Explanation: At starting when slip is 1, the voltage induced is maximum. Explanation: Starters are needed in induction motors to limit the starting current.
In which method starting a motor the starting current is maximum?
The autotransformer is used to limit the starting current of the induction motor. The above three starters are used for the cage rotor induction motor.
Which starting method is best in induction motor Mcq?
The decrease in the current is dominated by increase in the power factor, as well as rated voltage applied across the stator which produces high staring torque. Technically this is the best way of starting slip-ring induction motor, because starting torque is high with low starting current.
Under Which method of induction motor is expected to take a large starting current?
In Direct on line starting, an induction motor is expected to take largest starting current. In Direct on line starting (DOL) , the contactor will be controlled by separate start and stop buttons, and an auxiliary contact on the contactor is used, across the start button, as a hold in contact.
What is the purpose of starter in 3 phase induction motor Mcq?
The starting torque could be increased by increasing starting resistance but due to high current in the rotor during starting will increase the copper loss which will decrease the motor efficiency.
How do you limit starting current?
Some of the techniques used to reduce the starting current of a squirrel induction motor:
- Soft starting (voltage control)
- Variable Frequency Drives (Voltage and frequency control)
- Star/Delta Starting.
- Stator impedance and/or resistance starting.
- Autotransformer Starting.
What happens if fifth harmonics is given to induction motor?
What happens if fifth multiples of harmonics is given to induction motor? It will rotates in reverse direction.
Which is very suitable starting method?
For the application requiring high starting torque and minimum starting current, the most suitable starting method will be? Explanation: Auto transformer provides the maximum starting torque.
Why starters are used in induction motor?
⇒ The starter is a device which is basically used to limit the starting current by supplying reduced voltage to the motor at the time of starting.
Why can’t an induction motor run at synchronous speed?
The rotor is placed in such a way that this magnetic field induces a current in the rotor. … Due to this difference in flux, the rotor will experience a torque and will start to rotate at speed less than synchronous speed due to lagging. So, theoretically, the Induction motor can never run at synchronous speed.