BASIC SQUIRREL CAGE INDUCTION MOTOR
This is a type of three phase induction motor and its function is depended on the electromagnetism it is rugged and simple in design and because of that, it is both economical and reliable. It is called a squirrel cage because the rotor inside it looks like a squirrel cage. The SCIM has two basic components one is stator (stationary component) Another one is rotor (the rotating element) it has bearing in motor and it allows the rotor to rotate freely
The rotor is a cylinder with steel lamination with highly conductive metal mainly aluminum or copper which is implanted into its surface a rotating magnetic field is produced when an AC current runs through stator windings.
The magnetic field from the stator cuts through the bars of the rotor and induces a current more current will be induced by the difference in speed between the rotor and magnetic field the difference determines the number of magnetic flux cuts through the rotor bar if the difference is high then it will induce more current. During the starting process when the power is applied the rotor rotates the current and torque will drop and torque will reach a minimum value and it is known as “pull up torque” when the motor speed increases torque also increases when the torque increases to a peak value and it is called as “breakdown torque”
When the load of the motor increases the motor slows down and the amount of magnetic flux cut through the rotor increase and it will generate more torque When the load torque increases more than breakdown torque current will increase but the torque value will go down and when this happens the motor stalls the rotor will heat up and it will be damaged unless it is tripped off if the motor’s breakdown torque is high then it will stall less
**APPLICATIONS AND ADVANTAGES**
• Low maintenance • Constant speed • Self-starting • Used in centrifugal pumps, large blowers and fan, lathes and other turning equipment • Better heat regulation • Small and lightweight • It is brushless so it avoids sparkling