Page 74 - CITS - Electrician - Trade Practical
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ELECTRICIAN - CITS




           TASK 3 : Apply STAR & DELTA connection in AC machines
           1  STAR & DELTA connection is applicable in AC 3 ph. Supply system and 3 ph. AC machines like Transformer,
              Alternator, induction motor.

           2  Take 3 ph. Induction motor and connect in STAR fashion.
           3  Apply 3 ph. Supply through TPST switch and record line & phase voltage and line & phase current.
           4  Similarly, connect the motor in DELTA fashion and record line & phase voltage and line & phase current.
           5  Switch OFF the supply and disconnect the motor.
           6  Calculate the line & phase voltage and line & phase current as per Star Delta equations.

           Safety precautions:
           1  Follow the correct sequence in STAR and DELTA connection.
           2  Never connect single bulb in the circuit, instead connect 2 bulbs in series.
           3  Do not make joints and loose connections.

           4  Select proper range in voltmeter & ammeter.
           5  Ensure proper earthing to TPST switch and induction motor.
           Tabular column:
                             Line voltage (V )  Phase voltage (V )   Line current (I )  Phase current (I )
               Connection                  L                   PH                  L                   PH

                  STAR
                  DELTA

















































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                                    CITS : Power - Electrician & Wireman - Exercise 29
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