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TRAIN LIGHTING SYSTEM
Train lighting is one of the essential passenger amenities, which influence the
image of Indian Railways.The basic purpose of train lighting is to provide light,
air-conditioning and fannage in railway coaches using electric power. Following
systems are currently in use in Indian Railways for accomplishing this function:
1.AXLE- DRIVEN / SELF GENERATION SYSTEM:
 WORKING ON 110 VOLTS D.C SUPPLY ------This system has proved more reliable and capable of meeting future increases in
load. It has, therefore been adopted as standard for all future builds of selfgenerating coaches. In this system 3.0 kW /4.5KW alternators are driven through
Flat/V-belts from axle.
Lead acid batteries 110 volt, 120 AH capacity arranged from 3cell monoblock
units, are provided in the BG coaches. Two number of emergency feed terminals
boxes for BG and one number for MG coach are provided on each end wall of for
interconnecting the coach to adjacent coach to receive power, in the case
generation fails. One number emergency terminal box provided centrally on each
side of underframe to facilitate charging of battery from external source. For BG
air-conditioned coaches, 18 KW/22.75/25 kW brushless alternators are used.
Two such alternators are used in ac-2 Tier / AC-3 Tier/Chair cars and only one
alternator is used in I.AC coach. Batteries of 800/1100 AH capacity at 10 hour
rate are used in ac-2 Tier /AC-3 Tier /Chaircar and 525 AH for IAC BGcoaches.
A schematic layout for 110Volt DC system is attached in annexture1.
Three Phase out put from 4.5 kW alternator mounted on the bogie of coach is fed
to the regulator cum rectifier for rectifying the AC out put to DC and regulating the
output voltage at different speeds and loads. The output from rectifier cum
regulator on the under frame is brought through cables on the coach. The load is
fed through four rotatory switches (RSW) and fuses connecting circuits L1, L2,F
and SPM.L1 feeds the essential lighting load like lavatories,gangways,doorways
and upto50% of lights in each compartment / bays corridor lights and night
lights,L2 feeds remaining lighting loads F feeds the fan loads and SPM feeds
Emergency Feed Terminals(FET).
An external battery charging terminal (BCT) is provided to charge the battery
from external charger, if battery is rundown condition due failure of alternator.
ADVANTAGES
 Each unit being independent can work as slip coach
 In case of failure of generating equipments in 2 or 3 coaches, power can be
drawn from adjacent coach by means of cable connection.
 Safe low working voltage.
DISADVANTAGES
 High initial cost
 High maintenance cost and more plifirages
 A large amount of locomotive power goes for driving the generators
BRUSHLESS ALTERNATORS
Brushless Alternators are governed by RDSO specification No EL / TL /47 "C" for
4.5 and 3.0 KW alternators. Approved manufacturers for the alternators are:
1. KEL ( Kerala Electrical & Allied Engineering Industries )
2. BEACON (Best & Crompton)
3. SIL (Stone India Limited )
4. HMTD Engineering.
5. CGL (Crompton Greaves Limited)
The Ratings in use are:
 4.5 KW,120V or 30V for BG non-AC coaches
 3.0 KW,120V or 30V for MG non-AC coaches
 12.0 KW,120V for MG AC coaches
 18.0KW,130V for BG AC coaches
 22.75 /25 KW,130V Optimised alternator for BG ac coaches (New)
18 KW Brushless Alternator & Regulator (KEL Make)
The brushless alternator is 3-phase Induction Alternator without any rotating
windings, commutator or sliprings. Both the field windings and AC windings are
located in the stator. The AC windings are distributed in 60 slots. The field coil
spans half the total number of stator slots.
The rotor is made up of silicon steel laminations and resembles a cogged wheel.
The teeth and slots are uniformly distributed on the rotor surface (skewing the
rotor axis)
The alternator is equipped with 2 numbers of 200MM PCD 6groove V pulley and
is driven through an axle pulley of 572.6 mm PCD, V belts type C-122 are used
for drive.
Technical Data of Alternator: Output Voltage
135V+ 5% on DC,side,(97V,3-phase
AC)
Current
140 Amp (Maxm)on DC side
Cut in speed
550 rpm (30 Km/h with half worn
wheels with pulley ratio 200/572.6
Maxm speed for 930 rpm for 135 AMP at 135V(51
full output
Km/h)
Maxm Speed
2800 rpm (156 Km/h)
Class
of F-Class
Insulation
Resistance
7.3 Ohm
between
field
terminals
RECTIFIER CUM REGULATOR UNIT OF 18 KW ALTERNATOR KEL- MAKE
 Power Rectifier (RP) :
This consists of 6 silicon diodes connected in 3-phase full Wave Bridge. The 3phase output of the alternator is rectified by these diodes to give a DC output at
terminal +L and - C. Each diode is protected against transient surge voltage by
capacitor C1.The whole bridge is protected against high frequency surges by
capacitor C3.The DC output is filtered by capacitor C2.
 Current Transformers (CT1,CT2&CT3)
The Current transformers are used to sense the load current for the current
limitor. When primary winding of each current transformer carries load current,
the secondary winding feeds a 3-phase voltage to the rectifier RT2 in the
regulator rake.
 Regulator Rake :
The Regulator Rake consists of the following parts: Excitation Transformer (TE) This is single winding transformer with tapping for
output and input.The transformer steps down the voltage for the field coils.The
output of the transformer is taken to the field through the Magnetic Amplifier
before being rectified by field rectifier diodes
Magnetic Amplifier (MA)
The magnetic amplifier forms the nucles of the
regulator circuit.It works on the principle of saturation of magnetic core.The
equipment has 6 sets of windings-- Two load windings 18-162 and 17-161 & Four
control windings 10-11,26-27,20-40,29-30.(Out of these only 10-11 and 20-40
are used in the circuit.10-11 for voltage and current control and 20-40 for gain
control) The field current passes through the load winding offers a variable
impedance to the field circuit.
Field Rectifier Unit
The 2 silicon diodes D 4 and D3 acts as full wave rectifier
for the field supply.These diodes conduct alternative,when the terminals 18 and
161 become positive with respect to the center tapping 19. The rectified current
from the diodes is
2.End on Generation System
INTRODUCTION:
Indian Railways has introduced the End on Generation System to cater the
increase in demand for faster trains having limited halts and improved
passengers amenities- air conditioning, fluorescent lighting, catering from pantry
cars in Rajdhani / Shatabdi Express services on several routes.
Since requirement of power for operating air conditioning load, cooking ranges /
refrigerators / bottle coolers in pantry car is considerable. The introduction of
power cars equipped with Diesel Generating Sets is the only solution, now a day.
CONNECTED LOAD FOR RAJDHANI EXPRESS:
The connected load of typical Rajdhani Service is as under
Sr.
No.
1
2
3
4
5
Type of
Coach
AC 3 T
AC 2 T
AC First
AC Pantry
AC Power
Car
(Work)
Total
No
of
coaches
8
6
1
2
2
19
Load in Total load
KW
in KW
40.00
320.00
34.75
208.50
15.75
15.75
76.75
153.50
49.00
98.00
795.75
(800.00)
Assuming a diversity factor of 0.7, The Maxm KW = 800  0.7 = 560 KW.
CAPACITY OF POWER CAR:
The old rakes of Rajdhani Express working in EOG system were provided with
three power cars having generation and supply voltage at 415V, 3 Phase.To
reduce the number of power cars from 3 to 2 and to feed the entire load of train
from either of power cars, the capacity of DG sets has been increased from
125KW to 250 KW and generation voltage has also been increased from 415V to
750 V with a view to overcoming the voltage drop in feeding system. The 750 V
power cars are the first and last vehicle in the EOG rake.
POWER DISTRIBUTION IN COACHES:
Two feeders run all along the entire rake through I.V couplers. Each coach on the
rake is provided with the control, distribution and feeder changeover
arrangements in the 750 / 415 V control panel.
750 Volt, 3 Phase supply is stepped down to 415-Volt supply system, contactors
with interlocks are provided to pass the step-down transformer. The 415 V, 3phase supply is stepped down through 415 / 190 Volt, Delta-Star transformer
separate panel is provided for control and distribution of 3 phase-4 wire, 190
volts for working lights and fans at 110 V, single phase.
Emergency lights provided in the power cars comes ON automatically through
No-Volt contactor which energises lamps from batteries as soon as main power
supply interrupts for any reason.
CAPACITY OF BRUSHLESS ALTERNATORS AND OF DIESEL ENGINE:
Load on both the feeders 560 kW
Load on each feeder = 280 / 0.8 KVA
Required output of Alternator = 350 KVA
500 KVA capacity alternators are being used to cater the future increase in load,
derating factor, unbalanced in the load e.t.c.
Two types of Diesel Engines are being used for high capacity 750-Volt Power
cars.
Kirloskar Cummins.KTA- 1150 G -- 450 BHP at 380 C (427 BHP at 550C )
INTACH 3406 B
-- 398 BHP at 550C
Kirloskar Cummins Engines are coupled with brushless Alternator of KEC make
(Kirloskar Electric Company Banglore). INTACH 3406 B engines are coupled
with Brushless Alternators of KEL (Kerala Electrical) make.
PROTECTIVE DEVICES:

DIESEL ENGINE PROTECTION
1.
2.
3.
4.
The following are the protective devices provided for Diesel Engine.
High water temperature.
Low water level in radiator.
Low lubricating oil.
Over speed.
The high water temperature protective device cuts off the load
automatically and the engine returns to idling speed and the other devices
cut-out the load as well as shut-down the engine.
All the protective devices are designed to give audio-visual
indication when they operate.
ALTERNATOR PROTECTION:
Alternators are provided with following protective devices.
1. Alternator overload.
2. Under voltage.
3. Earth leakage.
4. Short circuit.
 FEEEDR PROTECTION
Following devices are provided for feeder protection:
1. Feeder Earth leakage.
2. Feeder overload.
 FIRE-EXTINGUISHERS
Each power car is provided with 2 nos of 5 Kg capacity dry power type fire
extinguishers conforming to specification IS-2171.One of the fire extinguishers is
located in the alternator and the other in the engine room.
ADVANTAGES:
 Low initial cost compared to Axle-Driven Generation system.
 Low maintenance cost.
 Higher efficiency
 Less current due higher voltage
 Better lighting and fannage.
 Additional coaches may be attached to the train as tare weight of the coaches
is reduced.
 No power is required to drive the axle generators.
DISADVANTAGES:
 Any disconnection of the feeder will cause a failure
 Failure of both the DG sets will result in total breakdown.
 Revenue earning space is occupied by power cars and operating staff.
 Storage of diesel oil poses a fire hazard.
 Interchangeability of coaches is restricted.
3.MID-ON GENERATION SYSTEM
By providing DG sets of adequate capacity in a coach at the centre, power can
be supplied throughout the train by feeders. This system has been introduced in
branch line trains, which are essentially slow speed trains having frequent
stoppages and is operating satisfactorily.
There are two DG sets of smaller capacities (30KVA/12.5KVAand 3-phase,
415V, 50C/S power is generated. Only one DG set runs at a time. One
transformer of matching capacity kept in the generator car itself, steps down the
generated voltage415V, 3-phase to190 V, 3-phase, star system that is supplied
to all coaches.110V is obtained between a line and earth.
The advantages and disadvantages of this system are same as those of EOG
system. The branch line trains are more theft prone and necessitates its
adoption.
4.HEAD-ON GENERATION SYSTEM
This system is being proposed to be adopted in electrified section. Power is to
drawn from the transformer of the electric locomotive through an auxiliary
winding and supplied to all coaches. Different forms of this system are being
considered.In one form ,single phase power at 750 Volts is to be supplied to
each coach which will be provided with a transformer for steeping it down to a
suitable level,and a rectifier for converting it into 110V DC.There will be battery
back-up also for maintaining continuity of supply.
BATTERIES USED IN TRAIN LIGHTING
Conventional Lead Acid cells for T / L applications are governed by IS 68-18
Types of cells in use for train lighting and coach air-conditioning are as under:
Capacity of battery in AH at Type of coach
270C at 10 Hours Rate
where
generally
used
120
110V,BG
210
24V,MG
320
24V,BG
450
MG AC coach
525
1st Class AC coach
800
II AC BG coach
1100
II AC/AC 3 Tier BG
coach
Principle of operation:
In a charged lead acid cell +ve active material consists of lead peroxide (PbO2)
and the -ve of spongy lead (Pb). Dilute sulphuric acid (H2SO4 +H2O) serves as
electrolyte.
The overall reactions inside the cell during discharge and charge are represented
most conveniently by a reversible equation as follows: PbO2 + Pb + 2H2SO4
During discharge--
↔ 2PbSO4 + 2H2O
The PbO2 on the +ve plates as wellas the spongy lead on the -ve plates are
converted into PbSO4.In this process, H2SO4 acid is consumed and H2O
formed. Consequently, the specific gravity of the electrolyte falls, the extent of fall
being proportional to the ampere-hours taken out. The process causes at first a
slow, and then a faster voltage drop, until a permissible lower limit (final
discharge voltage )is reached,which depends on the rate of discharge
currrent.The amount of ampere-hours (constant current x time ) taken out is
called the capacity of the cell at this rate.
The chemical process during charge is the reverse of that during discharge. The
PbSO4 on the +ve plates is converted into PbO2 and the PbSO4 in the -ve plates
into spongy lead. H2SO4 acid is formed and H2O consumed. The specific gravity
of the electrolyte rises.there is at first a slow, later a faster rise of cell voltage.
Electrolyte: --It is dilute Sulphuric Acid of Specific Gravity 1.18-1.22. It can be prepared by
mixing concentrated battery grade Sulphuric Acid as per IS:266 of sp.gr.1.835
with Water of approved quality as per IS:1069.
To get approx.100 Lts of Electrolyte of sp.gr.1.18 , water 86 Lts + Acid 17 Lts (by
weight)
To get approx.100 Lts of Electrolyte of sp.gr.1.22 , water 82 Lts + Acid 21 Lts (by
weight)
--In our country, the standard temperature for measuring sp.gr. Of any electrolyte
is 270C.As such the correction is as under Correction
For every 100C above 270C,add 0.007 or 7 points to the sp.gr.reading on the
hydrometer and for every 100C below 270C,substract 0.007 or 7 points from the
readings.
Features Affecting Life of L.A.Battery:---
1.
2.
3.
4.
Necessity for frequent topping up cells
Leakages of electrolyte on lid and on container body
Failure of one cell in monoblock unit
Undercharging / Overcharging :
SMF (Sealed Maintenance Free) Battery:
To overcome problems of frequent topping up of electrolyte, SMF lead acid
batteries
have been developed and are under trial.These batteries are governed by RDSO
specification EL/TL/59.Electrolyte in these batteries is in immobilized form and
can be used in any position-horizontal or vertical.
Such battery requires only periodic cleaning of terminals. It has self sealing vent
plug, which normally does not open out in service.
Maintenance:
Train lighting batteries of coaches by the very nature of service conditions can
not be expected to have steady rate of charge / discharge,left to idle for long
duration or charged at higher rates.The running maintenance of storage batteries
falls under 4 categories: Trip Examination--1. To know the condition of cells during "Trip Examination"some cells in a
battery are treated as pilot cells. On arrival of train in the maintenance line,
the disconnect at inter vehicle connections. Record the specific gravity of
"pilot cell" in each battery.
2. Check and record of total voltage of the battery.
3. Keep vent plug tight and ensure the healthy condition of battery.
4. Check anti-theft arrangements and ensure it.
 Fortnightly Maintenance:
1. Clean the interior of battery box.
2. Clean the cell tops and deposit of sulphate,if any,in intercell and end cell
connections
3. Remove end cells connectors, clean the connecting surface both in cell and
connector thoroughly and provide back. Check proper crimping of terminal.
4. Check whether cell packing is tight and provide additional packing, if
necessary.
5. Apply petroleum jelly on intercell connections and cell connections
6. Check battery fuse condition
7. Check battery boxes condition.
8. Charge the battery and on completion of charging record the sp.gravity of
individual cells
9. Record each cell voltage and total voltage on full load of the coach
 Quarterly Maintenance:
In addition to the fortnightly maintenance
1. Switch off load and charge the cells at 50% of normal rate of charge i.e. at
1/20th the rated capacity of cells. Record hourly cell voltage and sp.gravity
reading.
2. Terminate charging when 3 successive readings are constant. Record sp. gr.
and no
load voltage of each cell 15 minutes after terminating charge.
 Intermediate Overhaul -- Facilities required in major dopots for maintenance
: