| Slip Ring Induction Motor | Squirrel Cage Induction Motor |
|---|---|
| The rotor of the slip ring induction motor is a slip ring type. | The rotor of the squirrel cage induction motor is the squirrel cage type. |
| In the slip ring induction motor, rotors are made from the cylindrical laminated core. Each slot is in parallel and each slot consists of one bar. | In the squirrel cage induction motor, the slots are not in parallel configuration but are skewed. |
| The slip ring induction motor is also called a phase wound rotor motor. | The squirrel cage induction motor is called a cage motor. |
| The construction of the slip ring induction motor is complicated. | The construction of the squirrel cage induction motor is simple. |
| The rotor of the slip ring induction motor has more turns than the squirrel cage induction motor. | The rotor of the squirrel cage induction motor has fewer turns than the slip ring induction motor. |
| The rotor of the slip ring induction motor consists of conductor bars that are permanently joined and shorted at ends by the end rings. So rotor winding and stator winding are not similar in slip ring induction motor. | The rotor winding and stator winding are similar in the squirrel cage induction motor. |
| In the slip ring induction motor, copper or brass slip rings and carbon brushes are used. | In squirrel cage induction motor slip rings and carbon brushes are not used. |
| In the slip ring induction motor more maintenance is required due to the use of slip ring and carbon brushes. | In squirrel cage induction, less maintenance is required because carbon brushes and slip rings are not used. |
| In slip ring induction motor rotor bars are connected to the external resistance with help of a slip ring and brushes. | In the squirrel cage induction, motor rotor bars are not connected to any external resistance. |
| The speed of the slip ring induction motor is changed by changing the slips. | The speed of the squirrel cage induction motor is changed by changing the number of poles. |
| The starting torque of the slip ring induction motor is maximum. | The starting torque of the squirrel cage induction motor is minimum. |
| The slip ring induction motor takes a lower starting current. | The squirrel cage induction motor takes less starting current. |
| The slip ring induction motor is costlier the squirrel cage induction motor because slip ring and carbon brushes are used in the slip ring induction motor. | The squirrel cage induction motor is cheaper than the slip ring induction motor because carbon brushes and slip rings are not used. |
| The slip ring induction motor provides less efficiency because more losses take place in resistances and slip rings. | The squirrel cage induction motor provides more efficiency the slip ring induction motor. |
| In slip ring induction motor more copper losses takes place due to slip rings. | In a squirrel cage induction motor has less copper loss takes place. |
| The slip ring induction motor improves the power factor from lagging to leading. | The squirrel cage induction motor can not improve the power factor. |
| In slip ring induction motor rotor resistance starter is used. | In squirrel cage induction motor rotor resistance starter is not used because the rotor does not have any external connections. |
| When higher starting torque is required slip ring induction motor is used. | When lower starting torque is required squirrel cage induction motor is used. |
| In slip ring induction motor poor cooling is available because there is no space in the rotor slots. | In a squirrel cage induction, motor better cooling is available because there is more space available in rotor slots. |
| The slip ring induction motor is rarely used because it is more costly. | The squirrel cage induction motor is widely used because it is less costly. |
| The slip ring induction motor is used in crane, elevator, and hoist where higher starting torque is required. | The squirrel cage induction motor is used in lathe machines, blowers, and fans where lesser starting torque is required. |
| In a slip ring induction motor, speed control is possible. | In squirrel cage induction motor speed control is not possible. |
| The overloading capacity of the slip ring induction motor is higher than the squirrel cage induction motor. | The overloading capacity of the squirrel cage induction motor is lesser than the slip ring induction motor. |
Key Points Between Slip Ring & Squirrel Cage Induction Motor
1. The rotor of the slip ring induction motor is a slip ring type. The rotor of the squirrel cage induction motor is the squirrel cage type.2. In the slip ring induction motor, rotors are made from the cylindrical laminated core. Each slot is in parallel and each slot consists of one bar. In the squirrel cage induction motor, the slots are not in parallel configuration but are skewed.
3. The slip ring induction motor is also called a phase wound rotor motor. The squirrel cage induction motor is called a cage motor.
4. The construction of the slip ring induction motor is complicated. The construction of the squirrel cage induction motor is simple.
5. The rotor of the slip ring induction motor has more turns than the squirrel cage induction motor. The rotor of the squirrel cage induction motor has fewer turns than the slip ring induction motor.
6. The rotor of the slip ring induction motor consists of conductor bars that are permanently joined and shorted at ends by the end rings. So rotor winding and stator winding are not similar in slip ring induction motor. The rotor winding and stator winding are similar in the squirrel cage induction motor.
7. In the slip ring induction motor, copper or brass slip rings and carbon brushes are used. In squirrel cage induction motor slip rings and carbon brushes are not used.
8. In the slip ring induction motor more maintenance is required due to the use of slip ring and carbon brushes. In squirrel cage induction, less maintenance is required because carbon brushes and slip rings are not used.
9. In slip ring induction motor rotor bars are connected to the external resistance with help of a slip ring and brushes. In the squirrel cage induction, motor rotor bars are not connected to any external resistance.
10. The speed of the slip ring induction motor is changed by changing the slips. The speed of the squirrel cage induction motor is changed by changing the number of poles.
11. The starting torque of the slip ring induction motor is maximum. The starting torque of the squirrel cage induction motor is minimum.
12. The slip ring induction motor takes a lower starting current. The squirrel cage induction motor takes less starting current.
13. The slip ring induction motor is costlier the squirrel cage induction motor because slip ring and carbon brushes are used in the slip ring induction motor. The squirrel cage induction motor is cheaper than the slip ring induction motor because carbon brushes and slip rings are not used.
14. The slip ring induction motor provides less efficiency because more losses take place in resistances and slip rings. The squirrel cage induction motor provides more efficiency the slip ring induction motor.
15. In slip ring induction motor more copper losses takes place due to slip rings. In a squirrel cage induction motor has less copper loss takes place.
16. The slip ring induction motor improves the power factor from lagging to leading. The squirrel cage induction motor can not improve the power factor.
17. In slip ring induction motor rotor resistance starter is used. In squirrel cage induction motor rotor resistance starter is not used because the rotor does not have any external connections.
18. When higher starting torque is required slip ring induction motor is used. When lower starting torque is required squirrel cage induction motor is used.
19. In slip ring induction motor poor cooling is available because there is no space in the rotor slots. In a squirrel cage induction, motor better cooling is available because there is more space available in rotor slots.
20. The slip ring induction motor is rarely used because it is more costly. The squirrel cage induction motor is widely used because it is less costly.
21. The slip ring induction motor is used in crane, elevator, and hoist where higher starting torque is required. The squirrel cage induction motor is used in lathe machines, blowers, and fans where lesser starting torque is required.
22. In a slip ring induction motor, speed control is possible. In squirrel cage induction motor speed control is not possible.
23. The overloading capacity of the slip ring induction motor is higher than the squirrel cage induction motor. The overloading capacity of the squirrel cage induction motor is lesser than the slip ring induction motor.