Page 91 - CITS - Electrician - Trade Practical

ELECTRICIAN - CITS

Tabular column:

Sl.No Supply Voltage (V) Starting current (I) Field current (I ) Load current (I ) Speed (RPM)
F L

TASK 4 :Start & run of DC compound motor
1 Make the connections of DC compound motor with 4 point starter as per circuit diagram.

2 Ensure that there is no mechanical load on the motor. (However, motor can be started with nominal load).
3 Check the connections & connect the motor to DC power supply unit through DPST switch.
4 Start the motor by operating DC 4 point starter.
5 Record the starting & running current, voltage and speed of the motor.
6 Now apply the mechanical load gradually on the motor and check the speed of motor by tacho meter. (Note-
Compound motor is capable to take heavy loads).
7 Switch OFF the supply and disconnect the motor.

Tabular column:

Sl.No Supply Voltage (V) Starting current (I) Field current (I ) Load current (I ) Speed (RPM)
F L

Safety precautions:
1 Ensure proper foundation & fixing of DC motors.

2 Never start DC series motor without mechanical load.
3 Never start DC motors without starter & protective MCB.
4 Ensure proper earthing for motors.
5 Do not load the motors excessively.

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CITS : Power - Electrician & Wireman - Exercise 37