Government Polytechnic, Muzaffarpur. Name of the Lab: Electrical Workshop Lab.

Sub Code: 1620309

Experiment No- 1

Aim: Identify, Dismantle, Sketch & Assemble Different Electrical Accessories

Electrical Symbols

Single-pole Single-throw

(SPST) Switch

Single Pole Double-throw (SPDT) Switch

Double-pole, Single Throw (DPST) Switch

Fuse

(No Connection)

Two Conductors Connected

Cell

Power Supply

(Usually identified by voltage & type)

Polarity would indicate DC Power Supply-

Voltage Source

AC Power Supply-Voltage Source

Capacitor

Inductor

Constant Current Source

Meter

The letter in the center identifies the type

V = Voltmeter, A = Ammeter

W = Wattmeter, G = Galvanometer

Resistor or Resistance (Fixed value)

Transformer

Variable Voltage Transformer

(Autotransformer / Variac) Iron Core

Relay Contacts

Normally Open (NC)

Normally Closed(NC)

Relay (Energizing) Coil

Experiment No: 02

Aim:- To wire up a circuit in conduit system one lamp controlled by one switch

TOOLS REQUIRED:-

Screw driver 200mm-1no,combination pair 150mm-1no,Line tester 500v-1no, Wire stripper-1

no,pocker-1no, Mallet-1no,etc….

ESTIMATE:-

SI

NO

NAME OF METERIALS SPECIFICATION QUATITY UNITS REMARKS

1

2

3

4

5

6

7

8

9

PROCEDURE:-

1. Draw the lay out and connection diagram.

2. Collect the required wiring materials.

3. Connect the required materials on the work board as per connection diagram.

4. Check the circuit for continuity.

5. Given the supply to the circuit after checking.

6. Finished the work neatly and correctly.

RESULT:-

Wired up a circuit in conduit system, one lamp controlled by one switch.

Experiment No: 3

Aim: To control two lamps by a one switch with provision for plug socket with switch control.

MATERIALS REQUIRED WITH DIMENSIONS:

1. 1/18”pvc wire of sufficient length

2. One way switch – 2 no.

3. Two-pin plug socket-1no.

4. Bulb-1no.

5. Bulb holder-1no.

TOOLS AND EQUIPMENT USED:

1. 6”cutting pliers

2. 1.5 IB ball peen hammer.

3. Wire stripper

4. Tester

5. 6”screw drivers

6. Hack saw

7. 12mm hand drilling machine.

OPERATIONS TO BE CARRIED OUT:

1. Fitting the wires

2. Connection of the bulb holder

3. Connection of plug socket

4. Connection of switch

5. Circuit connections

6. Power from mains

7. Operation the bulb

8. Testing the plug socket.

PROCEDURE:

1. The outline wiring diagram marked on the wooden board and clips are nailed to the board

following the diagram, six wire pieces are taken and insulation is removed at the ends by

using wire stripper.

2. A phase wire is connected to one point switch s1 and s2.

3. The lower points of switches s1ands2 are connected to one point of bulb holder and one point

of plug socket respectively.

4. Two neutral wires are taken and one in connected to the remaining point of the bulb holder.

5. The other is connected to the remaining points of plug socket.

6. After checking the proper circuit connections the power supply is given.

7. Now the bulb is ready to glow bright and the plug socket is also ready with control.

PRECAUTIONS:

1. All the wire connections of the switches, bulb holder and sockets be tight.

2. Too many load connections fr4om a single junction are avoided.

RESULT:

1. In series connection if one bulb does not glow the bulb also does not glows.

2. In parallel connection if one bulb does not glow the other bulb blows.

Experiment No- 4

Aim:- To wire up a circuit in conduit system as per layout and conditions (go down wiring)

TOOLS REQUIRED:-

Screw driver 200mm-1no,combination pair 150mm-1no,Line tester 500v-1no, Wire stripper-1

no,pocker-1no, Mallet-1no,etc….

ESTIMATE:-

SI

NO

NAME OF METERIALS SPECIFICATION QUATITY UNITS REMARKS

PROCEDURE:-

1. Draw the lay out and connection diagram.

2. Collect the required wiring materials.

3. Connect the required materials on the work board as per connection diagram.

4. Check the circuit for continuity.

5. Given the supply to the circuit after checking.

6. Finished the work neatly and correctly.

RESULT:-

To wire up a circuit in conduit system as per layout and conditions (go down wiring)

Experiment No- 5

Aim: To measure Energy consumed in a single phase circuit using Energy meter.

Apparatus required:

SL.NO. Components Required Range Type Quantity

1 Ammeter (0-10) MI 1

2 Load ------ LAMP --

3 Volt meter (0-300) MI 1

4 Energy Meter 1 Ph,300V, 10A -- 1

5 Autotransformer 1KVA

230/(0-240) V

1PH 1

Formula used:

1200 Rev = 1kwhr

1Rev =1x1000x3600/1200 = 3000(Watt-sec)

For N Rev Indicated energy (Ei) = N x 3000 (Watt-sec)

% Error = (E I -E a) x100/Ei

Calculated energy Ea = (VL x IL) x T (Watt-sec)

Where

VL –Load voltage

IL-Load current

Energy meter constant = ---------------- (Rev/sec)

ENERGY METER INTERNAL CONNECTION

TABULATION:

S.NO Volt meter

readings (Volts)

Ammeter

readings

(Amps)

Time taken

for

5 Rev(Sec)

Calculated

Energy

(Ea)

Indicated

Energy (Ei )

Procedure:

1. Connections are made as per circuit diagram.

2. Supply is switched on and load is applied and Ammeter, Voltmeter readings and

Time taken by the discs for particular number of revolution are noted using stop

Watch.

3. Step 2 is repeated for various load conditions.

4. % Error is calculated

RESULT:

Thus energy consumed in a single phase circuit is measured.

Experiment No- 6

Aim: Wire Up Consumers main board with ICDP and Distribution Fuse box and 0.8 hours with

LCB.

Apparatus Required: SL.NO. Components Required Range Quantity

1 One way Switch ---- 1

2 Energy Meter 1 Ph --

3 Indicator ----- 1

4 Lamp ---- 1

5 Wires ---- Required amount

Power is supplied to domesticate installations through a phase and neutral, forming a single

phase AC 230 v to wire system. For individual establishment power is supplied through three

phase two wire system. To give 440V, the neutral is earthed at to the domestic utilities; power is

fed to kilo watt meter and then to distributes power along several circuits. It also protects these

circuits from over load by safety devices like fuses or circuit breakers.

ELEMENTS OF HOUSE WIRING:

1. Fuses and circuit breakers

2. Electric switch

3. Plug

4. Socket out let

5. Lamp holder

6. Main switch

7. Incandesant tight

WIRING METHOD: A circuit is path along which the electric current flows from negative side

of power source to positive side.

COMMON HOUSE WIRING REPAIRS:

1. Replacing a fuse

2. Resulting a circuit beaker

3. Resulting a switch or an out let

4. Repair of house hold appliances

Procedure: 1. Connections are given as per the circuit diagram.

2. When the Switch is closed, the Lamp will glow and the metering is running.

3. The corresponding readings are noted from energy meter by observing number of

cycles of the disc for a particular time period.

To prepare residential wiring using Fuse, Switch, Indicator, Lamp and Energy meter .

Result: Thus the residential wiring is implemented and tested for its operation.