21 - Feb. 2002


PREVENTIVE MAINTENANCE CHECK LIST OF HT MOTORS Sheet 3 of 4

UNIT NO. : R-3/R-4 CHECK LIST NO. : EMP/50100/01/PM/01 C) MEASUREMENT & TESTING : Note : Cross check the present measurement with the commissioning / design data and if difference of the order of 5% or more is observed, this may be informed immediately to group-in-charge In the column "DESIGNED / EXPECTED VALUE", the values obtained in the previous measurement should be filled

Sl. No. DESCRIPTION

DESIGNED / EXPECTED

VALUE (See note above)

AS FOUND

AS LEFT REMARKS

R-Y Y-B B-R

i) Measure winding resistance in M ohm.

ii) Space Heater

R-Y Y-B

(iii) Winding inductance in mH

B-R

iv) Insulation Resistance at 5 KV DC (*) R+Y+B to Earth

a) 15 sec b) 1 Minute c) 10 Minute d) PI

v) Capacitance & tan delta (By RT lab) a) Capacitance ( R+ Y+B) to Earth b) Tan delta ( R+Y+B) to Earth

1.

vi) Insulation resistance of space heater at 500V DC

D) AREA CLEANING:

Clean the work area and remove all defective consumable, spares etc. (*) QA check point for category A equipment

(PM carried out by) (Checked by)

NAME & Designation : SIGNATURE (with Date & Time)


Rev. No. 0 - 22 - Feb. 2002


PREVENTIVE MAINTENANCE CHECK LIST OF HT MOTORS Sheet 4 of 4

UNIT NO. : R-3/R-4 CHECK LIST NO. : EMP/50100/01/PM/01 Feed Back Session : To be filled by Supervisor or above. (Checking Authority)

(Use extra sheets if space is not sufficient)

S. No. Description Observation Remark

1. Consumable used Write the name & Qty.

2. Spares used

3. Duration of job Write the actual duration

4. Man power used Write the name of man power

5. Entry done History file/CMMS file

6. Setting changed Write any setting changed

7. Area cleaned Switchgear area cleaned

8. Other abnormality

Name & Signature Name & Signature Checking Authority Reviewing officers


Rev. No. 0 - 23 - Feb. 2002


BREAK DOWN MAINTENANCE CHECK LIST OF HT MOTORS

Sheet 1 of 4 UNIT NO. : R-3/4 CHECK LIST NO : EMP/50100/01/BM/02 REVISION : 1 EQUIPMENT TAG NO.


CATEGORY : A / B / C/ D PREPARED BY : C.P.SHARMA / S.P.GUPTA SO/E SO/E

FREQUENCY : NEED BASED APPROVED BY : VIVEK JAIN SME (E)

DATE :


:


TOOLS : MOTOR CHECKER, SPANNER SET, SCREW DRIVER SET

DURATION OF JOB : 08 HRS. TO 40 HRS.

MATERIAL : COPPER WIRE, PAPER INSULATORS, VARNISH, SOLDERING/BRAZING EQUIPMENT, PRE-FABRICATED HT WINDING

A) PREREQUISITES:

(i) Work permit is available ( No…. …………. Dt---------------) (ii) Proper isolation has been provided on CB / MCC cell (iii) Proper tools & equipment are available. (iv) Consumable are available.

B) BM CHECKS:

Sl. No. DESCRIPTION DESIGNED / EXPECTED VALUE

AS FOUND

AS LEFT

REMARKS

1. Name plate - Details of Motor a) KW b) Voltage

c) Full load current d) RPM e) Frame size f) Make g) S.No.

h) Connection i) Bearing

j) Class of insulation

2. Pre & post repair inspection a) Insulation Resistance (M? )

R - E Y - E B - E R - Y Y - B B - R


Rev. No. 0 - 24 - Feb. 2002



Sheet 2 of 4 UNIT NO. : R-3/R-4 CHECK LIST NO. : EMP/50100/01/BM/02


AS FOUND

AS LEFT

REMARKS

b) Winding Resistance (? )

R1-R2 Y1-Y2 B1-B2 R - Y R - B B - Y

c) Winding Inductance (mH)

R1-R2 Y1-Y2 B1-B2 R – Y R – B B – Y

d) RTD Resistance at ____?C

RTD – 1 RTD - 2 RTD - 3 RTD - 4 RTD - 5 RTD - 6 RTD - 7 RTD - 8

e) Space Heater Resistance (in ohm)

IR Value (m? )

f) Condition of bearings No rusting smooth operation

g) General condition of motor No rusting, No damage

3. Repair / Overhauling / Replacement of part/ Rewinding

Dismantling of motor with proper identification Tag

All dismentaled parts properly tagged


Rev. No. 0 - 25 - Feb. 2002





AS FOUND

AS LEFT

REMARKS

a) Cleaning of stator / rotor with cleaning agent & air blower and bearing with turpentine oil and pre-post cleaning inspection Stator

Rotor Temp. Sensor Space Heater

Bearing Oil supply unit

Clean Clean Clean Clean Clean

c) Varnishing of stator by class "F" varnish

Properly varnished

d) Rewinding i) Size of wire ii) No. of wires / slot iii) No. of slots iv) Single / Double layer v) Make & class of insulation vi) Make & class of varnish e) Baking of stator core in oven at 130 ? C

Completed

f) Details of work (other than rewinding) carried out (like shaft metalising, replacement of fan, any major repair etc.)

Post repair / rewinding measurement Note : Any variation of 5% or more from design values, shall be informed to group engineer

a) HV test (KV for 1 min) (R+Y+B) - E

b) Insulation resistance at 5KV DC (*)

i) 15 Sec ? 100 M? ii) 1 Minute ? 100 M? iii) 10 Minute ? 100 M? iv) PI ? 1.8

c) Capacitance & tan delta (at 1 KV AC) (*)

i) Capitance (R+Y+B) to E

4.

ii) Tan delta (R+Y+B) to E


Rev. No. 0 - 26 - Feb. 2002





AS FOUND

AS LEFT

REMARKS

d) No load current As per Name plate R - Phase Y - Phase B - Phase

e) Speed As per Name plate f) Operation of motor Smooth without any noise &

vibration

C) AREA CLEANING:

Clean the switchgear area and remove all defective consumable, spares etc.

(*) QA check point for category A equipment

(BM carried out by) (Checked by)

NAME & Designation : SIGNATURE (with Date & Time) Feed Back Session : To be filled by Supervisor or above. (Checking Authority)



1. Consumable used Write the name & Qty. 2. Spares used 3. Duration of job Write the actual duration 4. Man power used Write the name of man power 5. Entry done History file/CMMS file

6. Setting changed Write any setting changed 7. Area cleaned Switchgear area cleaned 8. Other abnormality



Rev. No. 0 - 27 - Feb. 2002


PREVENTIVE MAINTENANCE CHECK LIST OF LT MOTORS

Sheet 1 of 3

UNIT NO. : R-3/R-4/R-3&4 CHECK LIST NO. : EMP/50100/01/PM/03 REVISION : 2

ISSUE DATE : DEC.’ 2002

EQUIPMENT TAG NO.

: PREPARED BY : C.P.SHARMA, SO/E

CATEGORY : A / B / C / D APPROVED BY : VIVEK JAIN, SME (E)

FREQUENCY : YEARLY/ TWO YEARLY


:

DATE : TOOLS : MOTOR CHECKER, VACUUM CLEANER, SPANNER SET, SCREW DRIVER SET, WIRE BRUSH.


MATERIAL : INSULATION TAPE, CLEANING AGENT, MASKING TAPE , LUBRICANT

DURATION OF JOB

: 4 HOURS-UPTO 90 KW MOTOR 8 HOURS-UPTO 200 KW MOTOR

:

A) PREREQUISITES :

i) Work permit is available ( No…. …………. Dt---------------) ii) Proper isolation has been provided on CB / MCC cell - iii) Proper tools & equipment are available. - iv) Consumable are available. - v) Inform CB/MCC group & protection group for taking up the PM. -

B) PM CHECKS : Note : Always stand on rubber mats while working on Bus bar.


AS FOUND

AS LEFT

REMARKS

1. VISUAL INSPECTION : Thoroughly inspect motor body, earthing connection, fan, cable, lugs, terminals etc., for any damage, corrosion, dust deposition, loose connection, over heating, blackening and tension.

No loose connection / No damage / No over

heating sign

CLEANLINESS/TIGHTNESS CHECKS a) Clean motor body, fan, earthing connection withvacuum cleaner/cloth and cleaning re-agent

Clean

2.

b) Check foundation bolt for tightness. Tight


Rev. No. 0 - 28 - Feb. 2002





VALUE

AS FOUND

AS LEFT

REMARKS

c) Check general condition of the terminal

box Properly glanded, No tension, No overheating sign.

d) Checks power cable for glanding and inside condition.

Clean, No damage

e) Check cable terminal tightness All connection tight & clean

f) Check star / delta link tightness (If accessible)

All connection tight & clean

g) Check cable lug for any overheating / de-

colourisation No overheating Sign, No loose connection

h) Check insulator, separator etc., for

cracks and correct installation No cracks, properly installed

i) Check gaskets of terminal box Installed no wear & tear

j) Check extra holes for proper sealing Sealed

k) Check space heater cable for proper

glanding, connection, tightness etc. (for 30KW & above)

All connection tight

l) Check cooling fan & cover for any damage & correct installations.

No damage properly installed, clean

m) Check tightness of both the earthing points.

Earthed at both points

n) At CB end, check connection of lugs for

over heating sign / loose connection (for CB fed motors)

No over heating / No loose connection

o) Check that thermal overload relay is calibrated (for MCC fed motors)

Set to _____A

p) Check that motor protection relay is

calibrated (by RT lab) (for CB fed loads)

Completed

q) Check that PM check of corresponding MCC cell/ CB is completed.

Completed

C) : MEASUREMENT & TESTING Note : Cross check the present measurement with the conditioning / design data and if any difference

more than 5% is observed this may be informed immediately to group-in-charge


Rev. No. 0 - 29 - Feb. 2002




*To be filled from commissioning data / history file


VALUE

AS FOUND

AS LEFT REMARKS

1. i) Measure motor winding resistance in ohm. along with cable from source end.

R-Y Y-B B-R Space heater resistance

ii) Measure motor winding inductance in mH along with cable from source end.

R-Y Y-B B-R

iii) Measure motor winding I R at 500 V DC along with cable from source end. (**)

a) (R+Y+B) to earth ? 20 ?

b) Space Heater terminal to earth ? 20 ?

D) AREA CLEANING: Clean the area and remove all defective consumable, spares etc. (**) QA check point for category ‘A’ equipment.


NAME & Designation : SIGNATURE (with Date & Time) Feed Back Session: To be filled by Supervisor or above. (Checking Authority) (Use extra sheets if space is not sufficient)


1. Consumable used Write the name & Qty. 2. Spares used 3. Duration of job Write the actual duration 4. Man power used Write the name of man power 5. Entry done History file/CMMS file 6. Setting changed Write any setting changed 7. Area cleaned Switchgear area cleaned




Rev. No. 0 - 30 - Feb. 2002


BREAK DOWN MAINTENANCE CHECK LIST OF LT MOTORS

Sheet 1 of 4 UNIT NO. : R-3 / 4 CHECK LIST NO : EMP/50100/01/BM/04 REVISION : 1 EQUIPMENT TAG NO.


CATEGORY : A / B / C / D PREPARED BY : C.P.SHARMA / S.P.GUPTA SO/E SO/E

FREQUENCY : NEED BASED APPROVED BY : VIVEK JAIN SME (E)

DATE :


:


TOOLS : MOTOR CHECKER, SPANNER SET, SCREW DRIVER SET

DURATION OF JOB : 08 HRS. TO 40 HRS. MATERIAL : COPPER WIRE, PAPER INSULATORS, VARNISH, SOLDERING/BRAKING EQUIPMENT

A) PREREQUISITES: Work permit is available ( No…. …………. Dt---------------) i) Proper isolation has been provided on CB / MCC cell ii) Proper tools & equipment are available. iii) Consumable are available. B) BM CHECKS:

Sl. No. DESCRIPTION

DESIGNED / EXPECTED

VALUE

AS FOUND

AS LEFT REMARKS

1. Name plate - Details of Motor k) KW l) Voltage

m) Full load current n) RPM o) Frame size p) Make q) S.No.

r) Connection s) Bearing

j) Class of insulation

2. Pre & post repair inspection (*) Insulation Resistance (M? )

R - E Y - E B - E R - Y Y – B B - R

(*) QA check point (post repairs) applicable for category A equipment


Rev. No. 0 - 31 - Feb. 2002




Sl. No. DESCRIPTION

DESIGNED / EXPECTED

VALUE

AS FOUND

AS LEFT REMARKS

2. iv) Winding Resistance ( ? ) R1 - R2 Y1 - Y2 B1 - B2 R - Y R - B B - Y v) Winding Inductance ( mH ) R1 - R2 Y1 - Y2 B1 - B2 R - Y R - B B - Y vi) RTD Resistance at _______ ? C RTD – 1 RTD – 2 RTD – 3 RTD – 4 RTD – 5 RTD – 6 RTD – 7 RTD – 8 vii) Space Heater Resistance (? ) IR Value (M? ) viii)Condition of bearings xi) General condition of motor

3. Repair / Overhauling / Replacement of part/ Rewinding

a) Dismantling of motor with proper

identificationTag All dismantled parts properly tagged

b) Cleaning of stator / rotor with cleaning agent & air blower and bearing with turpentine oil and pre-post cleaning inspection

Stator Clean Rotor Clean Temp. Sensor Clean Space Heater Clean Bearing Clean Oil supply unit Clean


Rev. No. 0 - 32 - Feb. 2002




Sl. No. DESCRIPTION

DESIGNED / EXPECTED

VALUE

AS FOUND

AS LEFT REMARKS

c) Varnishing of stator by class "F" varnish Properly varnished

d) Rewinding i) Size of wire ii) No. of wires / slot iii) No. of slots iv) Single / Double layer v) Make & class of insulation vi) Make & class of varnish

e) Baking of stator core in oven at 130 ? C Completed

f) Details of work (other than rewinding) carried out (like shaft metalising, replacement of fan, any major repair etc.)

4. Post repair / rewinding measurement Note: Any variation of 5% or more from design value shall be informed to group engineer. g) HV test (1KV for 1 min) *

(R+Y+B) to E

With stand successfully

b) No load current

R – phase Y – phase B – phase

As per name plate details

c) Speed As per name plate details

d) Operation of motor Smooth without noise & vibration

* - QA check point for category A equipment. C) AREA CLEANING:

Clean the area and remove all defective consumable, spares etc.

(BM carried out by) (Checked by) NAME & Designation : SIGNATURE (with Date & Time)


Rev. No. 0 - 33 - Feb. 2002



Sheet 4 of 4 UNIT NO. : R-3/R-4 CHECK LIST NO. : EMP/50100/01/BM/04 Feed Back Session : To be filled by Supervisor or above. (Checking Authority)



1. Consumable used Write the name & Qty.

2. Spares used

3. Duration of job Write the actual duration

4. Man power used Write the name of man power

5. Entry done History file/CMMS file

6. Setting changed Write any setting changed

7. Area cleaned Switchgear area cleaned




Rev. No. 0 - 34 - Feb. 2002

RAJASTHAN ATOMIC POWER STATION-3&4

ELECTRICAL MAINTENANCE UNIT PREVENTIVE MAINTENANCE CHECK LIST FOR

VENTILATION FAN Sheet 1 of 2

UNIT NO. : R-3/4 CHECK LIST NO. : EMP/50100/01/PM/05

EQUIPMENT TAG NO.

: REVISION : 0

FEEDER NO. : ISSUE DATE

:

CATEGORY : A/B/C/D PREPARED BY

: S.KANDPAL/PRATEEK AGRAWAL SO/B SO/E

FREQUENCY : APPROVED BY

: VIVEK JAIN SME (E)

DATE : RUN/SHUTDOWN CONDITION

:

CREW : SUPERVISOR - 1 TECHNICIAN - 2

TOOLS/EQUIP : SPANNER SET, ALLEN KEY SET, SCREW DRIVER, MALLET, PULLER

DURATION OF JOB

: 2 HOUR MATERIAL : MARKENE CLOTH, LUBRICATION GREASE

A) PRE-REQUISITE: 1) Work permit is available. (No. __________ Dt. _______________) 2) Drawings are available. : __________________________________ 3) Proper tools and instruments are available. : __________________________________

4) Consumables are available. : __________________________________

5) Before starting the job ensure isolation

is been given. :___________________________________

S.No Description Expected value As found As left Remarks

1 Cleanliness of ventilation fan Clean 2 Check for corrosion No corrosion on the

blade

3 Tightness of fan blade on hub Blade tight on the hub


Rev. No. 0 - 35 - Feb. 2002


PREVENTIVE MAINTENANCE CHECK LIST FOR VENTILATION FAN

Sheet 2 of 2 UNIT NO. : R-3/R-4 CHECK LIST NO. : EMP/50100/01/PM/05 S.No Description Expected value As found As left Remarks

4 Tightness of hub and fan blade

assembly on shaft Fan blade assembly is tight

5 Check for axial and radial play No play axially (ensured by key in key way) No play radially (ensured by circlip or tightening screw)

6 When mounting in duct check fan blade for clearance with duct.

Clearance ensured for free rotation of blade


SIGNATURE : (Date & Time) Name & Desgn. : Feed Back Session : To be filled by Supervisor or above. (Checking Authority)



1. Consumable used

Write the name & Qty.

2. Spares used 3. Duration of job Write the actual duration 4. Man power used Write the name of man

power 5. Entry done in History file/CMMS file 6. Area cleaned Area should be cleaned 7. Other

abnormality

Signature : Signature : Name : Name : Checking Authority Reviewing officer

Electrical Motor

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