PANTOGRAPH :

It is a collapsible frame work made of metallic tubes and articulated by ball bearings. Pantograph is used for smooth and flash less current collection from OHE and two fed the transformer primary winding through air blast circuit breaker. It is designed to maintain the continuous flow of current in spite of oscillation at high speed and variation in height of the contact wire at different places.

PANTOGRAPH COMPRESSOR (AUX. CP)

The minimum air pressure required for rising of pantograph should be 4.5 kg/cm2. The pantograph should start lowering when the air pressure drops to 3-3.5 kg/cm2.One additional compressor is often provided on units which have air operated pantographs, i.e. those which are raised or lowered using compressed air as the power medium. Energizing a completely dead locomotive is only possible if there is battery power and some compressed air which can be used to raise the panto. As soon as panto is up, the function of the panto compressor ends, full power is available to the main compressor.

SERVO MOTOR

It is the air operated pneumatic motor which is used to raise the pantograph.

PNEUMATIC SERVO MOTOR

AIR BLAST CIRCUIT BREAKER (ABB/VCB)

It is an electro-pneumatic high speed circuit breaker. It extends the 25 kv power supply from pantograph to the transformer primary winding. The operation of ABB is remote controlled from driving cab and it gets tripped automatically in cases of abnormality in the unit. ABB has two pair of contactors connected in series, primary and secondary. The closing and opening of ABB is controlled by operation of two electro-pneumatic valves named as closing and holding valve.

STATIC BALANCE OF PANTOGRAPH

The static forces should be adjusted to 7kg following the detailed procedure laid down by the makers. Using a dynamometer, the static forces while raising and lowering of panto should be measured for heights between 0.25m and 2.25m. For the same height the differences in static forces for raising and lowering panto should be maximum of 200gms.

MAIN PARTS OF PANTOGRAPH

1. Air Reservoir.2. Pin type insulator3. Hollow insulator4. Air chamber insulator5. Primary contact6. Insulator with control resistor7. Closing coil8. Holding coil9. Control block10. Minimum pressure device.

LIGHTENING ARRESTER

This is provided on the roof ton protect roof equipments as well transformer unusual high voltage surging.

PANTOGRAPH

The different mechanisms used in local trains of eastern railway are mainly based on basic engineering principles. Since, modern technology has been updated very much, keeping that in mind railway technical infrastructure must be improved vastly. Followings are a few changes that can be efficient according to me-

1. The different components of EMU like traction motor, compressor, rectifier, tap changer all these are of very robust mechanism especially applicable for rough and heavy use. For improvement of the train both technically and visually we can apply various micro-processors and micro-controllers. In the modern age of Electronics, all these would be highly efficient for fast application of different mechanisms used in EMU.

2. The rectifier used in EMU to convert AC to DC is mainly formed of silicon diodes, even in modern coaches also. Electronics has been far improved from its basic p-n junction diodes to the fast operating devices like thyristor rectifier.

3. DC EMU system can be introduced in step by step which includes AC single phase traction motors as the running device. This technology is used in all modern countries like Japan, France, and USA etc. Even in our metro enabled cities like Kolkata, Delhi and Bangalore metro services run by AC traction motors which are useful and effective for achieving desired speed at a very short time.

4. Lastly, there is a major challenge of energy efficiency. Recent concern about environmental issues is prompting railways to step up energy saving efforts which can be expectedly done by developing hardware and controllers to improve operating efficiency of the motors and different control equipments even while using regenerative braking.

On a negative note, inverter control produces high- harmonic noise affecting signaling and communication systems. Research is required to solve this problem. Some other technical hurdles including noise reduction and optimized control for wheel slip remain to be corrected.

SIGNATURE PAGE

SECTION NAME SIGNATURE

1. E3 RUNNING

2. E3 OVERHAULING

3. M5

4. E1

5. E2

6. M1

7. PANTOGRAPH

8. M3

9. M2

10.E5

11.E4

7. ABR- AIR BLAST CIRCUIT BREAKER

LOCATION: Relay Panel NORMAL ASPECT: SETFUNCTION: It ensures supply from panto, MCP working properly and Aux. circuit 1 is ok.WHEN TRIPS: ABB/VCB of that unit will trip and ABB off indication will glow.

8. CR- COMPRESSOR RELAY

LOCATION: Relay Panel NORMAL ASPECT: SETFUNCTION: When it is SET, it ensures that main compressor is working.WHEN TRIPS: ABB/VCB of that unit will trip and ABB off indication will glow.

9. ARR- AIR BLAST CIRCUIT BREAKER RELAY

LOCATION: Relay Panel NORMAL ASPECT: TRIPFUNCTION: When the unit is energized, it is SET and ensures supply receiving from the OHE.WHEN TRIPS: ABB/VCB of that unit will trip and ABB off indication will glow.

10. SR- STARTING RELAY

LOCATION: Relay Panel NORMAL ASPECT: TRIPWhen notch is taken SR will SET in step by step. The conditions for pick up of SR are-

1. CBAR, TTR, RFAR & NVR is SET.2. WCO (Winding Change Over) must be in LV (low voltage) side.3. All tap changers are de-energized i.e. all tap changer contactors are open.

FUNCTION: It sets the unit to start the driving unit.WHEN TRIPS: ABB/VCB of that unit will trip and ABB off indication will glow.

RELAY BOARD

TRAINING SCHEDULE: According to TRS/BARASAT/CS, our training schedule was as follows-

DATE SECTION DESCRIPTION

2.07.2012 E3(RUNNING) Rotating machines like Traction Motor, Auxiliary Motors etc. inspection and running

3.07.2012 E3(OVERHAULING) Traction Motors and Auxiliary Motors Overhauling section

4.07.2012-5.07.2012 M5 Pneumatic equipments for brakes, exhausters, compressors, valves inspection, repair & overhaul

6.07.2012-7.07.2012 E1 Electric trouble shooting, engine examination, testing of locomotives, blowing and cleaning of locomotives.

9.07.2012-10.07.2012 E2 Electric inspection and repairing of parts noticed to be defective on the locomotive itself during inspection. Only control equipments like tap changer, transformer and rectifier fall under this section.

11.07.2012-12.07.2012 M1 Inspection of mechanical parts of locomotives like under frame, brake gear wheels and axles and running mechanical repairs.

13.07.2012 PANTOGRAPH Inspection, repair and overhauling of Pantograph & Main Compressor, Auxiliary Compressor & Servo Motor.

14. 07. 2012 M3 Passenger amenities section, repair of coaches and their interiors

16.07.2012 M2 Heavy Mechanical Repairing Section. Lifting of locos in the lifting bay removing of roofs, hoods and all equipments requiring crane work in the lifting bay.

17.07.2012 E5 Heavy electric repairs, immediate overhaul of electrical equipments other than rotating machines, relays, circuit breakers etc. Also includes repairing of all defective electrical equipments removed during inspection by E2

18.07.2012 E4 Inspection, repair and overhaul of all delicate and precision electrical equipments like relays, speedometers,

ammeters, voltmeters, circuit breakers etc.