Motor Current

[QUAVIET]

Sirs, If I have a 400HP 480VAC FLA 450A induction three phase motor operating at a no load conditon. What would be the app. current drawn? The shaft is free rotating. Thank You

 

[ozmosis]

about 20% of FLA

 

[edison123]

Somewhere between 25% of FLA for high speed motors to about 45% for slow speed motors in open shaft (uncoupled) state.

 

[sgelec]

u have not mentioned the motor winding connection, feeder rating should be capable of drawing the starting current, the motor no load current will be as observed in many such practical cases is about 20-25% of FLC.

 

[electricpete]

I agree with edison.

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[Marke]

Thumbs up for edison.

Mark Empson

http://www.lmphotonics.com

 

[QUAVIET]

Thank You all for the info. I have notice that on small three phase motors, 1 to 1.5A FLA that the motor current can be as high as 50% to 60% of FLA, standard RPM when uncoupled and that it is less on larger motors. Thanks Again