What is the approximate slip when an induction motor is at no load condition?
Q1 A 3-phase, 6-pole, 50 Hz induction motor has a slip of 1% at no-load and 3% at full-load.
What is a slip in an induction motor?
“Slip” in an AC induction motor is defined as:
As the speed of the rotor drops below the stator speed, or synchronous speed, the rotation rate of the magnetic field in the rotor increases, inducing more current in the rotor’s windings and creating more torque. Slip is required to produce torque.
When can only slip of an induction motor is zero?
In motors the number of rotor slots and stator slots are different and thus cogging (magnetic locking) can’t happen. And thus The slip motor can’t run at rated speed. Torque developed by induction motor is proportional to the slip. At synchronous speed,slip is zero and hence torque developed by the motor is zero.
What is no load slip?
At no load, the rotor speed is very close to the synchronous speed. … At full load, the rotor speed is less than that of no-load case. So, the slip, in this case, is greater than that of slip at no load.
What happens if fifth harmonics is given to induction motor?
It will rotates in normal operation. Either short circuit or open circuit occurs. The sinusoidal components having frequency five times of fundamental are known as fifth harmonics. … Hence induction motor will rotates in reverse direction because of reverse phase sequence of fifth harmonics.
What happens if slip of induction motor is 1?
When the Value of Slip is >1
If the slip value of the motor is greater than one then the rotor will turn in the opposite direction to the revolution of magnetic flux. So if the magnetic flux is revolving in the direction of clockwise, then the rotor will turn rotating in the anti-clockwise direction.
What happens when slip is zero?
Zero slip means that rotor speed is equal to synchronous speed. If rotor is rotating at synchronous speed in the direction of rotating magnetic field the, there will be no flux cutting action, no emf in the rotor conductors, no current in rotor bar conductor and hence no development of electromagnetic torque.
What is slip in 3 phase induction?
This speed difference is called slip. Therefore, the difference between the synchronous speed Ns of the rotating stator field and the actual rotor speed N is called slip. The slip increase with load and is necessary for torque production. Slip speed is equal to the difference between rotor speed and synchronous speed.
Can slip be negative?
If slip is negative, the “input power” to the electrical terminals will be negative, implying that power is flowing out of the electrical terminals. Rotational losses are 2450W.