Which of the following is a key maintenance practice for reliable operation of a 3-phase induction motor?
Regular lubrication of bearings and periodic insulation resistance testing.
To ensure the reliable operation of a 3-phase induction motor, certain key maintenance practices are essential. Let's evaluate the given options:
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Regular lubrication of bearings and periodic insulation resistance testing:
- Lubrication of Bearings: Bearings are crucial for the smooth rotary motion of any motor. Regular lubrication reduces friction, wear, and overheating, thus prolonging the motor's lifespan.
- Insulation Resistance Testing: Testing the insulation resistance of the motor windings helps detect deterioration before it leads to failure. It is an essential preventive maintenance practice.
This is a critical maintenance practice for ensuring the reliable operation of the motor.
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Short-circuiting the stator windings when the motor is idle:
This is an incorrect practice as short-circuiting the windings can cause excessive current flow, leading to overheating and potential damage to the motor.
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Increasing slip by intentionally weakening rotor bars:
Increasing slip by weakening rotor bars is not a maintenance practice and could result in decreased efficiency and potential damage, thus reducing reliability.
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Running the motor continuously at no-load to avoid heating:
This is inefficient as running a motor at no-load increases operational costs without any productive work. Additionally, continuous no-load running does not prevent heating issues; rather, it can still allow electrical losses to cause heating in the motor.
Conclusion: The correct and best practice for maintaining reliable operation of the 3-phase induction motor is Regular lubrication of bearings and periodic insulation resistance testing.
Similar Questions
Consider the following statements about torque in synchronous motors.
I. The torque in a synchronous motor is produced only when the rotor is locked into synchronism.
II. The torque is directly proportional to the sine of the load angle (δ).
III. Synchronous motor develops starting torque proportional to the power input.
IV. Maximum torque occurs at δ = 180°.
Which of the above statements are correct?
If the frequency of an AC source is doubled, the impedance of a pure resistor ____________.
Which of the following sets of statements about the causes of errors in current transformers is correct?
i) Leakage reactance in secondary winding contributes to ratio error
ii) High magnetizing current increases phase angle error
iii) Burden with low power factor increases phase angle error
iv) Core saturation reduces both ratio and phase angle errors
A single-phase preventer continuously monitors and protects preferably which motor against phase failure?
Important Questions from Three Phase Induction Motor
For a slip 's' and supply frequency 'f', the frequency of current in rotor will be-
The rotating magnetic field in a three-phase, 6-poles, 50 Hz slip ring induction motor will rotate at-
The synchronous speed of a three phase induction motor having 20 poles and connected to a 50 Hz source is-
The rotor current frequency in a slip-ring induction motor depends on-
The power factor of an induction motor operating at no load is around:
