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    Swinburns'S Test On D.C Shunt Machine

    Uploaded by

    harimadhavareddy
    The document describes procedures for conducting tests on DC machines and transformers to determine their performance characteristics. It includes the aim, apparatus required, circuit diagrams, procedures, calculations, graphs and results for open circuit and short circuit tests on a single phase transformer, no-load and load tests on a DC shunt machine as both a motor and generator, and a brake test on a 3-phase induction motor. Precautions are outlined for each experiment to ensure accurate measurements and safe operation of electrical equipment.

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    Swinburns'S Test On D.C Shunt Machine

    Uploaded by

    harimadhavareddy
    79 views15 pages
    The document describes procedures for conducting tests on DC machines and transformers to determine their performance characteristics. It includes the aim, apparatus required, circuit diagrams, procedures, calculations, graphs and results for open circuit and short circuit tests on a single phase transformer, no-load and load tests on a DC shunt machine as both a motor and generator, and a brake test on a 3-phase induction motor. Precautions are outlined for each experiment to ensure accurate measurements and safe operation of electrical equipment.

    Original Description:

    depu

    Original Title

    Deepu

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    The document describes procedures for conducting tests on DC machines and transformers to determine their performance characteristics. It includes the aim, apparatus required, circuit diagrams, procedures, calculations, graphs and results for open circuit and short circuit tests on a single phase transformer, no-load and load tests on a DC shunt machine as both a motor and generator, and a brake test on a 3-phase induction motor. Precautions are outlined for each experiment to ensure accurate measurements and safe operation of electrical equipment.

    Copyright:

    © All Rights Reserved
    Download as DOC, PDF, TXT or read online from Scribd
    Download as doc, pdf, or txt
    79 views15 pages

    Swinburns'S Test On D.C Shunt Machine

    Uploaded by

    harimadhavareddy
    The document describes procedures for conducting tests on DC machines and transformers to determine their performance characteristics. It includes the aim, apparatus required, circuit diagrams, procedures, calculations, graphs and results for open circuit and short circuit tests on a single phase transformer, no-load and load tests on a DC shunt machine as both a motor and generator, and a brake test on a 3-phase induction motor. Precautions are outlined for each experiment to ensure accurate measurements and safe operation of electrical equipment.

    Copyright:

    © All Rights Reserved
    Download as DOC, PDF, TXT or read online from Scribd
    Download as doc, pdf, or txt
    of 15

    Exp 1

    SWINBURNSS TEST ON D.C SHUNT MACHINE

    AIM: Pre determination of percentage efficiency of a given DC shunt machine working as


    motor and generator at different load currents.

    NAME PLATE DETAILS:

    S.NO Characteristic D.C Motor


    1 Voltage 220V
    2 Current 12A
    3 Speed 1500 R.P.M
    4 Power 5 HP
    5 Field Current 0.6 A
    6 Insulation Class B

    APPARATUS REQUIRED:

    S.NO Description Type Range Quantity


    1 Volt meter M.C 0-300V 01
    2 Ammeter M.C 0-2A 01
    0-1A 01

    3 Tacho meter Digital 0-10000 R.P.M 1


    4 Rheostat Wire wound 300/2A 01

    5 Connecting ---- ---- As required


    Wires

    \
    CIRCUIT DIAGRAM: SWINBURNSS TEST ON D.C SHUNT MACHINE

    CIRCUIT DIAGRAM:
    TABULAR COLOUMN:

    SNO Voltmeter reading Ammeter Ammeter Speed in


    V Volts Reading reading RPM
    I in Amps If in Amps

    ARMATURE RESISTANCE (Ra):

    Sl.No Voltage Current

    PROCEDURE
    1) Connect the circuit as per circuit diagram.
    2) Close the DPST switch keeping the SPST switch in closed condition and field
    rheostat in minimum position..
    3) Start the motor by using the 3-point starter and open the SPST switch.
    4) By using the field rheostat bring the motor to rated speed.
    5) Note down the readings of voltmeter, ammeters at noload condition.
    6) Bring the rheostat to minimum position and open the DPST switch
    TO FIND ARMATURE RESISTANCE(RA):
    1) Connect the circuit per the circuit diagram
    2) Keep the rheostat in maximum position.
    3) Now excite the motor terminals by 30V supply by closing DPST switch.
    By varying the rheostat & motor down the readings of Ammeter and voltmeter.
    MODEL CALCULATIONS:-
    For motor:
    IL= Ia+If
    Constant losses = Pc = VILo Iao2Ra
    Input = VIL
    Cu losses = Ia2 Ra
    Total losses = Constant losses + cu losses
    %Efficiency( ) = (Output/Input)*100
    Output = input-total losses
    For generator:-
    Ia= IL+If
    Constant losses = Pc = VILo Iao2Ra
    Output = VIL
    Cu losses = Ia2 Ra
    Total losses = Constant losses + cu losses
    %Efficiency( ) = (Output/Input)*100
    Input = Output + total losses
    CALCULATION TABLE:
    As a Motor:

    Total
    Ia=(IL-Ish) PV =Ia2 Ra
    Sno Load IL in A losses in %Efficiency
    in A in watts
    Watts

    As a Generator:

    Total
    Ia=(IL+Ish) Pv =Ia2 Ra
    S.NO Load IL in A losses in %Efficiency
    in A in watts
    watts
    MODEL GRAPH:

    PRECAUTIONS:

    1.Take the reading without parallax error.


    2.The connections must be tight.
    3. If voltmeter gives ve reading then interchange voltmeter terminal connecting of
    voltmeter.

    RESULT:
    Exp 3

    BRAKE TEST ON D.C SHUNT MOTOR

    AIM:
    To conduct the brake test on a given D.C shunt motor and to determine its performance

    characteristics.

    NAME PLATE DETAILS:

    APPARATUS REQUIRED:

    S.NO Description Type Range Quantity


    1 Volt meter M.C 0-300v 01
    2 Ammeter M.C 0-10A 01
    3 Rheostat Wire wound 300/2A 01
    4 Tacho meter Digital 0-10000 R.P.M 01
    5 Connecting ---- ---- As required
    Wires

    PROCEDURE

    1. Connect the circuit as per circuit diagram

    2. Keep the field rheostat in minimum position and studs S1 and S2 at 0 position. Close
    the DPST switch and start the motor using 3-point starter.

    3. By using the field rheostat bring the motor to the rated speed.

    4. Note down the readings of all meters without applying load.

    5. Gradually increase the load to desired value by tightening the belt.


    6. Note down the readings of all meters.

    7. Repeat the steps 6 & 7 until the ammeter reads the full load current.

    8. Decrease the load gradually and keep the rheostat in minimum position.

    9. Now open the DPST switch.

    PRECAUTIONS:

    1. Initially 3-point starter should be kept at OFF position and later it must be varied
    slowly and uniformly from OFF to ON position.
    2. The field rheostat must be kept at minimum position.
    3. Pour the cold water in the motor drum frequently..
    4. The motor should be started without load.

    MODEL GRAPH:

    FORMULAE:

    Torque = 9.81*(S1-S2)*R
    Power output=(2**N*T)/60 (w)

    % Efficiency= (output/input)*100

    RESULT:
    Exp 2

    OC & SC TESTS ON 1 PHASE TRANSFORMER

    AIM:
    To conduct Open circuit and Short circuit tests to pre-determine the performance of
    the single phase transformer.

    APPARATUS:

    S.NO NAME TYPE RANGE Quantity


    1 AMMETER MI (0- 5) A, 1
    (0- 20) A 1
    2 VOLTMETER MI (0- 300 )V, 1
    (0- 50 )V 1
    3 WATTMETER UPF 150 V/ 20 A 1
    4 WATTMETER LPF 300 V/5 A 1
    5 AUTO 1- 230 V / (0- 270) V/ 15 1
    TRANSFORMER A

    PROCEDURE (OC TEST):


    1. Connect the circuit as per the circuit diagram
    2. Initially variac should be kept in its minimum position
    3. Close the DPST switch
    4. By varying Auto transformer bring the voltage to rated voltage
    5. When the voltage in the voltmeter is equal to the rated voltage of LV winding note
    down all the readings of the meters
    6. After taking all the readings bring the variac to its minimum position
    7. Now switch off the supply by opening the DPST switch
    PROCEDURE (SC TEST):
    1. Connect the circuit as per the circuit diagram
    2. Short the LV side and connect the meters on HV side
    3. Initially variac should be kept in its minimum position
    4. Now close the DPST switch so that the supply is given
    5. By varying the variac bring the current to the rated current then note down all the
    readings
    6. Bring the variac to minimum position after taking the readings and switch off the
    supply by opening the DPST switch.
    Model calculations:
    PRECAUTIONS:

    1. Loose connections should be avoided


    2. Variac should be in minimum position initially before closing & opening the DPST
    switch
    3. Take the readings without parallax errors.
    MODEL GRAPHS:
    1. Load Vs Efficiency
    2. Pf Vs Regulation
    1)

    2)

    RESULT:
    Exp 4

    BRAKE TEST ON 3 -PHASE INDUCTION MOTOR


    AIM:
    To perform Brake test on 3- phase induction motor to determine performance
    characteristics.

    NAME PLATE DETAILS:

    APPARATUS:

    S.NO NAME TYPE RANGE QUANTITY


    1 Voltmeter MI 0-600 V 01No
    2 Ammeter MI 0-10 A 01No
    3 Wattmeter Dynamo meter 600 V/ 10 A 02No
    UPF(F/R)
    4 Tachometer Digital (0-10000)RPM 01NO
    5 Connecting ---- ---- Required
    Wires number

    PROCEDURE:
    1. Connect the circuit as per the circuit diagram
    2. Initially there is no load on the motor
    3. Close the TPST switch.
    4. Bring the motor to the rated voltage by using the 3- auto transformer.
    5. Measure no load voltage, current, speed and power
    6. Apply the load by tightening the brake drum measure the values of voltage, current ,
    . wattmeter,speedand spring values.
    7. Repeat the above step until the meter reads the rated current.
    8. Now remove the load gradually and bring the auto transformer to the minimum
    . position
    9. Now open the TPST switch.

    PRECAUTIONS:
    1. While starting the motor the load should not be there on the drum
    2. The applied load on the brake drum does not exceed its rated value
    3. The readings should be noted without parallelex errors
    4. Always the drum should be kept cool by pouring the cold water in the brake
    drum
    RESULT:

    .
    Exp 4
    SPEED CONTROL OF DC SHUNT MOTOR

    AIM:
    To obtain the speed characteristics of a DC shunt motor by armature voltage
    control and field flux control methods.

    NAME PLATE DETAILS:

    APPARATUS:

    S.No Name Type Range Quantity


    1 Voltmeter MC 0-300V 1
    2 Ammeter MC 0-20A 1
    3 Ammeter MC 0-2A 1
    4 Rheostat WW 360/1.7A 1
    5 Rheostat WW 50/5A 1
    6 Tachometer Digital 0-10000 1
    7 Connecting As per
    wires required
    PROCEDURE:
    ARMATURE VOLTAGE CONTROL:
    1. Connect the circuit as per the circuit diagram.
    2. Keep the armature and field rheostats in minimum position.
    3. Close the DPST switch and start the motor with the 3-point starter.
    4. By varying the field rheostat bring the motor to the rated speed.
    5. By varying the field rheostat from minimum to maximum position note down the
    readings of voltage and speed.
    6. Bring the both rheostats to the minimum position.

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