ASCT/EEE/LAB/BEE-05 (Star & Delta Connections)

EXPERIMENT NO. - 05

AIM: - Study of Star & Delta Connections of 3-phase circuit.

INSTRUMENTS REQUIRED:

S. No. Instruments Range Quantity

1. 3-Phase bulb load 230V, 400V star 1

2. Ammeter 0-2A 1

3. Ammeter 0-10A 1

4. Voltmeter 0-250V 1

5. Voltmeter 0-500V 1

THEORY:

Star Connection:In a 3-phase AC circuit, line voltage is equal to 1.732 times of the phase voltage and

line current is equal to the phase current.

i.e.VL = √3 VPh;ILine = IPh

Delta Connection:In a 3-phase delta connection line current is equal to 1.732 times of the phase current

and line voltage is equal to phase voltage.

i.e.IL = √3 IPh;VLine = VPh

Circuit Diagram:

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ASCT/EEE/LAB/BEE-05 (Star & Delta Connections)

PROCEDURE:1. For star connection, connect the voltmeters and ammeters as shown in circuit

diagram. Switch ON the supply & note down the readings of voltmeters and ammeters

2. For Delta connection, connect the voltmeters and ammeters as shown in the circuit

diagram. Switch ON the supply and note down the readings of voltmeters and

ammeters

OBSERVATION TABLE:

Type of Connection Vline Vphase Iline Iphase

Star

Delta

RESULT:1. For star connection, Vline / Vphase = 1.732

2. For delta connection, Iline/Iphase = 1.732

PRECAUTIONS:

1. Use the instruments of the given range.

2. Make the connections tight.

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