The squirrel-cage induction motor

1. A THREE-PHASE
SQUIRREL CAGE
INDUCTION MOTOR

2. Three-phase induction motors
construction consist of :
 The Stator
 The Rotor
 The squirrel-cage and the wound-rotor
induction motor have nearly the same stator
construction and winding arrangement.
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3. The three-phase
induction motor
 The squirrel-cage
induction motor
The wound-rotor
induction motor
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4. Mainly we discuss a
three-phase squirrel
cage induction motor.
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5. Squirrel cage construction, the rotor
winding consists of a number of rotor
bars, short-cut by rings from both side,
see figure below.
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6. PARTS OF SQUIRREL-CAGE MOTOR
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7. TYPES OF SQUIRREL-CAGE
Split phase
Capacitor start
Capacitor start capacitor run
Permanent split phase capacitor
run
Shaded pole
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8. 8

9. CLASSIFICATION OF SQUIRREL
CAGE INDUCTION MOTOR
It is classified six types.
There are class A, class
B, class C, class D, class E
and class F
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10. CLASS A
Starting Torque :
Normal
Starting Current :
Normal
Slip :
Normal
Uses :
Fans, Pumps, Low inertia loads which
are frequently started and stopped 10

11. CLASS B
Starting Torque :
Normal
Starting Current :
Low
Slip :
Normal
Uses :
Loads which has High Moment of inertia,
large fans pumps. 11

12. CLASS C
Starting Torque :
High
Starting Current :
Low
Slip :
Normal
Uses :
Crushers, boring mills, conveyors, textile
machineries, wood working equipments. 12

13. CLASS D
Starting Torque :
High
Starting Current :
Low
Slip :
High
Uses :
Bulldozers, shearing machines, punch
presses, hoists, foundry & stamping
machines. 13

14. CLASS E
Starting Torque :
Low
Starting Current :
Normal
Slip :
Low
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15. CLASS F
Starting Torque :
Low
Starting Current :
Low
Slip :
Normal
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16. Finally, We can discuss
advantages &
disadvantages of squirrel
cage induction motor.
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17. ADVANTAGES
No commutator and brush.
Low weight, volume and
cost.
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18. DISADVANTAGES
Requires a complicated and
costly power modulator and two
stages of power conversion.
Control is more involved.
Slow response.
Drive is costly.
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19. THANK YOU.
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