Industrial Motor Control
7th Edition
ISBN: 9781133691808
Author: Stephen Herman
Publisher: Cengage Learning
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Question
Chapter 38, Problem 1RQ
To determine
The reason for the why it is desirable to disconnect the autotransformer from the circuit when the motor reaches the run state.
Expert Solution & Answer
Explanation of Solution
Consider the autotransformers are used in the starting of the squirrel cage induction motor. The autotransformer reduces the voltage that is applied to the motor to reduce the inrush current at the starting.
As the motor reaches 75% of the normal speed the motor is in the run stage.
As the rotor reach the run stage of the normal speed is applied the full voltage.
After the run stage autotransformer to supply the full load voltage is the waste of energy as the same voltage is applied by connecting the motor to the supply.
Therefore, it is desirable to disconnect the transformer as the motor reaches the run stage to save the energy and extend the life of transformer.
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Chapter 38 Solutions
Industrial Motor Control
Ch. 38 - Prob. 1RQCh. 38 - Explain the differences between open and closed...Ch. 38 - Prob. 3RQCh. 38 - Refer to the circuit shown in Figure 382. Assume...Ch. 38 - Prob. 5RQCh. 38 - Prob. 6RQCh. 38 - Prob. 7RQCh. 38 - Refer to the circuit shown in Figure 385. Explain...Ch. 38 - Prob. 9RQCh. 38 - Refer to the circuit shown in Figure 38–5. Assume...
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