Slip ring induction motor SRIM vs squirrel cage induction motor SCIM:
- SRIM Rotor consists of a three-phase winding Similar to the stator winding, But in SCIM the rotor consists of bars which are shortened at the ends with help of end rings.
- SRIM rotor construction is very complicated but in SCIM the rotor construction is very Simple
- SRIM the resistance can be added externally to improve starting torque, in SCIM the same cannot be added.
- SRIM Slip ring and brushes are present to add external resistance which makes the contact between external résistance to rotor winding. In SCIM there is absent of Slip ring and brushes
- SRIM needs frequent maintenance (For brushes and resistance) we need to keep on checking the brushes at least once in a month, Also it need special MOC brushes, in case if you are using water resistance starter the water level should be maintained otherwise leads to motor or rotor winding failure, But in SCIM no such frequent maintenance is needed.
- SRIM Rotor is very costlier, the rotor winding takes 60 % of the total rotor cost but in SCIM cheap and one-time installation is enough to maintain entire life.
- SRIM: In industry 1-5% uses, SCIM: 95 % of the Industry uses. Even My factory I am using only one SRIM out of 1268 motor
- High starting Torque obtained in SRIM but in SCIM high starting torque cannot be obtained
- SRIM: Rotor resistance stator is used, But SCIM: Suitable for all starter, VFD, Soft starter
- Rotor should have wound and the rotor poles is equal to stator poles. In SCIM: there is No such an equality, it will maintain automatically.
- SRIM: Speed control can be done through rotor resistance But SCIM We need costlier electronics VFD drives which generate harmonics. It is 3 times costlier than the motor. Also, we need to maintain separate rooms for these electronics drives. It needs periodic maintenance.
- Rotor copper loss is high due to rotor resistance in SRIM, In SCIM maintains high efficiency.
- Used in high torque applications such as lifts, hoists, cranes, elevators, grinders etc, SCIM is used for pump application, fan application such as low starting torque application.
That’s all about Slip ring induction motor SRIM vs squirrel cage induction motor SCIM