E&E LAB II

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NTTF TECHNICAL EDUCATION CENTRE ANTC), PANTNAGAR

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NTTF Technical Education Centre, Pantnagar

Certificate program in Manufacturing Technology

Semester- III

Sub code: S3.P3

LAB ManualFor

Electrical & Electronics Lab -II

Compiled byDebjit Dey

Guided and Approved byR Varadarajan

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LIST OF EXPERIMENTS

1. Direct on line starting of an Induction motor

2. Familiarization test on no load voltage ratio on a

transformer.

3. Open circuit test for a Transformer

4. Transformer on load

5. Speed control of DC shunt motor.

I. By varying field current, Armature voltage kept

constant.

II. By varying armature voltage field current kept

constant.

6. To draw open circuit characteristics curve for a DC shunt

generator.

7. To draw load characteristics curve of a DC generator.

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EXP NO-1. DIRECT ON LINE STARTING OF

A INDUCTION MOTOR

AIM:

To design control circuit and power circuit for adirect on line starting of a three phase induction

motor.

OBJECTIVES:

1. To wire the control circuit & power circuit.2. Observe the on & off control on the motor.

EQUIPMENTS:

1. A three phase power supply with neutral(for control ckt)

2. Fuse4 NO.3. Contactor (4NO)4. Over load relay(1Amps).5. Three phase induction motor (1HP).

6. Push button switches (NO+NC)-2Nos.

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POWER CIRCUIT CONTROL CIRCUIT

PROCEDURE:

1. The three phases (R, Y&B) are connected to the threefuses on the panel board.

2. From the fuses it is connected to the NO point of thecontactor (K1).

3. And from the contactor (K1) it is connected to the threephase induction motor through the over load relay. This isthe power circuit.

4. For the control circuit, any one of the phase is taken and itis connected to the NC of OLR.

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5. Then it is connected to NC of switch (S1) and then to NO

of switch (S2) as shown in the figure.6. Across the switch (S2) NO of the contactor is connected

& it is given to the coil (A1) and another end to neutral.7. When (S2) is pressed the contactor coil gets energized

which makes all NOs to close so the motorwill run sinceits connected to 3phase supply in power circuit.

8. When (S1) is pressed motor goes off since it demagnetizethe contactor coil.

PRECAUTIONS:

1. Check whether all the three phases are available.2. Check the contactor and relay before connecting.3. Check the continuity of the motor to ensure that no phase

coil is open.

4. For control circuit check whether neutral isavailable.

Result:-

This is one of the common and easy method to startand run a 3phase induction motor below 5hp capacity.

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EXP N02: FAMILIARIZATION TEST ON NO LOAD

VOLTAGE RATIO

AIM:

To measure the terminal voltage and voltageratio on no load condition.

OBJECTIVES:

1. To measure the terminal voltage at secondary side ofgiven transformer.

2. To find out the voltage ratio on no-load condition.3. To find the polarity of the given transformer.4. To find the iron loss & copper loss of the transformer.5. To determine the efficiency of the transformer.

EQUIPMENTS REQUIRED:

1. Transformer 1 kvA, (230/115) volts.2. A.C voltmeter (0-300) volts.

CIRCUIT DIAGRAMS:

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TABULAR COLUMN:

Vp VsVoltage

ratio=Vp/Vs

PROCEDURE:

1. Identify primary and secondary winding of giventransformer.

2. Connect transformer to source as per the circuitdiagram.

3. Measure terminal voltage(Vs) at secondary side without load.

4. Measure voltage at primary side(Vp).5. Tabulate the readings in tabular column.

6. Find out voltage ratio.

RESULT:

This experiment is useful to shows the method of

measuring voltage and finding voltage ratio.

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EXP NO-3: OPEN CIRCUIT TEST ON A

TRANSFORMER

AIM:

To measure iron loss and copper loss of atransformer

OBJECTIVE:

1. To measure total iron loss and cos factor2. To measure total copper loss under full load.


1. Auto transformer(0-270V/5A)

2. Transformer(230/115V, 1KVA)3. Ammeter(0-5A)4. Voltmeter(0-250V)5. Wattmeter(2500W/5A)

CIRCUIT DIAGRAM:

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TABULAR COLUMN:

V I W COS =W/I.V

Watt meter reading is total iron loss

PROCEDURE:

1. Connections are made as shown in figure.2. Keep auto transformer in the minimum position.3. Switch on the A.C power supply.4. Vary the voltage, still the voltmeter shows the rated

value.5. Note down the readings of voltmeter, ammeter,

wattmeter & the watt meter constant (k).6. Note down the value of (iron loss) Wattmeter reading.

Result:

This is the one practical method to measure ironloss in transformer test with out loading transformer.

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EXP NO-4: TRANSFORMER ON LOAD

AIM:

To verify load characteristic of transformer.

OBJECTIVES:

1. To measure No-load voltage.2. To measure primary and secondary load current.3. To measure primary and secondary load voltage.4. To measure primary and secondary power.5. To find out % voltage regulation.6. To find out % efficiency.


1. 230/115 volts, 1KVA transformer-1 no.2. A.C voltmeter (0-300 V)-2 nos.3. A.C single phase watt meter (0-2500 watts)-2 nos.4. A.C ammeter (0-5A)-2 nos.5. Tools and connecting wires.6. Resistors or lamps(200W)5nos

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CIRCUIT DIAGRAM:

SLNO Vo I W1 VL Is W2 =W2/W1*100%VR=Vo-

VL/Vo*100

1.

2.

3.4.

5.

6.

7.

8.

9.

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PROCEDURE:

1. Connect the circuit as per the circuit diagram.2. Measure No- load voltage at secondary side.3. Connect and vary the load gradually step by step.4. Measure primary and secondary voltage step.5. Measure primary and secondary voltage in each step.6. Measure the primary and secondary power in each step.7. Calculate % voltage regulation.8. Calculate % efficiency.

Result:

This experiment helps to find out voltage regulationand efficiency of the transformers at different load.

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EXP NO-05: SPEED CONTROL OF DC SHUNT

MOTOR1. BY VARYING FIELD CURRENT, ARMATURE

VOLTAGE KEPT CONSTANT

2. BY VARYING ARMATURE VOLTAGE FIELD

CURRENT KEPT CONSTANT.

AIM:

To control the speed of a D.C motor by armaturecontrol method & field control method.

OBJECTIVES:

1. To control the speed of a D.C motor by armature &field control method.

2. To plot the graph speed (N) Vs Armature voltage(Va).

3. To plot the graph speed (N) Vs Armature voltage(Va).


1. D.C motor (shunt type) 1hp -1 no.2. Auto transformer 0 to 230V3. Tachometer.4. Voltmeter 0-300V -2 nos.5. Ammeter 0 to 10A -2 nos6. Connecting wires.

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PROCEDURE:a. Field control method:

Tabular column:

SLNO IF N1.

2.

3.

4.

5.

MODEL GRAPH

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1. Connect the circuit as per the circuit diagram.2. Vary the field supply and apply the rated voltage.3. Vary the armature voltage from zero to its rated value.4. Note down the readings of voltmeter Connected across

Armature and speed by tachometer for each reading.5. Plot the graph speed (N) Vs armature voltage (Va).6. Repeat the experiment with different field voltage.

b. ARMATURE CONTROL METHOD:

TABULAR COLUMN:

SLNO VA N

1

23

4

5

6

7

8

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MODEL GRAPH

1. Connect the circuit as per the circuit diagram.2. Vary the field supply and apply some voltage.3. Vary the armature voltage from zero to some

constant value.

4. Keeping armature voltages constant vary the fieldvoltage to rated value.

5. Note down the readings of ammeter connected in serieswith field and speed by tachometer for each reading.

6. Plot the graph speed (N) Vs field current (If).7. Repeat the experiment with different Armature voltage.

RESULT:

These are the methods to control the speed of dc motorand that speed is directly proportional to armature voltageand inversely proportional to field N=Es/Q. This is veryuseful in traction field.

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EXP NO-06: TO DRAW THE OPEN CIRCUITCHARACTERISTICS OF CURVE FOR A

SEPERATELY EXCITED DC SHUNT GENERATOR.

AIM:

To draw open circuit characteristic curve forD.C shunt generator.

OBJECTIVES:

1. to build up voltage in D.C shunt generator.2. to measure terminal- voltage.3. to measure field current.4. to plot graph between terminal-voltage and field

current.


1. D.C separately excited shunt generator coupled toInduction motor (1.5kw, 6A)-1 set.

2. D.C variable power supply (0-300 v, 10 A) -2 nos.

3. D.C voltmeter (0-10 A)-1 no.4. D.C ammeter (0-10 A)-1 no.5. Tools and connecting wires.

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PROCEDURE:

1. Connect the circuit as per the circuit diagram.2. Vary the field voltage of generator from 0 to rated

voltage.3. Measure the field current in each step.4. Measure the terminal- voltage in each step.5. Plot the graph between terminalsvoltage to field

current.

RESULT:

This experiment helps to achieve the no loadcharacteristic of dc shunt generator at which clearly

shown that the terminal voltage is directly to fieldcurrent.

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EXP NO-07: TO DRAW LOAD CHARACTERSTICS

CURVE OF A DC GENERATOR

AIM:

To draw load characteristic curve of D.C generator.

OBJECTIVES:

1. To measure No-load terminal voltage.2. To measure load voltage and load current for

different readings.

3. To find out % voltage regulation.4. To find out % efficiency.5. To plot graph between voltage and load current.


1. D.C shunt generator coupled to D.C motor.

(Separately excited)-1 set.2. D.C variable source (0-300 V) -2 nos.3. D.C voltmeter (0-300 V)-1 no.4. D.C ammeter (0-10A)-1 no.5. Lamp load -1 set.6. Tools and connecting wires.

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MODEL GRAPH

PROCEDURE:

1. Connect the circuit as per the circuit diagram.

2. Measure the No-load voltage.3. Connect and vary the load gradually step by step.4. Measure the load voltage and current in each step.5. Calculate % voltage regulation.6. Calculate % efficiency.7. Plot the graph between voltage & load current.

RESULT:

This experiment helps to analyze the loadcharacteristics of dc generator and to find voltageregulation and efficiency practically.

E&E LAB II

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