A 5Hp, 400v, 4-pole,50Hz induction motor having 36 slots in the stator and 40 slots in the rotor may crawl synchronously at?

Question

Answer

150RPM

Answer

Ns=120*50/4=1500rpm

Nc=1/7Ns
Nc=1/7*1500=214.28rpm
so ,Nc=200RPM

Answer

Calculation of synchronous speed of the induction motor

Given data:

Power (P) = 5 Hp

Voltage (V) = 400 V

Number of poles (p) = 4

Frequency (f) = 50 Hz

Stator slots (Ns) = 36

Rotor slots (Nr) = 40

Formula for synchronous speed (Ns)

Synchronous speed is given by the formula:

Ns = 120f/p

Calculations

Substituting the given values in the above formula, we get:

Ns = 120 x 50/4 = 1500 rpm

Therefore, the synchronous speed of the induction motor is 1500 rpm.

Explanation

The synchronous speed of an induction motor is the speed at which the rotating magnetic field produced by the stator winding moves around the rotor. It is given by the formula Ns = 120f/p, where Ns is the synchronous speed in revolutions per minute (rpm), f is the supply frequency in hertz (Hz), and p is the number of poles of the motor.

The number of slots in the stator and rotor affects the performance of the motor. The number of stator slots must be a multiple of the number of poles, while the number of rotor slots must be slightly greater than the number of stator slots to ensure proper rotation of the magnetic field.

In the given problem, the synchronous speed of the motor is calculated using the formula and the given values. The result shows that the motor can crawl synchronously at 1500 rpm.

Similar SSC JE Doubts

The power input to a 3-phase, 50 Hz, 400 V, the 4-pole induction motor is 60 kW, and its stator losses are 1 kW. If this motor is running at 4% slip, the rotor copper loss is

If the induced emf in the stator of an 8 pole induction motor has a frequency of 50 Hz and that in the rotor is 1.5 Hz, at what speed is the motor running and what is the slip?

Why no-load current in the induction motor more than in the transformer?

The power input to a 3-phase induction machine is 60 kW. The stator loses total 1 kW and neglect the air gap loss in the machine. Find the rotor copper loss per phase if the motor is running with a slip of 3%.?

An induction motor having full load torque of 60Nm when DELTA connected develops a starting torque of 120Nm, For the supply voltage if motor is changed to STAR connection, the starting torque developed is ____?

Top Courses for SSC JE

Suggested Free Tests

Related Content

Mock Test Series

Related Question Answers

Other Engg Branches

Related Exams

Company