SUB CODE:436
SEMESTER-5

1.OPEN CIRCUIT TEST OF TRANSFORMER
AIM:-
To conduct a open circuit test in given transformer. Predetermine the Ro&Xo
MACHINE DETAILS:-
METERIALS REQUIRED:-
1.
Ammeter (0-5A) MI 1NO
2.
Voltmeter (0-250v) MI 1NO
3.
Wattmeter (300v,15A,lpf) 1NO
THEORY:-
The purpose of the OC test to determine the no load loss (core loss) at rated voltage and frequency. Shunt branch parameters of equalent circuit r0&x0 and the no load current of the transformer on winding of the transformer. In the open circuit test the primary load current is very small(2.6 of rated current )copper loss is negligibly small in the primary and is nil in the secondary is opened. The equalent circuit parameters r0&xo referred to LV side can be calculated from the test result.
The no load power loss, Pi=V0*I0*COS φ0
COSφ0=Pi/V0*I0

PROCEDURE:-
1. Collect the materials for the given work.
2. Connection are done as shown in connection diagram.
3. Keep auto transformer at zero position.
4. Adjust the auto transformer up to rated voltage.
5. Take voltmeter, ammeter and wattmeter reading.
𝑽
𝑶𝑪
𝑰
𝑶𝑪
𝑾
𝑶𝑪
MODEL CALCULATION
𝑽
𝑶𝑪
=

𝑰
𝑶𝑪
=
𝑾
𝑶𝑪
=
𝑾
𝑶𝑪=
= 𝑽
𝑶𝑪
𝑰
𝑶𝑪
𝑪𝑶𝑺∅
𝟎
∅
𝟎
= 𝒄𝒐𝒔 −𝟏
(
𝑾
𝑶𝑪
𝑽
𝑶𝑪
𝑰
𝑶𝑪
)
Wattles component
Magnetizing component 𝒊 𝒘
= 𝒊
𝟎 𝒄𝒐𝒔∅
𝟎 𝒊
µ
= 𝒊
𝟎 𝒔𝒊𝒏∅
𝟎
𝑹
𝟎
=
𝑽
𝑶𝑪
𝑰
𝑾
𝑹
𝟎´
=
𝑹
𝟎
𝑲 𝟐
𝑿
𝟎
=
𝑽
𝑶𝑪
𝑰
µ
𝑿
𝟎´
=
𝑿
𝟎
𝑲 𝟐
RESULT:-
1) Equivalent circuit of single phase transformer was plotted.
2) Efficiency curve were plotted.
3) Regulation curve were plotted.
4) Value of max. efficiency =…………………………….
5)

2.SHORT CIRCUIT TEST OF A TRANSFORMER
AIM:-
To conduct a short circuit test in given transformer. Determine the efficiency and regulation for different load .plot the following graphs
1.
Efficiency vs out put
2.
%regulation vs p f
3.
Predetermine max efficiency
MACHINE DETAILS:-
METERIALS REQUIRED:-
1.
Ammeter (0-15A) MI 1NO
2.
Voltmeter (0-150v) MI 1NO
3.
Wattmeter (300v,15A,lpf) 1NO
THEORY:-
In the test with low voltage winding short circuited, allow voltage applied to the high voltage winding, the full load current are flow through both windings. The applied voltage is a small percentage of the normal voltage; the mutual flux is also small. Also the core losses are very small.
The watt meter reading represents the full load Cu loss pf the transformer

PROCEDURE:-
1. Collect the materials for the given work.
2. Connection are done as shown in connection diagram.
3. Keep auto transformer at zero position.
4. Adjust the auto transformer up to rated current
5.Take voltmeter, ammeter and wattmeter reading.
𝑽
𝑺𝑪
𝑰
𝑺𝑪
𝑾
𝑺𝑪
MODEL CALCULATION
𝑽
𝑺𝑪
=
𝑰
𝑺𝑪
=
𝑾
𝑺𝑪
=

Zsc=Vsc/Isc
𝑹𝒔𝒄 = 𝑽𝒔𝒄/𝑰𝒔𝒄
𝟐
Xsc= (𝒁𝒔𝒄² − 𝑹𝒔𝒄²)
Ro1=Rsc
X01=Xsc
R01 ´ =R01xk²
X01’=X01x k²
TO DRAW EFFICIENCY CURVE FOR A GIVEN P.F
Out put at X times F.L=X(rated KVA x 1000) cos ∅
Core loss Wi= W0
Copper loss Wcs= X²Wsc
Efficiency=(Output /output+losses) x100.
Sl no Load Output(Watt) Wi(watt) Wcx(watt) Input=Output+Wi+Wcx %efficiency
TO DRAW REGULATION V/S PF CURVE
% regulation at F.L for a given P.F=
𝑰𝒓𝒂𝒕𝒆𝒅(𝑹𝒄𝒐𝒔∅±𝑿𝒔𝒊𝒏∅
𝑽
Sl No cos ∅ sin ∅
RESULT:-
% Regulation

Conducted SC test of transformer and Pre determined the efficiency and regulation .
Ploted the graphs
3.LOAD TEST ON SINGLE PHASE TRANSFORMER
AIM:-
To conduct a no load test on given SINGLE PHASE TRANSFORMER and predetermine the regulation for deferent load.
MACHINE DETAILS:-
METERIALS REQUIRED:-
1.
Ammeter (0-15A) MI 1NO
2.
Voltmeter (0-150v) MI 1NO
3.
Wattmeter (300v,15A,upf) 1NO
4.
Ammeter (0-5A) MI 1NO
5.
Voltmeter (0-250v) MI 1NO
6.
Wattmeter (300v,30A,upf) 1NO
THEORY:-
When the secondary of transformer is loaded the terminal voltage drops.

PROCEDURE:-
1.
Close the DPST switch.
2.
Adjust the autotransformer till the voltmeter reads rated voltage.
3.
Note the no load readings and enter them as first set of readings in tabular column.
4.
Close DPST switch.
5.
Load the transformer gradually and take all meter readings each time till the secvondary current reaches rated value.
TABULATION
Sl No I1 in
Amps
V1 in volts
W in watts
I2 in
Amps
V2 in volts
Input in watts
Output=V2xI2 %efficiency %
Regulation
CALCULATION
Output=V2xI2.
Input= W
%efficiency=
𝑶/𝒑 𝒊/𝒑
x100.
Regulation= 𝒐𝑽𝟐−𝑽𝟐 𝒐𝑽𝟐
x100.
RESULT:-
Load test on single phase transformer is conducted and efficiency and regulation curve are plotted.

4.
SWIMBERN’S TEST
AIM:-
Conduct no load test on dc shunt motor and [predetermine the efficiency of the machine under the following working conditions. a)machine working as a generator b) Machine working as a motor c) plot efficiency vs output
MACHINE DETAILS:-
METERIALS REQUIRED:-
1) Ammeter
2) Ammeter
3) voltmeter
4) voltmeter
5) Rheostat
6) Rheostat
7) Tachometer
0-5A MC 2NO
0-3A MC 1NO
0-300v MC 1NO
0-30v MC 1NO
100Ω,5A
370Ω,1.1A
1NO
1NO
1NO
THEORY:-
This is a no load test to determine the losses of the machine. the losses in the motors are
Iron loss or core losses, frictional losses, windage losses, arm copper losses
Work as generator 𝒐𝒖𝒕𝒑𝒖𝒕
Efficiency= 𝒐𝒖𝒕𝒑𝒖𝒕−𝒍𝒐𝒔𝒔𝒆𝒔
Work as motor

Efficiency = 𝒊𝒏𝒑𝒖𝒕−𝒍𝒐𝒔𝒆𝒔 𝒊𝒏𝒑𝒖𝒕
PROCEDURE:-
1.
Connection are as shown in connection diagram.
2.
Armature rheostat at maximum position.
3.
Field rheostat at minimum position.
4.
Switch on the supply and run the motor at no load.
5.
Adjust the field rheostat bring motor speed to rated speed.
6.
Note the readings and tabulate the readings
TABULATION
𝑰
𝑨𝟎
Si no
Voltage V
(in volts) AMPS
𝑰
𝑺𝑯
AMPS
𝑰
𝟎=
𝑰
𝑨𝟎
+ 𝑰
𝑺𝑯

AS MOTOR:
Sl No Fraction of load(X)
Voltage(v) Current Ia in Amps
Total loss=
X²Ia²Ra+Wc
Input power o/p power efficiency
AS GENERATOR
Sl No Fraction of load(X)
Voltage(v) Current Ia in Amps
Total loss=
X²Ia²Ra+Wc
Input power o/p power efficiency
CALCULATIUON:
Constant losses Wc= V ( Iao+ Ish)-Iao²Ra.
AS MOTOR:
I/p power=F.L o/p Power+Ia²Ra+Wc.,O/p power= V 𝑰
𝑳
, 𝑰
𝑳
=Ia+ Ish.
Total loss= Ia²Ra+Wc.

O/p=I/p-Losses.
Efficiency=
𝑶/𝒑 𝒊/𝒑
x100.
AS GENERATOR:
Full load o/p power=Vx 𝑰
𝑳
.
I/p=o/p+ losses.
%efficiency=
𝑶/𝒑 𝒊/𝒑
x100.
RESULT:
Efficiency of the DC shunt machine when work as
1)Motor 2) Generator are pre-determined also efficiency curves are plotted.

AIM;
To conduct a load test on DC series motor and plot the following graph.
1) Torque v/s armature current
2) Speed v/s armature current
3) Speed v/s torque
4) Efficiency v/s o/p
MACHINE DETAILS:
APPARATUS REQUIRED:
1) Voltmeter
2) Ammeter
3) Tachometer
0-250V(MC)
0-15A(MC)
1No
1 No
THEORY:
In series motor the torque is directly proportional to armature current. Speed N is proportional to
Ed / ∅. In a series motor the field carries same current as the armature ie, ∅ ∝Ia. The series motor cannot be started without load.
Toque= (S1-S2)xgr
Output=
𝟐П𝑵𝑻
𝟔𝟎
.
Input=VI .
%efficiency=
𝑶/𝒑 𝒊/𝒑
x100.

TABULATION:
Sl
No
Voltage(V) Speed(RPM) Spring balance Torque=
S1 S2 S1~s2
(S1s2)rg
Output(W) Input(W) Efficiency(%)
CALCULATION:
V= ………………..
Speed,N=………………………….
Spring balance, S1=…………………………….
S2=……………………………………………..
Torque,T= (s1~s2)rg, r=Radius of break drum g= 9.8
Output=
𝟐П𝑵𝑻
𝟔𝟎
.
%efficiency=
𝑶/𝒑 𝒊/𝒑
x100.

PROCEDURE:
1) Connections are made as per diagram.
2) Apply a small load to the motor and start the motor.
3) Note the meter readings
4) Vary the spring balance at different load.
5) Note the corresponding readings.
6) Tabulate the reading and plot the graph.
RESULT:
The load test on series motor is conducted and plotted the graphs.

AIM;
To conduct a load test on DCshunt motor and plot the following graph.
5) Torque v/s armature current
6) Speed v/s armature current
7) Speed v/s torque
8) Efficiency v/s o/p
MACHINE DETAILS:
APPARATUS REQUIRED:
1) Voltmeter 0-250V(MC)
2) Ammeter 0-15A(MC)
3) Ammeter 0-3A (MC)
4) Rheostat 500Ω,3A
5) Tachometer
1No
1 No
1No
1No
THEORY:
A load test is direct method,and this method is used only for small motors, because in the case of large motors it is difficult to dissipate large amount of heat generation
Toque= (S1-S2)xgr
Output=
𝟐П𝑵𝑻
𝟔𝟎
.
Input=VI .
%efficiency=
𝑶/𝒑 𝒊/𝒑
x100.

TABULATION:
Sl
N o
Voltage(V) Speed
(RPM)
Ish Ia IL=I a+
Ish
Spring balance
S1 S2 S1~s2
Torque
=
(S1s2)rg
Outp ut(W
)
Input(W
)
Efficien cy(%)
CALCULATION:
V= ………………..
Speed,N=………………………….
Spring balance, S1=…………………………….
S2=……………………………………………..
Torque,T= (s1~s2)rg, r=Radius of break drum g= 9.8
Output=
𝟐П𝑵𝑻
𝟔𝟎
.
%efficiency=
𝑶/𝒑 𝒊/𝒑
x100.

PROCEDURE:
1) Connections are made as per diagram.
2) Rheostat kept in min. position
4) Start the motor using 4 point starter
5)Note the meter readings
6) Vary the spring balance at different load.
7) Note the corresponding readings.
8) Tabulate the reading and plot the graph.
RESULT:
The load test on shunt motor is conducted and plotted the graphs.
7.POLARITY TEST AND TURN`S RATIO TEST ON SINGLE PHASE T RANSFORMER
Aim : To conduct polarity test, and determine turn`s ratio, transformation ratio, and magnetizing component of No Load current of single phase transformer. (115/ 220 V, 5 KVA)
Apparatus required :

Theory:- Turns ratio of a transformer = No of turns of primary/No of turns of secondary.
Transformation ratio K = Secondary induced EMF/ Primary induced EMF= E
2
/E
1
E
1
= 4.444 φm.f.N
1
Volts., and E
2
= 4.444 φm.f.N
2
Volts
.
.
.
K= E
2
/E
1
K =4.444 φm.f.N
2
/4.444 φm.f.N
1
, =N
2
/N
1
.
.
.
Turns ratio, N
1
/N
2
=E
1/
E
2
No load input power, W
0
= V
0
I
0
Cosφ
0
, Cosφ
0
= W
0
/ V
0
I
0,
.
.
.
φ
0
=Cos
-1
(W
0
/ V
0
I
0
)
Magnetizing component of no load current Iµ = I
0
Sinφ
0

Procedure:- 1) Polarity test.
1 Connections are made as shown in figure (1)
2. Checked the connections and given a specified voltage to primary.
3. Noted the volt meter reading and verified the polarity of the transformer.ie If the voltmeter reading in the inter connected voltmeter is greater than the input voltage, then the polarity is additive , So Opposite polarity on the other adjacent terminal on secondary.

4. Interchanged the connections to confirm first determined polarity.
Turn`s ration and transformation ratio;
1.
Connections are made as in figure (2)
2.
Checked the connections and given the supply gradually from minimum voltage to rated voltage of primary using autotransformer.
3.
Noted the V/m readings on primary and secondary and the A/m and W/m reading when applying the rated primary voltage.
4.
Completed the experiment neatly and correctly.
Result:- Checked the polarity and determined the turns ratio transformation ratio, and magnetizing component of no load current of 115/220/V 5 KVA transformer.
Turns ratio= Transformation ratio=
Magnetizing component of no load current Iµ =
Determined the polarity of the transformer also.
Sl No Prim V/m reading E
1
Sec V/m reading E
2
Watt meter reading W
0
A/m reading I
0
Turns ratio Transf. ratio =K