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(For Official Use Only)

Hkkjr ljdkj GOVERNMENT OF INDIA jsy ea=ky; MINISTRY OF RAILWAYS

egkjktiqj, Xokfy;j & 474 005 Maharajpur, GWALIOR - 474 005

CAMTECH/E/18-19/EP-2/OCB/Rev.0

May, 2018

End User : Maintenance Staff of 3 Phase Electric Locomotives

HANDBOOK ON

OIL COOLING BLOWER (OCB) OF

THREE PHASE ELECTRIC

LOCOMOTIVE

QUALITY POLICY

“To develop safe, modern and

cost effective Railway

Technology complying with

Statutory and Regulatory

requirements, through

excellence in Research, Designs

and Standards and Continual

improvements in Quality

Management System to cater to

growing demand of passenger and

freight traffic on the railways”.

FOREWORD

During operation of the locomotive, the traction converter

and transformer assemblies produce a considerable amount of

heat. As excess heat adversely affects the performance of these

units, cooling is required to keep them operating at optimal

performance levels. Oil cooling blower supplies air to heat

exchanger unit to remove this excess heat from oil circulating

through the traction converter and transformer assemblies.

CAMTECH has prepared this hand book on Oil Cooling

Blower (OCB) of three phase electric locomotive to cover

general description and maintenance activities along with

testing with the objective to create awareness among the

maintenance personnel.

I hope this handbook will prove to be useful for the

staff working in electric loco sheds/ workshops maintaining

three phase locomotives.

CAMTECH, Gwalior Executive Director

Date : May, 2018

PREFACE

The traction converter and transformer assemblies of three

phase electric locomotive are cooled by circulating the oil

through heat exchanger unit and forced air is supplied by oil

cooling blower through heat exchanger unit to remove this

excess heat.

The continuous working of oil cooling blower is necessary for

safe and efficient running of locomotive which can be ensured

by proper maintenance.

CAMTECH has prepared this handbook on “Oil Cooling

Blower (OCB) of three phase electric locomotive” to

disseminate the knowledge among the maintenance personnel.

This handbook comprises technical data of OCB,

maintenance activities, and testing along with MUST CHECK

POINTS with useful standards.

It is clarified that this handbook does not supersede any

existing provisions laid down by Railway Board, RDSO or

Zonal Railways. This hand book is for guidance only and it is

not a statutory document.

I am sincerely thankful to all field personnel who helped us in

preparing this handbook.

Technological up-gradation & learning is a continuous

process. Please feel free to write to us for any addition/

modification in this handbook. We shall highly appreciate your

contribution in this direction.

CAMTECH, Gwalior (Peeyoosh Gupta)

Date: 24 May, 2018 Director/ Electrical

e-mailid: [email protected]

CONTENTS

Sr.No. Description Page No.

Foreword iii

Preface iv

Content v

Correction Slip vii

1. INTRODUCTION 01

1.1 Technical Data 01

1.2 Tools & Special Tools 02

2. BEFORE-REMOVAL OF OCB FROM OPERATION 03

3. SPECIAL CHECK POINTS FOR O/H OF OCB 07

4. OPERATION CHART FOR OVERHAULING 11

i. Incoming testing. 11

ii. Remove the extended lead with flexible pipe 12

iii. Remove the impeller 13

iv. Remove the motor from dome 14

v. Remove terminal box 14

vi. Stripping of motor 14

vii. Stripping of rotor 14

viii. Clean the following parts 15

ix. Checking and attending of various part 16

x. Rotor balancing. 18

xi. Stator varnishing. 19

xii. Fitting of terminal box. 20

xiii. Testing of stator. 20

xiv. Motor assembly. 21

xv. Light run test 22

Sr.No. Description Page No.

xvi. Assembly of blower. 22

xvii. Load testing. 23

5. CHECK POINTS 25

6. RELIABILITY ACTION PLAN 29

FOR 3-PHASE LOCOMOTIVES

(Rev. ‘10’, May.’14)

7. MODEL QUESTIONS 33

8. ANSWERS 41

9. AN APPROACH TO EQUIPMENT FAILURE

INVESTIGATION 42

REFERENCE 44

ISSUE OF CORRECTION SLIP

The correction slips to be issued in future for this

handbook will be numbered as follows:

CAMTECH/E/18-19/EP-2/OCB /1.0/ C.S. # XX date---

Where “XX” is the serial number of the concerned

correction slip (starting from 01 onwards).

CORRECTION SLIPS ISSUED

Sr.No. Date of

Issue

Page no. & Item

no. modified

Remarks

CAMTECH/E/18-19/ Loco OCB 1

Handbook on Oil Cooling Blower (OCB) May, 2018

of 3 Electric Locomotive

1. INTRODUCTION

During operation of the locomotive, the traction

converter and transformer assemblies produce a

considerable amount of heat. As excess heat adversely

affects the performance of these units, cooling is

required to keep them operating at optimal performance

levels. To remove this heat, cooling oil is circulated

through the traction converter and transformer

assemblies. This oil is then passed through a heat

exchanger which removes excess heat. This oil cooling

unit draws air in through filter panels located in the

pantograph roof hatch. These filters remove impurities

and debris from the air. This debris is then removed

from the filter panels by the scavenge system.

1.1 TECHNICAL DATA

Oil Cooling Unit

Oil volume total 150L

Volume converter oil 78L

Volume transformer oil 72L

Weight empty 840kg

Painting Topcoat RAL 7030

stone gray silky 45±

5%

Test excess pressure

converter oil

4 bar

Test excess pressure

transformer oil

4 bar

2 CAMTECH/E/18-19/3 Loco OCB

May, 2018 Handbook on Oil Cooling Blower (OCB)


Oil Cooler Blower Fan Electric Meter

Type Three phase squirrel-cage motor

Motor model 200L55-RH2A

Voltage 3 x 415V ± 10%

Current 43A

Power supply Square wave (inverter operated)

Degree of protection IP54

Frequency 50Hz

Normal speed 2,930rpm

Output 25kW

Insulation class

F

Weight 265kg

1.2 TOOLS & SPECIAL TOOLS

In addition to conventional railways workshop

tools and equipment, the following are also required for

the maintenance of oil cooling blower procedures

described in this chapter.

Cleaning grate, part 04.882.30.500, BHER Industrie

technik. Required for Oil Cooler Blower, refer to

Chapter 5, Oil Blower of Volume F10, and Suppliers

Documentation.

A high pressure cleaner capable of delivering water at 80 bar at 70 °C.

An industrial grade vacuum cleaner.

An external compressed air supply capable of delivering air at 6 bar.




A suitable heating oven capable of fitting the oil cooler and heating to 105-110°C.

A fluid cleaning system with a filter with a mesh size of 25 microns.

A lifting eye-bolt suitable for attachment and lifting of the fan wheel and motor.

1.3 BEFORE-REMOVAL OF OCB FROM

OPERATION

General

Isolate the locomotive electrical systems. Set the

„Oil Cooling‟ circuit breaker to the Off position. Circuit

breaker for the No.1 End is situated auxiliary circuits

cubicle-1(HB1) and circuit breaker for the No.2 End is

situated in auxiliary circuits cubicle-2 (HB2).

Set the “Traction Motor Blower and oil cooling

unit scavenge blower” circuit breaker to the Off

position. Circuit breaker for the No.1 End situated

auxiliary circuits cubicle-1 (HB1) and circuit breaker

for the No.2 End is situated in auxiliary circuits cubicle-

2 (HB2).

Set the “Oil pump converter” circuit breaker to

the Off position. Circuit breaker for the No.1 End

situated auxiliary circuits cubicle-1 (HB1) and circuit

breaker for the No.2 End is situated in auxiliary circuits

cubicle-2 (HB2).

Set the “Transformer oil pump” circuit breaker

to the Off position. Circuit breaker for the No.1 End is

situated auxiliary circuits cubicle-1 (HB1) and circuit




breaker for the No.2 End is situated in auxiliary circuits

cubicle-2 (HB2).

Oil cooler assembly

First drain the oil from the system. Disconnect

the oil cooling piping from between the transformer and

the oil cooler.

Disconnect the oil cooling piping from between

the traction converter and the oil cooler.

Removed oil cooler and blower assembly

If necessary, remove the traction converter oil pump from the cooler assembly.

If necessary, remove the transformer oil expansion tank from the cooler assembly.

Disconnect the electrical harness from the outside of the oil cooling unit.

Unbolt the earth lead to the cooling unit




Cut the cable ties securing the wiring to the looming bar, then move cabling out of the way.

Unbolt and remove the looming bar, if necessary.

Remove the three bolts, spring and plain washers along each side of the cooling assembly.

NOTE:

The oil must be sealed to prevent damage from

foreign materials. Seal the oil cooler opening using a

clean cardboard sheet and masking tape.

All oil flanges must be sealed with dummy

flanges before the oil cooler is moved to prevent the

ingress materials and any possible outflow of oil.

Lift the oil cooling unit from the locomotive

using suitable lifting equipment attached to the lifting

lugs. Take care not to damage any part of the assembly

or other machine room components during the removal

of the cooling unit assembly.

Blower fan and motor

The blower fan and motor may be removed

from the oil cooling assembly without removing the

assembly from the locomotive. Once the filter has been

removed, the fan and motor can be removed.




Oil cooler assembly

Oil cooler

may be unbolted and

removed from oil

cooler assembly if

required. This may

be required for the

oil cooler cleaning

procedures described

in section inspection

and repair.

Remove the looming bars (3) if not removed previously

Attach suitable lifting equipment to the lifting lugs (4)

Remove the eight bolts, spring washers and washers (5,6,7) securing the oil cooler assembly (1)

to the oil cooler (2)

Lift the oil cooler assembly (1) from the oil cooler (2)




2. SPECIAL CHECK POINTS FOR O/H OF OCB

Sr. Check point Standard

*. Incoming Sr.No./Make record

*. Outgoing Sr.No./Make record

1. Incoming test

a. IR value with 1 KV Meggar record

b. Check the bearing noise record

c. Any abnormality record

d. Vibration record

e. Any abnormal noise normal

f. Incoming run test parameter of VVVF

test plant at full speed for 10 minutes

a. Voltage record

b. Current record

c. Frequency record

d. Direction OK

2. a. Check the condition of terminal block

and connecting leads, overheating/

breakage of lugs & breakage of stand

near crimped portion.

Provision of transparent heat shrink

sleeve near lug.

OK

3. Measure the shaft dia at bearing seat DE

NDE

record

4. Measure the end cover bearing housing

dia

DE,

NDE

record





5. Check the rotor bars and short circuiting

end rings for any crack by means of

growler test as per SMI-163 & rotor

body looseness at shaft by sound test for

healthiness/ dullness.

done

6. Condition of key, keyway & shaft

threaded portion to be checked

good/

damage

7. I.R. value of stator with 1 KV meggar

after baking 10M

(min.)

8. Baking of stator to be done before

varnishing & after anti track

done

9. perform dielectric test on stator by

applying 1.5 KV AC supply for 1

minute

stand for 1

minute

10. Measure the winding resistance between

the phases

a. UV b. VW c. WV

record

11. Surge comparison test on stator at 2KV

for old, SKV for new

Wave form

matched

12. Bearing details:-

a. Check the bearing as per SMI-16,23,79 & 148

done

b. SPM reading to be recorded as per SMI-58

record

c. New bearing provided Monthly/ year should be inscribed

done

d. Detail of the grease used in bearing GHY-72

e. Record bearing make DE & NDE side

record





13. Light run test parameter at VVVF test

plant at full speed for 10 minute

a. Voltage record

b. Current record

c. Frequency record

d. Speed record

e. Direction OK

f. Bearing Noise DE NDE

record

g. Check for free run No abnormality

14. a. Check visually dome for any crack

& damage

No crack

No damage

No deformation

b. Check impeller for any crack by

RDPT test & also check the

impeller blades for any dull sound

by ring test

No crack healthy

sound

15. Check the alignment of impeller with

respect to cone

Alignment is

poor

16. Check the tightness of locking bolt &

plate securing the impeller

Properly

tightened/ locked

17. Check for any abnormal noise during

starting & running

Normal noise.

18. RTV compound is to be applied at

every joint & terminal connection box

Applied

19. Load run test parameter at VVVF test

plant at 3 stages

a. Voltage record

b. Current record

c. Frequency record

d. Speed record

e. Direction OK

f. Bearing Noise Normal





20. a. Check the blower assembly for

balancing by portable balancer

Balancing done

(Limit 40 cu/sec.)

21. Check the blower assembly

vibration level by SKF vibration

pen

5mm/ sec (Max.)

22. Winding scheme for oil cooling

blower of 3 phase loco as per SMI -

0239

Followed

23. Any other remarks




3. OPERATION CHART FOR OVERHAULING

i. Incoming testing.

a. Shift the OCB from pallet to

the working place.

b. Remove OCB dome

inspection cover

c. Remove terminal box cover

from OCB dome.

d. Test winding insulation resistance both.

i. In between windings and

ii. Between earlier body and winding by 1 KV

meggar.

e. Check the free movement of impeller by hand.




f. Put OCB on test bench

g. Connect the 3 phase VVVF supply to terminal and

start from zero speed and check the

h. Check the equipment various parameters at different

stages of speed like frequency, current, voltage,

bearing noise, vibration and any other abnormalities.

i. Check visually for any defects and deficiencies.

j. Remove 3-phase supply.

ii. Remove the extended lead with flexible pipe

a. Remove extended lead

connection from dome

terminal box.

b. Remove dome terminal box.




c. Remove clamp from flexible pipe.

d. Remove extended lead connection from motor terminal

box.

e. Remove motor terminal box cover.

iii. Remove the impeller.

a. Put the OCB from test bench to working place.

b. Remove the top cone.

c. Remove the bottom cone.

d. Put the OCB in horizontal condition with the help of

crane.

e. Remove the locking bolt with locking plate of impeller.

f. Fit the hydraulic puller and remove the impeller with

key




iv. Remove the motor from dome

a. Unscrew the 4 nos. bolt with

washer of motor foundation.

b. Remove the motor from

dome by crane.

v. Remove terminal box

a. Remove the lead connection

b. Remove the SB

c. Remove terminal box

vi. Stripping of motor

a. Place the motor in horizontal

condition

b. Unscrew the hex. hd. Screw

of end cover of DE side.

c. Remove DE side end cover.

d. Unscrew the hex. hd. Screw of end cover of NDE side.

e. Remove NDE side end cover.

vii. Stripping of rotor




a. Remove circlip from NDE side rotor shaft.

b. Remove bearing from both sides by 3 leg puller.

c. Remove inside grease cap from both sides.

d. Remove rotor from stator

viii. Clean the following parts

a) Dome b) Cone

c) Dome Impeller

d) Rotor




e) Stator

f) End covers

g) Terminal box and other parts.

ix. Checking and attending of various part

a. Check the dome for any

defect and damages and

repaired if required.

b. Check the cone for any

defect and damages and

repaired if required.

c. Checking and repairing of

dome inspection cover.

d. Measure the shaft dia of bearing seat.

e. Measure the bearing housing dia of end covers.

f. Checking attending/ replacement of damage parts of

terminal box.

g. Prepare the rubber gasket.




h. Check attending/replacement of damaged part of terminal

box.

i. Replace rubber gasket of

various part

j. Check the impeller after cleaning for DPT and MPT test.

k. Paint the following parts.

a) Dome

b) Cone

c) Stator from out side

d) End covers

e) Terminal box and other parts.




x. Rotor balancing.

a. Check the rotor bars for any crack with the help of

growler test.

b. Fit the impeller on shaft.

c. Fit the attachment to the shaft for making it suitable

to fit on the balancing machine.




d. Send rotor with impeller for balancing.

e. Load the impeller on balancing machine with the

help of crane.

f. Rotate at specified speed.

g. Note the balancing weight value and location.

h. Repair the balancing weight and fit the balancing

weight at appropriate location.

i. Re-rotate and check the balancing position.

j. Repeat the above process if required.

k. Get it certified by inspection and unloaded it from

balancing machine.

l. Bring in assembly shop.

m. Remove attachment from shaft.

n. Remove impeller.

o. Paint the impeller.

xi. Stator varnishing.

a. Put stator into oven for

backing.

b. Remove stator after

backing.

c. Apply varnish to stator

winding.




d. Put stator into oven for backing.

e. Remove stator after backing.

f. Clean extra varnish.

g. Clean the threaded portion of stator.

xii. Fitting of terminal box.

a. Fitting of terminal box with backside gasket.

b. Fitting of SB.

c. Tinning of short link and lugs.

d. Connection of connecting lead on SB.

xiii. Testing of stator.

a. Bring the stator and do connection for HV test.

b. Remove connection after HV test.

c. Bring stator in surge testing both and connect the

leads to do surge testing.

d. Disconnect the connection and shift the stator on

work bench.

e. Measure the winding resistance of all 3-phase with

the help of W stone bridge.

f. Measure the insulation resistance with 1 KV

megger.




xiv. Motor assembly.

a. Insert the rotor into the stator.

b. Check the bearing clearance.

c. Inscribed the date on new bearing.

d. Heat the bearings by induction heating.

e. Fit the bearings on both side of shaft with shims.

f. Provide the specific quantity of grease into the

bearing.

g. Provide the circlip to the

shaft in front of bearing.

h. Fit both side end covers.




i. Fit grease nipples.

xv. Light run test.

a. Check the insulation resistance by 1 KV meggar.

b. Connect the 3-phase VVVF supply to motor

terminal.

c. Run the motor at various speeds and record the

parameters.

d. Check for any abnormal noise.

e. Check the vibration.

f. Measure the bearing noise by dBN meter.

g. Check the bearing temp. rise.

xvi. Assembly of blower.




a. Place the dome in vertical position.

b. Place the motor in the bracket in dome with the

help of crane.

c. Fit the motor in dome.

d. Fit the key on shaft.

e. Fit the impeller duly balanced on motor shaft if

crank fit new impeller.

f. Fit the locking bolt with locking plate.

g. Fit both the cranes.

h. Fit the flexible pipe with extended loads.

i. Clamp the flexible pipe.

j. Fit the insp. cover of dome with gasket.

xvii. Load testing.

a. Lift the blower assembly and

put on test bench.

b. Connect the 3-phase VVVF

supply to the motor terminal.

c. Run the motor at full speed.

d. Check the bearing noise by

SPM.




e. Check the following parameters at different speed

i.e. 1000, 2000 & full speed.

a) Voltage b) Current c) Frequency, air flow

by anemometer.

f. Check the temperature rise of bearing after 2 hrs.

load run test.

g. Check the vibration by portable balancing machine.

h. Check for any

abnormal noise &

vibration.

i. Offer the inspection staff for checking.

j. Attend the bookings offered by inspection staff.

k. Disconnect the power supply from terminal box.

l. Fit the terminal box cover.

m. Fit the extended leads on dome with terminal box.

n. Write the equipment No. Loco No. and location of

equipment on blower assembly.




4. CHECK POINTS :

Auxiliary

motors

Rewinding of all auxiliary motors except

MRB/SCMRB by corona resistant wire. (Ref.

EL/2.2.8/17 dt 14/08/08)

All new motors procurement except

MRB/SCMRB from indigenous sources must

be with corona resistant wire only. ( Ref.

Amendment 3 to spec no E-10/3/09 (motor)-

Aug‟ 1997 issued vide EL/3.2.176/1 dt

28/1/09)

Replace MS impeller with Aluminum impeller.(

Ref. CLW‟s letter no ELDD/3743/CRH dated

08/05/09. For OCB).

Replacement of 10 mm2

cable type 4GKW-AX

(cable no.1147,1148 & 1149) of oil cooling unit

with 16 mm2 cable type 4GKW-AX to improve

the reliability of three phase loco.

(RDSO/2011/EL/MS/0395, Rev.‟0‟ dated

28.02.2011)

Other Air delivery measurement in 3-phase electric

locomotive to ascertain proper cooling and

pressurization of machine room .(EL/SMI

/0255 Rev.-0 date 06.05.2009)

Motors Ensure replacement of all must change items

during MOH, IOH & POH as per guidelines.(

Ref. EL/3.1.35/16 dated 30/03/2007).

Procedure for rewinding of auxiliary motors.(

Ref. RDSO/ELRS/ SMI/3 (Rev.‟1‟) issued

vide letter no. EL/3.2.70 dated 30.11.2000).




Procedure for connecting the lead wire with the

stator winding wires of auxiliary motors.( Ref.

RDSO/ELRS/ SMI/5 issued vide letter no.

EL/3.2.70/D4 dated 21.12.1977).

Fits and limits on bearings Of auxiliary motors

used on Electric locomotives. (Ref.

RDSO/ELRS/SMI/16 issued vide letter no.

EL/2.2.48/J2 dated 3.5.1978).

Procedure for measuring the bearing clearances

of a “free bearing” that is a bearing off the

machine( Ref. RDSO/ELRS/SMI/23 issued

vide letter no. EL/2.2.48/J2 dated 7.5.1978).

Procedure for fixing the socket with the lead

wires of auxiliary motor stator Winding. (Ref.


EL/3.2.70/J2 dated 21.11.1978).

Conditioning monitoring of bearing.( Ref.

SMI/58 issued vide letter no. EL/8.11.12/DB3,

dated 20.07.1979).

Fitment of outer race of bearing in the bearing

housing.(Ref. RDSO/ELRS/SMI/78 issued vide

letter no. EL/2.2.48 dated 2.5.1981).

Testing/checking of new bearings for Auxiliary

motors .( Ref. RDSO/ELRS/SMI/79 issued vide


Procedure for impregnation of stator auxiliary

motors.( Ref. RDSO/ELRS/SMI/86 (Rev.1)

issued vide letter no. EL/3.2.70 dated

29.11.2000).




Hard chrome plating of bearing/housing shafts

of auxiliary machines.( Ref. SMI/94 issued vide

letter no. EL/3.2.48/JTMU, dated 15.10.1982).

Use of button type of grease nipple on auxiliary

motors fitted on Electric loco. (Ref.


EL/3.2.70/J3 dated 30.10.1992).

Guidelines to identify genuine and spurious/

reconditioned bearings.( Ref.


EL/2.2.48 dated 21.10.1992).

Special instruction for surge test on 3 phase AC

auxiliary motors.( Ref. RDSO/ELRS/SMI/149

issued vide letter no. EL/3.2.70 dated

Oct.‟92).

General guidelines to follow for balancing of

rotor and blower impellers.( Ref.


EL/3.2.70/J3 dated 15.12.1992).

Characteristic properties of enamel used on

enameled winding wires.(Ref.

RDSO/ELRS/SMI/153 (Revised April‟98)

issued vide letter no. EL/2.2.8/4 dated

20.04.1998).

Special instructions for essential requirements

of facilities to rewind 3 phase AC auxiliary

motors in loco sheds and rewinding shops.( Ref.


EL/3.2.70 dated 22.04.1993.




Rewinding material for auxiliary motors.( Ref.

RDSO/ELRS/ SMI/185(Rev. „1‟) with Amend

1 &2 issued vide letter no. EL/3.2.70

30/10/2000, 28/12/2000, 15/03/2001).

General guidelines to follow for balancing of

rotors and cooling blower impellers in

position.( Ref. RDSO/ELRS/SMI/199 issued

vide letter no. EL/3.2.70 dated 01.04.1998).

Characteristic properties of impregnating resins

and insulating varnishes (Superseding SMI154).

(Ref. RDSO/ELRS/SMI/200 (Revised) issued

vide letter no. EL/2.2.8.4 dated 30.12.1999).

Special Instruction for essential requirements of

facilities to rewind 3-Phase AC Auxiliary

Motors used in Electric Locomotives in Loco

Sheds and rewinding shops. ( Ref.

RDSO/ELRS/SMI/222, Rev.„0‟ issued vide





5. RELIABILITY ACTION PLAN FOR 3-PHASE LOCOMOTIVES (Rev. ‘10’, May.’14)

a All Auxiliary Blower and Motors- Visually check

the oil cooler radiator for any oil leakage/external

damage.

i. Check all the auxiliary motors for any abnormal sound and proper functioning.

ii. Measure the current of all auxiliary motors

iii. Visual examination / RDPT of impeller of OCB.

iv. Check tightness of foundation bolts of all auxiliary motors.

v. Check the electrical connections of all auxiliary motors.

vi. Check the condition of all flexible hoses connected with various auxiliary blowers and

replace, if required.

vii. Check tightness of SB and cable connections at terminal box.

viii. Greasing of all motors with recommended grease

ix. Ensure that the terminal covers of various auxiliary motors are intact and water tight.

Special attention needs to be given to main

compressor motor cable layout and water

tightness of its entry point into the motor terminal.




b. Oil Cooling Piping

Replace the 'O' rings in the main transformer and main

converter oil pipes.

c. Oil Cooler Radiator

Examine flange joint for sign of cracks, oil leakage and

loose/missing screws.

Vacuum clean the radiator chamber via the machine

room access cover and then clean the radiator by high

pressure hot water jet. Check that the radiator is not

blocked.

d. Oil Cooler Blower

Remove and clean the oil cooler blower filter duct.

Remove all traces of dirt, duct and debris.

Clean the oil cooler blower fan impeller. Remove all

traces of dirt, dust and debris.

Remove the air cone from the oil cooler blower filter

panel. Remove all dirt, debris and obstructions.

Check for abnormal noise and measure vibration level

on OCB before and after inspection.

Air velocity measurement of OCB to be taken before

and after inspection.

Conduct RDPT of Impeller and check for unbalancing

Replace the Impeller of oil cooler blower

Check the condition of Rubber bellows of OCB duct to

TM Scavenger Blower. If damaged, replace it.




Check the condition of roof filter & OCB duct gasket

if damaged - replaced

Check the condition of rubber hosepipe and clamps.

Replace if damaged. Check the tightness of clamps.

Check the condition of the filter screen, inspect for

cracks or damage. Rectify any faults found.

Check the security of the bolts around the duct flanges.

Check all flanges on the ducting for cracks around the

hoses. Rectify any fault found.

Remove any build up of dirt and foreign material from

around the filter screen.

e. Oil Cooler Blower Motor

Checking of bearing condition by SPM/Noise and

changing on condition basis

Overhaul the oil cooler blower motor. Replace the

bearings along with associate components & grease.

Remove all dust and dirt from motor body using a

vacuum cleaner and soft non- metallic brush.

Conduct RDPT of motor foundation brackets.

Securing of motors cables.

Check Current & Voltage of OCB Motor




f. Oil Cooler Blower Seals

Replace the seals between the oil cooler blower & the

filter duct, between the oil cooler blower filter & the

pantograph roof hatch on the oil cooler blower unit,

between the oil cooler blower & machine room floor,

on the oil cooler blower filter & ducting and on the oil

cooler blower inspection door (WAP5/WAP7)

Replace the seals between the oil cooler blower & the

filter duct, between the oil cooler blower filter & the

pantograph roof hatch on the oil cooler blower unit,

between the oil cooler blower & machine room floor,

on the oil cooler blower filter & ducting and on the oil

cooler blower inspection door (WAG9/ WAG9H)

Check the seal between the filter screen and

pantograph roof hatch. If necessary conduct a water

test. Replace the seal if any leakage occurs.




6. MODEL QUESTIONS

OBJECTIVE

1. Before starting work on faulty circuit it should be ensured

that

a. The faulty circuit has been isolated from power supply

and earthed.

b. The worker is capable to do the work.

c. The connections are not approachable.

d. None of the above.

2. One can protect himself from electric shock by wearing

hand gloves of good.

a. Conducting material

b. Insulating material

c. Semiconductor material

d. Any of the above.

3. Which of the following are safety precautions?

a. Don‟t touch live wire or equipment with bare hands.

b. Before switching on DJ, see no one is working inside

loco.

c. Use insulated meting and hand gloves.

d. All of the above.




4. Which material is recommended as fire extinguisher in

electrical cases?

a. Carbon tetra chloride

b. Carbon dioxide

c. Sulphur hexafluoride

d. Any of the above.

5. The BDV of transformer oil should be

a. 20kV

b. 30kV

c. 40kV

d. 50kV

6. The colour of moisturized silica gel is

a. Pink

b. Blue

c. Yellow

d. Green

7. Which of the following is not the function of transformer

oil

a. Cooling of winding and core.

b. Providing additional insulation

c. Media for are quenching

d. Provides inducting coupling

8. Transformer oil should be free from

a. Odour

b. Gases

c. Temperature

d. Moisture




9. Dielectric strength of oil should be performed using

12.5 mm ball electrodes with a gap of-

a. 04mm

b. 05mm

c. 2.5mm

d. 03mm

FILL IN THE BLANKS

1. Transformer is a ………….device

2. WAG-9 Loco transformer has…………….windings

3. WAG-9 Loco transformer has………………..tank

4. WAG-9 Loco Required variable voltage is achieved by the use of ……….………….

5. An emf induced in a coil due to variation of flux in another coil is called……

6. The coils of a transformer are wound on a …………core of ………….material

7. The conductors used in HV and LV windings of loco transformer are…………

8. In WAG-9 Loco The primary side is protected from the voltage surges by means of ………….placed on the roof

of the locomotive.

9. The auxiliary winding is protected from sudden rises in voltage by means of ………………connected across the

winding.




10. Ingress of moisture is prevented by means of …………….

11. The complete cooling arrangement includes……….., ………..and…………..

12. The oil pump and the cooler are connected to the conservator and radiator by…………………

13. The breather is attached to ………………and contains……………

14. Pink colour of silica gel indicates……………..

15. The colour of transformer oil become dark brown, it indicates presence of …… ……

16. Operating vacuum of transformer oil purification plant should be ………….

17. DGA stands for …………………..

18. Transformer must never be lift without its……………….

19. Oil BDV Test six consecutive reading should not lie more than……

20. The lifting ropes should not make a smaller angle then….with the horizontal.

SAY ‘TRUE’ OR ‘FALSE’

1. Transformer transforms power from one AC circuit to another AC circuit, at same frequency.

2. Transformer can raise or lower the voltage.

3. Transformer can raise or lower the frequency.




4. Two circuits in a transformer linked by a common magnetic flux through a path of low reluctance.

5. In case of step up transformer, the transformation ratio will be more than one.

6. Constructional features of a loco transformer are more or less same other power transformer.

7. 25 kV condenser/ cable head bushing is mounted on the top of the tank cover.

8. The cooling arrangement of the loco transformer is force oil forced air type.

9. In G-9 Loco the complete cooling equipment is mounted on the cover of the loco transformer.

10. In G-9 Loco spring-loaded safety valve is fitted to the top of the conservator.

11. Presence of moisture in transformer oil is highly desirable.

12. The oxygen present in transformer reacts with insulation and forms an organic acid.

13. The solid impurities present in insulation oil strengthen its dielectric strength as well as insulation of windings.

14. The slackness of winding is desirable factor to create electrical and magnetic unbalance of the coils.

15. Meggering is done to check the insulation resistance of the windings.

16. The tightening torque of the bolts of tank and lid must be 70 Nm.

17. To arrest the oil leakage from bushing RDSO has recommended to use ISI make gaskets.

18. Bushing gaskets to be replaced as per TC- 076.




19. New M.S. hardware may be used in transformer flange joints fitting.

20. Periodic maintenance of transformer is essential to ensure safety, reliability and trouble free operation of

Locomotives.




Electrical GK QB

21. For the protection of single-phase 1.5 kW motor, a MCB of ____ rating should be provided

(a) 10 A (b) 16 A (c) 32 A (d) 63 A

22. The low power factor results in

(a) Increased losses

(b) Decreased losses

(c) No effect on losses

(d) Better generating efficiency

23. Low power factor

(a) Aids the voltage regulation

(b) Increase the voltage regulation

(c) Decrease the voltage regulation

(d) None of the above

24. The power factor of the AC supply can be improved by using

(a) Synchronous generator

(b) Universal motor

(c) Synchronous condenser

(d) SCR

25. A distribution line of 440 V is classified as

(a) LV (b) MV (c) HV (d) EHV

26. Which of the following reduces the power factor

(a) Motor on no load

(b) Tube lights

(c) Fans

(d) All of the above

27. Unit of energy is

a) Kilo volt hours

b) Kilo watt hours

c) Kilo watt




28. As per Ohm‟s law

a) V = IR

b) V = I/R

c) R = VxI

29. Unit of resistance is

a) Ampere

b) Volts

c) Ohm

30. In three phase 415 volts 50 Hz supply, the phase to phase voltage is

a) 220 Volts

b) 415 volts

c) 440 volts

31. In three phase 415 volts 50 Hz supply, the phase to neutral voltage is

a) 220 volts b) 230 volts c) 440 volts

32. In 4 sq. mm PVC wire, 4 sq. mm stand for

a) Thickness of wire

b) Length of wire

c) The area of thickness of wire

33. 10 hours use of 500 watt Motor will consume the energy

a) 10 units b) 20 units c) 5 units

34. No. of poles in MCB/TPN is

a) 2 poles b) 4 poles c) 3 poles




7. ANSWERS

Model Question

1 (a), 2 (b), 3 (d), 4 (b), 5 (d), 6 (a), 7 (d), 8 (a), 9 (c).

Fill In the Blanks

1. Static, 2. 04,

3. Aluminium Alloy, 4. GTO or IGBT,

5. Metual Induction, 6. Laminated, Silicon Steel,

7. Continuous Transposed Cu Conductor,

8. Lightening arrester, 9. RCL Damping,

10. Air dehumidifire, 11. Radiator & Blower,

12. Oil Pipe, 13. Conservator, Silicagel,

14. Humid 15. Acid & Impurties,

16. 1Torr, 17. Incipien fault,

18. Lid, 19. 15%,

20. 60°.

True or False

(1)-T, (2)-T, (3)-F, (4)-T, (5)-T, (6)-T, (7)-T,

(8)-T, (9)-F, (10)-F, (11)-F, (12)-T, (13)-F, (14)-T,

(15)-T, (16)-T, (17)-F, (18)-T, (19)-F, (20)-T.

Electrical (G.K.)

21-a, 22-a, 23-c, 24-c, 25-a 26-d, 27-b, 28-a,

29-c, 30-b, 31-a, 32-c, 33-c, 34-b,




8. AN APPROACH TO EQUIPMENT

FAILURE INVESTIGATION

A. On Failure Aspects

1. Occurrence

2. Date of occurrence

3. Past similar occurrences if any

4. Analysis of failure i.e. why did it happen?

5. Whether the rate of failure is worse than other installations?

B. On Maintenance Aspects

1. Whether schedule maintenance & required testing have been carried out on the failed equipment as

per norms stipulated?

2. Does the frequency of maintenance require change?

3. Was the work properly supervised?

4. Was any RDSO modification required to be done?

5. Is any modification possible to avoid failure?

C. About Staff

1. Is the quality of work done satisfactorily?

2. Is the skilled staff properly trained to carry out the work?

3. Is the SMI available with them?

4. Are proper tools available with the staff?




D. About Material

1. Is the material received from approved source?

2. Whether the material is as per approved specification?

3. Can a better material be used?

E. About Testing

1. Is the testing equipment available?

2. Could testing procedure be improved to weed out the failures?

3. Whether testing equipment are calibrated?

F. General Points

Whether following points were checked / performed

properly?

1. Proper contact

2. Clearances

3. Capacity

4. Proper contact pressure

5. Crack detections

6. Cleaning

7. Proper connections/alignment

8. Cross checks/super checks




REFERENCE

1. ABB Maintenance manual.

2. Electrical Technology Books.

3. RDSO/SMI-

3,5,16,23,32,58,78,79,86,94,147,148,149,152,

153,155,163,185,199,200,222,239,255.

4. RDSO MS 0360,395.

5. Details collected from various field units (Shed

and workshop).

6. Suggestions received during the seminar held on 23.04.2018 organised by CAMTECH/

Gwalior.




OUR OBJECTIVE

CAMTECH is continuing its efforts in the documentation and up-gradation

of information on maintenance practices of electrical assets. Over the years

a large number of publications on electrical assets have been prepared in the

form of handbooks, pockets books, pamphlets & video films etc. These

publications have been uploaded on the internet as well as rail net.

For downloading these publications please do following:

1. On internet visit : www.rdso.indianrailways.gov.in

Go to Directorates CAMTECH Publications for download

Electrical Engineering

2. On Railnet visit RDSO website at 10.100.2.19

Go to Directorates CAMTECH Publications for download

Electrical Engineering Year wise/ Subject wise For any further information regarding publications please contact:

Director (Elect.) – 0751- 2470740 (O) BSNL, 9752447030 (CUG)

SSE/Electrical - 9755549297 (CUG)

E-mail at [email protected]

Fax to 0751- 2470841

Write at : Director (Electrical)

Indian Railways

Centre for Advanced Maintenance technology,

In front of Hotel Adityaz,

Airport Road, Maharajpur,

Gwalior, Pin code – 474 005

To upgrade maintenance technologies and

methodologies and achieve improvement in

productivity and performance of all Railway assets

and manpower which inter-alia would cover

reliability, availability, utilisation and efficiency.

http://www.rdso.indianrailways.gov.in/

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