Hello, friends, I hope you all are doing great. In today’s tutorial, we will discuss the Difference Between Slip Ring and Squirrel Cage Induction Motor. The most common type of AC motor is a squirrel cage induction motor. It is mostly used in industries due to less price, high efficiency, and reliability. While the use of a slip ring is limited in industries. Due to different disadvantages such as regular maintenance, a large copper loss slip ring motor is used five to ten percent is used.
The basic difference between the slip ring and squirrel cage motor is that in slip ring motor exterior resistance circuitry is used to control the speed of the motor while in a squirrel cage motor exterior circuit is not required since bar is fixed at the end of the ring. In today’s post, we will have a detailed look at both slip ring and squirrel cage induction motor with the detailed compare them to find their differences. So let’s get started with Difference Between Slip Ring & Squirrel Cage Induction Motor.
Difference Between Slip Ring & Squirrel Cage Induction Motor
Slip Ring Motor
- The motor whose rotor has a construction like the slip ring is called a slip ring motor.
- Its rotor is like a cylinder that has a laminated core with the parallel slots and in the slots bar is placed.
- This motor is also called a Phase wound rotor.
- The construction of this motor is complicated than the squirrel cage motor.
- In this motor, exterior resistance is added with the rotor.
- It uses a starter of rotor resistance.
- It provides large starting torque.
- This motor consists of brushes.
- It needed maintenance on a regular basis.
- Its P.F is less than the squirrel cage motor.
- The speed control of this motor can be done.
- It is expensive than the squirrel cage motor.
- It provides less starting current.
- Its common applications are in hoist, cranes, elevators since these applications needed large starting torque.
Slip Ring Motor Construction
- The structure of this motor is like the squirrel cage motor having some difference like in structure of rotor.
- The difference is that in squirrel cage rotor bars are used that are wounded through coils and has connection star combination.
- At the endpoint of coil there is slip rings are assembled the high value resistor is attached to the end point in serries combination with rings operates as exterior circuitry.
Squirrel Cage Motor
- The configuration of the rotor used in this motor is like the squirrel so it called the squirrel cage motor.
- The slots used at the rotor of the motor are not parallel but placed at an angle.
- This motor is also called a Cage motor.
- The construction of this motor is easy than the slip ring motor.
- The bars of rotors are fixed at the end of the ring so it is not required to add extra resistance.
- It this motor rotor resistance starter is not required.
- Its starting torque is less than the slip ring motor.
- In this motor, brushes are not used.
- Its efficiency is larger than the slip ring motor.
- Its speed control is not possible like the slip ring motor.
- Its power factor is large.
- This motor is less expensive than the slip ring motor.
- It provides a large starting current.
- It used in lathe machines blower, fan profting machines.
What is Slip Ring Motor
- The motor that used a wound rotor is called a slip ring motor and also called a phase wound motor.
- It comprises of the laminated cylindrical core that has a partially closed slot at outer structure and holds the 3 phase winding.
- At rotor there are similar quantities of poles like the poles of the stator.
- At rotor 3 end terminals of windings are attached in a star configuration and 3 starting points are attached with the 3 copper slip rings mounted at the shaft.
- The shaft constructed with the mild steel is passed through the rotor and used to transfer of power.
What is Squirrel Cage Motor
- In this type of motor, the rotor is liked the squirrel so it called squirrel cage motor.
- The designing of the motor’s rotor is simple and it comprises of the cylinder shape laminated core that has partially closed circular slots and that are short-circuited at every end with the copper.
- In this motor circuitry, it is not possible to add any exterior resistance.
- The slots of the rotor are not straight lines but are placed at some angle and this skewed provides some advantage.
- Due to the squirrel-like configuration of rotor humming decreases and enhance the running of the motor.
- Due to the skewed rotor, the torque curve is smooth for different positions of the rotor.
- It also decreases the magnetic locking between the stator and the rotor.
- The resistance offered by the rotor also increases as it increases the length of rotor conductors bars.
Comparison between Slip ring Motor and Squirrel Cage Induction Motor
- The motor that has a wound rotor is called a slip ring induction motor while the motor whose rotor is squirrel-like configuration is called squirrel cage rotor motor.
- In the wound, the rotor core is like a cylinder and has parallel slots that have bars. While slots of the squirrel cage rotor are not aligned but placed at some angle.
- The other name of the slip ring motor is phase wound rotor motor and squirrel cage motor called cage motor.
- Due to the use of slip ring and brushes slip ring motor construction is complicated and the construction of the squirrel cage is simple.
- There can use an exterior circuitry in the wound rotor motor and can not be added in squirrel cage motor.
- For starting rotor resistance starter is used inn slip ring motor and not needed in squirrel cage not needed.
- The initial torque of slip rin is large than the squirrel cage motor.
- the repairing price of the slip ring motor is large than the squirrel cage motor.
- The occurrence of copper loss is larger in the slip ring motor than the squirrel cage.
- The slip ring motor uses brushes for power transfer while squirrel cage motor not.
- The efficiency of slip ring motor is less than the squirrel cage motor.
- Speed of slip ring motor can be varied with the use of exterior circuitry and not controlled in cage motor.
- The P.F of slip ring is less than the cage motor.
- The wound motor is expensive and the squirrel cage is less costly.
- The initial current of the wound motor is less than the squirrel cage motor.
- The use of squirrel cage at such an application where high initial torque is needed.
So friends that is a detailed post about the difference between slip ring motor and squirrel cage motor. If you have any question ask in comments. Thanks for reading.