Motor

Causes of Motor Suffers from Heavy Vibrations and Excessive Noise when Operating

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Causes of Motor Suffers from Heavy Vibrations and Excessive Noise when Operating  Q. What are the probable causes, if the motor suffers from heavy vibrations and excessive noise when operating ? The induction motor’s performance is affected by the harmonics in the time variations of the impressed voltage.  Air-gap flux harmonics are produced due to … Read more

Need of Energy Conservation In Induction Motor

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Need of Energy Conservation In Induction Motor Q. Explain the necessity of energy conservation in electrical motors. India is a growing economy and the economic growth of any country largely depends on industrialization and energy consumption. The growing cost of energy due to limited stock of energy sources calls for power saving at each possible … Read more

Factors Governing Selection of Induction Motor

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Factors Governing Selection of Induction Motor Q. State the factors governing the selection of induction motor Electrical motors are universally adopted as electric drive. Hence,  has become necessary for the manufacturer to manufacture motors of various designs according to suitability and use in various classes of Industry. This has resulted into numerous types of motors. … Read more

Automatic Star-Delta Starter

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Automatic Star-Delta Starter Q. Automatic Star-Delta Starter. Automatic Star Delta Starter is used to save energy during variable load conditions in three-phase induction motor.  This is done by using a micro controller.  The three-phase winding inside the motor can be connected in star or delta. About 25-30 % of energy gets saved by incorporating delta … Read more

Activities That are Done During Preventive Maintenance of Induction Motors

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Activities That are Done During Preventive Maintenance of Induction Motors Q. State any six activities that are done during preventive maintenance of induction motors. The activities that are done during preventive maintenance of induction motors are :  Attention towards brushes :  Sparking at the brushes : Sparking is produced due to misalignment of commutator, mechanical … Read more

Direct, Indirect and Regenerative Type of Testing on Machine

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Direct, Indirect and Regenerative Type of Testing on Machine  Q. Compare direct, indirect and regenerative type of testing. Sr. No Point  Of comparison Indirect Test Direct Test Regenerative Test 1 Loading Method It is a not load indirect test. It is a direct load test. It is an indirect back to back or regenerative test. … Read more

Permissible Limits of Variation of Supply Voltage to Motor and Variation of Frequency

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Permissible Limits of Variation of Supply Voltage to Motor and Variation of Frequency Q. Give the permissible limits related to terminal voltage, frequency, temperature rise and speed variation for safe working of electrical machines. Permissible Limits of Variation of Supply Voltage to Motor and Variation of Frequency :  The performance of Electric Machines particularly working … Read more