3P Induction Motors

A six-pole, three-phase squirrel-cage induction motor is connected to a 60-cps supply. At full load, the rotor’s induced emf makes 72 complete cycles in 1 minute. Find the rotor speed.

A three- phase induction motor is taking 40 kW, the slip being 4 , stator losses amount to 800 watts, calculate the total power developed.

At a slip of 4% the maximum possible speed of 3Ø, 60HZ squirrel cage induction motor is

A three-phase induction motor having an input power of 30KW running at a slip of 4%. The stator loss is 1KW and friction and windage loss is 1.5KW. Determine the motor efficiency.

A 220 volt, 10 HP, 60 HZ, three-phase induction motor having four poles is operating at full-load slip of 3%. What is the frequency of the rotor current at full-load?

A three-phase motor is rated 50 HP, 440 volts and 85% power factor. What is the rated current if the motor efficiency is 89%?

What is the speed of an induction motor of four poles if the percent slip is 3%?

Find the rotor frequency of an induction motor having 4 poles if the rotor speed is 1,746 rpm.

A 3 phase, 60 Hz, 6-pole induction motor delivers 25 HP at 1,150 rpm. If the rotor copper loss is 300 watts, what is the rotor power input?

A six-pole induction motor is connected to a 60 Hz supply and at full load the rotor emf makes 105 complete cycles in 2 minutes. Find the rotor speed.

Slip ring are made of

A 12-pole, 3- phase alternator driven at a speed of 500 rpm supplies power to an 8-pole, 3-phase induction motor. If the slip of the motor at full-load is 3%, calculate the full-load speed of the motor.

If the stator voltage of a SCIM is reduced to 80% of its rated value, the torque developed is reduced by ____ percent of its full-load value.

An induction motor is analogous to

A three-phase, 4-pole, 50 Hz induction motor supplies a useful torque of 160 N·m at 4% slip. If friction and windage losses are 500 watts, determine the rotor input.

A three-phase induction motor has a nameplate speed of 1,720 rpm. What is the rotor frequency?

A 6-pole, 50 Hz, three-phase induction motor has a maximum torque of 200 N·m when it is running at a speed of 900 rpm. The resistance of the rotor is 0.25 Ω. Neglecting stator impedance, determine the torque at 5% slip.

What is the formula for the synchronous speed of a motor?

A 4-pole, three-phase 50 Hz induction motor develops a maximum torque of 20 N-m at 1,440 rpm. Obtain the torque exerted by the motor at 5% slip.

The frequency of the emf in the stator of a 4-pole induction motor is 60 Hz, and that in the rotor is 2 Hz. At what speed is the motor running?