Page 1 of 11 Issued on : 24.07.2018 Report No. RDSO/2018/EL/TAR/0018 Rev. ‘0’

Prepared by Checked by Issued by

GOVERNMENT OF INDIA

MINISTRY OF RAILWAYS

Technical Audit Report of Electric Loco Shed

Ghaziabad, for maintenance of bearings of three phase

locomotive Traction Motors

Report No.: RDSO/2018/EL/TAR/0018 Rev. ‘0’.

Issue Date: 24.07.2018

Approved by

PEDSE Signature

Issued by

Electrical Directorate

Research, Designs and Standards Organisation

Manak Nagar, Lucknow-226011

lR;eso t;rs

Page 2 of 11 Issued on : 24.07.2018 Report No. RDSO/2018/EL/TAR/0018 Rev. ‘0’

Prepared by Checked by Issued by

Status of Revision

SN. Date of Revision Page No. Revision Reason for Revision

1. All 0 First Issue

Page 3 of 11 Issued on : 24.07.2018 Report No. RDSO/2018/EL/TAR/0018 Rev. ‘0’

Prepared by Checked by Issued by

Technical Audit Report Of ELS/GZB

Technical audit of ELS/GZB for maintenance of three phase locomotives traction motor

bearings was carried out earlier on 25.02.2016. Technical audit report was issued as

Report No. RDSO/2016/EL/TAR/0005 Rev. ‘0’ dated 30.03.2016.

Technical Re-audit of ELS/GZB for maintenance of three phase locomotives traction

motor bearings had been carried again by RDSO on 04.06.2018 to check the compliance

with previous recommendations.

1. Observation related to storage:

1.1. Storage of bearings in the main storage depot

Bearings were not directly stored on the floor, but kept very close to the walls which

were damp. About eight bearings were stacked together in a column. Dust and dirt also

observed on the stacked bearing cartons.

Photo 1 & 2: Storage of bearings in the stores depot

Photo 3 & 4: Dampness on the walls in the stores depot

Page 4 of 11 Issued on : 24.07.2018 Report No. RDSO/2018/EL/TAR/0018 Rev. ‘0’

Prepared by Checked by Issued by

Recommendation:

(i) The bearings should be kept a little away from walls to avoid ingress of

water/moisture in a stack of not more than 5 bearings.

(ii) Bearings should also not be stored directly on floor.

(iii) First In First Out (FIFO) system should be used to avoid prolonged storage.

(iv) If bearings are to be stored for more than one year, it is advised to dip the same

in preservation oil and repack the same for further use / storage.

1.2. Non availability of air-conditioned storage ward and deep freezer

There is no air conditioned storage ward for storage of varnishes, rubber components,

insulating items etc. for which prescribed storage conditions includes specific

requirements of temperature. Similarly deep freezer is also not available which is

required for storage of varnishes etc. at less than 10 degree Celsius. It is observed that

finishing varnish TVA-1410 of Hitachi TM is also stored in the depot with other

material, whereas, as per Hitachi specification AO209 , shelf life of TVA-1410 is only 5

months when stored at less than 10 degree Celcius.

Recommendation:

It is recommended to develop an air-conditioned storage ward and procure deep freezer

for storing the items with specified storage temperature requirements.

1.3. Storage of bearings in section

There is no separate room for storage of bearings in the sections. Bearings were kept in a

dusty area with other materials. Storage area is prone for dust, moisture & rain water

entry.

Photo 5: Bearings stored in section

Recommendation:

(i) Bearings should be stored in a separate covered room/dust free environment

(ii) Bearings should also not be stored directly on floor.

Page 5 of 11 Issued on : 24.07.2018 Report No. RDSO/2018/EL/TAR/0018 Rev. ‘0’

Prepared by Checked by Issued by

1.4. Storage of Lubricants in main stores depot

Grease drums were kept near the fencing of the open shed with lot of dirt and dust aside.

Rain water may enter the lubricant storage area. It is observed that grease drums were

also kept in horizontal condition and barrel bungs of some of the transformer oil drums

were not in the clock position of 3 & 9.

Photo 6 & 7: Lubricants storage in the stores depot

Recommendation:

i. All barrels must be stored, preferably indoors, away from extreme heat/cold,

dust, acidic fumes and moist atmospheric conditions.

ii. Lubricating oil barrels should be stored horizontally preferably on wooden rails

dunnage to avoid contact with ground. The barrel bungs should be in the clock

position at 3 & 9

iii. Grease barrels must be stored vertically preferably covered with tarpaulin, if not

stored indoors

iv. Technical circular No. RDSO/2010/EL/TC/0104 (Rev.0) should be followed for

storage & handling of lubricant/greases used for Electric Locomotives

Page 6 of 11 Issued on : 24.07.2018 Report No. RDSO/2018/EL/TAR/0018 Rev. ‘0’

Prepared by Checked by Issued by

2. Observations related to 3-Phase Traction Motor assembly procedure:

2.1. Non availability of bore gauge for internal diameters: Bore Gauge for measurement of internal diameters of End Shield/ Racer during bearing

fitment as per SMI-318 dated 16.10.2017 is not available and bore diameter is measured

by inside micrometer with least count of 10 micron.

Photo 8: Measurement of bore diameter with inside micrometer.

Recommendation: Bore Gauge for measurement of internal diameters of End Shield/ Racer as per SMI-318

to be procured and used.

2.2. Non availability of snap gauge for shaft measurements Dial Snap Gauges for measurement of shaft diameter as per SMI-314 dated 29.9.2017 is

not available. Two point micrometers with 10 microns least count is used for measurement

of shaft diameter for bearing fitment.

Photo 9: Two point micrometer for measurement of shaft diameter

Recommendation:

Dial Snap Gauges for measurement of shaft diameter as per SMI-314 to be procured and

used.

Page 7 of 11 Issued on : 24.07.2018 Report No. RDSO/2018/EL/TAR/0018 Rev. ‘0’

Prepared by Checked by Issued by

2.3. Measurements of mating components before bearing fitment ELS/GZB had started the measurements of mating components. However, from the

available record, it is observed that readings for several TMs are same.

Recommendation:

Mating components (bore diameter of end frame & outer diameter of outer racer, shaft

diameter & inner diameter of inner racer) needs to be measured and matching of

components should be done as specified in RDSO SMI-278 dated 24.12.2013 to get

required interference between mating components.

2.4. Measurements of free Radial Clearance (RC) of Driving End(DE) Bearing:

Measurement of unmounted radial clearance of bearings is not in practice.

Recommendation:

Unmounted radial clearance to be measured as specified in SMI-278 dated 24.12.2013.

2.5. Measurement of Radial Clearance (RC) after assembly

ELS/GZB is measuring Drive End RC by using jack and dial gauge. But the point of

measurement is not as per SMI 278 and measured reading is not multiplied by factor of

0.86 as per SMI-278 dated 24.12.2013.

Recommendation:

It is advised to fix the dial gauge sensor at 40 mm away from outer labyrinth and

multiply the reading of dial gauge by 0.86 to get value of Radial Clearance as per SMI-

278.

2.6. Measurement of the axial play:

ELS/GZB is not measuring the axial play.

Recommendation:

Axial play needs to measured and recorded as specified in SMI-278 dated 24.12.2013.

2.7. Measurement of Insulation Resistance of NDE bearing

Insulated bearing NJ320 is used in Non-Driving End (NDE) side of 3 Phase traction

motor type 6FRA6068. Its insulation resistance needs to be measured and recorded

during assembly. However, ELS/GZB is not measuring the insulation resistance of

NDE bearing.

Recommendation: Insulation resistance of insulated bearings needs to measured and

recorded with 1KV megger as specified in SMI-278 dated 24.12.2013.

2.8. Colour Matching of the pinion:

Dye transfer test (Colour matching) of pinion with ring gauge is not carried out. Colour

matching of pinion with shaft taper is started by ELS/GZB.

Recommendation: Colour matching of pinion needs to be done as per procedure

specified in SMI-278 dated 24.12.2013.

Page 8 of 11 Issued on : 24.07.2018 Report No. RDSO/2018/EL/TAR/0018 Rev. ‘0’

Prepared by Checked by Issued by

2.9. Mounting of the pinion ELS/GZB had started to ensure the pinion travel of 12mm during mounting of the pinion as

per SMI-278 dated 24.12.2013.

2.10. Greasing of Bearings: Greasing is done with bare hands. Grease quantity provided is not weighed and recorded.

Grease dispensing meter was defective.

Photo 10: Greasing with bare hands Photo 11: Defective Grease dispensing meter

Recommendations:

i. It is recommended to uses disposable hand gloves while handling the bearings.

ii. The grease shall be kept in proper covered container to avoid contamination.

iii. Lint free cloth should be used for cleaning purpose.

iv. ABB manual (Volume F-5 Propulsion System – Document No. 3EHM620902

Grease instruction for roller bearings with synthetic grease) prescribes greasing

by means of grease gun using the prescribed tool. These instruction needs to be

followed.

v. Grease gun equipped with digital grease meter to be used for greasing as per

SMI-322 dated 27.4.2018.

vi. Re-greasing to be carried out in every alternate schedule for TM type

6FRA6068 as per SMI-307 dated 5.6.2017.

2.11. Non availability of Shock Pulse Meter Shock pulse meter is not available for monitoring of condition of the bearings as

prescribed in SMI-58 of July 1979.

Recommendation: Shock pulse meter to be procured and used for condition

monitoring of the bearings.

2.12. Implementation of MS-466

Modification in drawing of Outer bearing cap DE to achieve adequate lateral thrust in

Traction motor (TM) assembly of 6FRA6068 TM had been advised by MS-466 dated

15.11.2017. However, implementation had not yet started.

Recommendation: Implementation of MS-466 to be expedited.

Page 9 of 11 Issued on : 24.07.2018 Report No. RDSO/2018/EL/TAR/0018 Rev. ‘0’

Prepared by Checked by Issued by

2.13. Availability and use of Torque Wrenches:

M20 screws of DE & NDE End frame are tightened without use of torque wrench during

assembly. Tightening Torque of 372 Nm is specified for M20 Coarse thread hexagon

head bolts and screws in ‘WAG-9 Maintenance and Repair Manual, Indent No. 3EHW

411479 Chapter Preface Page 17/18’. It was informed that torque wrench is available but

not used. Staff and supervisor counselled for using the torque wrenches as prescribed.

Photo 12: Tightness of M20 screws without use of torque wrench

Recommendation: i. Sufficient number of torque wrenches to be procured and used during assembly

ii. It is preferable to use torque wrench with fixed predefined torque. In torque wrench

with adjustable torque, there is a probability that torque may not be set at required

value

iii. Torque wrenches should be calibrated periodically

2.14. Bearing mounting area: Bearing mounting area needs improvement in terms of cleanliness. Other activities like

component cleaning, air blowing etc. are also done near the bearing assembly area.

Photo13: Bearing mounting area

Page 10 of 11 Issued on : 24.07.2018 Report No. RDSO/2018/EL/TAR/0018 Rev. ‘0’

Prepared by Checked by Issued by

Recommendation: Bearing assembly area should be clean and dust free. No other activity should be

performed near bearing assembly area. It is recommended to separate the bearing assembly

area from cleaning area. Further scope of improvement to clean the area is still there.

2.15. Induction heating of End frames assembly components & inner racer:

Induction heater of TM for heating inner racer and End frame was found defective, it

was informed that induction heater of auxiliary section is used for heating of racers.

Photo 14: Induction heater

Recommendation:

i. Induction Heater to be used for heating of End Shields/End frames of traction

motors for bearing fitment as per SMI-301 dated 8.11.2016.

ii. ELS/GZB should procure sufficient number of induction heaters equipped with

essential features like temperature display, temperature hold, auto cut off & de-

magnetization.

iii. Induction heating should always be done in temperature mode as same/similar

components of different manufactures may have different properties.

Page 11 of 11 Issued on : 24.07.2018 Report No. RDSO/2018/EL/TAR/0018 Rev. ‘0’

Prepared by Checked by Issued by

3. Other observations:

3.1. Use of expired Anti tracking varnish RE118 in TAO TM

Anti-tracking varnish RE118 which had expired in July 2017 was in use. Shelf life of

RE118 is 6 months when stored at or below 25 degree Celcius. However, there was no

AC ward for keeping the varnish.

Photo 15: Expired Anti-tracking Varnish RE 118

Recommendation:

(i) It is advised not to use expired varnish.

(ii) Staggered supply of shelf life material is required so that it is used within shelf life

period.

(iii) Proper storage facilities are required for storing shelf life items in prescribed

storage conditions.

3.2. Defective High Current Injection kit

High current injection kit available was defective and not able to generate the required

current of 500A. High current injection kit of 500 A is required to check the brazed

joints of stator during AOH/IOH/POH as per SMI-271 dated 17.11.2011.

Recommendation: SMI-271 needs to be followed for testing of brazed joints of

interconnectors of field coils and compole coils in Traction motors type HS15250A and

TAO659 using high current injection test.

3.3. Defective Ferrous Debris Monitor (FDM)

Analex Ferrous Debris Monitor used for debris analysis of gear case oil is defective.

Shed is using portable grease steel dust meter SDM-72 for analysis of used grease.

Recommendation:

Repairing of Analex Ferrous Debris Monitor to be expedited.