30-10-2012, 05:49 PM
HOPKINSON’S TEST
HOPKINSON’S TEST.docx (Size: 72.99 KB / Downloads: 24)
PRECATUIONS:
1. The field rheostat of the motor should be in the minimum position at the time of starting and stopping the machine.
2. The field rheostat of the generator should be in the maximum position at the time of starting and stopping the machine.
3. SPST switch should be kept open at the time of starting and stopping the machine.
PROCEDURE:
1. Connections are made as per the circuit diagram.
2. After checking the minimum position of field rheostat of motor, maximum position of field rheostat of generator, opening of SPST switch, DPST switch is closed and starting resistance is gradually removed.
3. The motor is brought to its rated speed by adjusting the field rheostat of the motor.
4. The voltmeter V1 is made to read zero by adjusting field rheostat of generator and SPST switch is closed.
5. By adjusting field rheostats of motor and generator, various Ammeter readings, voltmeter readings are noted.
6. The rheostats and SPST switch are brought to their original positions and DPST switch is opened.