Eee Ees Manual

8/3/2019 Eee Ees Manual

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AllCours

es

IIDEGR

EEINE

NGINEE

RIGAN

DTE

CH

NOLOG

Y

AllCours

es

SEMEST

ERIEE

SsGROUPOF

INST

ITU

IONSC

OE&T.

EESS GROUP OF INSTITUTIONS FOR ENGINEERINGAND MANAGEMENT STUDIES,

A Laboratory Manual for EEE

(Elements of Electrical Engineering)


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2Elements of Electrical Engineering

Certificate

This is to certify that Mr. / Ms________________________________________

Roll no. __________of first year__________branch___________has completed

the term work satisfactorily in Elements of Electrical Engineering for the

academic year 20 to 20 ... as prescribed in the curriculum.

Place: _____________ Examination Seat No.: _____________

Date: ______________

Subject Teacher Head of the Department Director

EESS GROUP OF INSTITUIONS COE&T

Seal of

Institution


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List of Experiments and Record of Progressive Assessment

Experiment No: 1


Sr.

No

.

Name of the ExperimentPage

No.

Date of

Performance

Date of

Submission

Teacher

Assessment

Sign. of

Teacher

and

Remark

1 Study of Multimeter.

2Verification of SuperpositionTheorem.

3Verification of Thevenins

Theorem.

4

Study of different type of

Wiring Systems.

5 Study of Fluorescent Lamp.

6 Measurement of 1-phase Power.

7Verification of Transformation

Ratio.

8

To determine the efficiency of a

Transformer by conducting

Open circuit test and Short

circuit test.


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Aim: To study the Multimeter and testing different Electronics Components.

Theory:

A multimeter is used to measure different electrical quantities such as

1. Voltage

2. Current

3. Resistance

Multimeters are also used to test different electronic components such as diode, transistor,

and rectifiers.

Basically there are two type of multimeter used in practice

1. Analog multimeter

2. Digital multimeter.

Now a days digital multimeters are widely used for the measurement of electrical quantities

because of their various advantages over analog multimeters

Advantages of digital multimeter over analog multimeter,

1. Simple in construction.

2. Light in weight.

3. Higher accuracy

4. Easy handling.

Construction:

It consists of moving coil instrument, number of ammeter shunts, voltmeter

multipliers, rectifier and selector switches all in single casing. Selection of particular mode of

measurement required ( i.e. D.C. or A.C. ) is affected by function selector switch & range

selector switch can be set to give a choice of several ranges of current, voltage & resistance.

A suitable protection is provided to the meter movement against possible overload during its

use.



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Operation:

Circuit diagram shows basic circuitry of multimeter for the measurement of different

electrical quantities. A multiplier provides a high voltage range while shunt resistance

provides higher current range. A series rectifier makes the measurement of A.C. voltage

possible with the same D.C. meter movement. Thus the same scales are used for both A.C. &

D.C. current & voltage. For resistance measurement, a set of voltage from an internal battery

is applied across the resistance & resulting current is measured. By Ohms law, this current

being inversely proportional to the resistance, scale is calibrated to give directly resistance in

ohms to use. The resistance scale is exactly reverse of the current scale i.e. full scale

deflection of pointer corresponds to maximum current in the range but on the resistance scale

it corresponds to zero resistance.

Even through the total circuit of multimeter is complex fig. A to fig. D shows the

simplified circuit diagram of different sections of typical multimeter circuit, used for various

measurements. This fig. is more or less self explanatory.

Resistance measurement:

For resistance measurement a set of different voltage from an internal battery is

applied across the resistance and resulting current is measured, by Ohms law current is

inversely proportional to the resistance.

D.C. Current measurement:

Multimeter is used for measurement of DC current as shown in fig. b, shunt resistors

are used for the measurement of higher currents.

D.C. Voltage measurement:

The range of the voltmeter can be increased by connecting high resistance in series

with the meter

A.C. Voltage measurement:



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For themeasurement of AC voltage or current, a meter is used with rectifier circuit to

convert ac quantity to dc quantity and this is now measured in the meter as usual.

Procedure:



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1. Measure the unknown ac and dc voltage by connecting the multimeter leads between

two terminals circuit or across the circuit

2. Measure the unknown ac and dc current by connecting the multimeter leads in series

with the circuit.

3. Measure the resistance and capacitance directly without connecting power supply

across it.

MULTIMETER



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Observation table:

Sr.No. Quantity to be measured Measured value of quantity

1 Resistance

2 AC voltage

3 DC voltage

4 DC current

Conclusion:



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Experiment No: 2

Aim:Verification of Superposition Theorem.

Theory:

Superposition theorem states that, In a linear bilateral network containing two or more than

two energy sources, the current flowing through any element may be determined by adding

together algebraically the currents produced by each source acting alone, when all other

energy sources replaced by their internal resistances.

According to superposition theorem, if there are number of sources (voltage and current

sources) acting simultaneously in any linear bilateral network then the current flowing

through any branch can be find out by keeping one source active at a time and replacing all

other sources by there internal resistances (if given) or the voltage source is replaced by the

short circuit and the current source by open circuiting that branch containing the source.

Following example shows procedure for applying the superposition theorem.

Consider an electrical network as shown in figure fig(2).

Step no.1: Replace the voltage source V2 by its internal resistance and find out current

supplied by source V1 with directions.

Step no.2: Replace the voltage source V1 by its internal resistance and find out current

supplied by source V2 with directions.

Step no.3: The total values of current I1 are find out by adding algebraically the currentsupplied by sources V1& V2 acting alone



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Apparatus:

DC ammeter (0-25) mA, DC voltmeter (0-15) V, Superposition theorem trainer kit etc.

Pro

cedure:



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1) Connect the mains cord to 230V, 50 Hz ac supply. Switch on the trainer kit.

2) Connect V1 to the voltmeter & adjust to read 10V on the meter.

3) Similarly connect V2 to voltmeter and adjust it to read 10V on the meter.

4) Now connect the Milliammeter with proper polarity.

5) Note the values of V1, V2 & current I when both sources are acting simultaneously as

shown in fig.2(a)

6) Now remove V1 and keep V2 acting alone. Note the value of current though R3.Let

that current be I1, as shown in fig.2(b)

7) Now remove V2 and keep V1 acting alone. Note the value of current though R3.Let

that current be I1, as shown in fig.2(c)

8) Now verify the superposition theorem that current I= I1+I1.

9) Repeat experiment for different values of V1&V2.Record the readings in observation

table.

Observation table:

Sr.

No.

V1

(volts)

V2

(volts)

I(mA)with

both

source

acting

I1(mA)

with V1acting alone

I1(mA)

with V2acting alone

I=I1+I1.

1

2

3

4

5



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Calculation: I=I1+I1

Conclusion:

Experiment No: 3

Aim: Verification of Thevenins Theorem.

Theory:

Thevenins theorem statement:- In a linear bilateral network the current through load

resistance RL connected across any two terminals A&B with constant resistances and constant

voltage sources, the network across the terminals A&B can be replaced by a single voltage

source (Vth) and the series resistance (Rth).

Where, Vth = Open circuit voltage across A&B,

Rth = Equivalent resistance of the network as viewed from the terminals A&B with all

sources replaced by their internal resistance.

Thevenins theorem provides a mathematical technique for replacing a given network, as

viewed from two output terminals, by a single voltage source with a series resistance. It

makes the solution of complicated circuits quite easy.

How to thevenize a given circuit: -

1. Temporarily remove the resistance (called as load resistance RL) whose current is required.

2. Find out open circuit voltage VOC which appear across the two terminals from where

resistance RL has been removed. It is called as Thevenins voltage Vth.

3. Find out equivalent resistance of the whole network as looked back from these twoterminals after all voltage sources have been replaced by their internal resistance and



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current sources by open circuit. This equivalent resistance is called as Thevenins

resistance Rth.

4. Replace the entire network by a single Thevenin voltage source V th in series with

Thevenins resistance Rth.

5. Connect RL back to its terminals from where it was previously removed.

6. Finally calculate the current flowing through RL by using the equation no. (1)

Vth

Rth RL+I .(1)

Component Values: -

R1=100 ohm R2=100 ohm R3=100 ohm

R4=100 ohm R5=100 ohm



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Procedure:

1) Connect the mains cord to 230V, 50 Hz ac supply. Switch on the trainer kit.

2) Connect voltmeter to the V1 & adjust to read 8V on the meter, and also connect V1 to

the network by connecting the jumper links.

3) Now connect the Milliammeter with proper polarity so that RL also gets connected in

the circuit.

4) Adjust RL to read load current of 5mA.



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5) Now to calculate this load current by using Thevenin theorem, remove the load

resistance RL by removing jumper links.

6) Now measure the open circuit voltage. Note down this voltage. This is a Thevenin

voltage Vth.

7) Now disconnect V1 by short circuiting the terminals of V1.

8) Measure the equivalent resistance of the network at a point from where the load

resistance RL has removed by using multimeter. This is a Thevenins resistance Rth.

Note down this resistance.

9) Measure the value of load resistance using multimeter & note down its value.

10) Calculate the load current I with Thevenins theorem using equation,

Vth

Rth RL+I

11) Compare the calculated value & observed value of load current.

12) Repeat the experiment for different values of load resistance.

Observation table:

Sr.

No.

V1

(volts)

IL

(mA)Thevenins

voltage

Vth in volt

Thevenins

resistance

Rth in ohm

Load

resistance RLin ohm

Load

current

calculated

1

2

3

4

5

Conclusion: -



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Experiment No: 4

Aim: Study of different type of Wiring systems.

Apparatus:

1. Kit Kat fuse: 1 Nos. 5 Amps.

2. Single pole switch: 2 Nos. , 5 Amps

3. Lamp holders: 2 Nos. , 5 Amps

4. Lamps: 2 Nos.

5. Battens, Nails, Clips, CTS wire, Fuse wire.

6. Round wooden block: 04 Nos.

7. Square wooden block: 01 Nos.

Theory:

House Wiring.

To control two lamps by two separate switches.



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Procedure:

1. Fix the battens at suitable distance as per the circuit diagram.

2. Cut the wire of suitable sizes. Fix the clips with nails on the battens & put

the wire as per circuit diagram, the wire should not cross each other on the

batten.

3. Fix the wooden blocks as per correct position & complete the wiring as per

circuit diagram.

4. Put fuse wire in kitkat fuse.

5. Test the complete wiring as per testing procedure.

TESTING:

1. Connect 230V AC supply to the circuit.

2. ON switch S1 which glows Lamps L1.



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3. ON switch S2 which glows Lamp L2 ( If this is not happen it means that

connections are somewhere wrong)

USE:

Such connections are used in house wiring. When one lamp or fan or any

electrical application are controlled by one switch in an interlocked fashion.

Stair-case Wiring:

To control one lamp by two 2-way switches.

Apparatus:

1. Kit Kat fuse: 1Nos. 5 Amps.

2. Single pole switch: 2 Nos. , 5 Amps

3. Lamp holders: 2 Nos. , 5 Amps

4. Lamps: 2 Nos.

5. Battens, Nails, Clips, CTS wire, Fuse wire.

6. Round wooden block: 04 Nos.

7. Square wooden block: 01 Nos.

Procedure:

1. Fix the battens at suitable distance as per the circuit diagram.

2. Cut the wire of suitable sizes. Fix the clips with nails on the battens & put

the wire as per circuit diagram, The wire should not cross each other on

the batten.



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3. Fix the wooden blocks as per correct position & complete the wiring as per

circuit diagram.

4. Put fuse wire in Kitkat fuse.

5. Test the complete wiring as per testing procedure.

TESTING:


2. ON & OFF switch S1 & check that either lamp L1 glows or not.

3. Check lamp L1 by S2.

4. ON the lamp by S1 & OFF that by S2. (If any given points in testing are not

working, it means that some where connections are wrong.)

USE:

Such connections are used in house for stair-case, for double application of fan,

night lamp etc.

Conclusion:

Experiment No: 5

Aim:Study of Fluorescent Lamp.

Apparatus: Fluorescent lamp

Circuit Diagram:



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Theory:

CONSTRUCTION:

The fluorescent lamp is a low pressure mercury discharge lamp. It is generally consist

of a long glass tube (G) with an electrode on each end (E1 & E2). These electrodes are

made of coiled tungsten filament coated with electron emitting material. The tube is

internally coated with a fluorescent powder & contains small amount of argon with a little

mercury at a very low pressure. The control circuit of tube consist of a starting switch (S)

known as starter, an iron cored inductive coil called a choke (L),& two capacitors C1 &

C2.

OPERATION:

A starting switch namely the glow type (voltage operated device) is used in tube

operation. The starter is glow type starter (S) shown in circuit diagram consist of two

electrodes sealed in glass tube filled with mixture of Helium & Hydrogen. One electrode



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is fix & another is U-shaped bimetallic strip made up of two different metals having two

different temperature co-efficient. Contacts are normally open.

When the supply is switched ON, heat is produced due to glow

discharge between electrodes of starter is sufficient to bend bimetallic strip until it makes

contact with fixed electrode. Thus circuit between two electrode E1 & E2 is completed &

relatively large current circulated through them. The electrodes are then heated to

incandescence by this circulating current & gas in their immediate vicinity is ionized.

After a second or two, due to absence of glow discharge a bimetallic strip cools

sufficiently. This causes to break contact & sudden reduction of current induces an emf of

the order of 800-1000V in choke coil. This voltage is sufficient to strike an arc between

two electrodes E1 & E2 due to ionization of Organ. The heat generated in the tube

vaporizes mercury & potential difference across the tube falls to 100-110V. This potential

difference is not sufficient to restart glow in starter.

FUNCTION OF AUXILLARY CIRCUIT COMPONENTS:

CHOKE

1. It provides a necessary high voltage to start discharge in the tube.

2. Since the voltage required across the tube during normal operation is small, the

excess voltage drop across the tube.

3. It acts as a stabilizer.

CAPACITOR (C1)

The choke lowers a power factor of the circuit C1 connected across the supply

improves this power factor.

CAPACITOR (C2)



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It is connected across starting switch to suppress radio interference due to high

frequency voltage oscillation which may occur across its contacts.

Advantages:

1. Low power consumption.

2. Longer life which is about 3 to 4 times that of the filament life.

3. Compared to filament lamp efficiency is also about 3 to 4 times, it gives

more light for the same wattage.

4. Superior quality of light.

5. No warming up period is required as in case of another discharge lamp.

6. Different colour light can be obtained, by using different types of fluorescent

powder.

7. Low heat radiation.

Disadvantages:

1. Initial cost of the lamp along with auxiliary equipment needed is very high

2. With frequent operation life reduces.

3. Voltage fluctuation affects it but not to the extent that filament lamp is affected.

4. Produce radio interference.

5. Fluctuating light output produces undesirable stroboscopic effect with rotating

machinery.

Applications:

They are very popularly used for interior light in residential buildings, shops &

hotels. They are also extensively used with reflectors for street lightings. Due to their

glare free shadow less light, they are ideal for workshop, factories, laboratories & drawing

rooms. The fluorescent tubes are normally manufactured with 20, 40 & 80 watts.



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Conclusion:

Experiment No: 6

Aim:Measurement of 1-phase Power.

Apparatus: Energy meter, wattmeter (0-1200w),Load bank.



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Theory:

Induction type energy meters are widely used in the domestic and industrial

applications. Energy meters are most common form of AC meters that are in use.

Circuit Diagram:

Figure:



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Fig. Induction type single phase energy meter.

Operating Principle:

The principle of operation of energy meter is very simple and based on the

electromagnetic induction. The force required for driving mechanism or driving torque is

produced by the interaction between eddy currents and the alternating fluxes.

Construction:

The constructional details of induction type energy meters are as follows.

There are four main parts of operating mechanism of Induction type energy meter.

1. Driving mechanism:

It mainly consists of two electromagnets, a shunt magnet and a series magnet.

Silicon steel laminations are used to built series and shunt magnets.



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A shunt magnet is a three limb magnet carries highly inductive coil also known as

pressure coil (PC) which is directly connected across the supply mains. The pressure coil

consists of large number of turns and carries current proportional to the supply voltage. The

current coil i.e. the coil of series magnet carries load current and so it is wound with a few

turns of relatively thick wire. A copper shading ring is placed over the central limb of shunt

magnet, which is used as power factor compensator. A metallic stamping L is used in order to

provide necessary compensation for friction.

2. Moving mechanism:

A moving mechanism of induction type energy meter consists of an aluminum disc.

This disc is mounted on a vertical spindle which is supported between the jewel bearings. The

disc is placed in the gap between the shunt magnet and series magnet. A pinion engages the

shaft with counting or registering mechanism.

3. Breaking mechanism:

In breaking mechanism a permanent magnet is used as breaking magnets placed near

the front edge of the disc forms the breaking or control system. This breaking magnet is so

placed that the disc revolves in the air gap between the polar ends of the breaking magnet.

The value of controlling torque can be changed by adjusting the position of the breaking

magnets.

4. Registering mechanism:

The registering mechanism used consists of train of gears driven by pinion gear on the

disc shaft. It records continuously a number which is proportional to the revolutions made by

moving system.

Errors in induction type energy meter:

1. Phase and speed error:



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The flux produced by shunt magnet does not lag behind the applied voltage by 900

because of coil resistance and iron losses. Therefore at zero power factor the torque is not

zero. A shading ring is used to compensate phase error. Speed error can be eliminated by

adjusting the position of breaking magnet

2. Frictional error:

The friction at rotor bearing and in the register mechanism produces an

unwanted braking torque on the disc. To eliminate this error metallic stamping L is used. This

stamping moves laterally with the help of some lever due to this a small driving torque is

exerted on the disc. This additional torque is used for compensation of reduction in speed due

to frication

3. Creeping error:

Creeping errors occur when there is no current flowing through the current coil

and only pressure coil is excited. The major causes of creeping are incorrect friction

compensation, stray magnetic field and excessive supply voltage.

4. Temperature error:

These errors are produced because of change in temperature and these errors

are very small.

5. Frequency error:

These errors are caused because of change in frequency. Energy meters are

normally used at 50Hz frequency if this frequency changes then there is change in reactance

of the coil and small errors occur in the coil.

Procedure:

1. Do the connections as per circuit Diagram.


3. ON the load (kept it constant throughout the experiment)

4. Take the readings of energy meter & wattmeter.

5. After 20 minutes take the second reading of energy meter



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Observations:

1. Initial energy meter reading (E1) = ________ KWH

2. Final energy meter reading (E2) = _________KWH

3. Wattmeter reading (W) =_________________Watts

4. Time required for final energy meter reading = 20 minutes.

Calculations:

E= Actual energy consumed = E2-E1= _________KWH-------------- (I)

E=Actual energy consumed calculated from wattmeter reading & time

= W x t= ____________watt minute.

= (W x t) / (1000x60) KWH------------------------------------------- (II)

Conclusion:

Experiment No: 7

Aim: Verification of Transformation Ratio.

Apparatus: Voltmeter (0-300) V .2 nos.



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Ammeter (0-10) A .2 nos.

Transformer (1Phase), Autotransformer (1Pphase), load bank.

Circuit Diagram:

Theory:

Working principle of transformer:

A transformer is a static device which transfers electric power from one circuit to the

other circuit without change in frequency. The transformer can raise or lower the voltage in a

circuit but with a corresponding decrease or increase in current. The physical basis for

transformer is mutual inductance between two circuits linked by a common magnetic flux. In

its simplest form , it consist of two inductive coils which are electrically separated but

magnetically connected with each other through the path of low reluctance as shown in figure

(1).

The two coils have high mutual inductance. If one of the coil is connected to source of

alternating voltage then an alternating flux is set up in the laminated core, this flux also links

with the other coil in which it produces mutually induced emf according to Faradays law of

electromagnetic induction. If the second coil circuit is closed, a current flow in it and in this



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way electrical energy is transferred from one electrical circuit to other without any electrical

connection. In brief, a transformer is a device,

1) Transfers electric power from one circuit to another.

2) It transfers power without any change in frequency.

3) The basis for transformer is mutual induction.

Transformer construction:

Fig.1

The simple element of transformer consists of two coils having mutual inductance and a

laminated steel core. The two coils are insulated from each other and a steel core other

necessary parts are: a suitable container for assembled core and winding; a suitable medium

for insulating the core and its winding from the container; suitable bushing.

Constructional, the transformers are of two types, distinguished from each other

merely by the manner in which the primary and secondary coils are placed on the laminated

core. The two types are known as,

1. Core type transformers

2. Shell type transformers

In core type transformers the winding surrounds a considerable part of laminated core

whereas in Shell type transformers the core surrounds the considerable part of the winding.



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Core type transformers: The coils used in core type transformers are form wound and of

cylindrical type. The general form of these coils can be circular or oval or rectangular in

shape. In small size core type transformer, a simple rectangular core is used with cylindrical

coils which are either circular or rectangular in form. But for large size core type transformer

round or circular cylindrical coils are used.

Shell type transformers:

Fig. (2)

In these types of transformers the coils used are form wound but are multi layer disc type

usually wound in the form of pancakes. The different layers of such multi layer disc are

insulated from each other by paper. The complete winding consists of stacked disc with

insulation space between the coils the space forms space for horizontal cooling and insulating

ducts.

Transformation ratio of transformer:



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The emf equation of transformer is given by,

Primary induced emf

E1= 4.44*f*N1*m.. (1)

Secondary induced emf

E2= 4.44*f*N2*m.. (2)

Where,

F = frequency in Hz,

N1 = no. of turns on primary winding,

N2 = no. of turns on secondary winding,m= maximum flux in wb.

From these two equations,

E2/ E1= N2/ N1 =K

This constant K is called as voltage transformation ratio,

1. If K>1, then the transformer is called as step-up transformer

2. If K


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2) Adjust V1 the primary voltage to 200V.

3) Gradually apply the load from load bank.

4) Measure the primary current I1, Secondary current I2 and Secondary voltage V2.

5) Repeat the procedure for different values of voltage V1.

6) Note down the reading in the observation table.

7) Perform the calculations and write down the conclusion..

Calculations:

Conclusion:

Experiment No: 8



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AIM: To determine the Efficiency of a Transformer by conducting Open Circuit test

and Short Circuit test.

APPARATUS REQUIRED:

S.No. Apparatus Range Type Quantity

1 Ammeter (0-2)A

(0-5) A

MI

MI

1

1

2 Voltmeter (0-150)V MI 2

3 Wattmeter (150V, 5A)

(150V, 5A)

LPF

UPF

1

1

4 Connecting Wires 2.5sq.mm Copper Few

PRECAUTIONS:

1. Auto Transformer should be in minimum voltage position at the time

of closing & opening DPST Switch.

PROCEDURE:

OPEN CIRCUIT TEST:

1. Connections are made as per the circuit diagram.

2. After checking the minimum position of Autotransformer, DPST

switch is closed.

3. Auto transformer variac is adjusted get the rated primary voltage.

4. Voltmeter, Ammeter and Wattmeter readings on primary side are

noted.

5. Auto transformer is again brought to minimum position and DPST

switch is opened.

SHORT CIRCUIT TEST:

1. Connections are made as per the circuit diagram.

2. After checking the minimum position of Autotransformer, DPST

switch is closed.

3. Auto transformer variac is adjusted get the rated primary current.



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4. Voltmeter, Ammeter and Wattmeter readings on primary side are

noted.

5. Auto transformer is again brought to minimum position and DPST

switch is opened.



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OPEN CIRCUIT TEST:

Vo

(Volts)

Io

(Amps)

Wo

(Watts)

SHORT CIRCUIT TEST:

Vsc

(Volts)

Isc

(Amps)

Wsc

(Watts)

FORMULAE:

Power output = Power input - Total losses

... Power input = Power output + Total losses

= Power output + Pi + Pcu

The efficiency of any device is defined as the ratio of the power output to power input.

So for a transformer the efficiency can be expresses as,

= Power output/power input

... = Power output/(power output + Pi + Pcu )

Now power output = V2 I2 cos

where cos = Load power factor

The transformer supplies full load of current I2 and with terminal voltage V2.

Pcu = Copper losses on full load = I22

R2e

... = (V2 I2 cos2 )/(V2 I2 cos2 + Pi + I22

R2e)

But V2 I2 = VA rating of a transformer

... = (VA rating x cos) / (VA rating x cos + Pi + I22

R2e)

http://1.bp.blogspot.com/-DJPgDR5N8pw/TigEgXKJGkI/AAAAAAAAA6Q/7cm2hXCSoww/s1600/ABB120.jpeg


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This is full load percentage efficiency with,

I2 = Full load secondary current

Calculations:

Conclusion:

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