ELECTRICAL COACHING DEPARTMENT

A

REPORT

ON

INDUSTRIALTRAINING

AT

COACH CARE CENTRE HAZARAT NIZAMUDDIN

SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENT

FOR THE AWARD OF THE DEGREE OF

BACHELOR OF TECHNOLOGY

IN

Electrical & Electronics Engineering

Submitted By

ASHWANI KUMAR

04413304912

Under the Supervision of SSE Mr. SHIV KUMAR

HMR INSTITUTE OF TECHNOLGY AND MANAGEMENT

Plot No. 370, Hamidpur, Delhi Pin code – 110036

DECLARATION

I hereby declare that all the work presented in this report in the partial fulfillment of

the requirement for the award of the degree of Bachelor of Technology in Electrical

& Electronics Engineering, HMR Institute of Technology and Management, Guru

Gobind Singh Indraprastha University, Delhi, is an authentic record of the work done

during the Industrial Internship carried out in Northern Railway under the guidance

of Mr. Shiv Kumar.

Date:

Signature

ACKNOWLEDGEMENT

I am very much grateful to the authority of the organization for taking initiative for the industrial training to upgrade my knowledge by placing me at Northern Railway (Chg. Depot/HNZM). I owe many thanks to several people who helped and supported me during this training.

I wish to express my gratitude to the officials and other members of Northern Railway who rendered their help during the period of my training.

I express my sincere thanks to SSE/Chg./HNZM Mr. SHIV KUMAR, who through her

expert guidance helped me throughout the course of this training. If it was not her

motivation and encouragement, I would not have seen through this training course

in an honest course to the splendor of success.

ASHWANI KUMAR

(Electrical& Electronics Engineering)

HMR Institute Of Technology & Management

CONTENTS

1. DECLARATION

2. ACKNOWLEDGEMENT

3. CERTIFICATE

4. INDIAN RAILWAYS

Introduction

History

Diesel Shed

Shed Layout

5. TRAIN LIGHTING

Introduction

Alternator

Rectifier Cum Regulator Unit(RRU)

Batteries

Carriage Fan

Carriage Lighting

6. POWER HOUSE

Introduction

Step-Down Transformer

Alarm/Hooter System(Buccholz Relay)

Isolator

Bus-Coupler

Protective Relays

Oil Circuit Breaker

Air Circuit Breaker

7. THE RAJDHANI EXPRESS

Introduction

Power Scheme In Rajdhani Express

Inductive Reactor

Inter-Vehicular Coupling

Disconnecting & Earthing Device

Battery-Box

Transformer

Water-Pumps

Coach Configuration

Linke-Hofmann-Busch-Coaches

Pantry-Car

Air Conditioning System

1. INDIAN RAILWAY

INTRODUCTION

Indian Railway is the state-owned railway company of India, which owns and operates most of the country's rail transport. It is overseen by the Ministry of Railways of the Government of India.

Indian Railways has one of the largest and busiest rail networks in the world, transporting over 18 million passengers and more than 2 million tons of freight daily. It is the world's largest commercial or utility employer, with more than 1.4 million employees. The railways traverse the length and breadth of the country, covering 6,909 stations over a total route length of more than 63,327 kilometers (39,350 mi). As to rolling stock, IR owns over 200,000 (freight) wagons, 50,000 coaches and 8,000 locomotives.

By 1947, the year of India's independence, there were forty-two rail systems. In 1951 the systems were nationalized as one unit, becoming one of the largest networks in the world. IR operates both long distance and suburban rail systems on a multi-gauge network of broad, metre and narrow gauges. It also owns locomotive and coach production facilities.

INDIAN RAILWAY HISTORY

First railway system in India was proposed in 1832 in Madras but it

never materialized. In the 1840s, other proposals were forwarded to the British

East India Company who governed India at that time. The Governor-General of

India at that time, Lord Hardinge deliberated on the proposal from the

commercial, military and political viewpoints. He came to the conclusion that the

East India Company should assist major companies from England and private

capitalists who sought to setup a rail system in India, regardless of the

commercial viability of their project.

On September 22nd, 1842, British civil engineer C.B. Vignoles, FRS, submitted

a Report on a Proposed Railway in India to the East India Company. By 1845, two

companies, the East Indian Railway Company (EIR) operating from Calcutta, and

the Great Indian Peninsula Railway (GIPR) operating from Bombay, were formed.

The first train in India was not a passenger train and was operational on 1851-12-

22, used for the hauling of construction material in Roorkee. A few years later, on

1853-04-16,the first passenger train between Bori Bunder, Bombay and Thana

covering a distance of 34 km (21 miles) was inaugurated, formally heralding the

birth of railways in India. Prior to this there was in 1832 a proposal to build a

railroad between Madras and Bangalore and in 1836 a survey was conducted for

this line.

After the first passenger train run between thane and bori bander, almost six

years later, on March 3, 1859, the first Railway Line in North India was laid

between Allahabad and Kanpur. This was followed, in 1889, by the Delhi-Ambala

Kalka line.

The North eastern Railway was developed rapidly after that. On October 19,

1875, the train between Hathras Road and Mathura Cantonment was started

running. By the winter of 1880-81, the Kanpur-Farukhabad line became

operational and further east, the Dibrugarh-Dinjan line became operational on

August 15, 1882.

Developments were fast and effective in South India also. The Madras

Railway Company opened the first railway line between Veyasarpaudy and the

Walajah Road on July 1, 1856. This 63-mile line was the first section, which

eventually joined Madras and the west coast. On March 3, 1859, a length of 119

miles was laid from Allahabad to Kanpur. Later In 1862, the railway line between

Amritsar and Attari was constructed on the Amritsar-Lahore route.

In 1900, the Great Indian peninsular Railways became a government owned

company. The network spread to modern day states of Assam, Rajasthan and

Andhra Pradesh and soon various independent kingdoms began to have their own

rail systems. In 1901, an early Railway Board was constituted, but the powers

were formally invested under Lord Curzon. It served under the Department of

Commerce and Industry and had a government railway official serving as

chairman, and a railway manager from England and an agent of one of the

company railways as the other two members. For the first time in its history, the

Railways began to make a profit.

In 1907 almost all the rail companies were taken over by the government. The

following year, the first electric locomotive made its appearance. With the arrival

of World War I, the railways were used to meet the needs of the British outside

India. With the end of the war, the state of the railways was in disrepair and

collapse.

Indian Railway provided an example of the British Empire pouring its money and

expertise into a very well built system basically designed for military reasons (after

the Mutiny of 1857), and with the hope that it would stimulate industry. The system

was overbuilt and much too elaborate and expensive for the small amount of

freight traffic it carried. However, it did capture the imagination of the Indians, who

saw their railways as the symbol of an industrial modernity—but one that was not

realized until a century or so later.

The British built a superb system in India. However, Christensen

(1996) looks at of colonial purpose, local needs, capital, service, and private-

versus-public interests. He concludes that making the railways a creature of the

state hindered success because railway expenses had to go through the same

time-consuming and political budgeting process as did all other state expenses.

Railway costs could therefore not be tailored to the timely needs of the railways

or their passengers.

By the 1940s, India had the fourth longest railway network in the world. Yet the

country's industrialization was delayed until after independence in 1947 by British

colonial policy. Until the 1930s, both the Indian government and the private

railway companies hired only European supervisors, civil engineers, and even

operating personnel, such as locomotive drivers (engineers). The government's

"Stores Policy" required that bids on railway materiel be presented to the India

Office in London, making it almost impossible for enterprises based in India to

compete for orders. Likewise, the railway companies purchased most of their

material in Britain, rather than in India. Although the railway maintenance

workshops in India could have manufactured and repaired locomotives, the

railways imported a majority of them from Britain, and the others from Germany,

Belgium, and the United States. The Tata Company built a steel mill in India

before World War I but could not obtain orders for rails until the 1920s and

1930s.

What is diesel shed?

It is a place where repair and maintenance work of diesel locomotives

Is carried out so as to increases its life and efficiency and to reduce

line failures to a minimum extent.

Diesel Shed TKD

Tughlakabad is one such premier shed in Northern Railways homing

162 Diesel Locos. Because of its geographical location and being

In the capital, it serves a large number of Mails /Express trains which across the length & breadth of the country casting to goods operation.

Diesel Shed, Tughlakabad is spread over an area of 1,10,000 m 2 out of Which 10,858 m2 is covered.

Diesel Shed, Tughlakabad was established in the year 1970 with a planned

Holding of 75 locomotives and initial holding of 26 WDM2 locomotives.

Today, after 36 years of its existence, the shed has grown to a total holding

Of 162 locomotives of five types, which include 59WDM2 (2600HP) 21 WDM4

(3100HP) 02 WDM2 (3300HP), 51 WDP1 (2300HP) and 29WDP3 (3100HP).

Shed is maintain a mail link of 122 locos, which is highest for any shed on Indian

railways. Some of the important and prestigious trains being run by the shed are:

Jammu Tawi and Guwahati Rajdhani express, Shatabdi express for Amritsar,

Dehradun and Ajmer, Puja Express, Uttar Sampark kranti, Lucknow Mail,

Kashivishwanath, Sharamjivi Express and the tourist train palace-on-wheels.

SHED LAYOUT:

The shed has a total berthing capacity for 17 locomotives under 4 covered bays.

The main bays are:-

1. The subassemblies section

2. The heavy repair and bogie section(3 berths for heavy repairs & 2 lifting

points)

3. Mail running repair bay (6 berths).

4. Goods and out of course running repair bay(6 berths)

There was one old steam shed. This shed had a capacity for berthing 4

locomotives. This shed was used for light repairs only. Now a days, a new

construction is being on for new locos of make WDP4 locomotives.

2. TRAIN LIGHTING

INTRODUCTION

Train lighting of a self-generated coach is being discussed here. The generation is

done by the under gear equipment i.e. a 3 phase brushless alternator with a

Rectifier cum Regulator Unit (RRU)

ALTERNATOR

SPECIFICATION OF ALTERNATOR:

Connection Star

Generated voltage 97V AC

Rating 4.5kW

No. Of V grooves 4

The alternator is mounted between two wheels. The V belts are attached in the V

grooves on the pulley attached to the shaft and the axis of the wheel.

External Components:

Bogie bracket

Suspension pin

Cutter pin

Split pin

Bogie nylon bush

Tension rod

Bogie bush

Alternator power supply

1. The alternator starts producing voltage when rotor achieves a minimum

speed of 350rpm.The alternator does not generate until the train achieves a

minimum speed of 22kmph.

2. The output of alternator is provided to RRU at an optimum speed of 38kmph

3. 110 V DC from RRU feeds the whole lighting system of the coach and

simultaneously charges the cells used underneath each coach .When the

train is at standstill the charged cells provide the lighting..

RECTIFIER CUM REGULATOR UNIT (RRU)

Main features of ERRU with UVC: Fast and reliable switching devices. Alternator identifying facilities and

Auto setting of parameters such as output DC voltage, battery current, load current which in turn increase the life of battery and the alternator itself.

Monitoring real time value of alternator voltage, load current, battery AH (IN), AH(OUT) etc., through interface fitted inside the coach.

Main Components of ERRU: The main components of the ERRU are as follows

Terminal Box Power Unit Universal Voltage Controller (UVC) Static Over Voltage Protection (OVP) Emergency Field Extension with interface High Reliable Components Hall Effect Sensor. ISOPACK Power Diodes.

Main advantages of ERRU:

Control circuit is Modular type design. Auto identification of alternator ratings and indications. Auto setting of parameter of voltage, load current, Battery

current, over voltage, over current and current limiting for all the regulator of 4.5 kW, 18 kW and 25 kW.

UVC is interchangeable with all types of Electronic Regulators from 4.5 kW to 25 kW.

Close regulation of voltage +/- 2 V over the entire range of load and speed to have uniform charging of batteries.

Less voltage and current ripple on Battery Charging current. Controlled Battery charging current to have longer life of

batteries.

Rating and Settings :

4.5 kW Regulator: Ratings: Voltage: 124 V

Full Load amps: 38 A Speed Range: 550 RPM to 2500 RPM.

Settings : Normal: 124V +/- 0.5 V at 19 Amp. And at 1500 RPM Facility available for setting: 120V, 122V & 124V Load Current: 42 Amp (Maximum) Battery charging current: 24 Amp (Max.)

HIGHLY RELIABLE COMPONENTS:

High reliable components are added to minimize the failure in the Electronic Regulator. The working principle of these components are ad mentioned below are explained here under.

Hall Effect Senor. Isopack Power Diodes.

HALL EFFECT SENSOR :

The Hall sensor is a transformer operating with a balanced magnetic flux principle to measure D.C. – A.C – pulsating current with galvanic Insulation between primary and secondary circuits. The primary current produces a magnetic field, which is detected by a Hall Effect device and, via an electronic amplifier, is immediately balanced by injecting a current into the secondary winding. The secondary current thus injected is the exact replica of the primary current times the turn’s ratio. This closed loop current sensing is fed into the main circuit to limit the output current and protect the equipment from over current. ISOPACK POWER DIODES :

These diode modules contain two diodes in a single pack and have a base plate, which is ceramic isolated from the power circuit. They can

be mounted directly on the heat sinks needing no insulation in between. This results in effective heat transfer to the heat sink and thereby reducing temperature of the device. These modules are tested for more than 1.5 kV isolation between live terminals and base place. The ratings of devices are as follows – VRRP: 1800 Volts peak to peak. I (avg): 350 Amps.

PERIODICAL MAINTENANCE INSTRUCTION FOR ERRU

1. Check all the connections are tight. If found any loose connection, tighten the connection. 2. Care must be taken for connecting the terminals in correct polarity. The reverse connection may cause severe damage in regulator. 3. Do not disconnect the connectors from UVC and terminals. If any disconnection is found, connect the connectors in original position. Do not connect any wrong side and wrong connection will cause damage in regulator. 4. Do not keep open the UVC door as well as regulator box and terminal covers. Open door may give chance to enter the dust and metallic things inside and this may cause any short circuit in the regulator. 5. In case of fuse blown, is suggested to use proper HRC fuse. Do not tie with wire and this wire-fuse will cause any damage in the regulator. 6. Protections are safety for our systems; so do not bypass the protecting systems lie, OVP and fuse.

BATTERIES

Description of different types of cells:

Lead acid cells demand less maintenance and are less costly.

Type of cells in use for train lighting and coach air-conditioning are:- Capacity of battery in AH Type of coach: At 27 Degree C at 10 Hr Rate where generally used 120 110 V, BG coaches 450 MG AC Coach 525 Jan Shatabdi Non - AC coaches 800 II AC BG Coaches (Old) (Under-slung type) 1100 II AC BG Coaches (new)/AC 3 Tier Coach PRINCIPLE OF OPERATION :

In a charged lead acid cell positive terminal consists of lead peroxide (PbO2) and the negative terminal 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 <=> 2PbSO4 + 2H2O During discharge, the lead peroxide on the positive plates as well as the spongy lead on the negative plates are converted into lead sulphate (PbSO4). In this process, sulphuric acid (H2SO4) is consumed and water (H2O) is formed. Consequently, the specific gravity of the electrolyte falls, the extent of fall being proportional to the ampere-hours taken out. The process at first causes 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 current. 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 lead-sulphate on the positive plates is reconverted into lead peroxide and the lead sulphate in the negative plates into spongy lead. Sulphuric acid is formed and the water consumed. The specific gravity of the electrolyte rises. There is at first a slow, later a faster rise of cell Voltage. From 2.4 volts onwards gassing sets in due to a strong decomposition of water into hydrogen and oxygen. Violent gassing is injurious to the plate material.

So after reaching this gassing voltage the rate of the charging current must be limited to within safe permissible values. MAINTENANCE :

Hydrometer is used to ascertain the specific gravity of electrolyte in a lead acid cell.

The specific gravity is the relative weight or density of the electrolyte as compared

with a similar volume of pure water. The specific gravity of a cell should be

maintained at the value given by the manufacturer in the fully charged condition.

This value for fully charged cells at 27 degree C shall be between 1,210 and 1,220

for cells up to 525 Ah capacity and between 1.245to 1.255 for cells over 525 Ah

capacity as per IS: 6848.Voltmeter is used for taking the individual voltage of cells

and the battery as a whole. This voltmeter shall preferably be of a dry cell operated

digital type with a range of D.C. from 0 to 200 V.

GENERAL The rating assigned to the cell or battery is the capacity expressed in ampere-hours (after correction to 27 degrees C) stated by the manufacturer to be obtainable when the cell or battery is discharged at the 10 Hr. rate to the end voltage of 1.80 V per cell. Train lighting batteries of coaches by the very nature of service conditions cannot be expected to have steady rate of charge/discharge. They are often left to idle for long duration or charged at higher rates. Such strenuous service of these cells therefore calls for systematic and thorough examination while in service, prompt remedial measures of defects/replacement of cells and quality POH work in Shops to achieve the expected life without any loss of efficiency below 80 %. Running maintenance of storage batteries falls under four categories:- 1. Trip examination, 2. Fortnightly examination, 3. Quarterly examination, 4. Intermediate overhaul. Replace vent plugs after taking specific gravity and ensure that they are tight. "SWITCH ON" lights and fans in each coach and take the voltage readings across the set of 56 cells. "SWITCH OFF" all lights and fans.

Tap the floats of each cell and check for correct electrolyte level as indicated in the float stem. Replace missing/defective floats. In case of low level, replenish with pure battery grade water. If any cell needs too much water for replenishing, watch for crack in the cells and also check the voltage on load which should not be less than 1.80 V. In case of any defect, remove the cell and replace by a spare one preferably of the same make and lug date or a lug date as close to the one already in the coach. Use special containers provided with automatic siphoning device to RDSO drawing no. SKEL 611 for topping up battery grade water. Check tightness of packing and use additional packing if required. Coaches with discharged batteries which show less than 22 V on load should be put on charge at double the normal rate of charges and continued as long as possible till gassing starts or till the specific gravity rises to the fully charged value which should be between 1.210 and 1.220 for the cell up to 525 Ah or as recommended by the manufacturers and which is stenciled on the battery box. Use the battery charging terminals provided in coaches For charging purposes. Never skin the insulation of cables near end cell connections for this purpose. Checkup correct polarity and connect the charging cables. Use a clip-on d. c. ammeter of 0-100 A range to check up the battery charging current. Note down the rate of charging and the number of hours of charge. Check the specific gravity of Pilot cells and the total voltage of battery on load at the end of charge and record. Keep vent plug tight. Ensure that washer is available for vent plugs. The person in charge of battery maintenance should record all the readings mentioned above in his diary and this information should be transferred to the register maintained for various trains. Check anti-theft rods and provision of nuts both inside and outside the battery box on either side. Replace if found missing. Secure battery box cover finally after all works are completed.

CARRIAGE FAN

GENERAL 400 mm, 300 mm and 200 mm sweep carriage fans are used on Indian Railways in SG, MOG, and EOG coaches where the system voltage could be

DC 110 V or AC 110 V. As a passenger amenity item, carriage fans have to be maintained in such working condition as to obtain good air flow and trouble free service for ensuring maximum passenger satisfaction.

SPECIFICATION

Railway carriage fans are either of the fixed or swiveling type and conform to specification IS: 6680. Performance requirements of these fans are as follows:

CARRIAGE LIGHTING

GENERAL Carriage lighting is provided from:- a. Axle driven generators in conjunction with storage batteries on D.C. 110 V system. b. Diesel generator sets with step down transformers on A.C. 110 V in MOG system. c. Diesel generator sets with step down transformers on A.C.110V in E.O.G system. Ceiling light fittings in I, II&III AC, II Sleeper, postal vans and dining cars On DC 110 V system: 18 W, 2 ft. long fluorescent lamps with inverters.

OVERALL SCHEMATIC DIAGRAM OF POWER DISTRIBUTION FROM ALTERNATOR

3. POWER HOUSE

Introduction

A substation is a part of an electrical generation, transmission and

distribution system. Substations transform voltage from high to low or

reverse or any of several other important functions. Electric power may flow

through several substations between generating plant and consumer, and its

voltage may change in several steps.

A substation has a step up transformer increase the voltage while decreasing

the current, while a step down transformer decrease the voltage while

increasing the current for domestic and commercial distribution .The word

substation comes from the days before the distribution system became a

grid. The first substation were connected to only one power station, where

the generators were housed and were subsidiaries of that power station.

IN NZM POWER HOUSE the control is divided into two sections.

1. THE LOW TENSION SECTION 2. THE HIGH TENSION SECTION

The main components of the power house are: Transformers{300 KVA &500 KVA}

Circuit breakers { Air circuit breakers on L.T side & vacuum circuit

breakers on H.T section }

Relays { Earth Fault Relay & Over Current Relay }

Bus Coupler

Hooter / Alarm

Isolator {P.F :1 Sub Station }

The components are described in brief from the power house below:-

STEP-DOWN TRANSFORMER

A transformer is a device that transfers electric energy from one circuit to another

circuit through inductively coupled conductors---the transformers coil---a varying

current in the first or primary winding creates a varying magnetic flux in the

transformer core and thus a varying magnetic field through the secondary

winding. This varying magnetic field induces a varying electromotive force (EMF)

or voltage in the secondary winding. This effect is called “mutual induction”.

If a load is connected to the secondary, an electric current will flow in the secondary winding and electrical energy will be transferred from the primary circuit through the transformer to the load. In an ideal transformer ,the induced voltage (Vs) in the secondary winding is proportion to primary voltage (Vp) and is given by the ratio of the number of turns in the secondary(Ns) to the number of turns in primary(Np) as follows-----

Vs/Vp=Ns/Np

By appropriate selection of the ratio of turns, a transformer thus allows an alternating current voltage to be “stepped up” by making Ns greater than Np

or “stepped down” by making Ns less than Np.

In the vast majority of transformers, the winding are coils wound around a ferromagnetic core, air-core transformers being a notable exception.

IN NZM POWER HOUSE two transformers are used, one 300KVA and another 500KVA.

A spare 300KVA transformer is kept for backup.

Transformer ratings:-

C SERIAL NO: 1581/D7-08

MAKER AUTOMATIC ELECTRIC GROUP

KVA 500KVA

VOLTS AT NO LOAD H.V: 6000V

L.V: 415V

AMPERES H.V: 48.11A

L.V: 695.62A

PHASES H.V: 3

L.V: 3

TYPE OF COOLING OIL NATURAL COOLING

FREQUENCY 50C/S

IMPEDENCE VOLTS 4.37%

VECTOR GROUP REF DY11

CORE & WEDGES 1140KG

WEIGHT OF OIL 451KG

ALARM/HOOTER SYSTEM (BUCCHOLZ RELAY)

The alarm is employed to the system to indicate the faulty condition. If any fault

occurs in the system components the alarm sounds to notify.

Diagram {bus coupler and buzzer (alarm/hooter) at NZM power house HT panel}

ISOLATOR

In electrical engineering, an isolator switch is used to make sure that an

electrical circuit can be completely de-energized for service or maintenance. Such

switches are often found in electrical distribution and industrial applications

where machinery must have its source of driving power removed for adjustment

or repair. High voltage isolation switches are used in electrical substations to

allow isolation of apparatus such as circuit breakers transformer and transmission

lines for maintenance.

TOTAL WEIGHT 2105KG

OIL AMOUNT 530LITRES

MAX. TEMP RISE IN OIL 45 DEGREE

BUS-COUPLER

Bus coupler provides electrical isolation bus by employing coupling

transformers and fault isolation resistors. The Bus couplers contain two isolation

resistors {one per wire} and an isolation transformer {with a ratio one to the

square root of two}. The purpose of bus coupler is to prevent a short on a single

stub from shorting the main data bus. The buses of two different voltage levels

cannot be connected in series. So, bus coupler is used to join the buses of

different voltage level.

PROTECTIVE RELAYS

A relay is fault sensing device. Many relay use an electromagnet to operate a

switching mechanism mechanically, but other operating principles are also used.

Relays are used where it is necessary to control a circuit by a low-power signal

(with complete electrical isolation between control and controlled circuit) or

where several circuits must be controlled by one.

Signal. The first relays were used in long distance telegraph circuits, repeating the

signal coming in form one circuit and re-transmitting it to another. Relays were

extensively used in telephone exchanges and early computers to perform logical

operations.

A type of relay that can handle the high power required to directly control an

electric motor is called a conductor. Solid-state relays control power circuits

with no moving parts, instead using a semiconductor device to perform

switching. Relays with calibrated operating characteristics and sometimes

multiple operating coils are used to protect electrical circuits from overload or

faults; in modern electric power systems these functions are performed by

digital instruments still called “protective relays”.

The Relays used in NZM Power House are of mainly two types:

OVER CURRENT RELAY

EARTH FAULT RELAY

THE RELAY SPECIFICATION :{ BASED ON ONE SAMPLE ON H.T. PANEL}

OVER CURRENT RELAY EARTH FAULT RELAY

Model No. CDG31EG001SBCH Model No. CDG31EG001SBCH

SERIAL NO. 130954160621011 SERIAL NO. 130954160621011

C.T. SEC: 5 AMPS;2.5-10 AMPS C.T. SEC: 5 AMPS;1-4 AMPS

FREQUENCY:50HZ FREQUENCY:50HZ

OIL CIRCUIT BREAKER{O.C.B}: The oil in OCB’s serves two purposes. It insulates between the phases and

the ground, and it provides the medium for the extinguishing of arc. When

electric arc is drawn under oil, the arc vaporizes the oil and creates a large

bubble that surrounds the arc. The gas inside the bubble is around

80%hydrogen, which impairs ionization. The decomposition of oil into gas

requires energy that comes from the heat generated by the arc. The oil

surrounding the bubble conducts the heat away from the arc and thus also

contributes to deionization of the arc.

Main disadvantage of the Oil Circuit Breaker is the flammability of the oil

and the maintenance necessary to keep the oil in good condition.

THE OIL CIRCUIT BREAKER SPECIFICATION :{BASED ON ONE SAMPLE

ON L.T.PANEL ON 1.NO PF SUB STATION}

SL.NO 2K2132

TYPE HN2T

NORMAL CURRENT 400A

SERVICE VOLTAGE 415V

DESIGN FREQUENCY 50HZ

BREAKING CAPACITY 25MVA

TRIP COIL RATING 5A

CALIBRATION 100/200%

C.T. RATIO 800/5

Protection circuit breakers of electrical machines {generators, motors,

transformers, capacitors}. They are used in all type of plants {civil, industrial, and

in the service selector} as well as in the equipment on-board ships, in mines, in

prefabricated substations, and for primary and secondary distribution in general.

THE AIR CIRCUIT BREAKER SPECIFICATION:

{SPECIFICATION BASED ON ONE SAMPLE ON L.T.PANEL}

MAKER PULSER

FRAME LH800 DM 1T3P

SL.NO. Y606183

IEC-947-2 IS:13947{PART-2}

UTILIZATION CATEGORY 8

RATED CHARACTERISTICS

IN 400A

ITH@40 DEGREE C 800A

ICS & ICU 50Ka

ICW 50Ka,1sec

POWER FACTOR 0.25

Ui=1000V Ue=415V FREQUENCY: 50/60HZ

U/V 40 AC

DIAGRAM {AIR CIRCUIT BREAKERS}

o THE SCHEMATIC DIAGRAM OF AIR CIRCUIT BREAKER

DISTRIBUTION SYSTEM

o A DISTRIBUTION SYSTEM FROM 11KV SUBSTATION

4. THE RAJDHANI EXPRESS

INTRODUCTION

Rajdhani Express is a passenger train service, offered by the Indian

Railways, operating between New Delhi and other important destinations,

especially state capitals.

Rajdhani Express was introduced in 1969, for providing fast connections

(up to 140 km/h or 87 mph, speed variation depending upon the

particular track section) from New Delhi to the capital cities of various

states in India. The first Rajdhani Express left New Delhi station for Howrah

station to cover a distance of 1,445 km in 17 hours 20 mins.

This superfast train service get highest priority on the Indian railway

network. They are fully air-conditioned. Passengers are served

complimentary meals during the journey. Depending on the duration and

timings of the journey, these could include Morning Tea, breakfast, lunch,

high tea, and dinner.

Presently the technology used in these trains has been obtained from

Germany, with each individual coach built and exported by LINKE-

HOFMAN & BUSCH (known as the LHB coaches).The newest coaches are

said to be manufactured by a German company ALHSTORM.

This superfast train service runs on electric locomotives drawing power

from overhead 25 kV lines with the help of Pantographs. However power

required for lighting, heating, air conditioning purposes is generated

using Diesel Generator sets(known as D.G sets), implementing EOG(End

on Generation) with two power cars at the two ends of the train.

All Rajdhani Express trains offer three classes of accommodation: AC First

Class with 2- or 4-berth lockable bedrooms, AC 2-tier with open berths

(bays of 4 berths + 2 berths on the other side of the corridor) with

curtains for privacy, and AC 3-tier (bays of 6 berths + 2 berths on the side)

with curtains for privacy (according to recent directive the curtains in all 3

tier accommodations have been removed).

POWER SCHEME IN RAJDHANI EXPRESS

The components used in the power supply system consists of the

following components:

Diesel Generator (DG) set (2 in each power car) comprising diesel

generator and an alternator coupled together.

Reactor

Inter Vehicular coupling (known as Z-S coupler) between

coaches.

Transformers

Disconnecting and Earthling Device

Battery Box

Fuses

Air conditioning system

Water Heater

Lights, fans, pantry, etc.

D.G set : Each Power car has two diesel engines coupled with alternators for power

generation. Each alternator produce 750 V ac supply, with a capacity to provide

approx. 385 ampere current .Each coach requires about 40 ampere current.

Generally the efficiency is around 80% so about 300 amperes can be used.

Diesel Engine:

The Diesel engines are manufactured by Cotton-Greaves .The engine provides

the mechanical energy required to rotate the alternator shaft for electrical

power generation. Each engine produces 496 BHP of mechanical energy.

Alternator:

The alternator is coupled with the diesel engine .Each power car has two

alternators. The alternator specifications are as follows:-

ALTERNATOR SPECIFICATIONS:-

MAKER KIRLOSKER ELECTRIC CO. LTD

FRAME 4AB355/7

KVA 500 KVA

EXTR. A.C

R.P.M 1500

VOLTS 750V

AMPS 385A

EXTN. 280V

EXTN. 1.5A

FREQUENCY 50 Hz

PHASE 3

P.F 0.8

CONNECTION Y

COOLING TEMPERATURE 55 DEEGREE C

The voltage required for usage for the appliances in the coaches

is 415 V. But the alternator generates more voltage because

there are transmission losses from the power car to the

coaches.

D.G SET INSIDE POWER CAR

INDUCTIVE REACTOR:

The power generated in an ideal alternator is totally sinusoidal without any

unwanted surges and other harmonics .Only the primary harmonics present in the

signal. Among them the odd order harmonics specially the 3rd order harmonics can

damage the electrical equipment severely .The reactor is used to remove these

unwanted signals and provide pure sinusoidal signal.

REACTOR SPECIFICATION

MAKER KERALA ELECTRICAL AND ALLIED ENGG.

CO. LTD.

VOLTS 125V

AMPS 50A

FREQUENCY 150 Hz

PHASE 1

INSULATION CLASS CLASS H

INSULATION LEVEL AC3

TYPE OF COOLING AN

MAX TEMP. RISE 115 DEEGREE C

CORE AND WINDING 60KG

TOTAL WEIGHT 110

INTER-VEHICULAR COUPLING:

The power generated at the power car alternator is supplied to the coaches via

inter – vehicular coupling or ZS coupling.

The fixed transmission lines are not used in the supply system. Because if any of the coaches is needed to be removed for maintenance or some other purpose then the transmission line is to be cut, which is not a good operation. At the time of coach removal, coupling is opened and the coach is disconnected from the supply. At the time of maintenance the coupling is connected to the dummy connector at the coaches.

I-V COUPLING

DISCONNECTING AND EARTHING DEVICE:

While maintenance all the live supplies are to be removed and switched off.

While starting the maintenance the device disconnects all supplies and after the

job completion the device connects the coach to the supply.

BATTERY BOX:

Under each coach there is a battery box. This is used for back up

supply to the coaches. Each box supplies 110V DC. Each box contains 9 batteries

and each battery supplies 12.2 V DC. The batteries are charged by regulated

battery chargers (RBC) in side of each coach. If somehow this unit fails to charge

the battery the Emergency Battery Charger (EBC) charges the battery.

Operation of RBC and EBC:

Regulated battery charger can sense the battery condition whether it is to be charged in the float mode (fully charged) or in boost mode (discharged below a certain level). Thereby it chooses the charging voltage. RBC consists of a rectifier and a step down chopper circuit. Rectifier unit converts 415V, 3 phase 50 Hz AC to 130V DC and step down chopper i.e. the DC to DC converter converts 110V to 24V.

In float mode the battery set of LHB EOG coach gets charged with a voltage of 121.5V i.e. 13.5V per mono block and in boost mode it gets charged with 128.5V – 129V.

When RBC fails to operate Emergency Battery Charger starts to operate giving a constant supply of 115V – 118V to the batteries.

When EBC also fails we can observe the backup time for other components from MVR (Minimum voltage relay) card.

When both the battery chargers fail to operate then the contact no. 8 gets opened instantly, resulting in turning off the PA system and the Music system.

After next 30 minutes of the failure the contact no. 9 gets opened resulting in turning off the water pump system.

After next 8 minutes of turning of the water pump system the contact no. 10 gets opened resulting turning off the lighting circuit.

Battery box under the coach

TRANSFORMER:

The power generated in the alternator is 750V. This is much higher than the

required value. The Transformers are used to step down the voltage level to 415V

AC. The transformers are located under the coaches. Under each coach there is one

transformer to supply power (excluding pantry cars which have two transformers

for each coach).

Transmormer Specifications:

MAKER Vimal Transformer Corporation

INPUT 750V AC

OUTPUT 415 V AC

CAPACITY 60 KVA

FREQUENCY 50Hz

IMPEDANCE <4%

LINE AMP. 46.2A

OUTPUT 83.2A

WEIGHT <440KG

VECTOR CONNECTION Y.Y.O

VECTOR TYPE Primary :Star Secondary :Delta

WATER PUMPS:

The 750V AC coming from the alternators is stepped down to 3

phase 415V AC by the 60 KVA transformer. This 415V AC drives two centrifugal

pumps located in a stainless steel casing at the under frame supply the water to

the tanks. One of the 415 V pumps is always kept running, while the other is kept

on standby for 4 hours maximum. After 4 hours a microcontroller switches the

operation to the other pump. These supply water in the coaches.

THE COACH CONFIGURATION RAJDHANI EXPRESS:

Almost every Rajdhani Express offers three classes of accommodation:

First class AC with 2 or 4 berth lockable bedrooms

AC 2 tier with open berth with curtains for privacy

AC 3 tier with curtains for privacy The Rajdhani Express contains 20 coaches in total. The coaches are as below::

First class AC: 1 coach :H1

AC 2 tier: 3 coaches : A1-A3

AC 3 tier: 10 coaches :B1-B12

Pantry car: 2 coaches :PC

Power car: 2 coaches :EOG

The coach configuration is as follows:

Rake/Coach Composition LOCO-EOG-H1-PC-A3-A2-A1-B12-B11-B10-B9-B8-B7-B6-B5-B4-B3-B2-B1-PC-EOG

LINKE-HOFMANN-BUSCH COACHES:

Linke Hofmann Busch (LHB) coaches are the passenger compartments of Indian Railways that have been developed by Linke-Hofmann-Busch of Germany (renamed Alstom LHB GmbH in 1998 after the takeover by Alstom) and produced by Rail Coach Factory in Kapurthala, India. The coaches are designed for an operating speed up to 160 km/h and could go up to 200 km/h. However, they have been tested up to 180 km/h. Their length of 23.54m and a width of 3.24m means a higher passenger capacity, compared to conventional rakes. The tare weight of the AC chair car was weighed as 39.5 Tons.

They are considered to be "anti-telescopic", which means they do not get turned over or flip in case of a collision (chiefly head-on). These coaches are made of stainless steel and the interiors are made of aluminum which make them lighter as compared to conventional rakes. Each coach also has an "advanced pneumatic disc brake system" for efficient braking at higher speeds, "modular interiors" that integrate lighting into ceiling and luggage racks with wider windows. The improved suspension system of LHB coaches ensures more riding comfort for the passengers compared to conventional rakes. The air conditioning system of the LHB coaches is of higher capacity compared to the older rakes and is controlled by a microprocessor which is said to give passengers better comfort than the older coaches during summer and winter seasons. They are relatively quieter as each coach can produce a maximum noise level of 60 decibels while conventional coaches can produce 100 decibels. Each LHB coach costs between Rs 15 million to 20 million, whereas the power car which houses a generator costs about 30 million.

LHB coaches of the Rajdhani Express

AC 2 TIER & AC 3 TIER COACHES:

The train has 3 AC 2 tier and 10 AC 3 tier coaches.

Each coach gets its own power supply from the transformer below them.

The 3 tier (6+2 berth) and the 2 tier (4+2 berth) coaches have their own controlling and safety units at the ends of the coaches.

Each coach is provided with music system and announcement system which is controlled from the panels at the end.

Each coach has its own storage selection for food and water. For this purpose 2 deep freezers, 2 bottle coolers and 2 hot cases are provided. This unit is operated by the compressors and the blower motors of its own mounted below this unit.

FIRST CLASS AC COACH:

The train has only one first class AC coach.

This may contain 2 berths or 3 berths system.

The coach has controllable music system. The announcement and the music volume can be regulated in the first class compartment.

The first class coach does not have any bottle cooler or freezer.

THE PANTRY CAR:

The pantry car is the coach to supply food to the passengers and the

staff members. There are two pantry cars at the two ends of the train after the

power cars.

The different components of the pantry car are as follows:

EQUIPMENT

DESCRIPTION

LOAD

(WATT)

QUANTITY TOTAL

LOAD(WATT)

Deep Freezer,

230ltr

400 1 400

Bottle cooler 90ltr 200 1 200

Hot case 140 meals 1600 1 1600

Insect killers 20 2 40

Oven toaster Grill 1200 1 1200

Water boiler1 2000/3000 1 2000/3000

Water boiler2 2000/3000 1 2000/3000

Water boiler1 2000/3000 1 2000/3000

Electric burner 1 2000 2 4000

Electric burner 2 2000 1 2000

Electric burner 3 2000 1 2000

Electric burner 4 2000 1 2000

Refrigerator, 310 ltr 300 1 300

Electric chimney 1 300 1 300

Electric chimney 2 300 1 300

Electric chimney 3 300 1 300

Total load (watt) with 2000 Watt water boiler 28540

Total load (watt) with 3000 Watt water boiler 31540

Due to all these high rating equipment’s are housed in the pantry car, it requires more electric supply than other coaches.

Due to the operation of the heater, water boiler and other high loading elements there are much more risk for fire hazards. To deal with this problem the Smoke Detector is kept mounted in the ceiling of the car connected with alarm system. The smoke detector has a simple thermostat switch that automatically switches on the alarm under critical conditions.

AIR CONDITIONING SYSTEM

Principle of Operation of the AC System: The air-conditioning process maintains a constant climatic condition by controlling temperature, humidity, cleanliness, and noise and air motion. The air-conditioning system includes both refrigeration and heating. The refrigerating system depends for its action of the following principles.

(i) Latent principle: Any substance in passing from the liquid to gaseous state absorbs at constant temperature s specific quantum of heat known as the latent heat of evaporation and gives up latent heat on passing from gaseous to liquid state. Application: Evaporator and Condenser (ii) Expansion principle: When a gas expands without external heat exchange it temperature falls and when it is compressed without external heat exchange its temperature decreases. The air-conditioning system adopted in air-conditioned coaches work on mechanical compression system and consists of the following: Evaporator unit consisting of cooling coil (heat exchanger), heater and

motor-driven blower unit. Thermostatic expansion valve. Motor-driven compressor. Air cooled condenser (with cooling fan driven by motor) Liquid receiver and dehydrator. Refrigerant piping for conveying the refrigerant(R-134A).

THE REFRIGERATION CYCLE

A typical refrigeration cycle in an air-conditioned coach can be represented also in a pressure enthalpy diagram as in figure. The refrigerant gas at low pressure (represented by point C) is compressed to point D. The compression process elevates the pressure from 37 psi(maximum 46 psi) to 150 psi(maximum 180 psi). The compression of the gas also heats up the gas to a superheat condition. The gas at the compressor outlet is superheat and latent heat are removed at constant pressure, the refrigerant reaching the point A at the end of this part of the cycle. The line A-B represents the expansion that takes place in the expansion valve while the line B-C represents the refrigeration effect that is obtained in evaporator. Apart from cooling, the air conditioning equipment is also required to provide heating when the outside temperature varies from 400 C to 200 C .The cooling and heating will nave be necessarily automatic by means of thermostatic controls incorporated in the unit. RDSO specification also lays down that the equipment

shall admit fresh air at the rate of 0.35 metro cube per minute per passenger in the non-smoking area and 0.7 meter cube per minute per passenger in the case of compartments where smoking is permitted.

DESCRIPTION OF VARIOUS COMPONENTS OF AIR-

CONDITIONING SYSTEM

Evaporator unit: The evaporator unit consists of a thermostatic expansion valve, a heat exchanger, a resistance- heating unit and a centrifugal blower driven by a motor. The function of the thermostatic expansion valve is to allow the compressed refrigerant liquid to expand to a lower pressure corresponding to the load demand. The expanded refrigerant passes through a heat exchanger; the heat in the air is transferred to the refrigerant causing the cooling of the air and the evaporation of the refrigerant inside the tubes. The cooled air is led through the ducting to the various compartments and diffused by means of air diffusers. Fresh air is drawn through filters to eliminate dust and is mixed with the return air in the plenum on the inlet side of the evaporator. Similarly, the return air filters so that the dust contained air in the return air is extracted. When the outside ambient is very low and when the refrigeration is not required, the heater is switched on according to the setting of thermostat. Expansion valve:

The primary function of the expansion value is to control the quantity of liquid refrigerant admitted into the cooling coils of the evaporator. The expansion valve admits more refrigerant when the air conditioning load is high, and reduces it to the minimum when the load is low. If the air-conditioning load varies greatly the superheat may be set between 101 O F to 150O F.

Compressor: The refrigerants vapour drawn from the evaporator is compressed by means of a multi cylinder reciprocating compressor. The work done due to compression raises the temperature of the refrigerant vapour. Condenser:

The condenser serves the function of extracting the heat absorbed by the refrigerant vapour in the evaporator and the heat absorbed during the compression process. The condenser consists of a heat exchanger, which is force-cooled by means of two or three axial flow blower fans. The refrigerant vapour is cooled at constant pressure by means of the air blown over the finned tubes and liquefied. The refrigerant liquid leaving the condenser is led into the liquid receiver from where it proceeds to the expansion valve on the evaporator. The liquid receiver is a cylindrical container which contains a reserve of the refrigerant liquid. A dehydrator and filter are also provided to ensure that the refrigerant is free from moisture and dust particles. High Pressure Cot-out:

The high pressure cut-out is essentially a safety device against buildup of excessive delivery pressure and protects the compressor and piping system from damage. I t is a pressure operative switch which switches off the compressor drive motor when the pressure exceeds a preset valve. Low Pressure cut-out:

This is also a pressure operated switch similar to the high pressure cut-out switch, but is shuts down the compressor if the suction pressure drops down below 10 psi gauge. It protects the system against unduly low evaporator temperatures and formation of frost on the evaporator.

Dehydrator and Filter: Water vapor or moisture will cause trouble in any refrigeration system. The moisture may freeze and block the expansion valve orifice, and. Also cause corrosion in working parts. This is best achieved by subjecting the system of vacuum for 2 or 3 days. The dehydrator is another drying device containing silica gel or other similar drying agent inserted in the refrigerant load for removing moisture from the refrigerant while in operation. It should be provided at least temperature when the installation is brought into operation to remove any moisture in the piping system.

Refrigeration piping: The refrigerant piping consist of the suction line (from the evaporator outlet to the compressor inlet) and the discharge line (from the compressor outlet to the condenser inlet), and liquid line (from the liquid receiver to the inlet side of the expansion valve). Connections to the gauge panel from the compressor delivery side(high pressure side), low pressure side and from the compressor crankcase, the lubricating oil connections, are also part of the piping system, only copper pipes are used for refrigerant piping.

AC CONTROL PANEL:- The control of the air conditioning system is achieved by means of air conditioning Control Panel.

A.C. Control Panel Components and their functions

Evaporator Fan Motor Contactor: Controls the supply of the evaporator motor.

Evaporator Fan Motor Proving Relay:

The prevents energisation of the compressor motor and condenser

motor or Heater till trio evaporator motor (16) comes ’ON’ and blows air into

the duct through the evaporator coil. This relay works in conjunction with a

“Vone Switch” provided in trio air circuit. If the evaporator blower motor

supply fails or the motor does not run, the compressor motor and the

condenser motors/Heater will get switched ‘OFF’ by this relay.

Low Voltage Relay- This will trip to stop the compressor motor and condenser motors/heater, and prevent them from starting by cutting off the supply to their control circuit if the voltage of the battery is below 100 and reset when battery voltage rises to 102 V. The relay is provides with a build-in time delay f 5 seconds, to avoid nuisance – tripping.

Cooling Pilot Relay – Acts as an electrical link between the cooling thermostats and the control circuit of the compressor and condenser. This is energized by electronic triggering set off by heat thermostat.

Heating Pilot Relay- Acts as an electrical link between the heating thermostats and the control circuit of heater. This is energized by electronic triggering set off by thermostats.

Main Control Switch- This is the control switch for starting or shutting down the plant. This has got provision to select blower only, LOW, MEDIUM and HIGH temperature setting.

Single thermostat, i.e. Electronic thermostat is used for heating & cooling purpose.

Oil pressure Cut-out Switch- This protect the compressor against lubrication failure either due to lesser oil, oil pump failure or blocking of oil piping, and acts in conjunction with thermal cut-out to shut down the compressor only if the low oil pressure persists.

Low pressure cut out- A pressure switch to protect against working of compressor with low suction pressure due to loss of Freon gas or other reasons. This switch has been connected by means of copper piping to the suction header of the compressor.

High pressure cut-out- A pressure switch to shut down the compressor when compressor discharge pressure is too high. The switch has been connected to the compressor discharge header by means of copper piping.

Pilot lights- These lights indicate respectively normalcy oh the mains, blower fan motor, compressor motor, heater and normal voltage. Indications are now by LEDs.

DESIRABLE PROPERTIES OF THE REFRIGERANT:-

It should be non-irritating, non-poisonous, non-inflammable and have

no fanning effect on food stuffs if it escapes.

It should not have any corrosive action on any working part of the

compressor, condenser and evaporator.

It should not have any disagreeable order.

Leak detection should be easy and simple.

Latent heat of vaporization should be large to minimize the quantity of

refrigerant used.

The volume of vapor for given weight should be low to reduce the size

of the compressor.

R-134a (Tetra fluro ethane) is used as refrigerant as it is environment

friendly replacing R-134a. It has excellent refrigerating properties and

is the first choice for most air conditioning plant. It is safe, non-toxic,

non-inflammable.

Comparison of roof mounted A.C system with conventional under frame Hung

1.Weight 900 Kg 2700Kg

2.Installation Time 4 Hrs 4 days

3. Refrigerant R-22 Monochlorodia fluoro methane

R-134a Tetra flouro ethane

4. charge Less than 3.0 kg 15-20 kg 5. system design Hermetically sealed Open

6.Roof leak potential Nil Enormous 7. Power Supply A.C Nil

8.Damage due to Cattle run

Nil Heavy

9. Damage due to flash floods

Nil Heavy

10. Performance Excellent Deteriorates quickly due to dust collection under coach

11.Technology Latest Old and obsolete 12.Water drop on Nil Passengers at end

13.Fresh air From roof Takes from toilet 14.Cpacity control 25%-100% 50-100%

15.Down time for repairs

4 hrs Very long repair require