Compare squirrel cage induction motor and slip ring induction motor any four points.

Compare squirrel cage induction motor and slip ring induction motor any four points.
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Answer :

Comparison Between Squirrel Cage Induction Motor and Slip Ring Induction Motor:

Sr. No.
Squirrel Cage Induction Motor
Slip Ring Induction Motor
1 Rotor is in the form of short circuited bars.
Rotor is in the form of 3-ph winding.
2 No slip-ring and brushes required.
3 slip-rings with brushes are present.
3 External resistance cannot be inserted in rotor circuit.
External resistance can be inserted in rotor circuit.
4 Small or moderate starting torque is obtained.
High starting torque can be obtained
5 Starting torque is fixed.
Starting torque can be adjusted by inserting external resistance in rotor circuit. 
6 Simple and rugged construction.
Comparatively complicated construction.
7 Power factor is poor in the range of 0.6 to 0.8 lagging. 
Power factor is better in the range of 0.8 to 0.9 lagging.
8 Size is compact for same HP.
Relatively size is larger.
9 Speed control by stator side control method only.
Speed control by stator as well as rotor side control method.
10 High efficiency.
Low efficiency.
11 Less cost.
More cost.
12 Less maintenance. 
Frequent maintenance due to slip-rings and brushes
13 High starting current i.e. about 5 to 6 times full load current.
Starting current can be restricted to 1.2 to 2 times full load current. 
14 Used as a constant speed drive e.g. Lathe machine.
Used where high starting torque is required e.g. Lifts.

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A 3-phase, 400 votts, 50 Hz, 100 KW, 4 pole squirrel cage induction motor with a rated slip of 2% will have a rotor speed of (A) 1500 rpm (B) 1470 rpm (C) 1530 rpm (D) 1570 rpm

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Last Answer : 1470rpm

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Description : What are the advantages of slip ring motor over squirrel cage motor?

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Last Answer : Answer: A

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Description : A 3-phase delta connected squirrel cage induction motor when started with a DOL starter has a starting torque of 600 NM. Its starting torque when star delta starter is used:

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In a double squirrel cage induction motor, good starting torque is produced as

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Last Answer : In a double squirrel cage induction motor, good starting torque is produced as Large current flows through the outer high resistance winding.

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The stator of a 415V, 50 Hz, 4-pole slip ring Induction Motor is excited by rated frequency with slip rings open

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Explain the construction of three phase induction motor with neat diagram.

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Discoloration of the rotor bars in a squirrel-cage motor is typical evidence of _____________. A. moisture B. overheating C. vibration D. all of the above

Description : Discoloration of the rotor bars in a squirrel-cage motor is typical evidence of _____________. A. moisture B. overheating C. vibration D. all of the above

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