How do you calculate no load current of motor?

Answer 1

On an average, the following assumptions will stand good for an induction motor: * Starting current (Ist) will be 5 times of the Full Load Amps (IFLA) * No Load Amps (INLA) can be any where between 0.3 to 0.5 times of IFLA; To the most, this figure depends upon the frame size of the motor; larger the frame size, smaller will be the INLA. This is also true for the wound rotor type induction motors. Manufacturers normally give two different current figures, one for the motor running with full load, and one for 'locked rotor'. Locked rotor current is the very high current drawn when power has been applied, but the motor has not had time to start spinning. <><><> No load current is important since this portion of the energy consumed will not be reflected in the process output, for a machine which is running continuously, no one can neglect whatever low value it is. Usually, the efficiencies will be mentioned and one can apply basic thumb rules to arrive no load current from those figures <><><> Manufacturers don't usually publish 'current at no load' for their motors. Since a motor with no load is not doing anything useful, no one really cares how much current is being drawn. It's kind of like putting your car up on a jack so the wheels are off the ground and asking how much fuel will the car burn sitting still with the wheels turning at 10 miles an hour - or at 100 miles per hour - who cares? !!!

Answer 2

You have to measure the amps while it is running with an "amp clamp" or other device while the motor is running without anything attached.

Some motors have a rating on the plate for "no load current"

Answer 3

No-Load Current of Motors usually approximated from 0.3 to 0.5 of its Rated Full Load Current.

Answer 4

to calculate no load cuurent you must operate the motmo without load and sure the friction is at lowest rate

the measured current is no load current

Answer 5

Wiv a triphase calculator, of course.