Why motor initial starting current is high?

Answer Posted / ravi

In ac induction motor it take starting current around 7 times the full load current. The reason is during starting when we applied a voltage to stator it produce a rotating magnetic field which is rotating with its synchronous speed. The rotor speed is zero and slip is 100% so a large amount of magnectic field cuts the rotor surface and produce heavy current to flow from its and when the rotor catch its speed the amount of field cutting the rotor reduce and slip is also low and current become normal.

Is This Answer Correct ?    38 Yes 10 No



Post New Answer       View All Answers


Please Help Members By Posting Answers For Below Questions

how to control dc motor?

1410


Mention how NPN and PNP transistor works?

689


1.dg on load alarm/stop alarm... 2.dg on load. piu alarm alarm kaise chek krte hai

1378


I AM GOING TO ATTEND APTRANSCO ON 26TH OCT 08.PLEASE SEND ME ANY MATERIAL OR TYPE OF QUESTIONS OR EXP QUESTIONS.

1504


What is signal flow graph?

644






What is a single phase autotransformer?

628


what will happen if OLR CT in all phases are short circuted

1667


Explain cmrr?

681


What are the two basic types of transformers?

614


State the frequency for rc phase shift oscillator?

578


what are your career plans upon completion of the programme and the relevance of recity generation to your professional development?

1745


If any cable burnt how can we identify it burnt by high current of high voltage? 

1991


Give some differences between open loop and closed loop control systems.

658


The 3 phase Delta connection RB=440V, BY=350V,.......* is Line to Line voltage RY= ? And Formula....?

1149


what are all types of cross section in AC cables?

1829