TECHNICAL TRAINING REPORT ON ELECTRICAL LOCO SHED AT SOUTH EASTERN RAILWAYS

TECHNICAL TRAINING REPORT ON ELECTRIC LOCOMOTIVE SHED AT SOUTH EASTERN RAILWAYS, SANTRAGACHI

PRESENTED BY AARTI OJHA(122604001002)BCETW, EE 4th YEAR

INTRODUCTIONThe ISO-9001-2008 certified South Eastern Railways Electric Loco Shed situated in SANTRAGACHI. It is a solo loco shed in Kharagpur Division that maintains the WAP-4locomotives .

The main objective of this loco shed is to inspect and maintain the locos that operate throughout the year.

WHAT IS AN ELECTRIC LOCOMOTIVE?WAP-4?

ELECTRIC LOCOMOTIVEWAP-4

An Electric Locomotive is a locomotive powered by electricityfrom overhead lines or on-boardenergy storage such as battery orfuel cell.WAP-4 stands for :-

W = Wide gauge (1.66m)A = AC Supply(25 KV)P = Passenger

TYPE AND ORIGIN POWER TYPE : ELECTRIC BUILDER : CHITTARANJAN LOCOMOTIVES WORK, W.B., INDIA BUILD DATA : 1990 TILL DATE TOTAL PRODUCED : 698CHARECTERISTICS OF WAP-4 LOCOMOTIVES

SPECIFICATIONS AAR WHEEL AAR : C-C UIC CLASSIFICATION : Co-Co GUAGE : 1.676 mm BOGIES : Co-Co flexible mark/ cast bogies; primary and secondary wheel springsWHEEL DIAMETER : New = 1,092 mm ( 3 ft 7) Half worn = 1,055 mm ( 3 ft 5.5 ) Full worn = 1,016 mm ( 3 ft 4)

LENGTH : 18.794 m WIDTH : 3.179 m HEIGHT : 4.323 m LOCOMOTIVE WEIGHT : 1,12,800 kgs ELECTRIC SYSTEM : 25 kv / 50 hz AC overhead CURRENT COLLECTION METHOD : Pantograph TRACTION MOTORS : Hitachi HST 5250

PERFORMANCE FIGURES MAXIMUM SPEED : Service 140 km/hr Test Run 180 km/hr PERFORMANCE OUTPUT : Maximum- 5350 hp Continuous 5050 hp LOCOMOTIVES BRAKES : Air/ Hand brakes TRAIN BRAKES : Air

THE VARIOUS SECTIONS PRESENT IN THE LOCO-SHED THAT WERE EXPLORED DURING THE TRAINING ARE AS FOLLOWS

E-3 SECTION2. E-4 SECTION3. E-5 SECTION

LETS EXPLORE THE SECTIONS ONE BY ONE ...

E-3 SECTION This section is responsible for the inspection and the overhauling of the traction motors that drives the locomotives

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LET USSEE WHAT ARETRACTION MOTORS...

It is one of the most important equipment of electric motor. A 6 pole DC series wound motor with commutating poles They are used for the propulsion of the vehicles. Locomotives have 6 axis. Each axis carry a single traction motor which is connected to wheel by direct spur gear meshing , these motor drive locomotives by taking current from the overhead lines through PANTOGRAPH. Ventilation system for these motors are forced and air is supplied from separate motor blower to cool these traction motors.

RATINGSCONTINUOUSONE HOURMAXVALUEVOLTAGE750 V750 V900 VCURRENT900 A960A1300 ASPEED(RPM)895 RPM877 RPM2150 RPMPOWER630 KW670 KW____

TECHNICAL DATA

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Motor is mounted in the bogie frame supported partially by the axle which it drive and partially by the bogie frame.The motor case is provided with a "nose" which is rested on a bracket fixed to the frame of the bogie.

WHEEL:Wheels are manufactured of cast steel.Railway wheels sit on the rails without guidance.The flanges should not touch the rails.The wheel tire is coned . Rail head slightly curved as shown in the diagram.

Let us have a lookover E-4 Section..

This section is in charge of relays, speedometers, microprocessors, battery chargers etc.E-4 SECTION

SPEEDOMETERSpeedometer combines the technology of the field proven indicators. It gives statistics of the speed of the locomotive along with the ability to store journey data in a flash memory in a single housing . Due to small size it can easily be installed and retrofitted in public transports such as locomotives, tramways, metro trains etc. This unit is very much suitable to work under severe environment conditions typically encountered in real road vehicles where accurate high speed indication is a very crucial factor. Inside SPM, data is recorded in a compact FLASH MEMORY CARD. This compact memory card can store long term data of the last 60 days of halt and run.

RELAYSThe purpose of relay in electrical circuit and fluid circuit is to check proper flow of current and circulation of the fluid and also to safeguard the appliance from getting damaged in an event of no flow or improper flow ofcurrent or no or improper circulation of fluid in the circuit.

In the absence of relay there would have been no protection of the appliance in the concerned circuit.

Depending upon the nature of controlling device, relays are classified into the following groups:

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1.Safety Relay Used for the safety of the entire system. Examples are QRSI, QLM, QE, QF, etc.

2. Protection/Sequence Relay Used for the protection of a particular device of the system. Examples are Q-45, Q-46, Q-51, Q-53, Q-54, Q-100, QSIT, QFL, Q-50, QCON, etc.

3. Time Lag Relay Used to delay the tripping of the locomotive under certain circumstances. For example QTD 105, QTD 106.4. Signalling Relay Used to indicate the proper functioning of particular devices in the locomotive. For example QV60, QV61, QV62, QV63, etc.

RELAYS PROVIDED IN ELECTRICAL LOCOMOTIVES

1.RELAYS USED IN LOCOS2.RELAY TEST BENCH IN LOCO SHED3. RELAY TEST UNIT IN THE LOCO SHED

MICROPROCESSORS....BUT WAIT!

YOU PEOPLE MUST BE THINKING WHAT IS THE USE OF MICROPROCESSOR IN AN ELECTRIC LOCO?LET US HAVE A LOOK AT IT...

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THAT WAS ALL WE HAD IN E-4 SECTION!

LETS MOVE AHEAD AND HAVE A LOOK AT E-5 SECTION...

E-5 SECTION

This section inspects and maintains the Transformer,Graduator(GR) and SMGR.

FRONT VIEW OF AN ELECTRIC LOCOLOWER FRONT VIEW OF AN ELECTRIC LOCO

FURTHER WE MOVED AHEAD TO THE DRIVERS CABIN WHERE WE EXPLORED THE FOLLOWING

SPEEDOMETERVOLTMETER AND AMMETERSIGNAL LAMP BOXTRACTION AND BRAKINGMPJAIR RESEVOIR/PENTO RESERVOIRBRAKE PIPEAIR FLOW INDICATORBRAKE CYLINDER

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TRANSFORMER

The TRANSFORMER used in loco is an autotransformer which is an electrical transformer with only one winding AUTO prefix refers to the coil acting on itself and not on any kind of automatic mechanism. In autotransformer, portions of same windings act as both the primary and secondary sides of transformer.

NOW ONE QUESTION MIGHT ARISE IN YOUR MIND THAT WHY DO WE USE AUTOTRANSFORMER IN ELECTRIC LOCOMOTIVE INSTEADOF USING ANY OTHER TRANSFORMER?

The reason being the part of winding does double duty along with it being smaller, lighter and cheaper. It also includes lower leakage reactance,lower loss, lower excitation current and increased KVA rating for a given size and mass.

FURTHER IN E-5 SECTION WE EVEN SAWMANY AUXILLARY MOTORS. LET US LEARN ABOUT IT ONE BY ONE:--

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1. ARNO2. MOTOR ALTERNATOR3. AIR COMPRESSOR4. MVSL5. MVMT

reverser

THE ARRANGMENT WITH THE HELP OF WHICH THE DRIVER OF THE LOCO REVERSES THE LOCO ON TRACKS.

DAMPING CIRCUIT

IT IS AN ARRANGEMENT OF RESISTENCE AND CAPACITENCE TO PREVENTDAMPING IN AN ELECTRIC LOCO.

SMGRSMGR is a motor that drives the loco. It contains 4 cylinders that contains pistons drivinga common crank shaft. Depending upon the sequence under which the compressed air enters the cylinder and the motor runs in every direction required. The SMGR is driven by airoperated pistons and it has high inertia. This ensures that the rotation is highly accurate and does not overshoot.

PANTOGRAPHFor collecting power from 25 KVAC contact wire pantograph are mounted on the roof of the tractionvehicles. They are provided with steelstripes for current collection. The raising and lowering of pantograph is by means of pneumatically operated servomotor. Used for suitable operation up to 140 km/hr.

Although we are now familiar with all the partsof an electric loco. One question still remains.

How does an electric loco work?

OVERHEAD TRANSMISSION LINE ( 250 KV)

Through the roof barsvia pantograph TRANSFORMER (5400 KVA)

AC supply is fed to the transformerwhich in turn steps down the voltage and feds it to

RECTIFIER

Rectifier changes AC to DC and is fed to SL

SOOTHING REACTORS

pulsating DC to smooth DC (DC-DC)and feds it to

TRACTIONMOTORS

PANTOGRAPHTRANSFORMERRECTIFIERSOOTHING REACTORSTRACTION MOTORSLOCO MOVES