CARMEL POLYTECHNIC COLLEGE

ALAPPUZHA – 04

DEPARTMENT OF

ELECTRICAL AND ELECTRONICS ENGINEERING

( 2015 - 2016 )

SIXTH SEMESTER ELECTRICAL ENGINEERING

PROJECT REPORT ON

POWER RECTIFIER

SUBMITTED BY

JESTIN JAISON

REG. NO : 13030158

FINAL YEAR DIPLOMA IN ELECTRICAL AND ELECTRONICSENGINEERING

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CARMEL POLYTECHNIC COLLEGE

ALAPPUZHA – 04

DEPARTMENT OF

ELECTRICAL AND ELECTRONICS ENGINEERING

CERTIFICATE

This is to certify that the project report entitled on POWER RECTIFIER presented by

JESTIN JAISON ( Reg. No : 13030158 ) in partially fulfillment of the award of Diploma in

Electrical and Electronics Engineering under the board of Technical Education, Kerala during

the year 2015-2016 Carmel Polytechnic College, Alappuzha

GUIDED BY HEAD OF DEPARTMENT

INTERNAL EXAMINER EXTERNAL EXAMINER

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ACKNOWLEDGEMENT

We are very much obliged and grateful to Smt. Lizz Joseph, Head of Electrical Engineering Department, for providing us with best facilities and atmosphere for the completion of this project.

We also take this opportunity to express our sincere thanks to Mr. Suraj S., Lecturer in Electrical Engineering Department for this valuable advice and guidance in this project.

We also grateful to Fr.Kunjumon Job CMI, Principal, Carmel Polytechnic Engineering, and all the staff members of Electrical Engineering Department for their encouragement and support.

We also express our sincere thanks to Sri. Thomaskutty Mampra, Sri. Lijo Sir, Sri. Manoj Sir Lab instructors for their valuable co-operation given to us.

We also thank our friends and colleagues for the help rended and the interest shown to make this project a great success.

JESTIN JAISON

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PROJECT TEAM

1. Abhishek A

2. Abu Benny

3. Akshay Dhanesh

4. Antony Xavier

5. Jestin Jaison

6. Shidhily I

7. Sujithmon Mathew

Guided by, Sri. Suraj S

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SYNOPSIS

Now a day’s Electrical energy is the most widely used power resources. In our day-to-day life the need of electricity is growing with the developments in any field that utilize electric current.

Proper handing of electricity is needed to ensure safety. Improper handling may cause hazards like fire, server damage to the machines etc. To ensure more safety and to avoid such hazards, we should adopt modern facilities and equipments.

This project is done as a step to modernize our electrical lab by replacing D.C. generator and old wooden panel board by rectifier circuit and new cubicle panel board.

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CONTENTS

1. Introduction 07

2. Panel Board Diagram 08

3. Wiring Diagram 09

4. Circuit Diagram 10

5. Accessories for Panel Board installation 11

SFU – Switch Fuse Unit 11

Auto Transformer 11

Rectifier 12

Voltmeter 29

Ammeter 29

Indicators 29

HRC Fuse 29

6. Fabrication & Assembling 30

7. Testing 31

8. Estimation 34

9. Some I.E & I.S Rules 36

10. Conclusion 38

11. Bibliography 39

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INTRODUCTION

In modern era, the world give most importance is given to

the saving of energy. One way of saving power is by using modern electrical

equipment and safety device. For example the regulator of fan changes from

electrical to electronics. This project is based on modernizing our lab by using

modern accessories.

A motor- generator set, provides D C supply in our lab. It was installed

many years back. This method has many disadvantages. It causes a noise

pollution. Greater power is wasted by using this method. Also as this method

have been installed several years back its proper working cannot be guaranteed.

So it is high time to find an alternative way for producing direct current.

The most modern technology for producing D C is by rectifying A C with

the help of rectifiers. The most common method for producing D C is by using

diodes. Now a days metal diodes are widely used as rectifiers.

By using this method, for producing D C , the main problem of noise

pollution can be totally wiped off. Compared to Motor- Generator set for

producing D C there is no wastage of power in this method. greater safety can

be assured, as this is the most modern method . Rather than the former method,

this method has little maintenance. The capital cost required for this method is

much less than the former one. Hence rectifier system is the most favored

system now a days

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PANEL BOARD DIAGRAM

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WIRING DIAGRAM

CIRCUIT DIAGRAM

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ACCESSORIES FOR POWER RECTIFIER

SFU- switch with fuse unit

SFU is expanded as switch fuse unit. Its purpose is to protect the rectifier from any fault occurring the supply. It consists of three high rupturing capacity fuses, each of rating 63A.

AUTO_TRANSFORMERThe operating principle and general construction of an auto transformer

is same as that of conventional two winding transformer. The auto transformer differs from a conventional two winding transformer in the way in which the primary and secondary are inter related. In the conventional transformer, the primary and secondary windings are completely insulated from each other but are magnetically linked by a common core. In the auto-transformer, the two windings primary as well as magnetically, in fact, a part of the single continuous winding is common to both primary and secondary.

The auto-transformers are of two type construction. In one type of auto transformers, there is a continuous winding with taps brought out at convenient points determined by the desired secondary voltages. In the other type of auto-transformers there are two or more distinct coils, which are electrically connected to form a continuous winding. In either case, the same laws governing convential two winding transformers apply equally well to auto-transformer.

The auto-transformer are of two type. Step down auto-transformer and step up auto-transformer. Here the number of turns in the primary side is greater than the number of turns in the secondary side i.e. the value of transformation ratio (k) is less than one. Fig. b shows a step up auto-transformer. Here the number of turns in the secondary side is greater than the primary side i.e. the value of transformation ratio (k) is high.

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Step down auto - transformer

fig.a

Step up auto-transformer

fig.b

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RECTIFIER

It is well known that electric energy available to us in our country India is in the form of alternating 230V, 50Hz. But almost all electronic devices require D.C Voltage for its operation. Hence D.C is to be obtained from the available A.C source by converting it to D.C. Thus most of the electronic equipments include a circuit that converts A.C voltage into D.C voltage. The process of conversion from A.C to D.C is called rectification and the circuit, which convert it, is known as rectifier.

Diode is a uni-directional device. It provides a high resistance in one direction and a low resistance in another direction. It can be therefore be usedas a rectifier for converting A.C to D.C. Power supply circuits using diodes as rectifiers are commonly used in many types of equipment such as radio , T.V , tape recorder, computer etc.

There are two types of rectifiers

Half wave rectifiers

Full wave rectifiers

HALF WAVERECTIFIER

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Half wave rectifier is a simplest form of rectifier. The circuit arrangement of a half wave rectifier is shown in the fig. the primary side of the transformer is connected to the power mains(230v,50Hz).an ac voltage induces across the secondary winding, which is equal to, less than or greater than the primary voltage depending upon the turns ratio of the transformer. This will be the input voltage Vin to the rectifier. When the transformer secondary voltage is on its positive half cycle, the diode is forward biased and current flows through RL , developing a voltage across it. When the secondary voltage is on its negative half cycle, the diode is reveres biased and no current flow through the RL. Thus there will be no voltage across the output terminal during negative half cycle. Fig. b shows the input and output wave forms of a half wave rectifier. Her only the positive half cycles are suppressed. Thus we get a pulsating dc in output.

Wave form of half wave rectifier

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Disadvantages

Low output because one half cycle only delivers output. A,c components are more in the output. It Requires heavy filter circuits to smooth out the output.

Peak inverse voltage (PIV)

In the rectifier circuit given above, during negative half cycle of the Secondary voltage, the diode is reverse biased. As there is no voltage across the load resistor RL during this half cycle, the whole secondary voltage will come across the diode. When the secondary voltage reaches its maximum value Vm in the negative half cycle, the voltage across the diode in reverse bias is also maximum. The maximum voltage known as the peak invers voltage (PIV).

In case of half wave rectifier PIV = Vm

Ripple factor

The purpose of the rectifier is to convert a c voltage to dc . but no type of rectifier converters ac to perfect dc . it produce pulsating dc . this residual pulsation is called ripple.

Ripple factor indicates the effectiveness of a rectifier in converting ac to d.c. It is the ratio of the ripple voltage to the dc voltage.

i.e = ??? ? ?? ? ? ??? ? ?

? ? ? ? ??? ? ?

= ? .? .? ? ? ?? ? ? ? ? ? ?? ? ? ? ? ? ? ?

? ? ?? ? ? ? ? ? ? ?

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= V1 rms / Vdc

=I1rms /I dc

Or γ = √ (I2 rms – I2 dc) / Idc

= √(I rms – I dc ) -1

= √ ((Im /2) /(Im/π))2 -1

= √1057-1

= 1.21

From this value it is clear that in half wave rectifier the ac component exceeds the dc component .

Thus the half wave rectifier is a poor rectifier.

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FULL WAVERECTIFIER

In full wave rectifier, current flows through the load during both half cycles of the input ac supply. Thus in a full wave rectifier alternate half cycles of the input a care inverted to get a unidirectional output current.

Full wave rectifiers are two types

Centre –tap full wave rectifier

Bridge rectifier

Centre-tap full wave rectifier

The circuit arrangement of a centre tap full wave rectifier is shown in the fig . during positive half cycle of the input signal the diode D1 is forward biased and diode D2 is reverse biased condition. Thus a current flows through D1, Rl and the upper half of the transformer secondary. During negative half cycle of the input voltage, diode D2 become forward biased and D1 reverse biased, then current flows through D2 , Rl and the lower of the secondary winding.

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Here the current through RL during both half cycle of the input a c is in same direction. Therefore the output voltage taken across RL will be DC . the input and output wave forms are shown in fig.b.

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Peak inverse voltage (PIV)

In centre tap full wave rectifier, during positive half cycle of the secondary voltage diode D1 conducts and when secondary voltage attain sits maximum value Vm , a voltage equal to Vm will develop across RL with the polarity marked in fig. the diode D2 at that instant is reverse biased and the voltage across it will be the sum of the voltages developed across the lower winding of the secondary (Vm) and the voltage developed across RL = Vm.

therefore peak inverse voltage across the diode in this case will be

Vm + Vm = 2 Vm

i.e; PIV= 2 Vm

Bridge rectifier

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Bridge rectifier is the most commonly used full wave rectifier. The circuit arrangement of a bridge rectifier is shown in the fig. it consist four diode, but avoids the need for a centre- taped transformer. During the positive half cycle of secondary voltage, diode D1 and D3 will be forward biased, at the same instant ,diode D2 and D4 are reverse biased. Therefore diodes D1 and D3 are conduct and current flows through D1 , RL and D3.

During negative half cycle of the secondary voltage diodes D2 and D4 are forward biased and D1 and D3 are reverse biased. Therefore current flows through D2, RL, and D4.

Here in the both condition the current flow through load resistor RL is in the same direction. Hence dc voltage is obtained as the output. The wave forms are shown.

Peak inverse voltage

At the instant, when secondary voltage is at its positive maximum value Vm

diodes D1 and D3 are forward biased and conduct. Since conducting diodes have zero resistance and zero voltage drops across the them.

PIV= Vm

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Advantages of bridge rectifier

1. It does not require centre-tap transformer.2. Can deliver an output double to that of the centre-taped full wave rectifier

for the same secondary voltage .3. Diodes of low PIV (=Vm) rating can be used.4. Suitable for high voltage rectification5. Small transformer is used, as current in primary and secondary flows for

the whole cycle.

Disadvantages

1. Needs four diodes2. As two diodes comes in series during each half cycle, voltage drop due to

their internal resistance is more and hence the circuit is not suitable for voltage application.

Ripple factor

γ = √(Imax / I dc )2 -1

= ? (?? /√? )?

(? ?? /? )? -1

=0.482

It shows that in case of full wave rectifier output dc components exceeds the ac component. Thus full wave rectifier is in rectification process.

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THREE PHASE HALF WAVE RECTIFIER

Phase and amplitude relation in a three phase system

Rectifier convert alternating current to dc current. We are already discussed about single phase ac to dc converters. That is half wave and full wave rectifiers. Such rectifiers are used only for small power application like radio, audio amplifiers, and television receiver.

The dc power requirement of industry are usually much greater than that which a single – phase rectifier system, can economically supply. To meet this demand for large quantities of dc power, industry may employ rotary converters. But these impose severe problems of transmission of the dc power. A motor desirable solution is supplied by the use of electronic poly phase rectifier system.

Polyphase rectifier produce less ripple voltage per equivalent filter section than do single –phase rectifiers. Moreover, even if the load does not require a filtered dc output, polyphase rectifiers are more efficient in that the dc output is smoother and hence contains less wasted ac power. Since polyphase rectifiers are normally required to supply large amounts of power, heavy-duty, solid –state rectifiers or gas or vapor filled tubes are used.

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Let us briefly review the phase relationships in a three phase system. In fig. a four wire system is used as a source of three phase power. If an oscilloscope were connected from line to common, the resulting sine wave would apper as A in fig. this is our reference waveform. Wave form B from line 2 to common is delayed by 1200 or one third of a cycle that is there is a 1200

phase lag between waveforms A and B. similarly , waveform C from line 3 to common starts1200 after the start of waveform B. fig. is a composite of the three waveform all plotted on a common time axis to show the phase relationshipsamong them. These waveforms further show that the peak amplitude and frequency of each of the voltages are the same.

It is interesting to that single phase power may be taken from any two the lines in fig. it should be noted, however, that the voltage between any two hot lines, say, 1and 2 ,is greater than the voltage between any one line , not including common. Thus in a balanced system the voltage between any two lines, not including common, is equal to the voltage from any one of line to common x √3.for example, if voltages A,B and C in fig.are equal to 120 V .moreover there is a 1200 phase difference between voltages A1 ,B1 and C1.

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THREE PHASE HALF WAVE RECTIFIER WITH TRANSFORMER

A transformer less rectifier has the disadvantage that it is not line isolated. A rectifier employing a transformer with isolated primary and secondary winding overcomes this disadvantage. Moreover, since the voltage across the secondary can be stepped either up or down, a greater range of dc output voltage is possible. The circuit shown illustrates a three phase half wave rectifier using a transformer.the transformer primary is connected in delta, the secondary in star. Secondary winding Q1, Q2 and Q3 relate respect to primary windings P1,P2 and P3. Lines 1,2and 3 apply a three phase voltage to the primary. Assume that switches S1 ,S2 and S3 are closed. Then voltage A appears across Q1 and is applied to the anode of D1. Voltages B and C appear across Q2and Q3 , and are applied to the anodes of diode D2 and diode D3. The cathodes of diode D1 ,D2 and D3 are connected together. The resistive load RL, common to the three rectifiers is connected from cathode to the common return.

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Secondary winding voltage A,B and C are 1200 apart, as are the primary voltages. Let us that the respective transformer windings are related in a ratio 1:1. Then , if 120V appears across each of the primary windings, 120V will also appear across each of the secondary windings. The only advantage we have gained in this circuit is the isolation of the circuit from the supply mains.

THREE PHASE FULL WAVE BRIDGE RECTIFIER

The rectifier shown in fig. is popular in industrial applications because it can operate directly from the three phase power line without the need of a transformer. However, the circuit in fig is that of a three phase full wave bridge rectifier whose operation is quite different from that of the six diode three phase half wave rectifier

Fig. shows that the cathodes D1,D2 and D3 are connected at a common point C. The anode of D4 ,D5 and D6 are tied together at point A. The load resistance RL is connected between A and C. We note, moreover , that line 1 of three phase power source is brought to the junction of the anode of D1 and the cathode D4. Similarly, line 2 goes to the junction of the anode of D2 and the cathode of D5, and line 3 is connected to the junction of the anode of D3 and the cathode of D6. Only the three phase lines of the three phase supply are used. Common is not directly connected to the rectifier circuit.

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METAL RECTIFIERS

The metal rectifiers are now a days preferred to valve rectifiers as they are mechanically strong, more reliable and do not require any voltage for filament heating. There are two types of metal rectifiers.

a)Copper Oxide Rectifiers b)Selenium Rectifiers

a) Copper Oxide RectifiersSuch rectifiers are made by means of coating on one side of the disc with layer of red cuprous oxide, which is very hard and is formed by heat treatment. Such layers offers low resistance for the passage of current from oxide to copper plate but prevents their passage in the opposite direction.

b) Selenium Rectifiers

This is the most common type of rectifiers used in the industries. It has an advantage that a layer of selenium can be formed over any type of metal , but generally nickel plated steel is used.

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Construction of Copper Oxide Rectifier and Selenium Rectifiers

Copper Oxide RectifiersCopper oxide rectifiers are made from refined copper plates or disc

which are usually 1mm thick and 25mm in diameter or smaller . These disc are heated in air to a temperature of about 1000? C until a layer of 1mm of cuprous oxide is formed over the plates. Then the disc are annealed to modify the crystal structure of the oxide layer. Usually , over the red cuprous oxide , a black layer of cupric oxide due to oxidation is also formed , which is removed chemically leaving the layer of cuprous oxide. Contact is made to the film through the copper on which it is formed and a soft metal disc pressed on the outer surface.

Over the red cuprous oxide is provide an aqueous suspension of colloidal graphite over which comes the electrode of soft material such as lead. The

construction of copper oxide is represented in fig. Each disc is so formed is not generally used singly, since the maximum voltage which can be applied to it is about 6 to 8 volts and the maximum current in the forward direction should not exceed 0.1 to 0.15A/?? ? at an allowable voltage of 8 volts per element . Such units are connected in series and are put under the pressure of about 3kg per. sq

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Selenium Rectifier

It consist of a supporting plate made of nickel plated steel as shown in fig. About 1mm thickness layer selenium is applied to the above base under a pressure at about 130℃ .Then its temperature is raised to 180 to 215℃ , which changes the crystalline selenium into grey form. A low melting point alloy, such as tin alloy, is then sprayed over the selenium , which acts as a second electrode. The cell is connected into circuit by means of tags which in contact with both electrodes. The units can be connected in series or in parallel to make the rectifier suitable for various voltages and currents are assembled in stacks.

The selenium cell has some advantages over the oxide cell. Changes in temperature have less effect on selenium cell then on the copper oxide unit .It can withstand large reverse voltage. It can be operated at temperature as high as 75℃.

Characteristics of Metal Rectifiers

The rectifier offer low resistance in the forward direction but offer high resistance in the reverse direction. Fig. represents the current relation of the copper and selenium rectifiers. For a reverse voltage of about 18 volts , the selenium rectifier is said to pass current in the reverse direction.

Application

The rectifier instruments use metal rectifier in connection with moving coil instruments for measurement of AC voltage and current at power and audio high frequency up to 100KHz.They can be employed on the poly phase circuits to supply large value of currents.

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VOLTMETERM C type vertical mounting with circular dial with Zero adjustment at

the front side .Class of accuracy 1.0 range -0.005V is selected . Using this voltmeter voltages upto 300 V can be measured using this meter is 50 V.

AMMETER M C vertical mounting square shapes ammeter is used for measuring the

d.c output .Current ranging up to 100 A can be measured with this ammeter. A shunt having a drop of 75 mV is connected across it. The dial is divided to 5 sections each of 20A . The smallest parallel current that can be measured accurately with this meter is 2A.

INDICATORSThis helps to the line indication .These three neon lamps i.e red , yellow ,

blue ,which indicates the RYB line (supply lines).They are either connected before or after the switch fuse unit .A resistance of suitable value is connected in series with the lamp in order to reduce the voltage across it to 110V.

H.R.C FUSE The primary objection of low and uncertain breaking capacity of semi

enclosed re wireable fuses is overcome by high rupturing capacity or H.R.C catridge fuse. They are capable of clearing high as well as low fault currents. They do not deteriorate and they have high speed operation.

Under normal working condition the fuse element at a temperature below its melting point. Therefore it carries the normal load current. When a fault occurs the current increase and the fuse element melts before the fault current reaches its first peak. The heat produced in this process vaporizes the melted silver element. The chemical reaction between the silver vapor and the filling powder results in the formation of high resistance substance, which helps in quenching the arc.

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FABRICATION & ASSEMBLING

FABRICATION

The sheets for fabrication and cut in to required sizes as per the design and welded to the required structure.

PAINTING

The sheet is pre-treated with surface pretreatment chemicals (PTC), which are commercially available. The sheet is further phosphatised with phosphating chemicals. After this, sheet dried under hot air oven. The high-pigmented Chromium oxide primer is applied by brush and dried at 105 deg. C for 30 minutes in an air oven. The surface is sanded for proper adhesion of topcoat. The paint is applied by spray guns and dried at 120 deg. C for 20 minutes in an air oven.

ASSEMBLING

The panel board is of front-hinged type with single door. The required numbers of holes of suitable sizes are drilled for fixing the accessories. Porcelain spacers are used to isolate the accessories from the metallic body. Protective fuses, Bridge rectifier, Switch fuse unit, Shunt of ammeter are provided inside the cabin. Separate cabin is provided in the cabin for laying the cables. Openings are provided at the bottom for incoming and outgoing cables.

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TESTING

Various test to ne carried out on panel. The Indian standards institution has clearly defined the various tests to be carried out on a medium voltage panel. (IS 8623). The tests are broadly classified into two categories.

1. Type tests2. Routine tests

Type Tests

The following constitutes type tests.

a). Verification of temperature rise limits

This test is designed to verify that the temperature rise emits for the different parts of the panel have not exceeded the values as specified in IS 8623. The test is normally carries out at the values of rated voltage, frequently of current for which the panel is designed. The test shall be made for a time sufficient for the temperature rise to reach constant value. In practice, the condition is reached when the variation does not exceed 1 centigrade per hour.

b). Verification of dielectric properties.

This test is conducted by applying a test voltage between all live parts and the frame of the panel. The value of test voltage is 2500V. For a rated insulation voltage of 660V.the tests is considered to have been passed if there is no puncture or flash over.

c). verification of the short circuit strengths

The test is not required for small panels. rated Upton 63A. In this test the outgoing terminals are provided with a bolted short circuit connection. The test voltage shall then be applied once and for a time sufficiently long to enable the short circuit protective device in the unit to operate and clear the fault. After the test conductors shall not show any undue deformation.

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d). Verification of the continuity of the protective circuit

The continuity of the protective circuit shall be ensuring before installing the panel. Connection between live parts and the protective circuit shall be verified. Short circuit strength of the protective circuit shall also be checked using single-phase supply. The continuity and the short circuit strength of the protective circuit shall not be impaired after the test.

e). Verification clearance and crept age distances

It shall be verified that the values are specified by the Indian Standards (IS 4327). These clearance and creep age distance shall be verified by measurement.

f). Verification of Mechanical Operation

Mechanical Operation of various switchgears shall be verified after installation. The number of operating circles shall be 50. The test is considered to have been passed if the operating conditions of the apparatus, interlocks etc., have not been impaired and if the effort required for operation is practically the same as before the test.

g). Verification of degree of protection

The degree of protection verified shall be in accordance with IS 2147.

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ROUTINE TEST

A). Inspection of the panel

Inspection of the panel including the inspection of wiring and if necessary, electrical operations tests shall be carried out. The effectiveness of mechanical activating elements interlocks locks etc., shall be checked. The conductors and cable shall be checked for proper laying and the devices for

proper mounting. A visual is also necessary to ensure that the prescribed degree of protection, creep age distance and Clarence are maintained. The continuous especially the screwed connections shall be checked for adequate contacts, possibly the random tests, further it shall be verified that information and markings are completed. In addition, the conformity of the panel to the circuit and wiring diagrams, technical data etc., provided by the manufacture shall be checked.

b). Di-electrical test

Test voltage as specified in the type is applied for one second. The test voltage shall be applied between the live parts and the frame of the panel with all switching devices closed. The test is considered to have been passed if there is no puncture or flash over.

c). Checking of protective measures and of the electrical continuity of the protective circuits

The protective measures with regard to electric shock in normal service and in case of a fault shall be checked. The protective circuit shall be checked by inspection to ascertain that the measures prescribed are complied within. In particular, screwed connections shall be checked for adequate contact, possibly by random tests.

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ESTIMATION

SL NoParticulars of

itemUnit Qty

Rate AmountRemarks

Rs. Ps. Per Rs. Ps.1 Tipple Pole

ON/OFF switch

No 1 1701 10 Each 1701 00

2 70 HMR 180 diode (common anode)

No 3 272 00 Each 816 00

3 70 HM 180 diode(common cathode)

No 3 272 00 Each 816 00

4 Heat Sink No 6 113 00 Each 678 005 Indication

LampNo 4 50 00 Each 200 00

6 Voltmeter(0-300V)MC

No 1 175 00 Each 175 00

7 Ammeter(0-10 A) MC

No 1 350 00 Each 350 00

8 AmmeterShunt(75 mV)

No 1 287 40 Each 287 40

9 HRC fuse(63 A)

No 3 66 41 Each 199 23 For TP switch

10 4mm2 PVC insulated copper conductor

m 25 22 75 Each 568 88

11 PorcelainInsulator

No 10 16 03 Each 160 30

12 Painting Lumpsum 380 0013 20mm dia.

PVC flexible conduit

m 1 20 00 M 20 00

14 4mm2 Lugs for connecting the cables

15 4 42 Each 66 36

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15 16mm2 Lugs for connecting the cables

6 8 1 Each 48 60

16 Hyllum Picece

1 130 00 Picece

130 00

17 Gum ml 100 15 00 Each 15 0018 Screws Lumpsum 60 0019 Nut and bolt Lumpsum 110 0020 Transportation

charges (travelling allowance)

Lumpsum 230 00

Total 7012 00

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SOME I.E & I.S RULES

1. Switchboard shall be created I easily accessible location away from combustible materials.

2. No article of clothing or any stones shall be kept at the back of the switchboard.

3. Where switch boards or distribution boards or a group of distribution boards are erected in a room of building isolated from the source of supply at a distance from it, adequate means of control and insulation shall be provided both near the board and at the origin of the supply.

4. HRC fuses in Electric circuit Each outgoing circuit from switch board (excepting fuse distribution

boards) shall be separately controlled by a suitable automatic circuit breaker on linked switch and cut outs.

In power circuit’s fuses shall be throughout of HRC type irrespective of current rating of the circuit.

N.B. the above rules is however not applicable to installation with transformer having a capacity of 150 kVA and less. All switches and circuit’s breaks shall perfectly be operated from the

front of the switchboard. Where circuit breaker handles, on switchboards or in panel boards are operated vertically rather than rationally or horizontally, the ‘UP’ position if the handle shall be the ‘ON’ position

Equipment intended to protect current at fault level shall have been interrupting rating sufficient for system voltage and the current, which available on the line terminal of the equipment. Equipment intended to protect current at the levels other than fault levels shall have been an interrupting rate at system voltage sufficient for the current that must be interrupted.

5. All wires and cables shall be provided with soldered on approved lugs on crimped joints.

6. Woodwork shall not be used in the construction of switchboard.

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7. Every switchboard shall comply with the following provisions viz.a. Clear space of not less than 1m in width shall be provided in front of

the switchboard.b. If there attachment on bape connections at the back of the

switchboard, the distance shall either less than 200mm or more than 750mm in width measured from the farest outstanding part of any attachment on conductor.

c. If the space behind the switchboard exceeds 750mm in width, there shall be a passage way from either end of the switchboard clear to a height of 1.8m.

8. All circuits shall be clearly and indelibly labeled for identification in English and vermicular.

9. Where circuits of different voltage and for AC and DC circuits ate installed on the same supports, they shall be so arranged and protected that they shall not come inn to contact with each other when live.

10.The neutral of each main and branch main circuits shall be provided with a suitable removable link placed in an easily accessible position, perfectly on the front, for the purpose of the string. The neutral not be bunched in inconvenient and in accessible positions at the back of the board.

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CONCLUSION

This project D.C. Cubicle Panel Board is done as per the I.S. standards. The panel is working satisfactorily. For the proper and effective working of this panel board, fuse ratings should be proper. We recommended, proper handling of the equipments for their longer life.

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BIBLIOGRAPHY

1. Industrial Electronics, Paul B. Zbar, Third Edition2. Power Electronics, Harish C. Rai3. Electronics Devices & Circuit, M. P. A. Jaleel4. I. E & I. S Rules of Indian Standards5. Electrical Design , Estimation & Costing , Bhattacharya