IN 3 PHASE INDUCTION MOTORS SOMETIMES COPPER BARS ARE PLACED DEEP IN ROTOR WHY

IN 3 PHASE INDUCTION MOTORS SOMETIMES COPPER BARS ARE PLACED
DEEP IN ROTOR WHY..?

Question Posted / farmesh vasava

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IN 3 PHASE INDUCTION MOTORS SOMETIMES COPPER BARS ARE PLACED DEEP IN ROTOR WHY..?..

Answer / farmesh vasava

TO IMPROVE STARTING TORQUE

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10 Yes

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IN 3 PHASE INDUCTION MOTORS SOMETIMES COPPER BARS ARE PLACED DEEP IN ROTOR WHY..?..

Answer / raul

This design is known as Deep bar rotor, which is basically
a modified rotor design in Squirrel cage induction motor.
During starting, the rotor frequency (i.e. Fr = slip *
supply frequency) is very high and the rotor reactance
value is very high, due to which the rotor current is
restricted to the near slot rotor copper and the area of
cross section of the conducting rotor conductors reduces
and the net resistance is increased due to which the
starting torque and the slip at which the max. torque takes
place also increases. And as the rotor picks up speed, the
rotor frequency and hence rotor reactance starts decreasing
and the complete deep bars carries uniform current and
torque reached steady state torque.

Another design with the almost the same above principle is
the DOUBLE CAGE ROTOR

Is This Answer Correct ?

6 Yes

1 No

IN 3 PHASE INDUCTION MOTORS SOMETIMES COPPER BARS ARE PLACED DEEP IN ROTOR WHY..?..

Answer / pramod attri

increasing the starting torque

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3 Yes

0 No

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