Page 246 - CITS - Electrician - Trade Practical

ELECTRICIAN - CITS

5 Free wheeling diode
6 Reference set voltage Vs
7 Feedback voltage Vf

3. Connect the DC motor and tacho generarator as in block diagram
Note : This example provides with tacho generator feedback.Refer manual of available DC drive

4 Keep the potentiometer in centre position
5 Switch on the supply.
6 Raise the speed by varying potentio meter

7 Note the armature voltage, armature current, set voltage Vs, feedback voltage Vf and speed(rpm)
8 Increase the speed and repeat previous step
9 Load the motor to the 1/4th rated current, observe speed variation and record final speed.
10 Load the motor to the ½ the rated current, observe speed variation and record final speed.

11 Load the motor to the rated current, observe speed variation and record final speed.
12 Reduce the Load to zero
13 Switch off the DC drive.
14 Switch off the mains supply to the unit.

SI. Armature Armature Set Voltage Feed back voltage Speed in RPM
No. Voltage Va Volts Current Ia Amps Vs Vf
1
2
3
4
5
6

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CITS : Power - Electrician & Wireman - Exercise 94