What is a Ferrel Cage Induction Motor? Write the use of its advantages and disadvantages? Mention the requirement of motor starter

What is a Ferrel Cage Induction Motor? Write the use of its advantages and disadvantages? Mention the requirement of motor starter

Write the use of fuerl cage induction motor and its advantages and disadvantages? "Fourel Cage Induction Motor: The rotor of this motor is made of high quality laminated steel core. It is firmly connected to the motor shaft with the help of necessary keys. This core has longitudinal grooves parallel to the shaft.Thick copper bars are placed in these grooves and both ends of the bars are short-circuited by copper rings. It looks a lot like a wooden cat cage. Hence its name squirrel cage induction motor.

Advantages : (a) Its structure is very simple and robust. (b) Its material cost is less than other motors. (c) Repair and maintenance cost of a motor is very low as it lasts for a long time. (d) Speed ​​of motor remains almost same at different loads. (e) The efficiency/efficiency of the motor is high. (f) Good running performance.

Disadvantages : (a) This motor draws more current from the line during starting. (b) The power factor of this motor is very low. (c) Starting torque of the motor is too low. (d) The speed of the motor cannot be controlled as required. Uses : (a) In machine shop operation of various types of machines. (b) In woodworking factories. (c) In a cement factory. (d) In factories of textile industry. (e) Flour or rice mills. Write phase wound or slip ring induction motor and its advantages, disadvantages and uses? Phase und induction

Motor: Squirrel cage induction motor has high rotor inductance and low resistance, so its starting torque is low. A phase wound type rotor is used to increase the starting torque. A three phase winding (with super enamel copper wire) is done on the rotor to increase the resistance of the rotor more. The stator has the same number of poles resides in the rotor. A three-phase winding in the rotor is usually in star connection.

Advantages: 1. As the resistance of the rotor circuit can be increased arbitrarily, the starting torque of the motor is very high. . 2. By increasing or decreasing the resistance of the rotor circuit as required. Speed ​​can be controlled. 3. This motor is suitable for starting with higher loads. 4. By increasing the rotor resistance as required, it can be run without a starter.

Disadvantages: 1. It is more expensive than squirrel cage induction motor 2. Additional external resistance increases the resistance of the rotor circuit resulting in higher power loss in the motor. 3. The efficiency of this motor is relatively low. Usage: 1. Crane 3. Pump 5. Rolling Mills 2. Mine shaft 4. Elevator 6. railway

What is the cause of low power factor of induction motor at no load condition? Reason: At no load the induction motor produces mainly magnetizing current which creates the required flux in the air gap. This magnetizing current causes poor power factor.When the motor is under load, the magnetizing current remains almost the same and the current is less than the input current of the motor at full load, resulting in an improved power factor. Due to this, the power factor of the motor at no-load condition is low.

Why is squirrel cage motor not possible to start with higher load? Reason: The rotor resistance of squirrel cage motor is very low and there is no way to increase the rotor resistance of the motor by adding additional resistance from outside. This results in poor starting torque. The starting current also increases and the power factor also decreases. Besides, during starting, the line voltage has to be reduced with the help of the starter and applied to the terminals of the motor.Since the torque of the rotor is proportional to the square of the supply voltage at the time of starting, the value of the torque decreases if the supply voltage is slightly reduced. Squirrel cage induction motor cannot start with higher load due to above mentioned reasons.

Mention the requirement of motor starter? Answer: The rotor of any electric motor is stationary at the moment it is started. As a result, a current of 5 to 7 times the normal current flows from its stator line. In the case of a large motor, this current is so high that if it is allowed to enter the motor, the stator coil will burn immediately and a great disturbance will be created in the voltage of the supply line. For that every motor above 7.5 horsepower is started with a suitable starter reducing the line voltage applied to the motor terminals. To keep the starting current within a safe range, the voltage applied during starting must be reduced and this is done by the starter itself.

List of three phase induction motor losses: 1. Waste of copper parts or coppers 2. Wasting of iron parts or corrals 3. Loss due to friction or air collision or friction and windows loss.