Why at the starting of induction motor current is high?
Answers were Sorted based on User's Feedback
Answer / anchal
coz at the start the slip is maximum,
Rotor conductors are stationary in the beginning and the relative speed between the rotor conductors and rotating magnetic field is maximum, and hence emf across rotor conductors is max in the beginning(e=blv) means current is max, as the rotor starts rotating the relative speed becomes less and hence does emf and current.
Is This Answer Correct ? | 7 Yes | 3 No |
Answer / sunil guru
AT START THEIR EXIST MAGNETIC FIELD & THE ELECTRIC FIELD IS ABSENT AND COMBINATION OF BOTH PRODUCES THE TORQUE AND ROTATES THE ROTOR...
TO PRODUCE THE FLUX IN THE CLOSE CIRCUIT OF THE ROTOR MOTOR CONSUMES THE CURRENT AND WITH THE CUTTING OF FLUX EMF IS GENERATED THEN THE GENERATED EMF IS CALLED BACK EMF OR COUNTER EMF .... AFTER THE PRODUCTION OF BACK EMF IT NEUTRALISE'S WITH SUPPLY VOLTAGE AND THEN WITH THE STAGE OF NORMAL RUNNING OF MOTOR THE CURRENT CONSUMPTION REDUCES...
SO AT START WITH THE WORK OF SETTING OF FLUX AND TO OVERCOME THE LOSSES THE STARTING CURRENT IS ALWAYS HIGH...
FOR ANY DISAGREEMENT MAIL ME AT parmar20072008@yahoo.com
Is This Answer Correct ? | 4 Yes | 3 No |
Answer / praveen kumar.bodu
when motor is off. it consists of some back emf in it.and
also it appears like a short circuited i.e it has a full
load connection. at the time of start motor again it is not
possible to run motor initially when fulload isconnected.so
motor sinks more current.
Is This Answer Correct ? | 1 Yes | 1 No |
Answer / viren
When motor at rest, the motor appears to be a transformer, with it's secondary winding short circuited, i.e. the rotor winding or squirrel cage is a closed circuit. This results in a low impedance to the system voltage and the motor has a "locked rotor" current of typically 6 times full load current, but also up to 8 and sometimes 10 times current.
Is This Answer Correct ? | 3 Yes | 5 No |
Answer / ali_asgher107
Because at the starting of induction motor, the emf is zero
Is This Answer Correct ? | 1 Yes | 8 No |
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