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CAMTECH/2007/E/HLFL/1.0 11

Maintenance handbook on Head Lights/ Flasher Lights February 2007 of AC Electric Locomotives

GOVERNMENT OF INDIA MINISTRY OF RAILWAYS

(For Official Use Only)

MAINTENANCE HANDBOOK

ON

HEAD LIGHT/ FLASHER LIGHT

OF

AC ELECTRIC LOCOMOTIVES

TARGET GROUP – TECHNICIANS & SUPERVISORS OF AC LOCO SHEDS

Centre for Advanced Maintenance TECHnology

Excellence in Maintenance

Maharajpur, GWALIOR - 474 020

CAMTECH/E/2007/ HLFL / 1.0

February 2007

CAMTECH/2007/E/HLFL/1.0


2

MAINTENANCE HANDBOOK

ON

HEAD LIGHTS/ FLASHER LIGHT

OF

AC ELECTRIC LOCOMOTIVES

TARGET GROUP – TECHNICIANS & SUPERVISORS OF AC LOCO SHEDS



3

FOREWORD Power cables are commonly used for transmission and distribution of electrical power. Knowledge of selection of proper size and type of cables, their laying, jointing and termination is important for economical, safe and reliable power supply system.

CAMTECH has prepared this handbook with the objective of improving the reliability of power cables used in Railways. The book covers different types of cables, their constructional features and applications etc. It also covers selection, laying, installation, jointing, testing and maintenance of cables.

I am sure the handbook will prove to be very useful to our field supervisors and technicians in their day-to-day work. CAMTECH, Gwalior Kulbhushan Date:23.03.2006 Executive Director



4

PREFACE Power cables are used for transmission and distribution of electrical power in thickly populated areas, in sub-stations, in industries and in workshops etc. General awareness about the power cables is essential for the electrical general service staff to keep the power supply system in safe and reliable condition.

This handbook has been prepared by CAMTECH with the objective of making our field staff aware of different power cables, their selection, proper procedure of laying, installation, testing and maintenance to be adopted in their day to day work.

It is clarified that this handbook does not supersede any existing provisions laid down by RDSO or Railway Board. The handbook is for guidance only and it is not a statutory document.

I am sincerely thankful to Director (PS & EMU) RDSO/LKO for his valuable comments. I am also thankful to all field personnel who helped us in preparing this handbook.

Technology upgradation and learning is a continuous process. Hence feel free to write to us for any addition or modification in this handbook. We shall highly appreciate your contribution in this direction. CAMTECH, Gwalior Randhawa Suhag Date: 23.03.2006 Director/Elect.



5

Chapter No. Description Page No.

Foreword iii Preface iv Contents v Correction Slip vi

1. GENERAL DESCRIPTION 01

1.1 TWIN BEAM HEADLIGHT 03

1.2 FLASHER LIGHT 09 1.3 TECHNICAL DATA 12

2. MAINTENANCE 14

2.1 PERIODIC SCHEDULES 14

2.2 INSTALLATION OF HEADLIGHT 16

2.3 TWIN BEAM ADJUSTMENT OF HEADLIGHT 17

2.4 TESTING OF DC-DC CONVERTER 20

2.5 PRECAUTIONS DURING MAINTANANCE 20

2.6 INSTALLATION OF FLASHER LIGHT 22

2.7 LIST OF SPARES 23

3. TROUBLE SHOOTING 25 3.1 DC-DC CONVERTER 25 3.2 FLASHER LIGHT 28

4. DO’S AND DON’TS 31

4.1 DC-DC CONVERTER 31 4.2 TWIN BEAM HEADLIGHT 32 4.3 FLASHER LIGHT 33

ANNEXURE I 34

ANNEXURE II 37

CONTENTS



6

ISSUE OF CORRECTION SLIP

The correction slips to be issued in future for this handbook will be numbered as follows: CAMTECH/E/2007/HLFL/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. and Item no. modified

Remarks

CAMTECH/2007/E/HLFL/1.0 11


CHAPTER 1

GENERAL DESCRIPTION

The electric locomotive is equipped with various major and minor components but their role is equally important. It is necessary that they should function properly because reliability of locomotive affected with the failure of any component whether it is major or minor. Head light and flasher light are the safety equipment provided in front of locomotive at each end. Head light illuminates front track ahead at nighttime or even at daytime when train passes through dark places e.g. tunnels etc.. It facilitates for driver to have good visibility to look for any obstruction or any abnormality on track. Accordingly driver can take necessary action for ensuring safe and efficient operation of the train.

To achieve higher illumination at lower power and to eliminate dependency on non-saturated single beam 32V, 250W incandescent head light lamp had been eliminated by twin beam 24V, 100/90W twin filament halogen lamp headlight.

Figure 1.1 Twin Beam Head Light



2

This headlight has two separate sets of reflector and halogen lamp arranged in one casing. Both lamps are connected in parallel so that in case of failure of one lamp other will still be glowing. This system has been provided with 110V DC to 24V DC, 400W, DC – DC converter connected from loco battery to feed power to twin beam head light. The head light beams are of pre-focused type with totally enclosed construction complete with reflector, lamp holder terminals and front glass etc.. The great advantage of this system is that headlight will always be available even in the neutral zone.

The provision of flasher light in locomotive has great significance from both the safety and operating point of view. It attracts the attention of driver of approaching train on the adjacent track and indicates him to be cautious and stop train in the event of any unsafe track conditions. The flasher light should be clearly visible on straight track of at least 2 kms. both during day or night. The conventional flasher light unit has been replaced with adoption of LED based flasher light unit.

These measures improve the reliability of

locomotive on line on account of working of head light as well as flasher light and also ensure safe operation.

Figure 1.2 Conventional & LED Based Flasher Lights



3

1.1 TWIN BEAM HEAD LIGHT

The twin beam head light assembly consists of the following components:

1.1.1 Parabolic shaped fabricated MS casing with toughened

glass front cover housing.

470

20 x 8mm Rubber Gasket

410

22.5° 22.5°

6-nos. 6 Holes

8-Nos. 8 Holes

235

215

470

at 450 P.C.D.

48°

48°

4

Figure 1.3 Head Light Mounting Plate



4

1.1.2 24V twin filament halogen lamp. 100W for bright operation and 90W for dim operation.

1.1.3 Reflector with spring loaded lamp holder and 3 way

input terminal having beam alignment facility.

Figure 1.4 24V Twin filament halogen lamp

Figure 1.5 Reflector with spring loaded lamp holder



5

1.1.4 Back cover having locking arrangement, which can be opened from inside the loco.

Details of Figure 1.6

1. 6-Nos. Nurled nut for beam alignment.

4. Two nos. spare halogen bulbs.

2. 4 mm sq bulb connectors. 5. Spare bulb holding plate

6. Back cover lock 3. 3 Way stud type BMC terminal strip C. Common, D. Dim filament B. Bright filament

7. Back cover.

Figure 1.6 Back View of Headlight

215

405

1

1 1

1

2 1

1

4

5

6

3

7

C D B



6

1.1.5 DC-DC Converter

DC-DC Converter is an electronic equipment connected to the 110V DC loco battery to deliver 24V DC, 400W power to the twin beam headlight (2 x 100W). It consists of two nos. 400W converters selectable through a change over switch. These converters are identical to each other and PWM controlled through very high speed MOSFET switching. It is naturally cooled equipment. Further, a complete stand by unit is also housed inside the same cabinet for necessary back up in case of any failure. (Operation by change over switch mounted in front of the DC- DC converter unit).

Figure 1.7 DC- DC Converters



7

Fig

ure

1.8

Blo

ck D

iagr

am o

f DC

-DC

Con

vert

er

INP

UT

110V

DC

OU

TP

UT

24 V

DC

0.1

mfd

HR

C 1

6AC

HO

KE

CO

NV

ER

TE

RI

CO

NV

ER

TE

R

II

CH

OK

E

1200

/200

1200

/200

HR

C 1

6A

F2

F1

Sw

-1

0.1

mfd

0.1

mfd

Sw

-II

0.1

mfd



8

Figure 1.9

Wiring Diagram Between DC – DC Converter to Twin Beam Light

FROM BATTERY (+)

110V DCFROM BATTERY (-)

16A MCB

INPUT 003

DC TO DCCONVERTER

258242BD SBCAB2

20

18BL2

231

BLPRD 2

BLPRF 2

BLPRR-2

233

234

232

(-)

BLPRD 1

BLPRF 1

BLPRR-1

SBCAB1

24

18BL1

231

234

233 232

245244

BRIGHT

100/9024V

DIM

COMMON

SBCAB1

B-

258PR1

TWIN BEAM HEAD LIGHT

100/9024V

BRIGHT

100/90 DIM

24V

COMMONSBCAB2

B-258TWIN BEAM HEAD LIGHT

PR2

24V100/90

8



9

1.2 FLASHER LIGHT

The flasher light unit consists of the following components:

1.2.1 Lamp Unit

The lamp unit is a cluster of 120 high intensity LEDs equally distributed in rounded profile.

The lamp unit assembly consists of current regulator, waterproof fitting, window toughened front glass and hood protection against glare. All the LEDs are arranged in such a way in series parallel circuits that average forward current and peak forward current through these LEDs is limited to 20 mA and 30mA respectively. The LEDs of each circuit are intermixed such that working of the unit as well as radiated area is not affected in case of failure of LEDs (not more than 20%).

Figure 1.10 Card profile of Flasher Light

Figure 1.11 LED Type Flasher Light



10

1.2.2 Control Unit

It consists of two independent electronic circuits i.e. main circuit and standby circuit. This unit drives lamp unit according to mode of selection. It provides adequate protections, ON/OFF switch, studs for terminal connections and selector switch for main and standby circuit. It has flash rate 35 to 45 flash per minute. It also facilitates repeater LED indication (red colour) and audio sound in the driver cabs.

Figure 1.12 Flasher Light Control Unit



11

F

igur

e 1.

13

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ng D

iagr

am o

f LE

D F

lash

er L

ight

Con

trol

Uni

t

PO

WE

R O

NR

ED

LE

D

SP

DT

SW

ITC

H-1

SP

DT

SW

ITC

H-2

FU

SE

-2

FU

SE

-1

I/PO

KO

/PO

KS

PA

RE

FLC

U C

AR

D-2

ST

D B

Y

DU

AL

CO

LOU

RLE

D-2

TO

BU

Z 2

MA

IN

DU

AL

CO

LOU

R

LED

-1

TO

BU

Z 1

FLC

U C

AR

D-1

- Ve + Ve110V 1/P 110V O/P

-Ve + F1FLASHER

Cab+

+Ve

-Ve

+

BUZ

R--VeGO/P+

-

TRANSFORMER 1 TRANSFORMER 2

AUTO

+

R-BUZ

-VeG

-

-Ve

+Ve



12

1.3 TECHNICAL DATA 1.3.1 DC-DC Converter for Twin Beam head Light

SN Parameter Standard Value

1. Input voltage 70V - 140V DC (Nominal 110V DC)

2. Input ripple Up to 30% peak to peak

3. Output voltage 24V – 26VDC

4. Load capacity 400W continuous at 24V output

i. 200W (2 x 100W) halogen lamps.

ii. 180W (2 x 90W) halogen lamps.

5. Efficiency More than 85% at 110V input and 400W load.

6. Insulation resistance

More than 5 MΩ measured with a 500V megger.

7. Dielectric strength

1.5 kV max. between any of the terminals and the casing for one minute.

8. Ambient temperature

0 -70°C continuous.

9. Short circuit Output current limited to 20A max.

10. Over voltage Tripped beyond 145V

11. Under voltage Tripped below 66V input



13

1.3.2 Flasher Light

SN Parameter Standard Value

1. System voltage Max. 136V

Normal 110V

Min. 70V

2. Current regulation More than 5% at 110V DC

3. Type of LED HLMP

4. Radiating area Not more than 50 cm2

5. Lux in axial direction Not less than 500 lux at 1 meter and 55 lux at 3 meters.

6. Diameter of display area lamp unit

140 ± 5 mm

Dimensions (Approx.) in mm

H W L

a. Control unit 75 100 175

b. Lamp hood 285 260 215

7.

c. Lamp unit 210 210 130



14

CHAPTER 2

MAINTENANCE 2.1 PERIODIC SCHEDULES (IA, IB, IC) 2.1.1 Twin beam head Light

1. Visually check and ensure that bulbs filaments are in good condition and fitment of bulb in beam.

2. Clean the twin beam headlight glass. If replacement

is required, mount the front glass with gasket and bird guard.

3. Keep the nuts & bolts properly tightened of

headlight. 4. Clean the reflector and ensure that it is in good

condition. Replace if required. Ensure headlight focusing.

5. Check the bulb holders/connector for tight grip.

Replace if required.

6. Check SB connections.

7. Replace connector for halogen lamp and bulbs irrespective of condition of bulb during major schedule.



15

2.1.2 DC-DC converter

1. Check tightness of foundation bolts. 2. Clean and check tightness of all connections. 3. Confirm that the input (i.e. left hand side) terminals

are powered from loco battery and the output (i.e. right hand side) terminals are used for headlight connection.

4. Check fuses and condensers during IC. If found

defective, replace following and wire them as per wiring diagram:

a. Power card

b. Control card

c. MOSFET card

2.1.3 Flasher Light 1. Clean and check the lamp front glass. Replace if

required. 2. Tighten all nuts & bolts of the lamp unit properly. 3. Check flasher light hood for proper fitment. Also

check condition of gasket. 4. Check tightness of foundation of control unit 5. Check for loose connection of flash unit and

control unit in SB and at terminals.



16

6. Physically check switch fuse and control unit for any abnormality. If found defective, replace following and wire them as per wiring diagram:

a. Buzzer b. Control Card c. Fuse

7. Check and ensure correct rating of spare fuses provided.

8. Replace lamp unit if partial LEDs are not glowing.

9. Confirm that the input (i.e. Left hand side) terminals

are powered from loco battery and the output (i.e. right hand side) terminals are used for lamp unit.

10. Check the nylon cap of the switch. If missing put

new cap. It saves switch from dust & moisture & help to prolonged operation from it.

2.2 INSTALLATION OF HEAD LIGHT

i. Fit Headlight from outside of the loco with its topside upwards. This is essential because in DIM position the light from the headlight will come close and in bright position the light will go a long distance (305 meters).

ii. Connect the three way terminal of the head light

using 4mm sq. wire crimped with 6mm round lugs.

iii. Connect the battery to the input of the DC-DC converter via a switch. Keep converter switch in converter-I position and switch on the battery.



17

If the input polarity is correct and the battery voltage is more than 45V DC the red LED marked INPUT will glow and the green LED marked OUTPUT will also glow in converter.

iv. Now change the converter switch to converter-II

position. Both input & output LED’s of converter-II will glow. This confirms the healthiness of the converter.

v. Measure the output voltage at the output terminal

of the converter. It should be 25.5V ± 1% DC.

vi. Now measure the voltage on the headlight terminals. There will be some drop in voltage depending upon the thickness of the wire due to DC supply. Make sure that the headlight voltage is 24.5V to get 4800 lux at a distance of 8 meters.

2.3 TWIN BEAM ADJUSTMENT OF HEAD LIGHT 2.3.1 Procedure

1. Mount the headlight on test fixture. 2. Set the target board at a distance of 8m from

fixture on its longitudinal axis. 3. Give power supply through DC-DC converter to

headlight and target the twin beam at the target board.

4. If the longitudinal axis of the headlight is matched with the centre of the target board then the picks of the individual beams shall coincide with the respective centre marked at 92.5mm on



18

left and right of the target board centre. In the event the same is not found, then do the following :-

a. Target the beam on the left centre of the target board by adjusting screws of left beam.

b. Target the beam on the right centre of the target board by adjusting screws of right beam.

In the event the two beams centre are equally displaced from the center of target board.

5. Adjust focus by loosing and tightening the focus adjusting screws.

2.3.2 Beam axis adjustment

Both beams should meet at the distance of 305 meter on track i.e. at ground level. Therefore decline the beam with respect to the locomotive axis required. The beam of light should fall below 98mm for WAG-7 & 57mm for WAP-4 locomotive at a distance 8.0 mtrs. from headlight with respect to the mounting arrangement as per figure 2.1.



19

At the distance of 8.0 meter from headlight

beams should make gap of 18.50cm as per figure 2.2.

Figure 2.2 Gap between two beams

Figure 2.1 Focusing of headlight

8 mtrs

X

Where X = 98mm for WAG 7 loco = 57mm for WAP 4 loco

Rail level

Headlight Focusing board

Rail level

8 mtrs

18.5cm

Focusing board

19cm

BEAM 1

BEAM 2



20

2.4 TESTING OF DC-DC CONVERTER

1. Connect power supply at 110V DC to the input terminals of the converter.

2. Switch on converter and check O/P of converter to be between 24-26 volts.

3. Connect load to the converter and observe that output remain 24 - 26 volts.

4. Vary input voltage between 70V to 140V. Observe that O/P remains regulated at 24 to 26 volts within 1%.

5. Reduce the input voltage below 70V on load, the converter should cut-off between 60-70V.

6. Increase voltage gradually above 140V. The over voltage trip should operate at 140V to 145V DC and output become zero volt.

7. Load testing of converter with twin beam headlight to be done for 8 hrs on test bench.

2.5 PRECAUTIONS DURING MAINTENANCE 2.5.1 Marking for Beam Fitting

i. The dim position of both beams should be in top direction.

ii. The position of clamp must be under clamp holder.

iii. Since the beams are mounted with spring load/ clamp therefore these should be fully tightened to provide maximum tension.



21

2.5.2 Beam Plate Fitting in Cabinet

a. Beam plate should be fitted in such a way that the dim position of the bulb should be towards connector side or upper side.

b. It should be fitted in the cabinet with big steel plane washer, hard spring and steel bolts.

c. Steel bolts should be tightened equally and beam axis should be checked and aligned with respect to the locomotive after tightening of the warranty plate bolts.

d. Apply pressure on the beam plate from front side to check tension of spring-loaded bolts. There should no undue play. The bolts should be kept as tight as possible while maintaining twin beam alignment with respect to loco axis.

2.5.3 Connectors Fitting

a. Connector should be fully tightened with steel nuts, bolts and spring washers.

b. Dim position thimbles should be in centre position of the connector, common thimbles towards knurled bolts side and bright thimbles should be at the upper side of the cabinet.

c. The bulb connector should be snugly fit with the bulb pins.



22

2.5.4 Bulb Fitting

a. Bulb should fit snugly in the reflector.

b. The bulb locking spring holder should not be bent.

c. Do not touch bulbs glass portion it will reduce bulb life & light.

2.5.5 Glass Frame Assembly

a. Face toughened glass should be cleaned properly from inside and outside.

b. Face toughened glass should be attached with aluminium frame using glass-bounding solution such that there should be no gap between glass and frame.

c. The unevenness of the joint should be sealed.

d. Gasket should be stuck with fevicol at outer and inner collar of glass frame.

e. The gasket of outer collar should be drilled with 6mm holes.

2.6 INSTALLATION OF FLASHER LIGHT

Flasher light contains two units i.e. lamp unit & control unit. The lamp unit is mounted outside on the loco where as the control unit is placed in the driver’s cab. Connect power supply 110V DC to the input positive/ negative terminals of the monitoring control panel and connect positive terminals of the lamp unit to positive ‘F’ terminals of monitoring control panel. Negative terminal of the lamp and monitoring panel is common. Power supply voltage ripple on load should be less than 15%. Flasher should have flash rate 35 to 45 per minute as well as the audio & visual indication.



23

2.7 LIST OF SPARES 2.7.1 Twin Beam Head Light

SN ITEM QTY

1. Double filament bulb 4

2. Bulb holder 2

3. Beam 2

4. Gasket front cover 1

5. Front glass assembly 1

6. DMC connector 1

7. Beam connector with PTFE wire 1

8. Spare bulb wire clamp 2

9. Reflector 2 2.7.2 DC-DC Converter

SN ITEM QTY

1. Input connector, 3 pin 1

2. Output connector, 2 pin 1

3. Nylon insulated bar 2

4. AC filter capacitor 2

5. DC filter capacitor 2

6. LED indicator 4



24

SN ITEM QTY

7. Input power filter capacitor 2

8. Output power filter capacitor 2

9. Power card 2

10. Control card 2

11. Fuse 2

12. Fuse holder 2

13. Metal oxide varistor 2

14. MOSFETS 8

15. Zener regulator 4

16. Switching diodes 6

17. Double diodes 2

18. Transistor 2

19. DPDT switch 1



25

CHAPTER 3

TROUBLE SHOOTING 3.1 DC-DC CONVERTER AND HEAD LIGHT

S. No.

Fault Rported

Reasons for failure

Remedy

Converter fuse blown.

Replace fuse with a new one of rated value. If fuse blows again then check MOV.

1 Zero output

Capacitor 220 mfd/ 25V defective.

Replace the capacitor with new one.

Burnt out tracks Disconnected box or electrolytic capacitor. Blown out other components & connections.

Open the unit and check out for burnt out tracks, blown out components and connections. Replace defective component and ensure healthiness of the unit.

Dry solder Clean old solder and re-solder properly.

2. Output voltage is low.

Transistor KA 431 defective.

Replace the same.



26

S. No.

Fault Rported

Reasons for failure

Remedy

I/P LED does not glow.

Input is not connected properly.

Check the I/p fuse and replace if required.

3.

If the input is OK but O/P is not present.

Converter may be defective.

Check voltage at I/P & O/P terminals of the converter. Apply power after checking circuit operation. If the fuse blows again and problem persists, the card may be faulty. Change converter from main to standby through change over switch.

4. Output voltage is normal 25V without load but goes down on load.

Output capacitor 2200 mfd/35V open circuited. One of the outputs MOSFET may be defective.

Replace capacitor 2200 mfd/35V and provide sealing on PCB side. Change both MOSFETs of output.



27

S. No.

Fault Rported

Reasons for failure

Remedy

5. Input fuse blows rapidly.

MOV shorted Capacitor C3 shorted, or output MOSFET shorted, due to wrong wiring.

1. Replace MOV, Capacitor C3

2. Check wiring according to wiring diagram.

Output capacitor 2200 mfd, 35V defective.

Replace the same.

Holder tips overheated or thin tips.

Quality of holder material and tips may be improved.

6. Head light flickering continuously.

Bulb loose fitting in reflector.

Reflector should have proper groove.



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3.2 FLASHER LIGHT

S. No.

Fault Rported

Reasons for failure

Remedy

1. Zero output

Fuse blown in the input of the control unit.

Replace the fuse of rated value.

2. In lamp unit 20% LED not blowing

Shunt resistance (820 KΩ) of LED or transistor 940 may be failed.

Replace with new lamp unit.

Wire dries soldering.

Ignore dry soldering

3. LED not working.

Lamp PCB defective.

Replace and box to be sealed properly to avoid ingress of moisture.

Control unit PCB defective.


Supply not available

Check supply on output terminal of control unit or input of lamp unit.

4. Flasher light not working.

Lamp unit fuse blown or loose.

Check fuse condition.



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S. No.

Fault Rported

Reasons for failure

Remedy

Fuse holder defective.

Quality of the material to be improved.

Flasher control unit main & stand by fuse blown or loose.


Wrong connection on lamp or control unit.

Check connection for proper polarity.

On/Off switch defective.

Check on/off switch condition.

Loose connection on lamp or control unit.

Check looseness of wires.

Lamp PCB defective.

Check PCB for any component burnt or defective.

5. Standby not working

Position switch may be defective

Ensure switch position. Replace switch with good quality.

Main stand by mode fuse blown/ loose.




30

S. No.

Fault Rported

Reasons for failure

Remedy

Control unit PCB defective.


Internal wires dry solder.

Clean old solder and re-solder properly.

Speaker defective.

Check the speaker function.

PCB defective. Replace PCB.

6. Speaker sound dull.

Internal wires dry solder

Clean old solder and re-solder properly.



31

CHAPTER 4

DO’S AND DON’TS 4.1 DC-DC CONVERTER 4.1.1 Do’s

1. Ensure connections as marked on the equipment.

2. Check converter’s output 24 to 26V by digital voltmeter.

3. Check protection system functioning properly.

4. Use 25V soldering iron at the time of maintenance of control/ power cards.

5. Avoid finger touch to MOSFET pins.

6. Return the bulb negative connection to DC-DC converter otherwise bulbs can fuse under check/ loose connection.

4.1.2 Don’t

1. Don’t connect wrong connection to input/ output terminals.

2. Don’t connect input/ output at switch ON position.

3. Don’t give input higher than 198V DC.

4. Do not use unfiltered/ unregulated power supplies.

5. Do not replace head light bulb keeping DC-DC converter switched ON.



32

4.2 TWIN BEAM HEADLIGHT 4.2.1 Do’s

1. Test headlight giving input through DC-DC converter only.

2. Always clean front glass with soft cloth/ fish bone powder.

3. Insert bulb with reflector in correct position. Verify through filament for 100W/90W.

4. Lock bulb through spring clamp holder properly.

5. Check focus before final installation on loco.

6. Adjust focusing through provided spring loaded screws.

7. Return the ground (negative) to DC-DC converter.

4.2.2 Don’t

1. Don’t try to test headlight without DC-DC converter.

2. Don’t give input 110V DC directly to headlight.

3. Don’t insert bulb in wrong position. It may get defocused.

4. Don’t keep loose bulbs.

5. Don’t install the headlight on loco without checking focus.

6. Don’t try to adjust focus through bulb.

7. Don’t keep loose back covers.

8. Don’t keep the front glass dirty.



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4.3 FLASHER LIGHT 4.3.1 Do’s

1. Connect 110V DC power supply to FLCU right polarity.

2. Connect lamp unit only with flashing mode with FLCU O/P as per wiring diagram.

3. Conduct lux test after 5 minutes of operation.

4. Tight all terminals screws properly.

5. Conduct over voltage test on 198V DC for two minutes only.

6. Tight fuse cap properly after replacing fuse.

7. Fit terminal cover properly after wiring schedule maintenance.

4.3.2 Don’ts

1. Don’t use DC power supply with ripple.

2. Don’t leave loose connections of terminals.

3. Don’t check lamp unit without control unit.

4. Don’t use AC voltage at flasher light system.

5. Do not overshoot the 1-0-2 position of rotary switch.

6. Don’t use non-standard rated fuse.



34

ANNEXURE I

PROBLEMS RAISED DURING SEMINAR HELD ON 25.08.2006 AT CAMTECH, GWALIOR BY VARIOUS

ELECTRIC LOCO SHEDS/ WORKSHOPS. S.N. Description Suggestions A. HEAD LIGHT PROBLEMS – MATSUSHI MAKE

1. There is no proper approach for adjusting the focus for the head light on WAP/WAG7 locos where headlight is mounted in the middle of the cab.

Either head light to be mounted on top or provision to be made from inside the cab.

2. Head light unit focusing is difficult from front side, as glass cover has to be removed for focusing.

Arrangement should be done similar to the SIGNOTRON make head light where the focus adjustment can be made from rear of the headlight.

3. Interchangeability of the various parts from MATSUSHI to SIGNOTRON not possible due to variations in the dimensions and fixing arrangement.

Drawing of the part should be made similar to avoid the same.

4. Reflector polish quality is poor since faded up during short period.

Quality of reflector polish should be improved.

5. Reflector should have proper groove for lamp holder to avoid loose fitting.

Proper groove arrangement to be made.



35

S.N. Description Suggestions 6. Headlight mounting plate bolt

getting slacked/free may be due to poor material.

Mounting plate material to be improved.

7. Unusual sound from PCB card of DC-DC converter.

Matter to be studied.

8. MOV burning repeatedly. Matter to be studied.

9. Input output MOSFETS are getting defective frequently.

Their rating may be improved.

B. HEAD LIGHT SIGNOTRON - MAKE

1. Quality of switch on DC-DC converter and head light lamp holder is poor. (Nylon)

Bakelite holder may be provided as in MATSUSHI

2. Provision of over voltage protection on O/P side in DC-DC converter should be done to avoid failure of bulbs as suggested by ELS/BZA.

Modification carried out by ELS/BZA/SCR may be tried. (Refer Annexure-II)

3. Unusual sound from PCB card of DC-DC converter.

Matter to be studied.

4. MOV burning repeatedly. Matter to be studied.

5. Input output MOSFETS are getting defective frequently.

Their rating may be improved.

6. Input diode terminals rubbing against the body.

Their location may be changed.



36

S.N. Description Suggestions

C. FLASHER LIGHT

1. Replacement of flasher light lamp unit PCB card requires removal of complete lamp unit which is impossible without placing loco on maintenance pit, isolation of OHE and also require fixing and sealing of lamp unit.

This PCB card should have self-locking or sliding type provision of fitment. This modification will not only save replacement time, man power but also improve reliability



37

ANNEXURE II

MODIFICATION CARRIED OUT BY ELS/BZA/SCR Modification on PCB of DC DC converter for over voltage protection to head light lamp in output circuit to avoid failure of head light in case of short circuiting of MOSFET. Rating of the components used are as under: S.No. Component Rating Type 1. PCB FR4 Glass epoxy

(green)

2. SCR 16A TYN 616

3. Resistor (Preset) 100 KΩ ± 5%, 0.5 W Carbon film 4. Fixed resistor 100Ω ± 5%, 0.25 W Carbon film 5. Zener Diode 33V IN4AC33PH

6. Capacitor 2200mfd, 35V --

CIRCUIT DESCRIPTION

FUSE +Ve

FROM DC-DC CONVERTER

BULB LOAD

- Ve

Existing Circuit



38

Modified Circuit

Whenever output voltage shoots up due to MOSFET

failure, the same will exceed the Zener knee voltage (33V) resulting in puncture of Zener junction due to which the Zener develops SCR’s gate trigger voltage (30V) with the help of preset threshold resistor. This causes turning ‘ON’ of SCR resulting in flow of short circuiting current through the output of DC-DC Converter and isolate the HL lamp load.

With the above circuitry modification, the drivers can easily changeover to standby mode during short-circuiting of MOSFETs in DC DC Converters without changing any HL lamps.

FROM OUTPUT OF DC-DC CONVERTER

ZENER DIODE 100 Ω 0.25w

10KΩ PRESET

10A CHANGE OVER SWITCH 10A 33V

A

G

K

TYN 616 15A SCR

2200 MFD 35V

BULB LOAD

- VE

+ VE



39

REFERENCES

1. RDSO specification No. TBHL-ELRS/ SPEC/ PR/

0024, Sep.04 (Rev.1) 2. RDSO specification No.ELRS/SPEC/DC-DC

Converter/ 0021 Rev. 1, Sep. 2004 3. RDSO Specification No. ELRS/SPEC/LFL/0017

(Rev. – 1, Sep. 2004) 4. OEM of M/s Matsushi Power Technologies M/s

Signotron (India) 5. Field study conducted at various electric loco sheds. 6. presentation by various participants during seminar

held at CAMTECH on dt. 25.08.06.

*****



40

If you have any suggestions and specific comments please write to us.

Contact person Director Electrical

Postal address Indian Railways

Centre for Advanced Maintenance Technology, Maharajpur, Gwalior,

Pin Code - 474 005

Phone 0751 – 2470740

0751 – 2470803

Fax 0751 - 2470841

To upgrade maintenance technologies and methodologies and achieve improvement in productivity, performance of all Railway assets and manpower which inter-alia would cover reliability, availability, utilisation and efficiency.

OUR OBJECTIVE

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