1. To determine the ability of motor to run equal and nearly equal to rated speed of the motor even at reduced voltage.
2. To see whether there is any tendency of crawling presents in the motor at reduced
3. To check whether, noise level, speed is within the tolerance limit or not
4. Run the motor with rated voltage & measure the speed.
5. Now apply the reduced voltage 1/3 of rated value and measure the speed
a) The motor below 37 KW, conduct the test in both
b) For motors above 37 KW, conduct the test only in
specified direction of rotation