A 3 phase 50 Hz induction motor has full load speed of 970 rpm. Calculate no of poles and slip frequency.

A 3 phase 50 Hz induction motor has full load speed of 970 rpm. Calculate no of poles and slip frequency.
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1 Answer

Answer :

The number of poles in an induction motor can be calculated using the following formula:

No. of poles = (120 * frequency) / speed

In this case, the number of poles would be calculated as follows:

No. of poles = (120 * 50 Hz) / 970 rpm

= 6 poles

The slip frequency is the difference between the frequency of the rotating magnetic field in the stator and the frequency of the rotor current. It can be calculated using the following formula:

Slip frequency = (speed * frequency) / (No. of poles) - frequency

Using the values given in the question, the slip frequency would be calculated as follows:

Slip frequency = (970 rpm * 50 Hz) / (6 poles) - 50 Hz

= 8.08 Hz

So the motor has 6 poles and a slip frequency of 8.08 Hz.
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