A. M. U., ALIGARH BEE-293

A. M. U., ALIGARH BEE-293

Electrical Engineering Lab

Name: ___________________________

Class: Diploma in Architechture Asstt.ship., II^nd Sem

College No.: ____________________

En. No.: _______________________

Group No: _____________________

Partners of Group:

1. _________________________

2. _________________________

3. _________________________

4. _________________________

Date of performing Exp:____/____/____ Date of Submission of Report:____/____/____

Object:________________________________________________________________

______________________________________________________________________

Apparatus Used:

S. No. Lab No. Equipment Used Range Make

Observation Table/Circuit Diagram:

Marks

ELECTRICAL ENGINEERING SECTION UNIVERSITY POLYTECHNIC

A. M. U., ALIGARH BEE-293

Electrical Engineering Lab

Name: ___________________________

Class: Diploma in LFT, II^nd Sem

College No.: ____________________

En. No.: _______________________

Group No: _____________________

Partners of Group:

1. _________________________

2. _________________________

3. _________________________

4. _________________________

Date of performing Exp:____/____/____ Date of Submission of Report:____/____/____

Object:________________________________________________________________

______________________________________________________________________

Apparatus Used:

S. No. Lab No. Equipment Used Range Make

Observation Table/Circuit Diagram:

Exp. No.

Marks

A. M. U., ALIGARH BEE-293

Electrical Engineering Lab

Name: ___________________________

Class: Diploma in Interior Design., II^nd Sem

College No.: ____________________

En. No.: _______________________

Group No: _____________________

Partners of Group:

1. _________________________

2. _________________________

3. _________________________

4. _________________________

Date of performing Exp:____/____/____ Date of Submission of Report:____/____/____

Object:________________________________________________________________

______________________________________________________________________

Apparatus Used:

S. No. Lab No. Equipment Used Range Make

Observation Table/Circuit Diagram:

Marks

DIPLOMA IN ENGINEERING ( I

& II

SEMESTER ) Mechanical, Production, RAC, Plastic, LFT, Civil, Architecture, ID

Electrical Installation Lab BEE-192, BEE-193 & BEE-293

LIST OF EXPERIMENTS

1 (a) To control one lamp with one switch.

(b) To control two lamps (in series) with one switch.

(c) To control two lamps (in parallel) with one switch.

2 (a) Study of stair case lighting system using two-way switch.

(b) Study of Intermediate switch and its application in corridor lighting system.

3 (a) To make connection for 230 V bell and 230 V buzzer.

(b) To make connection for 6 V bell using 230/6V transformer.

(c) To make connection for bell with indicator.

4 Practice in making Plastic Casing-Capping wiring for one point.

5 Testing of following faults of electrical installation by Megger.

(a) Open circuit fault (b) Short circuit fault.

(c) Earth leakage test.

6 a) To make connections of an Energy Meter.

b) To measure energy consumed by a 1000 watt load in given time.

c) To measure error in the meter.

7 (a) Study of various types of Multi-meters.

(b) Measurement of Resistance with the help of Analog and Digital multi-meters.

8 (a) To measure the resistance of heating element of the Kettle.

(b) To determine the efficiency of Electric Kettle.

Object:

(a) To control one lamp with one switch.

(b) To control two lamps (in series) with one switch.

(c) To control two lamps (in parallel) with one switch.

Apparatus used:

S. No. Tool/ Material Specification Quantity

Theory: One of the two wires (phase) of a single phase supply is connected to the load through fuse and one way switch. The other wire (neutral) is connected to the load directly. Fuse is provided to protect the circuit from over current and the switch controls the load. The load can be single lamp (Fig:1), lamps in series (Fig:2) or lamps in parallel (Fig:3). The combination of the switch and the load is connected across (in parallel) to the electrical supply (Fig:4).

Procedure:

1. Study the circuits as per fig 1, 2 & 3.

2. Make connections as per fig. 4

3. Get the connections checked before connecting to supply.

Circuit Diagrams:

Observations:

S.No. Switch Positions

Lamp condition

S1 S2 S3

1 ON OFF OFF

2 OFF ON OFF

3 OFF OFF ON

Precautions:

1. Use fuse wire of appropriate size with each load.

2. Connections should be made tight.

3. Supply should be given only after thorough check of the circuit.

Report:

1. Why does the glow of two lamps decreases when they are connected in series?

2. What are the different materials used as filament of lamp? Also write down the characteristics of the material used.

3. Make the diagram of four-point wiring (one fan, two lamps & one plug socket point)

Object:

(a) Study of stair case lighting system using two-way switch.

(b) Study of Intermediate switch and its application in corridor lighting system.

Apparatus used:

S. No. Tool/ Material Specification Quantity

Theory:

Stair case lighting: In this system, one lamp can be controlled from two different places as shown in figure 1. For this purpose two-way switches are used. If switch S1 at ground floor is at position A1 and switch S2 at first floor is at B2, the Lamp L will be in OFF condition. If any of the switch is made in to another position i.e. either S1 taken to A2 position or switch S2 is taken to B1 position the lamp will be ON. So lamp can be switched ON or OFF from ground floor or first floor.

Corridor lighting: In this system three switches placed at different places can control one lamp. For this purpose two numbers of two-way switches and one intermediate switch are used.

If the connections are made as shown in figure 2, the lamp will not glow. If position of any of the three switches is changed, the lamp will glow. To bring the lamp back to its not glow position again, change the position of any of the switches.

Intermediate Switch: The intermediate switch is used in corridor lighting. In fig 2 the intermediate switch attains a position in which terminal A1 and B1 are connected to terminal A2 and B2 respectively. If the position of the switch is changed, the terminals A1 will switch over from A2 to B2 and terminal B1 will switch over from B2 to A2.

Circuit Diagrams:

Observations:

Stair case lighting

S. No. Switch Positions Lamp Condition Remark

S1 S2

1 up up

2 up down

3 down down

4 down up

Corridor lighting

S. No.

Switch Positions

Lamp Condition

Remark S1 Intermediate

Switch

S2

1 up down up

2 down down up

3 down up up

4 down up down

5 up up down

6 up down down

7 down down down

8 up up up

Precautions:

1. Use fuse wire of appropriate size with each load.

2. Connections should be made tight.

3. Supply should be given after thorough check of the circuit.

Report:

1. Describe with neat sketches the function of two-way and intermediate switches.

2. What is the use of two-way switch?

3. What are the different materials used for making switches?

Object: (a) To make connection for 230V bell and 230V buzzer.

(b) To make connection for 6V bell using 230/6V transformer.

(c) To make connection for bell with indicator.

Apparatus used:

S. No. Tool/ Material Specification Quantity

Theory: In case of lighting system, lamps are required to glow continuously where as in case of bell system, bells are required to operate intermittently (i.e. non-continuously).

The 230 V bell and 230V buzzer are connected to the supply as shown in the figure 1 figure 3 respectively. The phase wire is connected to the bell / buzzer through a fuse wire and a push button switch. The other terminal of the bell / buzzer is connected to the neutral wire directly. Transformer of 230 V/6 V is used in 6 V bell circuit. The purpose of transformer here is to transform available A.C. voltage (i.e. 230 V A.C.) to the desired voltage (i.e. 6 V A.C.). Primary winding of transformer is connected to the supply through a push button switch. The secondary winding is connected across the two terminal of 6 V bell.

Bell indicator is used where a number of bells are used like in hospitals and hotels. When push button switch S₁ is operated, plunger P₁ operates to give the idea of a call from the location where switch S1 is placed. Likewise number of plungers denotes different location.

Circuit Diagram:

Procedure:

1. Study the circuits as per fig 1, 2 & 3.

2. Make connections as per fig. 4.

3. Study the circuits as per fig 5 and make connections.

4. Get the connections checked before connecting to supply.

Observation:

Transformer

Primary Input Voltage = volts

Secondary Output Voltage = volts

Report:

1. State the purpose of using transformer in electric bell circuit.

2. What is the purpose of iron core in a transformer?

3. Can you connect a transformer across D.C. mains?

4. Why a bell indicator is used in hotels etc ?

5. Write the difference between a bell and a buzzer?

6. What do you mean by armature of bell?

Object: Practice in making Plastic Casing-Capping wiring for one point.

Apparatus used:

S. No. Tool/ Material Specification Quantity

Connection /Procedure:

Fix the casing (base) part of casing-capping on a wooden board in „T‟ shape. Fix the lamp and switch on wooden blocks and mount these wooden blocks on the board as shown in the fig.

Make wiring for one point i.e. one lamp controlled with one switch. Connect phase wire to the lamp through one way switch and connect neutral wire directly to the other terminal of the lamp. Cover the wiring with capping (cover) part of the casing capping.

Perform open circuit and short circuit tests on the wiring and write down the findings in observation table.

Wiring Diagram:

Observation:

S.No. Switch Position Lamp Condition Megger Reading Remark

1 OFF Without Lamp

2 ON Without Lamp

3 OFF With Lamp

4 ON With Lamp

Advantages:

I) Its installation is quick and easy.

II) It has longer life.

III) It is quite cheaper than other type of wiring.

IV) Its appearance is good.

Disadvantages:

I) Good workmanship is required for installation.

II) This type is not used for open places.

Uses:

It is suitable for domestic, commercial and industrial wiring.

Report:

1) Make a line diagram for three point wiring.

2) What are different types of wiring system used in house wiring? Write their merits and demerits.

Object: Testing of following faults of electrical installation by Megger.

(a) Open circuit fault (b) Short circuit fault.

(c) Earth leakage test Apparatus used:

S. No. Tool/ Material Specification Quantity

Theory:

A megger is a high resistance-measuring instrument. It is a hand driven small generator, which provides voltages to the measuring circuit that causes deflection of the instrument pointer. The reading of the instrument indicated whether there is any fault in the circuit under test.

Open circuit test: The open circuit test indicates whether there is any break or discontinuity in the circuit. To perform this test, the megger is connected to phase and neutral, the load is connected and the switches are in ON position i.e. all the open points of the circuit are closed. In this test, the megger will show zero resistance if the circuit is complete but if there is any discontinuity in the circuit the megger will show infinity or the infinite resistance.

Short circuit test: This test indicates whether phase and neutral wire are shorted or not.

In short circuit condition, phase and neutral wires come in contact without any load. To perform this test, the megger is connected to phase and neutral, the load is removed from the circuit and switches are in ON position i.e. the circuit is kept open at load to keep the phase and neutral separate. In this test, if the megger shows zero this means that despite the phase and neutral wires being kept separate, the resistance between them is zero and hence there is a short circuit. If the megger indicates infinity this means that the neutral wire has no contact with phase and hence there is no short circuit.

Earth leakage test: This test indicates whether there is any leakage between phase and earth wire or between neutral and earth wire. This fault occurs generally due to damage of insulation. To perform this test, the megger is connected to phase and earth, the load from the circuit is removed and the switches are in ON position. The insulation resistance between earth & phase and between earth & neutral is measured. If the megger shows zero or any resistance, it means that there is an earth leakage. If it shows infinity it means that the earth wire has no contact with phase or neutral wires and hence there is no earth leakage.

Circuit Diagram of Megger:

Observation:

S.

No. Type of Test Circuit No.

Megger

Reading Remark

1 Open Circuit Test

1 2 3 4 5

2 Short Circuit Test

1 2 3 4 5

3 Earth Leakage Test

1 2 3 4 5

Report:

1) Discuss the purpose of earthing.

2) What are the different methods of earthing?

Object:

a) To make connections of an Energy Meter.

b) To measure energy consumed by a 1000 watt load in given time.

c) To measure error in the meter.

Apparatus used:

S. No. Tool/ Material Specification Quantity

Theory:

An energy meter measures electric energy consumed by a circuit in kWh (commercially known as one unit). The number of units or kWh consumed is proportional to the number of revolutions of the disc (in mechanical meters) or number of blink (in case of electronic and digital meters). The meter records the number of unit consumed in digits. The induction type energy meter consists of a current coil (connected in series with the circuit) and a potential coil (connected in parallel with the circuit). The potential coil carries full voltage of the circuit.

Meter Constant: Meter constant is the revolutions of the disc or blink (depending upon the type of meter) per kWh. This is generally indicated on the front panel of the meter.

Circuit Diagram:

Observation:

1. Meter constant = blinks/kWh

1. Power consumed by the load = watts

2. Time taken for

(a) 50 blink = sec

(b) 75 blink = sec

(c) 100 blink = sec

3. Correct value of energy meter corresponding to (a) 50 blinks

50 × Energy in one blink = watt sec.

(b) 75 blinks

75 × Energy in one blink = watt sec.

(c) 50 blinks

100 × Energy in one blink = watt sec.

4. Observed value of energy meter corresponding to (a) 50 blinks

Time for 50 blink × Load wattage = watt sec.

(b) 75 blinks

Time for 75 blink × Load wattage = watt sec.

(c) 100 blinks

Time for 100 blink × Load wattage = watt sec.

5.





Percent error

observed value 100%

 

Report:

1. Write down the constructional details of an energy meter.

2. What do you understand by the term “one unit of energy”?

Object:

(a)Study of various types of Multimeters.

(b)Measurement of Resistance with the help of Analog and Digital multimeters.

Apparatus used:

S. No. Tool/ Material Specification Quantity

Theory:

A multimeter is an instrument used to measure various electrical parameters such as voltage, current and resistance. In analog multimeter, the measurement is indicated by the deflection of the pointer, where as in digital multimeters the measurement is directly shown in digits on the display screen. Since the instrument i.e. multimeter measures circuit resistance, hence it can be used for checking the continuity of the circuit.

Analog multimeter: This is basically a galvanometer provided with suitable external circuit to measure the desired electrical parameters. Rotary selector switch of the meter provides resistance of appropriate value in series or in parallel to increase or decreases the range. This selector switch also provides facility to use the meter for measuring different electrical parameters such as voltage, current and resistance.

Digital Multimeter: It is an electronic device, which contains integrated circuits (ICs).

Before making any measurement the selector switch knob should be kept on desired parameter to be measured. Range knob should also be kept on desired value.

Precautions:

1. Do not connect voltage source to the instrument while measuring resistance.

2. Keep the switch in OFF position while not in use.

3. In case of analog multimeter, adjust zero setting before taking any measurement.

4. Check the position of the Range selection switch before any measurement. The range should be selected higher than the expected value of voltage/current.

Diagram:

Observation:

S. No. Resistance Box (Ω)

Analog Multimeter (Ω)

Digital Multimeter

(Ω) Remark

Report:

1. Explain with suitable diagram the operation and construction of Digital and Analog

Object: (a) To measure the resistance of heating element of an electric kettle.

(b) To determine the efficiency of electric kettle.

Apparatus used:

S. No. Tool/ Material Specification Quantity

Theory:

(a) Resistance of the heating element

Resistance R of the heating element Voltage (volts)

(ohm, ) Current (amp.)

V

  I 

(b) Energy Input E_i   V I t

Where V = Mean voltage in Volts (V) I = Mean current in ampere (A)

t = Time taken for heating water in seconds

(c) Energy Output Eo = Mass of water in gm × Rise in temp. in °C × 4.2

(d) Efficiency of kettle (η)

100 %

o i

E

  E 

Procedure:

(i) Make the connections as shown in the figure below.

(ii) Take 1250 gm. of water in kettle.

(iii) Note down the initial temperature of water (iv) Heat it up to 80 °C.

(v) Note down the reading of voltmeter and ammeter, first after switching on the circuit (initial) and again before switching off the circuit (final).

(vi) Record the time taken for heating the water from initial temperature to 80 °C.

Circuit diagram:

Observation:

Mass of water =

Initial temperature of water =

Final temperature of water =

Rise in temperature =

Ammeter reading at room temp. (Initial) = Ammeter reading at final temp. (Final) = Voltmeter reading at room temp. (Initial) = Voltmeter reading at final temp. (Final) = Time taken to raise the temperature = Report:

1. What is meant by temperature co-efficient of resistance?

2. What is meant by Joule‟s constant?

3. Why is electric heating preferred over other types of heating?