ELECTRIC LOCO SHED LUDHIANA PUNJAB

1. SIX WEEK INDUSTRIAL TRAINING REPORT
(22 JULY 2022 – 31 AUGUST 2022)
ON
ELECTRIC LOCOMOTIVE SHED, LUDHIANA
Submitted in partial fulfilment of the
Requirement for the award of the degree
Of
Bachelor of Technology
Electronics and Electrical Engineering
Submitted By: -
Harsh Kumar Shrivastav (2121914)
GULZAR GROUP OF INSTITUTES, KHANNA
I.K. GUJRAL PUNJAB TECHNICAL UNIVERSITY,
JALANDHAR

2. CANDIDATE’S DECLARATION AND CERTIFICATE
This is to certify that the SIX WEEK INDUSTRIAL TRAINING Report that is
being submitted by the following members: ~
Harsh kumar Shrivastav (2121914)
is in partial fulfilment of the requirements for the award of Bachelor of
Technology, is a record of bonafide work done under my guidance. The contents of
this project work, in full or in parts, have neither been taken from any other source
nor have been submitted to any other Institute or University for award of any
degree
Candidate’s Signature
This is to certify that the above statement made by the candidate is correct on the
best of my knowledge and belief
Signature of HOD Signature of Supervisor
HOD Name Supervisor Name
Date

3. We declare that this written submission represents our ideas in
our own words and where Others’ ideas or words have been
included. We have adequately cited and referenced the original
sources. We also declare that we have adhered to all principles
of academic honesty and integrity and have not misrepresented
or fabricated or falsified any idea/data/fact/source in our
submission,
We understand that any violation of the above will be cause for
disciplinary action by the Institute and can also evoke penal
action from the sources which have thus not been properly cited
or from whom proper permission has not been taken when
needed
NAME ENROLLMENT
NUMBER
SIGNATURE
HARSH KUMAR
SHRIVASTAV
2121914

4. ACKNOWEDGMENT
It is our pleasure to acknowledge the contribution of all who have helped
us and supporting us during this project.
First we thank God for helping us in one way or another and providing
strength and Endurance to us. We wish to express my sincere gratitude
indebtedness to our supervisor, Er. Mohit Jambu (Electronics and
Electrical Engineering) ,Gulzar Group of Intuitions Khanna Punjab for
his intuitive and meticulous guidance and perpetual inspiration
completion a this report. In spite of his busy schedule. He rendered help
whenever needed, giving useful suggestions and holding informal
discussions. His invaluable guidance and support throughout this work
cannot be written down in few wools We also thank them for providing
facilities for my work in the Electronics and Electrical Engineering
department We are also humbly obliged by the support of our group
members and friends for their love and caring attitude, The sentimental
surmor1
they rendered to us is invaluable and everlasting. They have helped tot in
thick arid thin and enabled us to complete the work with joy mid vigor.
We thank the group members for entrusting in each other and following
directions, without them this report would never have been possible. We
also have thankful to our parents, elders and all family members for their
blessing, motivation and inspiration throughout our work mid bearing
with us even during stress and bad temper They have always provided us
a high moral support arid contributed in all possible ways in completion
of this capstone report.

5. ABSTRACT
The six weeks training is conducted by the institutions to increase the
practical experience of the student . the student should have to achieve as
more as he could from this training. This training is conducted during the
period from July 2022 to August2022. I had achieved the practical
experience about the electric loco shed during this period.
The D.E.E (director of electric Engg.) MR. Rachit Khanna allowed me to
do training from the ELECTRIC LOCO SHED , LUDHIANA. I have done
my training at electric loco motive shed Ludhiana. The whole staff pf the
loco shed is well qualified and experienced . they share their experience with
me during the training.

6. INDEX
SR .NO. Content PAGE NO.
▪ 1 INTRODUCTION 1
▪ 2 INDIAN RAILWAY, HISTORY 2
▪ 3 About the Locomotive shed & Block
Diagram
3-6
▪ 4 Components of locomotive 7-10
▪ 5 Electric power Supply 11-12
▪ 6 Abbreviations and Acronyms 13-19
▪ 7 AC Electric loco motive 20-21
▪ 8 Pantograph 22-24
▪ 9 Circuit Breaker 25
▪ 10 Batteries 26-27
▪ 11 Traction transformer 28-35
▪ 12 DC- Link 36
▪ 13 Camshaft 37
▪ 14 Relays 38-52
▪ 15 Dynamics braking 54
▪ 16 Resistance control 57
▪ 17 Wheel Spin 58
▪ 18 Shoes And Shoe gear 60-62
▪ 19 How to loco start 63-64
▪ 20 How to start loco charge 65

7. INTRODUCTION
● Locomotives in India consist of electric and diesel loco motives.
Loco motives are also called locos or engines
● An electric loco motive is a locomotive powered by electricity
from over head lines, on -board energy storage device such as a
chemical battery or fuel cell.
● Electricity is used to eliminate smoke and take advantages of the
high efficiency of electric motors.
INDIAN RAILWAY ELECTRICLOCOMOTIVE
WAG-9
In Indian railway electric locomotive WAG-9 was the new version of
the electric locomotive and it located in view states It is an important
railway junction connecting north India. We have Electric Locomotive
WAG-9 in LUDHIANA Loco Shed.
Figure-1 Indian railway electric locomotive WAG-9
Indian railway electric locomotive WAG-9 the picture was taken from
inside the electric locomotive shed
1

8. INDIAN RAILWAYS
Indian Railways (IR) is India's national railway system operated by the
Ministry of Railways. It manages the fourth largest railway network in
the world by size, with a route length of 67,368-kilometer (41,861 mi)
and total track length of 121,407-kilometre (75,439 mi) as of March
2017. Routes are electrified with 25 kV AC electric traction while thirty
three percent of them are double or multi-tracked. This locomotive is
referred to as the "Heavy Haul" freight locomotive of the Indian
Railways (IR).This locomotive was conceived owing to the extreme
growth in the rail freight transportation sector. The growth in this sector
is considered to be of great importance in the growth of the economy of
India. This need had arisen the need for more electrification and electric
locomotives in India. Around 60-65% of thefreight haulage of IR takes
place on the electrified section of the Golden Quadrilateral (Indian
Railways) & diagonals (which account for 25% of the route). These
routes are very busy routes, so clearance is a necessity. This power Give
it a great sectional clearance Ability. Thus these locomotives are
important for the Indian Railways.
HISTORY
The first railway proposals for India were made in Madras in 1832. The country's
first train,Red Hill Railway (built by Arthur Cotton to transport granite for road-
building), ran from RedHills to the Chintadripet bridge in Madras in 1837. In 1845,
the Godavari DamConstruction Railway was built by Cotton at Dowleswaram in
Rajahmundry, to supply stone forthe construction of a dam over the Godavari
River. In 1851, the Solani Aqueduct Railway wasbuilt by Proby Cautley in
Roorkee to transport construction materials for an aqueduct over the Solani River.
ndia's first passenger train, hauled by three steam locomotives (Sahib, Sindh and
Sultan), ran for 34 kilometres (21 mi) with 400 people in 14 carriages on 1,676 mm
(5 ft 6 in) broad gauge track between Bori Bunder (Mumbai) and Thane on 16
April 1853.Eastern India's first passenger train ran 24 miles (39 km) from Howrah,
near Kolkata, to Hoogly on 15 August 1854. The first passenger train in South
India 60 miles (97 km) from Royapuram- Veyasarapady (Madras) to
Wallajah Road (Arcot) on 1 July 1856.
2

9. ABOUT THE LOCOMOTIVE SHEDS
Each railway company had its own architectural design of engine shed
but there were three basic designs of shed. Engine sheds would carry
out basic maintenance and the bigger sheds would carry out more
complex repairs. Locomotives that required further repair were sent to
the company’s locomotive works. Withdrawn locomotives could often
be found at some depots before their final trips to the scrapyard.
Electric Loco Shed, Erode is one of the premiere engine sheds located
in Erode in the Indian state of Tamil Nadu. It is located along the
Jolarpettai-Shoranur line, about 1 km to the east of ErodeJunction, under
the administrative control of Salem railway division of Southern
Railway Zone.Being one of the three electric engine sheds in Southern
Railway, various major and minor maintenance schedules of electric
locomotives are carried out here. It has the sanctioned capacity of 175
engine units. Beyond the operating capacity, this shed houses a total of
199 engine units, including 100 WAP-4 and 96 WAG-7. It also housed a
few WAG-6 temporarily.[2]
Electric loco Shed, Erode is now housing the
largest fleet of WAP-4 in Indian Railways and it caters to many long
distance electric trains. In October 2017,Erode received first two 3-phase
AC locos of the class WAP-7. Currently holds 4 WAP-7 locomotives.
One of them was named Cauvery Along with the electric loco shed, the
diesel loco shed of Erode also maintains some electric locos.
2. Block Diagram of Electric Locomotive WAG-9
The block diagram was showing every part located in electric
locomotive WAG-9.
The parts names and Description are show in below the block
diagram (figure 2).
3

10. Figure-2-Block Diagram of modern AC Electric
Locomotive
In this figure-2 the parts are named and clearly indicates by
the arrow marks of block diagram modern AC electric
locomotive. There are:
 Main Transformer.
 Auxiliary Inverter.
 Auxiliary Rectifier.
 Axle brush.
 3-phase AC motor (total 4 motors).
 Motor blowers.
 Compressor.
 Cooling fans.
 Main rectifier.
 Circuit breaker.
 Pantograph.
 Main inverter.
4

11.  Main transformer
A transformer is a static electrical device that transfers
electrical energy between two or more circuits. A varying
current in one coil of the transformer.
 Auxiliary inverter
The Auxiliary Power Converter supplies the auxiliary AC-power
needs of the diesel-electric locomotive.
It charges also the batteries. The unit is installed inside the
locomotive. The unit enables use of maintenance free AC-motors for
the auxiliary drives.
 Auxiliary rectifier
Power from the motor comes from the on-board electrical supply or,
sometimes, directly from the traction supply.
On electric locomotives, the supply can come from the
transformer, via a rectifier and on a diesel locomotive, from the
auxiliary alternator.
 Axis brush
A brush or carbon brush is a device which conducts current between
stationary wires and moving parts, most commonly in a rotating shaft.
Typical applications include electric motors, alternators and electric
generators.
 3-phase AC motors
A traction motor is an electric motor used for propulsion of a vehicle,
such as an electric locomotive. An AC induction motor only
generates useful amounts of power over usually, the traction motor is
three-point suspended between the bogie, Air cooling, Electric vehicle
battery. Induction motor & Three-phase AC.
 Motor blowers
An electric locomotive consists of various equipment.
Traction motor cooling blower and its motor is one of the
important auxiliary machine.
5

12. There are two traction motor cooling blowers fitted in a locomotive.
Each for cooling of one group of three traction motors.
 Compressor
The compressor itself consists of a pump driven by an electric motor.
Cooling fans
Locomotive radiators keep engines cool. The radiator system is
intended to keep the engine operating at nearly the same temperature,
regardless of the ambient air outside the locomotive.
 Main rectifier
Rectifier, A converter consisting of thyristors and diodes which is
used to convert AC to DC. A modern locomotive will usually have at
least two, a "Main Rectifier" for the power circuits and one or more
for the auxiliary circuits. Relay a remotely controlled switch which
uses a low voltage control circuit.
 Circuit breaker
An electric train is almost always provided with some sort of
circuit breaker to isolate the power supply when there is a
fault, or for maintenance. On AC systems they are usually on
the roof near the pantograph. There are two types - the air
blast circuit breaker and the vacuum circuit breaker or VCB.
 Pantograph
A pantograph is an apparatus mounted on the roof of an electric train,
tram or electric bus to collect power through contact with an overhead
line. It is a common type of current collector. Typically, a single or
double wire is used, with the return current running through the track.
 Main inverter
An electric locomotive is a locomotive powered by electricity from
overhead lines, a third rail or on-board energy storage such as a
battery or a super capacitor. Newer electric locomotives use AC
motor-inverter drive systems that provide for regenerative braking.
6

13. 3. Components of Electric Locomotive WAG-9
In this Table-1,we are showing electric locomotive WAG-9
components and weight as well as units, volume, electric components
and mechanical components are clearly mention below. The
components are taken and the weights are calculated, units are taken,
Volume are approximately And also electric and mechanical
components are taken, the values are calculated accurately and the
Volume are approximately.
Components
Weight
[t]
Numbers Total
weight
[t]
Volume
(Approx.)
[m3]
Electrical Mechanical
Traction
motor 2.3 6 13.8
0.9 yes
Yes
Transformer
10.4 1 10.4
3.7 yes
Pantograph
0.8 1 0.8
1.5 yes
Sandboxes
0.05 1 0.05
0.4
Yes
Auxiliary
reservoir 0.1 1 0.1
1
Yes
Main
reservoir 0.3 1 0.3
1.1
Yes
Filter cubicle
0.4 1 0.4
1.2
Yes

14. Oil cooling
unit 1.0 1 1.0
1
Scavenge
blower to
machine
room blower
0.04 1
0.04
0.5
yes yes
Cubicle
auxiliary
circuits 1
0.2 1 0.2 0.4
yes
Cubicle
auxiliary
circuits 2
0.11 1 0.11
0.6
yes
Cubicle
control
circuits 1
0.17 1 0.17
0.7
yes
Cubicle
control 2 0.18 1 0.18 yes
Central
electronics 1 0.03 1 0.03
0.3
yes
Central
Electronics 2 0.03 1 0.03 yes

15. 2 HCBO-
605-
115 type
Traction
Motor
Blowers by
Flakt and
ABB
0.4 1 0.4
0.5
yes Yes
2 2A3200
C13-T32
type
Main
Compressors
by D&M
0.6
1
0.6
0.4
yes Yes
2 HCBO-
415-
60 type
Machine
Room
Blowers by
Flakt and
ABB
0.1
1
0.1 yes Yes
FF 3145
type
Auxiliary
Compressor
by D&M
and
Bristol
0.05 1 0.05
0.4
yes Yes

16. Scavenge
blower to
traction
motor
blower
0.04
1 0.04
0.3
yes Yes
General
coach 49 1 49
5
Wheels
1 8 8
0.5
yes
Total 87.8
Components of electric locomotive WAG-9 From Table-1,
this all are the components, weight, units, volume and
electric & mechanical components, and the total electric
locomotive WAG-9 weight was 88t
4. Electric Power Supply to WAG-9
In this Table-2, we are showing the electric power supply to
WAG-9, the electric power produce to the components and as
well as the units are mention below the table-2.
Electric locomotive WAG 9 power Supply

17. Components Power produce Units
Traction motor 850 kW
Transformer 1000 Voltage
2 power drives 2800 Voltage
Transformer oil
Pump motor 415 Voltage
Main compressor motor
415 Voltage
Auxiliary converter by ABB
415 Voltage
Blower motor 415 Voltage

18. Heater capacity 2.2 kW
INDIAN RAILWAYS WAG LOCOMOTIVE
This manual is created by ALSTOM INDIA LTD. and it provides the
information required for the operation and maintenance of the WAG12
electric locomotives. The operation manual consists of all essential
locomotive information required for the operator. This manual includes
technical data, locomotive operation, major equipment locations,
safety standards, description and functions of the systems.
12

19. ABBREVIATIONS AND ACRONYMS
Acronym Description
AC Alternating Current
AHU Air Handling Unit
ALP Assistant Locomotive Pilot
BC Brake Cylinder
BCEP Brake Cylinder Equalizing Pressure
BP Brake Pipe
BRIO Basic Remote Input/Output Unit
BVR
Key Box (Boite Verrouillage) [Alstom
Terminology]
CCB Close Control Brake
CCR
Cab Cabinet Right
CFM Centralized Fleet Maintenance
CRS Consist Ring Switch
MR Main Reservoir
DC Direct Current
DDU Driver Display Unit
DER Dead Engine Regulator
DMI Driver Machine Interface
E Block Traction Block
EBV Electro Brake Valve
ECN Ethernet Consist Network
ED End Device
EDB Electric Dynamic Brake
ELS Electric Loco Shed
EMC Electro Magnetic Compatibility

20. EPCU Electro Pneumatic Control Unit
ETB Ethernet Train Backbone
FBS Functional Breakdown Structure
GELF Green Field Electric Loco Project
GSM Global System for Mobile
H(HT) High Voltage Disconnector
H(O-M) VCB Earthing Switch
HV High Voltage
HVAC Heating Ventilation and Air Conditioning
IFD
Insulated Fault Detection
IGBT Insulated Gate Bipolar Transistor
IOS Incorrect Operating Sequence
I/O Input/Output
LED Light Emitting Diode
LHD Linear Heat Detector
LP Locomotive Pilot
MPU Main Processing Unit (TCMS Equipment)
LV Low Voltage
MCB Miniature Circuit Breaker
MMI Man Machine Interface
MU Multiple Unit Operation
MV Medium Voltage
NC Normally Closed
NO Normally Open
OCC Operation control center
PB Parking Brake
PC Personal Computer
PER Back-up Pneumatic Cock

21. OHE Over-head Electric Cable
RIOM Remote Input/Output Module
Sr. DEE Sr Divisional Electrical Engineer
TLC Traction Loco Controller
TCMS
Train Control and Monitoring System
TCU Traction Control Unit
TE/BE Traction Effort/Braking Effort
TPWS Train Protection and Warning System
TRS Train Router Switch
UTM Unified Train Maintenance
UMB Ambala
VCB Vacuum Circuit Breaker
WAG Wide Gauge AC Goods
Z-sec High Voltage Disconnection Key Switch
WAG locomotive is composed of two sections (Section 1 and Section
2). Each section of the locomotive consists of two traction E-blocks
located inside the machine room which contains the power converters
for propulsion and auxiliaries. The locomotive is fed by a 25 kV AC, 50
Hz overhead catenary.
The following table provides the overall view of the main equipment
installed on each section of the locomotive.
Equipment
Quantity
Section 1 Section 2
Traction motor 4 4
Bogie 2 2

22. HVAC 1 1
Brake Unit 1 1
Pantograph 1 1
Surge arrester (Before Main Circuit
Breaker) 1 1
Potential transformer 1 1
Current transformer 1 1
3 Function Main Circuit Breaker 1 1
High voltage disconnector 1 1
Sectional current transformer 1 1
E-block 1 (with auxiliary converter) 1 1
E-block 2 1 1
HV cubicle 1 1
Main transformer 1 1
HV return current transformer 2 2
LV cubicle 1 1
Battery box 2 2
Brake panel 1 1
Main air supply unit 1 1
Automatic coupler 1 1
Equipment
Quantity
Section 1 Section 2

23. Draw bar 1 1
Gangway 1 1
Technical Specification
Traction Motors
Alstom TAO 659 (575 kW, 750 V, 1070 rpm)
or TAO 656; or Hitachi HS 15250A. Axle-
hung, nose-suspended. Six motors.
Gear Ratio
62:16 or 62:15 with Alstom motors, some
64:18 (Hitachi motors), many now 58:21 for
mixed use. There are also 17:77
Transformer
BHEL, type HETT-3900. 3900 kVA, 22.5
kV, 182 A. 32 taps, 11730 kg, Forced oil
cooling, 'A' Insulation.
Rectifiers
Silicon rectifiers (two) using 64 S-18FN-350
diodes each from Hind Rectifier. 2700 A /
1050 V per cubicle. 64 cells per bridge.
Starting current at 3300 A. Motor (380 V,
970-1460 RPM)

24. Max Haulage
capacity
2375 t (WAG-5 original)
Pantographs
Two Faiveley AM-12 of 285 kg with four
insulators
Current Ratings 1100 A / 10 min, 750 A continuous
Sandboxes 8
Auxiliaries
2 Head lights (32 V, 250 W), Lead-acid
Battery (50 cells, 110 V)
3 Elgi Compressors 3 motors (12.5 hp, 380 V)
2 SF India Ltd.
Traction Motor
blowers
MLBR-42.51-1-H4 type, 2 Siemens Motors
(22 kW, 380 V, 41 A, 3000 rpm)
2 SF India Ltd.
Smoothing reactor
blower
2 motors(3 hp, 380V, 2860rpm)
BHEL Breaking
resistor blower
Dy-3423M type, Moto r(532 kW, 70 hp, 325
V, 175 A, 3500 rpm)

25. 2 SF India Ltd.
Silicon rectifier
blower
Axial type
SF India Ltd. Oil
cooler blower
MLBH-60-1-H2 type, 22.2 m/hr, Motor
(30 hp, 380 V, 6.6 A, 2865 rpm)
2 Smoothing reactors
SL42 type, 1250 V, 950 A, 0.00718 ohms at
110 °C
BEST & Co. Pvt.
Ltd. Oil pump for
transformer
Motor (3.3 kW, 380 V, 6.6 A, 2865 rpm)

26. A.C. ELETCRIC LOCO MOTIVE
An electric locomotive is a locomotive powered by electricity from
overhead lines, a third rail or
on-board energy storage such as a battery or a supercapacitor.
Electric locomotives with on-board fueled prime movers, such as diesel
engines or gas turbines,
are classed as diesel-electric or gas turbine-electric and not as electric
locomotives, because the
electric generator/motor combination serves only as a power
transmission system.
Electric locomotives benefit from the high efficiency of electric motors,
often above 90% (not
including the inefficiency of generating the electricity). Additional
efficiency can be gained from
regenerative braking, which allows kinetic energy to be recovered
during braking to put power
back on the line. Newer electric locomotives use AC motor-inverter
drive systems that provide
for regenerative braking. Electric locomotives are quiet compared to
diesel locomotives since
there is no engine and exhaust noise and less mechanical noise. The lack
of reciprocating parts
means electric locomotives are easier on the track, reducing track
maintenance. Power plant
capacity is far greater than any individual locomotive uses, so electric
locomotives can have
20

27. higher power output than diesel locomotives and they can produce even
higher short-term surge power for fast acceleration.
Electric locomotives are ideal for commuter rail service with frequent
stops.
Electric locomotives are used on freight routes with consistently high
traffic volumes,
or in areas with advanced rail networks. Power plants,
even if they burn fossil fuels, are far cleaner than mobile sources such as
locomotive engines.
21

28. PANTOGRAPH
This is to be conducted on arrival on loco examination pit after making the OHE
dead by operating isolators and grounding the loco and placing earthing poles
on either sides of the loco.
a. Check the condition of high carbon strips for any breakage,
grooving, globules, loose fasteners and sharp edges.
b.Check the proper flexibility of pantograph.
c. Check all springs, pins and flexible shunts.
d.Check the articulation tubes, actuating rod eyelet and raising
springs for any abnormality.
e. Check HPT1 and HPT2 for proper fixation.
f. Check the panto base insulators, servomotor and pneumatic pipe
connection for any abnormality.
22
21

29. Direct Air operated Pantograph (Schunk make)
1. Direct air operated Pantograph have distinct advantages of light
weight, improved dynamic behaviour, practically maintenance
free operation over the conventional metallic spring operated
Pantographs.
2. The direct air operated Pantograph uses state of art air spring and
does away with more failure prone components such as servo
motor and the metallic spring of the conventional Pantograph.
3. Improved dynamic behaviour of air operated Pantograph also
results in better current collection.
OVER HEAD EQIUPMENT
This article is about the transmission of electrical power to road and rail
vehicles. For transmission of bulk electrical power to general
consumers, see Electric power transmission. For powerlines mounted on
pylons, see Overhead power line. For lines carrying information,see
Overhead cable.To achieve good high-speed current collection, it is
necessary to keep the contact wire geometry
23

30. within defined limits. This is usually achieved by
supporting the contact wire from a second wire known as
the messenger wire (in the US & Canada) or catenary (in
the UK). This wire approximates the natural path of a
wire strung between two points, a catenary curve, thus the
use of "catenary" to describe this wire or sometimes the
whole system. This wire is attached to the contact wire at
regular intervals by vertical wires known as "droppers" or
"drop wires". It is supported regularly at structures, by a
pulley, link or clamp. The whole system is then subjected
to mechanical tension. Depot areas tend to have only a
single wire and are known as "simple
24

31. equipment" or "trolley wire". When overhead line systems were
first conceived, good current collection was possible only at low speeds,
using a single wire. To enable higher speeds, two additional types of
equipment were developed. Earlier dropper wires provided physical
support of the contact wire without joining the catenary and contact
wires electrically. Modern systems use current-carrying droppers,
eliminating the need for separate wires.
Circuit breaker
An electric train is almost always
provided with some sort of circuit breaker to isolate the power supply
when there is a fault ,or for maintance. On ac system usually air blast
circuit breaker and the vaccum circuit breaker. The vcb is popular in the
UK and the air blast circuit breaker is more often seen on the continent
of Europe
25

32. BATTERY
A battery is a device consisting of one or more electrochemical cells with external
connections provided to power electrical devices such as flashlights, mobile
phones, and electric cars.When a battery is supplying electric power, its positive
terminal is the cathode and its negative terminal is the anode. The terminal marked
negative is the source of electrons that will flow through an external electric circuit
to the positive terminal. When a battery is connected to an external electric load, a
redox reaction converts high-energy reactants to lower-energy products, and the
free-energy difference is delivered to the external circuit as electrical
energy.Historically the term "battery" specifically referred to a device composed of
multiple cells, however the usage has evolved to include devices composed of a
single cell
Batteries convert chemical energy directly to electrical energy. In many cases, the
electrical energy released is the difference in the cohesive or bond energies of the
metals, oxides, or molecules undergoing the electrochemical reaction. For instance

33. energy can be stored in Zn or Li, which are high-energy metals because they
are not stabilized by d-electron bonding, unlike transition metals.
Batteries are designed such that the energetically favorable redox
reaction can occur only if electrons move through the external part of the
circuit
27

34. Traction transformers for locomotives
More than half the world’s electrical locomotives and train sets are powered
by ABB transformers, and the vast majority of the world’s train
manufacturers and rail operators rely on them. ABB's traction transformers
are integral to this capability. Their function is to transfer electric power from
the catenary to the motor by lowering the network’s high voltage to low
voltage for use by the converters. They have to compact, lightweight and
exceptionally reliable, as they are often a non-redundant traction
component.
Engineered for very harsh and demanding environments, the
transformers are designed to power heavy freight loads over long
distances of more than 1,000 km and on tracks with many challenges -
steep profiles, short curve radii, excessive wear, voltage drops in long
sections, and extreme low and high temperatures.
28
Electrical
o Power: 6,000 - 12,500 Kva,

35. o Network: 25 kV/50 Hz; 15 kV/16 2/3 Hz; 1.5 kV/DC; 3 kV 7
DC; 11 kV/16 2/3
o
o Hz; 12 kV/25 Hz; 12.5 kV/60 Hz; 25 kV/60 Hz
o
o Insulating fluid: ester or mineral
o
o Insulation class: A, Hybrid, F and H
Mechanical
o Weight: 6,000 - 15,000 kg
o
o Size (L x I x H): approx. 2.5 x 2 x 1 m and 4.5 x 2.5 x 1.5
m (under frame)
o
o Assembly on vehicle: under frame or machine room
o
o Tank material: aluminium, low and high temperature steel
Accessories: cooling system, pumps and oil flow indicator, oil
level detector,overpressure valve, PT100 for thermal control,
thermostat, filling and draining valves, relay Buchholz, current
measurement
29

36. AUXILIARY MACHINES AND EQIUPMENTS
Electric locos derive tractive effort from Traction Motors which are
usually placed in the bogie of the locomotive. Usually one motor is
provided per axle but in some older generation of locos two axles were
driven by a single Traction Motor also.A short description of the power
circuit of Electric Locos operational on the Indian Railways calbe seen
here. The article referred to describes the main components of the Power
Circuit of the Electric Locomotive comprising of the following
parts:Transformer Oil Circulating Pump (MPH)
30

37. The transformer tank is filled with oil which serves two purposes. It
provides enhanced insulation to the transformer and its surroundings and
the oil absorbs the heat generated inthe transformer and takes it away to
the Transformer Oil Cooling Radiator. The circulation of this oil is
carried out by the MPH. A flow valve with an electrical contact is
provided in the oil circulating pipe. As long as the oil is circulating
properly, the contacts on the relay remain closed. However, in case the
MPH fails or stops the relay contacts open which in turn trips master
auxiliary protection relay Q-118. This trips the main circuit-breaker(DJ)
of the loco. Thus the transformer is protected.
Transformer Oil Cooling Radiator Blower (MVRH)
The MPH circulates the transformer oil through a radiator array on top of the
transformer. Air is blown over the radiator by the MVRH.
This discharges the heat from the radiator into the atmosphere. A flow
detecting relay is provided in the air-stream of the MVRH. The flow detector
is a diaphragm type device. The flow of air presses diaphragm which closes
an electrical contact. This relay is known as the QVRH.In case the MVRH
blower fails the QVRH releases and trips the DJ through the relay Q-118
31

38. Rectifier Cooling Blowers-MVSI-1 and MVSI-2
One blower is provided for each of the rectifier blocks. As rectifiers are
semiconductor devices,
they are very sensitive to heat and hence must be cooled continously.
The switching sequence of the MVSI blowers is setup in such a way that
unless the blowers are running, traction cannot be
32

39. achieved. A detection relay of diaphragm type is also provided in the air
stream of these blowers.
However, the detection relay (QVSI-1 & 2)are interlocked with a
different relay known as Q-44.
This is a much faster acting relay with a time delay of only 0.6 seconds.
Hence the failure of a MVSI blower would trip the DJ in less than 1
second
Auxiliaries of Traction Motors (MVMT 1 & 2)
In the course of normal operation the traction motors also generate a lot
of heat. This heat is dissipated by two blowers namely MVMT 1 & 2
which force air through a duct into the traction motors of Bogie-1
namely TM-1, TM-2, TM-3 and Bogie-2 namely TM-4, 5, 6
respectively. The traction motor cooling blowers require a large quantity
of air which is taken from vents in the side-wall of the loco. Body-side
filters are provided to minimise the ingress of dust into the loco. Their
running is detected by Air-Flow sensing relay QVMT 1 & 2 (Pic-2)
which in turn give there feed to the Q-118 relay.
33

40. Air Compressors (MCP 1, MCP-2, MCP-3)
Electric locos need compressed at a pressure ranging from 6 kg/cm2
to
10 kg/cm2
. Compressed air is used for the loco's own air brake system as
also for the train brakes, for raising the pantograph, for operating the
power switchgear inside the loco such as the power contactors, change-
over switches, windscreen wipers, sanders, etc.This compressed air is
obtained by providing three air compressors, each having a capacity
topump 1000 litres of air per minute. However depending on the current
requirement, more than two compressors are rarely needed.
34

41. Arno Convertor
This is a rotary convertor which has a combined set of windings and is
used to convert the single phase supply from the Tertiary winding of the
Loco transformer to Three-Phase AC which is fit for use by the various
Auxiliary machines in the loco.

43. Dc link
Used on modern electronic power systems between the single phase
rectifier and the 3-phase inverter. It is easier to convert the single phase
AC from the overhead line to the 3-phase required for the motors by
rectifying it to DC and then inverting the DC to 3-phase AC.
Static Invertor
The Arno convertor suffers from various disadvantages chief of which is
output voltage imbalance which can cause heating up of the auxiliary
motors, varying output voltage because of the variations in OHE
voltage, problems related to starting of the Arno, etc. To overcome these
shortcomings and to improve loco reliability, the Indian Railways have
started providing Static Invertor power supply for auxiliary machines in
locomotives.The supply from the transformer tertiary winding is fed into
the rectifier of the Invertor which is force commutated and is usually
composed of IGBTs. The rectified supply is fed into the DC link which
is a large capacitor and is charged by the DC supply. The DC link also
has an inductor to suppress the AC ripple left over from the
rectification cycle and harmonics generated by the invertor.
Additionally the DC link maintains the supply to the invertor in
case of temporary supply failure and also absorbs transient
voltages generated during switching heavy loads. In some
models if the Static Invertor, an IGBT type switch is provided
which is used to switch the DC link in and out of the circuit as
per requirement. An electronic control system is provided which
monitors the complete functioning of the Static Invertor. The
control system gives the gate firing impulses to the various
IGBTs and also controls the phase angle of the firing pulse to
ensure proper phase sequencing. In addition it monitors the
Static Invertor for internal and external faults.
36

44. Camshaft
Most DC electric traction power circuits use a camshaft to open
or close the contactors controlling the resistances of the traction
motor power circuit. The camshaft is driven by an electric motor
or pneumatic cylinder. The cams on the shaft are arranged to
ensure that the contactors open and close in the correct sequence.
It is controlled by commands from the driver's cab and regulated
by the fall of current in the motor circuit as each section of
resistance is cut out in steps. The sound of this camshaft stepping
can be heard under many older (pre electronics) trains as they
accelerate. See also Notching Relay.
The Contactor
As we have seen from the description above, the relay must have a current
applied to it all the time it is required to be closed. To avoid having
current on to, say, a lighting control relay all thetime, a different type of
remotely controlled switch is used.
This is called a contactor The contactor is really a latched relay. It can
also be called (in the US) a" momentary switch". It only requires current
to be on for a "moment" for it to operate. In order to keep the contacts
closed once the control current is lost, the power circuit contacts are held
in position by a mechanical latch. When it is necessary to open the power
circuit, the latch is released and the contacts drop open.
37

45. Converter
Generic term for any solid state electronic system for converting
alternating current to direct current or vice versa. Where an AC supply
has to be converted to DC it is called a rectifier and where DC is
converted to AC it is called an inverter. The word originated in the US
but is now common elsewhere.
38

46. Ground Relay
An electrical relay provided in diesel and electric traction systems to
protect the equipment
ground relay detects high tension (traction) current running between the
positive or negative traction circuit and the loco frame (ground). It is a small
relay located in the main electrical cabinet and calibrated so that when a small
current flow is detected, the relay will energise against damage from earths and
so-called "grounds". The result of such a relay operating is usually a shut-
down of the electrical drive. Also sometimes called an Earth Fault Relay.
38

47. Rectifier
A converter consisting of thyristors and diodes which is used to convert
AC to DC. A modern locomotive will usually have at least two, a "Main
Rectifier" for the power circuits and one or more for the auxiliary circuits.
39

48. Relay
A remotely controlled switch which uses a low voltage control circuit. It will close
(or open) a switch in a local circuit, usually of higher power. To see the principle of
how it works, look here. See also Contactor.
A relay is an electromagnetic device, which is used for closing or opening of
an electrical circuit. The relay may be classified as Shelf type and Plug-In-
Type Plug -in-type relays which are plugged in to prewired terminal boards. It
works on electromagnetic principle. Each relay has a base electromagnet,
armature, contact spring, contacts, transparent cover, and handle. A non-
magnetic residual pin is fixed on the inner face of armature, in all relay except
magnetic latch relays. When current is applied through the coil, it sets up a
magnetic flux through the bar magnet, core, L shape heelpiece and armature.
The flux causes armature to attract towards the pole face. Armature picks up
and fronts contact closes. The residual pin maintains small air gap in attracted
position. When current interrupts, magnetic flux collapses the contact spring
fixed above the armature helps in restoring to its full released position thus
front contacts open.
1.1. Classification of Signaling Relays
Relays may be classified into various ways depending upon the following factors:
i) Mounting of relay
• Shelf Type
• Plug –in type
ii) Feed source
• DC Relay
• AC Relay
• Electronic Relay
DC relays are further classified as under
• Neutral
• Polar
• Neutral Polar
40

49. iii) Contact material
• Proved Type
• Non proved Type
iv) Application
• Track
• Line
• Special
v) Importance / vitality
• Vital
• Non Vital
Now a days Electronic relays are also used in signalling circuit to achieve time
delay.
1.2 Definition
Non – fusible contacts
i) A pair of contacts in which one contact element comprises
of non – fusible material which present practically no risk
of welding of contacts.
ii) Carbon contacts
“Carbon” in the expression “ Carbon to metal contacts” is used as a general term covering graphite
and compounds and mixtures of carbon and metals.
iii) Metal contacts
Metal in the expression “Carbon to metal contacts” and “Metal to Metal contacts” is used as a
general term covering the use of silver, silver cadmium oxide, tungsten, platinum or any other
suitable material to an approved specification.
41

50. iv) Front contact :-That contact which is made with the arm contact when the
relay is energised.
v) Back contact
That contact which is made when the relay is de energised.
vi) Arm contact (Armature contact)
That contact which is the movable part of the pair of contacts and makes
with front contact when the relay is energised and with back contact when
the relay is de-energised.
vii) Arm
The movable part of the pair of contacts.
viii) Dependent contact
The condition in which a movable arm contact connects to a front contact
when the relay is energised. And the same arm contact connects to a back
contact when the relay is de-energised.
ix) Independent contact
The condition in which the movable arm contact connects to either a front
or a back contact but not to both.
42

51. x) Pickup value (Operate value)
The value of the current or ampere turns which is just sufficient to close
all the front contacts of relay under specified conditions.
xi) Drop –away (release) value
The value of the current or ampere turns at which all the front contacts of
relay get open under specified conditions.
xii) Proved type Relay
Means a relay having Metal to Metal contacts. They are used for
controlling non vital circuits and hence also called as non vital relays.
xiii) Non proved Relays
Means a relay having Metal to Carbon contacts, as front contact. They
are used for controlling vital circuits and hence also called as vital relays.
1.3 Comparison between Shelf and Plug in type relays
Sr. Shelf type
relays
Plug - in -type
relays
1 Mounted on
Shelf
Plugged in to the
board.
2. Heavy and
Large
Light and
compact.
3. More space
required
Less space
required.
4. Less No. of contacts More no. of contacts.
5. Replacement takes
more time
Quicker and easy.

52. 6. Circuit must be
tested after
replacement,
due to chances
of dislocation of
wiring.
Circuit need be
tested for contact
is making after
replacement.
7. Coding
arrangement is
not required.
Coding is needed
on the relay to
avoid
interchangeability
with relay of
different contact
configuration.
8. Anti tilting
arrangement is
required
Not required
9. Pre- wiring is
not possible.
Pre- wiring
is possible.
Table-1
1.4Metal to carbon & Metal to metal Relay
♦ Metal to carbon Relay
All shelf type relays, “Q” series relays and all
“G” type relays except S1 type are metal to
carbon relays.
♦ Metal to metal Relay
These relays are also known as Proved type
relays.

53. Track and Line Relay
♦ Track Relay
Track relays are relays, which is directly
connected across the rails of the track to
detect the occupation of track.
♦ Line Relay
Line relays are used for any other purposes
other than track circuit.
Difference between track and line relays
Sr. Track Relay Line Relay
1 Directly
connected across
the track circuit.
Any relay other
than track. Such
as HR, DR,
NWKR etc.
2 Functions with
less or more
current.
Functions either
with normal
supply voltage or
JSR
A5 N24
R2
A7
A6
TH
JSR A3
A4
JSR
R1 R3
JSR
A1
C contact A8
R4 A2
JR
)
)
B24
‘H’ Contact
R3 R4
LR
(R) Coil
(N) Coil

54. with no supply at
all.
3 Always associated
with loss of
energy.
Preferably
should work with
low power
consumption.
Not so.
4 More sensitive to
variation in
supply so
percentage
release should be
high.
Comparatively
low in percentage
Release.
5 Reliability of
operation is very
important since
the facility to
prove the de-
energisation of
the relay is not
available.
Back contacts are
proved in the
circuits.
6 Non fusible
contact for front
contact is
Necessary.
(carbon) are used.
Not necessary.
Sr. Track Relay Line Relay

55. 7. Coil resistance is
low permitting
low working
voltage which
reduces ballast
leakage current.
Coil resistance is
high to work on
low current which
reduces line
voltage drop.
Table-2
2. Plug In Type Relays
These are Miniature, Proved/ Non Proved, plug -in type relays. Some of
the commonly used Plug–in type relays in Signaling are listed below
Non proved Type
2.1 Style “Q” Relays ( Metal to Carbon)
2.2 Style “G” Relays( Metal to Carbon)
2.3 “P” Type Relays ( Metal to Carbon)
Proved Type
2.1 Siemen ‘s Relays (Metal to Metal)
2.2 IHC’S relay (Metal to Metal)
2.3 Hytronicis Relays ( Metal to Metal)
Common features of plugging type
relay.
♦ Standard plug boards are used for each
type of relays for mounting the same.
♦ Pre-wiring facilities are available for each
type of relay.

56. ♦ Facilities are available for terminating the
wiring on plug board connectors both by
crimping or soldering.
♦ All relays are provided with registration
devices with specified coding combination
to prevent plugging in wrong relay
♦ Unless code pins are correctly engaged no
electrical connection between the relay
and the plug board connector is possible.
Non Proved Type Plug- In -Relay
For their front contacts, these relays make use of M to C contact.
Normally following two styles of relays are in use under this group :
♦ Style “Q”
♦ Style “G”
2.1 “Q”- Series Relays
• This series of plug –in relay consists of more than 25 varieties.
Out of which about 12 varieties are very commonly used on
Indian Railways.
• These relays normally Operate on 12,24 or 50V DC and can be
provided with a max. of 16 independent contacts.

57. (Figure-1)
Plug board for “Q” series relay
• This is divided into 4 vertical columns (A.B.C.D.) and 10
horizontal rows numbered as 1 to 8 from top to bottom.
• The 9th
and 10th
rows are for coil terminals (R1,R2,R3 & R4) .
• Plug board is a one piece molding of the same material as that
of the relay base.
• It is supplied with a wire clip, the purpose of which is to retain
the relay on the plug board tightly by engaging with a groove
provided in the handle of the relay.
Registration Device
• Each relay is fitted with code pins commonly known as
Registration Device to prevent against plugging of relay in a
wrong base.

58. • For this purpose 10 pin positions numbered as
A.B.C.D,E,F,G,H,J,& K are assigned on the relay base for
fixing the pin.
• Plug board is provided with corresponding hole position which
allows the relay base pins to fit while plugging.
• Out of the ten only five pins are used on the relay base &
corresponding holes are drilled in the plug board for the
purpose of providing passes to the pins fitted in the relay base.
• Under this arrangement 252 different codes can be formed.
• Relays of the same type having different contact arrangement
will have different code numbers.
• Plug board front & rear view is shown in the fig.
given below.
Rear View
Front View
(Plug Board for ‘Q’ Series Relay)
(Figure-2)

59. Contact Arrangement
• QN 1 Relay can be have max. 16 Nos. of independent
contacts.
Types of Q- Series Relays
Q – Series relays are following type.
2.1.1 Track Relay
2.1.2 Line Relay
2.1.1 Track Relay
♦ QT2 Style Relay
• The construction of this relay is similar to that of a Q – Series
line relay except that its contact load is reduced drastically.
• The relay is more sensitive and workable on a low voltage.
• Earlier version of this type is QT1 relay.
• QT1 relay has a double core magnet with 2Fcontacts while
QT2 relay has only one core and 2F – 1B contacts.
• The back contact is used for cross protection for TPR circuit.
This has a single coil unlike the shelf type relay, which has two
coils with open ends.
1. Core and coil
2. Heel Piece
3. Armature
4. Residual Pin
5. Front contact
6. Arm for front contact
7. Arm for Back contact
8. Back contact
9. Base
10. Pusher spring
11. Adjusting arm
12. Operating arm
13. Cover
14. Handle

60. (Figure-3)
QTA 2 relay (AC Immunised Relay)
• This is similar to QT2 relay except a copper slug.
• This copper slug is provided on the core to achieve AC
immunity.
• Its AC immunity is not less than 75 Volt.
• QTA2 relays are available in 9 Ohms coil resistance.
• This relay requires more D.C. operating power and it take more
time to pick up and drop due to the copper slug.
QBAT relay
• This relay has a A.C. immunity level of 80 Volt A.C.
• This is achieved by the provision of a biasing permanent
magnet on its core along with its copper slug.
• This is made to RDSO specification. No. 84 / 88.
♦ The particulars of the Q- series track relay (plug-intypes) are
tabulated as under.
52

61. Air/oil pressure relay for (WAG-5 LOCOS)
Air pressure relay: (introduction) The air brakes is the standard ,fail-safe
train brake used by railway all over the world. It is based on the simple
physical properties of compressed air. So here is a simplified description
of the air brake system.
53

63. Dynamic Braking
A train braking system using the traction motors of the power vehicle(s)
to act as generators which provide the braking effort. The power generated
during braking is dissipated either as heat through on-board resistors
(rheostatic braking) or by return to the traction supply line (regenerative
braking). Most regenerative systems include on board resistors to allow
rheostatic braking if the traction supply system is not receptive. The
choice is automatically selected by the traction control system.
Content
Basics- A moving train contain energy,known as kinetic energy, which
needs to be removed from the train in order to cause it to stop. The
simplest way of doing this is to convert the energy in to heat. The
conversion is usually done by applying a contact material to the rotating
wheels or to the discs attached to the axles . The material creates friction
and converts the kinetic energy in to heat. The wheels slow down and
54

64. eventual lthe train stops.
No-Volt Relay
A power circuit relay which detected if power was lost for any reason and
made sure that the
control sequence was returned to the starting point before power could be
re-applied.
Bucholz Relay
A device inserted in the oil cooling circuits of electric locomotive
transformers to detect low oil pressure. If low oil pressure is detected, the
relay trips out the power system. Often a source of spurious circuit
breaker trips if not carefully calibrated.
Notching relay
A DC motor power circuit relay which detects the rise and fall of current
in the circuit and inhibits the operation of the resistance contactors during
the acceleration sequence of automatically controlled motors. The relay

65. operates a contactor stepping circuit so that, during acceleration of the
motor, when the current falls, the relay detects the fall and calls for the
next step of resistance to be switched out of the circuit.l
Overload Relay
A power circuit relay which detected excessive current in the circuit and
switched off the power to avoid damage to the motors. See Motor
Protection above.
Wheel Spin Relay (WSR)
A relay in older traction motor control circuits used to detect wheel spin
or slide by measuring the current levels in a pair of motors on a bogie and
comparing them. The idea is to prevent motor damage by preventing an
overspeeding motor causing an unacceptable rise in current in the other
motor of the pair. If detected, the imbalance causes the control circuits to
open the line breakers and reset the power control to the start position like
a “no-volt" relay
Master Controller
Driver's power control device located in the cab. The driver moves the
handle of the master controller to apply or reduce power to the locomotive
or train. Modern systems often have controllers that incorporate braking.

66. Resistance Control
Method of traction motor control formerly almost universal
on DC electric railways whereby the power to the motors
was gradually increased from start up by removing
resistances from the power circuit in steps. Originally this
step control was done manually but it was later automatic,
a relay in the circuit monitoring the rise and fall of current
as the steps were removed. Many examples of this system
still exist but new builds now use solid state control
with power electronics.
Electric motors are a common means of powering a train,
whether the energy required is carried on-board the train in
the form of a diesel engine and its fuel or obtained from
outside the train by connection with an external power
supply carried by an overhead line or third rail. Electric
traction is widely used around the world, particularly for
routes with dense traffic, like urban and suburban railways
or long distance, high speed lines that need electric traction
to obtain the speeds required for inter-city travel.
57

67. Wheel Spin
On a steam locomotive, the driver must reduce the steam admission to
the cylinders by easing
closed (or partially closed) the throttle/regulator when he hears the
wheels start to spin. On
diesel or electric locomotives, the current drawn by individual or groups
of traction motors are
compared - the motor (or group) which draws proportionally less amps
than the others is deemed
to be in a state of slip - and the power is reduced. Some systems - EMD
Super Series for one – measure known wheel speed against ground speed
as registered on a Doppler Radar. Many locomotives additionally use
sand, which is applied to the wheel/rail contact point to improve adhesion
- this is either controlled automatically, or manually by the driver
(Foamer? No Way,25 Apr 98).
58

68. Cooling Fans
To keep the thyristors and other electronic power systems cool, the
interior of a modern locomotive is equipped with an air management
system, electronically controlled to keep allsystems operating at the
correct temperature. The fans are powered by an auxiliary
inverterproducing 3-phase AC at about 400 volts.
Power Supply
To begin with, the electric railway needs a power supply that the trains
can access at all times. It must be safe, economical and user friendly. It
can use either DC (directcurrent) or AC (alternating current), the former
being, for many years, simpler for railway traction purposes, the latter
being better over long distances and cheaper to install but, until recently,
more complicated to control at train level.
Transmission of power is always along the track by means of an
overhead wire or at ground level, using an extra, third rail laid close to
the running rails. AC systems always use overhead wires, DC can use
either an overhead wire or a third rail; both are common. Both overhead
systems require at least one collector attached to the train so it can

69. always be in contact with the power. Overhead current collectors use a
"pantograph", so called because that was the shape of most of them until
about 30 years ago. The return circuit is via the running rails back to the
substation. The running rails are at earth potential and are connected to
the substation.
Shoes and Shoegear
Third rail current collection comes in a variety of designs. The simplest
is what is called "top contact" because that’s the part of the rail upon
which the pick-up shoe slides There is also a side contact system. Side
contact is not much better than top contact but at least it is less exposed.
Bottom contact is best - you can cover effectively most of the rail and it
is protected from the worst of the cold weather. This diagram shows a
DC 3-Rail Traction System with the location of the current rail in
relation to the running rails. The third rail system uses a "shoe" to collect
the current on the train
Motor Control and Protection
As described above, DC motors are controlled by a "notching relay" set
into the power circuit (Figure 3). But there are other relays provided for
motor protection. Sharp spikes of current will quickly damage a DC

70. motor so protective equipment is provided in the form of an "overload
relay", which detects excessive current in the circuit and, when it occurs,
switches off the power to avoid damage to the motors. Power is
switched off by means of Line Breakers, one or two heavy-duty switches
similar to circuit breakers which are remotely controlled. They would
normally be opened or closed by the action of the driver's controller but
they can also be opened automatically by the action of the overload
relay.A further protective device is also provided in the classic DC
motor control circuit. This is the "no-volt" relay, which detects power
lost for any reason and makes sure that the control sequence is returned
to the starting point (i.e. all the resistances are restored to the power
circuit) before power could be re-applied. This is necessary to ensure
that too much current is not applied to a motor which lost speed while
current was off.
Thyristor
A type of diode with a controlling gate which allows current to pass
through it when the gate is energized. The gate is closed by the current
being applied to the thyristor in the reverse direction. Thyristors (also
referred to as choppers) are used for traction power control in place of
resistance control systems. A GTO (Gate Turn Off) thyristor is a
development in which current is turned off is by applying a pulse of
current to the gate.
Transistor
The original electronic solid state device capable of controlling the
amount of current flowing as well as switching it on and off. In the last
few years, a powerful version has been applied to railway traction in the
form of the Insulated Gate Bipolar Transistor (IGBT). Its principle
advantage over the GTO Thyristor is its speed of switching and that its
controls require much smaller current levels.
61

71. Tap Changer
Camshaft operated set of switches used on AC electric locomotives to
control the voltage taken off the main transformer for traction motor
power. Superseded by thyristor control.
Inverter
Electronic power device mounted on trains to provide alternating current
from direct current. Popular nowadays for DC railways to allow three
phase drive or for auxiliary supplies which need an AC supply. See
also converter with which it is often confused
62

72. HOW TO LOCO CHARGE
First, We set a key (BL All lock at open. ZPT key is
pantograph. Its Regular meter, there are 3 position 0,1,2. We start HBA
Switch is on, That is position 0 & I . 0 Position is low & I Position is
high. HBA Switch as a regulator switch is worked. This fuse name is
called C FUSE.IN Case The switch is not supply , The fuse are throw out.
We checked the pressure value check, whose pressure is minimum 4.5 kg
& Maximum up to 6 kg. But Most in stored in compressed air into 4.5 kg
Above. The Compressor in which stored pressure air 6 kg, In case the
63

73. pressure air are not to become to start the Baby compressor switch
(ZCPA) is on. The pressure count check we can see the Pressure meter.
To become pressure 4.5 kilo to above the baby compressor switch is turn
off. What you know that cab is work on if you Panto key is turn on 2 cab
will start the pento & 2nd
cab is turn on panto See the I cab pantograph is
on. Because the cross/ Reverse connection. Panto graph is touched on .
But the supply is not to transfer to step-down Transformer. First From
the panto passes the supply to VCB (VACCUM CIRCUIT BREAKER).
Vcb to input supply passes threw coil & and gives output i.e( BL-DJ
SWITCH) It is another name is called pressure switch because they are
up ward to panto . By chance The panto is down ward to position the BL
DJ Switch is turn on. The pressure Maintance is keep constant Pressure
Automatic switch in engaged. The electric loco is speed is high that is
Notching(B2). There is speed limit up to high in 140/ 71 in New loco
engine NEW
SERIES(32), 180 / 110 old loco engine WAG-9 One loco engine is 6 TM
Was Engaged The number of total wheels In loco engine is 12. I pair of
each wheel the Axle is fit with the TRACTION MOTOR . The Switch is
(BL BMT) TRACTION MOTOR BLOWER, That is cooling the Traction
Motor
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74. HOW TO START LOCO CHARGE
1. The panto are touched in OHE.. The supply are VCB to transfer
DIODE. The diode is forward to supply then convert to Rectifier
A.C to D.C . A Modern Loco engine is mostly used in. (i) Main
Rectifier for power circuit & (ii) Auxiliary circuit •The First supply
dc battery connecting in series & check the Ampere 10 Mah (Milli
Ampere hours) . To check the reading & total no. Of battery in 10 .
The count of battery of Ampere 110 Ampere . The supply are contact
to compressor up to '1.5 kg panto will be toughed on OHE .The
compressor Making pressure air up to 6 kg. After save pressure will
be released Braking System . FOR EXAMPLE. (i) Boggy brake sa -
9 (ii) Engine Brake A-9BRAKING• The electric logo engine Are
brakes of 2 types are : (i) Sa -9 ,(ii) A-9 (i) SA-9 are Brakes works as
Boggi brake, (ii) A-9 Brakes Work as Engine boggi brake.
2. 2.EARTHING• The Railway loco Engine are inside the Ear thing
Relay . TheElectric loco engine , The OHE are PHASE & the rail
track are Neutral. So the over loadsupply passes to the track to
neutral . The electric loco engine Engaged Earth fault relay. Earth
Relay Works High voltage supply passes threw the neutral.
3. SPEEDO METER • The speedo meter is working how to see
the strain speed in Engine Manage to speed. The speed is limited up
to 71 km to 80 kmh . And speed meter up to high speed is 0 to 180 .
first we start the key to on the speedo Meter. Test all the meter
working position Click all the buttons to check the train name , time
date speed control , & to check the memory reading internal Memory
& external memory. The internal memory size in 4 &6 MB(Mega
Byte) and external Memory size is 125 MB. The speedo meter
Supply is 24kwh (kilo watt hour
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