Industrial Motor Control
7th Edition
ISBN: 9781133691808
Author: Stephen Herman
Publisher: Cengage Learning
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Textbook Question
Chapter 38, Problem 10RQ
Refer to the circuit shown in Figure 38–5. Assume that timer TR1 is set for a delay of 10 seconds and timer TR2 is set for a delay of 5 seconds. When the Start button is pressed, the motor starts. After 10 seconds, the S1 contacts open and the motor continues to accelerate but never reaches full speed. After a delay of about 30 seconds, the motor trips out on overload. Which of the following could cause this problem?
- a. TR1 coil is open.
- b. S2 coil is open.
- c. S1 coil is open.
- d. R coil is open.
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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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- Refer to the circuit shown in Figure 241. Assume that timer TR is set for a delay of 10 seconds. When the START button is pressed, the motor starts in low speed. After a delay of 30 seconds the motor is still in its lowest speed and has not accelerated to normal speed. Which of the following could not cause this condition? a. The START button is shorted. b. Timer coil TR is open. c. Contactor coil R is open. d. Timed contact TR did not close after a delay of 10 seconds.arrow_forwardRefer to the circuit shown in Figure 247. Assume that all timers are set for a delay of 5 seconds. When the START button is pressed the motor starts in its lowest speed. After a delay of over 10 seconds, the motor is still running in the lowest speed. Which of the following could cause the problem? a. TR1 coil is open. b. TR1 coil is shorted. c. S2 coil is open. d. S1 coil is shorted.arrow_forwardRefer to the schematic diagram in Figure 318. Assume that the motor is not running. When the third speed push button is pressed, the motor starts in its lowest speed. After a delay of 3 seconds, the motor accelerates to second speed and 3 seconds later to third speed. After a period of about 1 minute, the fourth speed push button is pressed, but the motor does not accelerate to fourth speed. Which of the following could cause this problem? a. Control relay CR2 coil is open. b. S2 contactor coil is open. c. CR3 coil is shorted. d. S3 contactor coil is open.arrow_forward
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- Refer to the circuit shown in Figure 252. Assume that timer TR is set for a time delay of 10 seconds. When the START button is pressed, the motor does not start. After a period of 10 seconds, the motor starts with full line voltage applied to it. Which of the following could cause this condition? a. Timer TR coil is open. b. CR coil is open. c. Contactor S coil is open. d. Contactor R coil is open.arrow_forwardRefer to the circuit shown in Figure 2614. When the START button is pressed, the control transformer fuse blows immediately. Which of the following could not cause this problem? a. Control relay coil CR is shorted. b. Starter coil 1M is shorted. c. Contactor coil S is shorted. d. Contactor coil 2M is shorted.arrow_forwardTo answer the following questions refer to the circuit shown in Figure 4110. Assume that the third speed push button is pressed and the motor starts in its first or lowest speed. After a delay of 3 seconds, the motor accelerates to its second speed, but never accelerates to its highest or third speed. Which of the following could cause this problem? a. CR coil is open. b. Coil 2TR is open. c. Coil 1TR is open. d. Coil 1S is open.arrow_forward
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