A SEMINAR presentation ON

RAILWAY WORKSHOP.

SUBMITTED BY: mahesh

CONTENTS

1. Air conditioner(A.C) shop. Introduction. Specification. RMPU. Safety protection of control panel. 2. Power shop. Introduction. Substation. Intro to protective devices. Testing of transformer coil.

3. PCO Shop Its meaning. Working & analysis. Inspection done by PCO(electric). Insulation testing.4. Train lightning shop. Fan section. Battery section.

AIR CONDITIONER.(Introduction)

To supply duty clean fresh air to keep low order concentration of carbon dioxide and smoke with in low limits.

To cool the air in summer and to heat in winter in order to maintain proper temperature inside the premises of air conditions.

To control the humidity of the air conditions.

Specification(AC):In one coach two alternator of 25kw are

employed, this type of alternator are connected to axle of wheel by two pulley

Early, under the coach conventional A.C unit is installed, in this unit compressor (6.5 or 7.5ton) i.e. very bulky is used.

Now a days RMPU(roof mounted package unit) are used, in this two compressor are use of 3 ton(very compact) which are not required the motor to run

RMPU(Roof mounted package unit)

In consists of two compressor & two condenser motor are use of 3 ton & they are very compact in size.

Vane relay are used to protect circuit of RMPU.Its work is to start other thing like compressor

condenser motor often the start of blower motor.Water tank employ under the coach, so that

water motor (3Ø,415,1.2A,2880RPM) also used for water flow.

Also consist of two condenser motor, one blower motor & the cooling coil.

SAFETY PROTECTION IN THE CONTROL PANEL

Temperature protective thermostat sets to switch OFF power to the heater element in case the surface temperature of the heater reaches 200deg.C.

Electro-pneumatic time delay relay are used to ensure delay in starting of each compressor when power is switched “ON” and to prevent both compressor starting at once.

TWO VANE RELAY are provided to ensure the start operation of condenser fans, compressor or heaters

2. POWER SHOP.

The electricity is supplied by RSEB (Rajasthan State Electricity Board) and is also generated by generator sets in case of supply failure. The requirement of electricity in workshop is as follows:

I. Connected Load-4600 KVAII. Demand-1360 KVAIII. Maximum Demand-1400 KVAIV. Actual Utilization:

i. Dayshift=1100-150 KVAii. Night shift=400-500 KVAAverage Consumption Per Day/Month-9000

units/95300 KWHLightning Consumption Per Month-15000 unitsTariff Applicable -HT-1 of RSEB

SUBSTATION:

Railway Workshop has its own 11/0.4 KV substation, the incoming feeder of 11 KV is coming from 66 KV OLD POWER HOUSE Jodhpur. The main equipments of the substation are as follows:

InsulatorsMetering and Indicating InstrumentsInstrument TransformerCapacitor banks

INTRODUCTION TO PROTECTIVE DEVICES:

1. High rupturing capacity fuse: It clears high as well as low faults current, disadvantage is that it is replaced after each operation in which fuse time limit is set for fault clearing.

2. MCB(miniature circuit breakers): They can be open a circuit for safety or maintenance reasons and provide automatic circuit protection & didn’t replaced after a dangerous over current(100A) is passed.

3. MCCB(moulded case circuit breaker): High rated version of MCB(i.e. 1000A) trip may be adjusted.

Railway Substation:Two set of APFC(automatic power factor

control) also employ, it operates manually & automatically both.

In this 3 different type capacitor are employee having capacity 150KVA(150KVA=5*12.5KVA-2 set) (5*5KVA-1set)

Testing of transformer coilIn this we take the sample of this & poured

into test cell, in which electrodes are polished spheres.

Preferly of brass arranged horizontally with their axes not less than 40mm above the bottom of the cell.

The test cell should be throughly cleaned and moisture & suspended particles should be avoided.

The voltmeter is connected onto the primary side of the high voltage transformer but calibrated on the low voltage side.

The voltage is increased gradually & continuously till a flashover of the gap. Note down this, & the voltage is known as rapidly-applied voltage.

3. PCO Shop

PRODUCTION CONTROL ORGANISATION (ELECTRICAL INSPECTION SECTION):

To make railways as protection of customer from the dangerous events (short circuit, faulty connections) which may cause a problem in the mid way of the journey.

It is the responsibility of the PCO department that no faulty coaches will move out from workshop.

LIST OF SOME IMPORTANT INSPECTION (CHECK) BEING DONE BY THE PCO ON THE OUTGOING COACHES:

All outgoing coaches have proper connections in between various equipments i.e Alternator, RCR, etc.

Suspension brush of alternator and the bogie should be modified made up of NYLON 66.

Capacity test of the batteries must be done and efficiency with capacity must be written on battery box.

Pulley joined to the alternator and axle of the wheel is perfectly OK and this is equipped with six new “V belt”.

It should not be repaired or not more than four years old. Flat belts should change into V belts.

Tube lights, fans and everything inside the coaches is in proper function. All equipments should be provided with ANTI THEFT ARRANGEMENT.

INSULATING TESTING:By this we check earth fault, short circuiting

between the connections, shocks to passenger insulation breakdown and leaking of the battery.

It is done by 500 volts MEGGER. This process is called “MEGGERING”. It is necessary because, if earth fault will occur than: checking can also be done using “TWO LAMP METHOD”.

In absence of insulation whole battery will collapse, because there will be continuous losses in the metal part of the coach.

PROBLEM OF COMMUNICATION EQUIPMENTS (mobile, pager, etc) may occur because as current flow in the metal frame of coach, some type of magnetic field may generate fire and it will affect severally the communication wave.

Railways being the public carrier bound to not only special safety and punctuality but also comfortably.

In view of this the lightning in coaches is an important electrical aspect with the steady increase in traffic.

4. TRAIN LIGHTNING SHOP

FAN SECTION:In railway three type of fans used in coaches.i. DC fan.ii. AC fan.iii. Brush less DC fan.

AC fan: AC fan same as over home ceiling fan. It has

starting winding running winding & capacitor(5µF±5%) range of supply voltage 90 to 140v.

In AC fan bearing used are 6200no. & consumes 60watts rotates at 950-1200RPM.

This type of fan only used in that coach which have INVERTER.

BL(Brushless) DC fan.Specification: 32W, bearing used 6200no. BL DC fan consists:a. FNN cab.b. Sensor magnet.c. Rotor magnet.d. PCB.e. Stator winding. Fan insulation on resistance is not less than

2MΩ it is checked by megger, in rainy season resistance should be 1MΩ.

DC fan:Fan(32watts bearing 6200no.) consists:i. Field coil.ii. Ball bearing.iii. Carbon brushes.iv. Bearing cap.v. carbon holder. Fan air flow also check in this section by

anemometer, its range=3.8m/s to 4.2m/s.

Battery section: Recharging or Repair of batteryIn railway two type of battery are used:i. LA (Lead acid) type.ii. VRLA(value regulated lead acid) type.

Lead acid type: In this firstly check specific gravity of

batteries which is needed to be 1200. Then the worker insert lead acid to make

specific gravity upto 1200. If it is greater than 1200 then add water to

make upto 1200 again.

Maintenance of LA battery:

LA type battery first charge at C10 (C10=10% rate of capacity for 12 hours).

After discharge by C10(10% rate capacity for 9 hours)

After second time charge at C10 rate for 12 hours & load in coach.

Maintenance of VRLA battery: They needed to be very less maintenance

because in VRLA battery lead acid in the form of viscous.

First change at C20(20% rate of capacity for 24 hours) & discharge by C10 rate for 9 hours.

Second time charge at C10 rate for 12 hours.In railway battery used in consideration of voltage:

i. 2V battery.ii. 6V battery.

Thank you