New First year Electrical lab manual
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Transcript of New First year Electrical lab manual
PPRREEPPAARREEDD BBYY VV..BBAALLAAJJII,, AAPP//EEEEEE,, DDCCEE PPaaggee 11
MEASURMENT OF VOLTAGE, CURRENT, POWER AND POWER FACTOR USING RLC LOAD
Aim: To measure power in a single phase AC circuit using wattmeter by RLC loading. APPARTUS REQUIRED:
SL.No Name of the Apparatus Range / Type Quantity
1 Voltmeter (0-300V) MI 1 No.
2 Ammeter (0-10A) MI 1 No.
3 Wattmeter 300V,10A,LPF 1 No.
4 RLC Load 5kW 1 No.
5 Connecting Wires 1/18 SWG As per requirement
THEORY:
Power in an electric circuit can be measured using a wattmeter. A
wattmeter consists of two coils, namely current coi l and pressure coil or potential
coil. The current coil is marked as ML and pressure coil is marked as CV. The
current coil measure the quantity that is proportio nal to the current in the circuit
the pressure coil measures quantity that is proport ional to the voltage in the
circuit. The given wattmeter is loaded by direct lo ading. The ammeter is
connected in series to the wattmeter. Since the sam e current flows in both the
coils, the current and voltage across the circuit a re constant. The power
consumed by the load is measured using the wattmete r and calculated using the
relation given below.
Expt No: Date:
PPRREEPPAARREEDD BBYY VV..BBAALLAAJJII,, AAPP//EEEEEE,, DDCCEE PPaaggee 22
CIRCUIT DIAGRAM:
AA ∼∼
VV ∼∼
Autotransformer 230V/(0-270)V
11 φφφφφφφφ 223300VV AACC SSuuppppllyy
5500HHzz
P
N
((00--330000))VV,, MM II
((00--1100))AA,, MM II
MM
CC
LL
VV
FFuussee
NNLL
RRLLCC LLOOAADD
((330000VV,, 1100AA,, LL PPFF))
DPST S
PPRREEPPAARREEDD BBYY VV..BBAALLAAJJII,, AAPP//EEEEEE,, DDCCEE PPaaggee 33
FORMULAE:
Actual power = W x Multiplication factor
Where W – Observed wattm eter reading
Apparent power = VI watts
Where V – Voltmeter reading
I – Ammeter reading
Power Factor, cos φφφφ = Actual Power / Apparent Power
PROCEDURE:
1. Connect the circuit as shown in the circuit diag ram.
2. Initially no load is applied.
3. Autotransformer is set to minimum voltage positi on before switching on
the power supply.
4. Set the rated voltage by using the autotransform er. Measure and record the
values of voltmeter, ammeter and wattmeter on no lo ad condition. Also
carefully note the multiplication factor of the wat tmeter that is mentioned in
the wattmeter itself.
5. Apply the load by adjusting RLC load.
6. Measure and record the values of voltmeter, amme ter and wattmeter.
7. Repeat the steps 5 and 6 until the ammeter readi ng reaches 10A.
8. After taking all the readings, reduce the load s lowly to the minimum and
bring the voltage to minimum in the autotransformer . Switch off the power
supply.
9. Calculated the Indicated power by the given form ula.
10. Calculate the power factor by the given formula .
PPRREEPPAARREEDD BBYY VV..BBAALLAAJJII,, AAPP//EEEEEE,, DDCCEE PPaaggee 44
OBSERVATION TABLE:
Multiplication Factor=
Sl.No Voltage
V (V)
Current
I (A)
Wattmeter Reading
(watts) Actual Power
(watts)
Power Factor
cosφφφφ Observed Actual
MODEL CALCULATION:
Result
A single – phase wattmeter is used to measure powe r in AC circuit using
RLC loading.
PPRREEPPAARREEDD BBYY VV..BBAALLAAJJII,, AAPP//EEEEEE,, DDCCEE PPaaggee 55
HOUSE WIRING
Aim: To Construct House wiring using Energy Meter METERIALS REQUIRED:
Sl.No
Name of the apparatus
Range / Type
Quantity
1 Switch SPST, 5A 3 Nos.
2 Incandescent Lamp 100W 1 No.
3 Lamp Holder Batten 1No.
4 Ceiling rose - 1No.
5 Socket 10A 1No.
6 Screws 1inch As per required
7 Wires 1/18SWG As per required
8 Switch Board 12″″″″ x 8″″″″ 1No.
9 Energy Meter 1 φφφφ 300V , 16A 750 rev 50Hz
1No.
10 Main switch Box 1 φφφφ 300V , 16A 1No.
EExxpptt..NNoo:: DDaattee::
PPRREEPPAARREEDD BBYY VV..BBAALLAAJJII,, AAPP//EEEEEE,, DDCCEE PPaaggee 66
TOOLS REQUIRED:
Sl.No Name of the tools Quantity
1 Combination Plier s
1 No.
2 Connector screw driver 1 No.
3
Screw driver 1 No.
4 Electrician knife 1 No.
THEORY:
Conductors, switches and other a ccessories should be of proper
capable of carrying the maximum current which will flow through them. The
following table shows the rating for different acce ssories. Conductors should be
of copper or aluminium. In power circuit, wiring sh ould be designed for the load
which it is supposed to carry. Power sub circuits s hould be kept separate from
lighting and fan sub – circuits. Wiring should be d one on the distribution system
with main and branch distribution boards at conveni ent centers. Wiring should
neat, with good appearance.
� Wires should pass through a pipe or box, and should not twist or cross.
� The conductor is carried in a rigid steel conduit c onforming to standards or
in a porcelain tube.
PPRREEPPAARREEDD BBYY VV..BBAALLAAJJII,, AAPP//EEEEEE,, DDCCEE PPaaggee 77
CIRCUIT DIAGRAM:
EENNEERRGGYY MM EETTEERR
MM AAII NN SSWWII TTCCHH
Lamp 100W
11 φφφφφφφφ 223300VV AACC SSuuppppllyy
5500HHzz
PP
NN
SS11 SS22 LL 22 LL 11
Ceiling rose
Switch Board
DDPPII CC
DPIC – Double Pole Iron – Clad Switch
PPRREEPPAARREEDD BBYY VV..BBAALLAAJJII,, AAPP//EEEEEE,, DDCCEE PPaaggee 88
PROCEDURE:
1. Study the given wiring diagram
2. Make the location points for energy meter, main witch box,
switchboard, lamp and ceiling rose.
3. Draw the lines for wiring on the wooden board.
4. Place the wires along with the line and fix.
5. Fix the bulb holder, Switches, Ceiling rose, Soc ket in marked
positions on the wooden board.
6. Connect the energy meter and main switch box in marked positions
on the wooden board.
7. Give a supply to the wires circuit.
8. Test the working of light and socket.
Result:
Thus the wiring for the bulb and ceiling rose was prepared and
tested.
PPRREEPPAARREEDD BBYY VV..BBAALLAAJJII,, AAPP//EEEEEE,, DDCCEE PPaaggee 99
STAIRCASE WIRING
Aim: To control the status of the given lamp by using t wo – way switches METERIALS REQUIRED:
Sl.No
Name of the apparatus
Range / Type
Quantity
1 Incandescent Lamp 100W 1 No
2 Lamp Holder Pendent Type 1 No
3 SPDT Switch 230V,5A 1 No
4 Wires 1/18” As per requirement
5 P.V.C Pipe 1/4" As per requirement
6 Wooden Board - 1 No
7 Round block - 1 No
TOOLS REQUIRED:
Sl.No Name of the tools Quantity
1 Combination Plier 1 No
2 Connector screw drivers 1 No
3 Screw driver 1 No
4 Electrician knife 1 No
Expt.No: Date:
PPRREEPPAARREEDD BBYY VV..BBAALLAAJJII,, AAPP//EEEEEE,, DDCCEE PPaaggee 1100
CIRCUIT DIAGRAM :
SPDT - 1
NN
PP
223300VV,, 5500HHzz AACC SSuuppppllyy
11
22
33
11’’
22’’
33’’
LLaammpp 6600WW,, 223300VV
SPDT - 2
PPRREEPPAARREEDD BBYY VV..BBAALLAAJJII,, AAPP//EEEEEE,, DDCCEE PPaaggee 1111
PROCEDURE:
1. Place the accessories on the wiring board as per the circuit diagram.
2. Place the P.V.C pipe and insert two wires into t he P.V.C pipe.
3. Take one wire connect one end to the phase side and other end to the
middle point of SPDT switch 1
4. Upper point of SPDT switch 1 is connected to the lower point of SPDT
switch2.
5. Lower point of SPDT 1 is connected to the upper point SPDT switch2.
6. Another wire taken through a P.V.C pipe and midd le point of SPDT
switch 2 is connected to one end of the lamp holder .
7. Another end of lamp holder is connected to neutr al line.
8. Screw the accessories on the board and switch on the supply.
9. Circuit is tested for all possible combination o f switch position.
PRECAUTIONS:
� While giving the connections be careful
� Handle the lame safely
� Be careful while handling the tools.
PPRREEPPAARREEDD BBYY VV..BBAALLAAJJII,, AAPP//EEEEEE,, DDCCEE PPaaggee 1122
SWITCH
POSITION TABLE:
Sl.No
SPDT1 SPDT2 Result
1 12 1’2’ OFF / ON
2 12 2’3’ OFF / ON
3 23 1’2’ OFF / ON
4 23 2’3’ OFF / ON
PPRREEPPAARREEDD BBYY VV..BBAALLAAJJII,, AAPP//EEEEEE,, DDCCEE PPaaggee 1133
Result:
PPRREEPPAARREEDD BBYY VV..BBAALLAAJJII,, AAPP//EEEEEE,, DDCCEE PPaaggee 1144
FLUORESCENT LAMP WIRING
Aim: To make and check the fluorescent lamp wiring METERIALS REQUIRED: TOOLS REQUIRED:
Sl.No Name of the tools Quantity
1 Combination Plier 1 No
2 Connector screw drivers 1 No
3 Screw driver 1 No
4 Electrician knife 1 No
S.No
Name of the apparatus
Range / Type Quantity
1 fluorescent lamp fixture
4 ft 1 No
2 fluorescent lamp 40W 1 No
3 Choke 40W, 230V, 1 No
4 Starter 1 No
5 wires 1/18” As per requirement
Expt..NNoo:: Date:
PPRREEPPAARREEDD BBYY VV..BBAALLAAJJII,, AAPP//EEEEEE,, DDCCEE PPaaggee 1155
CIRCUIT DIAGRAM:
Choke 40W, 230V
SS
Starter
PP NN 11φφ,, 223300 VV ,,
5500HHzz AACC SSuuppppllyy
40W Fluorescent lamp Filament Filament
PPRREEPPAARREEDD BBYY VV..BBAALLAAJJII,, AAPP//EEEEEE,, DDCCEE PPaaggee 1166
THEORY: Tube light has filament on either side. They are c oated with tungsten
material. The inside of the tube has phosphorous co ating which is used to
convert ultraviolet into visible light and to give the required color sensation. A
choke is used to give transient high voltage so as to initiate the electron
movement which is an iron starter capacitor is used to suppress radio-
interference with the switch closed. The current fl ows through the choke and the
starter. The glow switch suddenly breaks thereby cr eating the circuit. Due to high
conductivity, inductive property of the choke, a tr ansient high voltage is available
across the filament. Hence the electrons are emitte d and travel through the tube.
Then tube light is produced.
PROCEDURE:
1. Give the connections as per the circuit diagram as shown in figure.
2. Fix the tube holder and the choke in the tube.
3. The phase wire is connected to the choke and neu tral directly to the
tube
4. Connect the starter in series with the tube.
PRECAUTIONS:
� While giving the connection be careful.
� Handle the lamp safely.
� Be careful while handling the tools.
� All the connections should be right and tight.
Result:
PPRREEPPAARREEDD BBYY VV..BBAALLAAJJII,, AAPP//EEEEEE,, DDCCEE PPaaggee 1177
MEASURMENT OF ENERGY USING ENERGYMETER
Aim: To measure the energy in a single in a phase phase circuit using direct loading APPARTUS REQUIRED:
SL.No Name of the Apparatus Range / Type Quantity
1 Single phase Energy meter 750 rev / kWh, 240V, 50Hz 1No.
2 Wattmeter 300V, 10A, UPF 1No.
3 Voltmeter 300V, MI 1No.
4 Ammeter 10A, MI 1No.
5 Load Resistive, 5kW 1No.
6 Wires 1 / 18 SWG As per requirement
THEORY:
The energy meter is an integrated type of instrume nt, where speed of
rotation of the aluminum to the power consumed and number of revolutions per
minute is proportional to the energy consumed by th e load.
The ratings associated with the energy meter are.
� Voltage rating
� Current rating
� Frequency rating
� Meter Constant
Expt No: Date:
PPRREEPPAARREEDD BBYY VV..BBAALLAAJJII,, AAPP//EEEEEE,, DDCCEE PPaaggee 1188
The driving system of the meter provides the rotati onal surface of the torque for
the moving system, which in turn activates the ener gy meter. The energy meter is
operated at induction principle in which eddy curre nt.
PPRREEPPAARREEDD BBYY VV..BBAALLAAJJII,, AAPP//EEEEEE,, DDCCEE PPaaggee 1199
CIRCUIT DIAGRAM:
DPSTS
AA ∼∼
VV ∼∼ 1 φφφφ
230V Ac Supply
50Hz
1 φφφφ Autotransformer
(0-270V)
(0-10A) MI
(0-300V)
MI
S1
S2
L1
L2
M
C
L
V
Fuse
NL
Resistive load 5 KW
P
N
PPRREEPPAARREEDD BBYY VV..BBAALLAAJJII,, AAPP//EEEEEE,, DDCCEE PPaaggee 2200
Indicated in the aluminum disc interacts with the main field and creates the
driving force.
FORMULAE:
Energy meter specification = 750 rev / kWh
True energy = Power (P) x time (s)
= P x t (ws)
= P x t / 3600 x 1000 kWh
Measured energy = n / 750 kWh
Where n - number of revo lutions / sec
`
PROCEDURE:
1. Connections are made as per the circuit diagram.
2. Supply is given to the switch by closing the DFS T switch.
3. By adjusting the voltage is brought to the rated voltage.
4. Load is switched On
5. Time taken for five revolutions in the energy me ter is noted and the
corresponding ammeter and voltmeter reading are not ed.
6. The above procedure is repeated for different lo ad current and for fixed
number of revolutions.
7. Then the load is gradually released and supply i s switched OFF.
PPRREEPPAARREEDD BBYY VV..BBAALLAAJJII,, AAPP//EEEEEE,, DDCCEE PPaaggee 2211
OBSERVATION TABLE:
M.F ----------------
Sl. No
Supply
Voltage
V
Load Current
I (A)
Wattmeter
Reading
P (W)
Time
t (sec)
True Energy
p x t
1000 x 3600
(kWh)
Measured
energy
n / 750 (kWh)
MODEL CALCULATIONS:
PPRREEPPAARREEDD BBYY VV..BBAALLAAJJII,, AAPP//EEEEEE,, DDCCEE PPaaggee 2222
Result:
Thus the energy in a single phase was measured usi ng energy meter.