Industrial Motor Control
7th Edition
ISBN: 9781133691808
Author: Stephen Herman
Publisher: Cengage Learning
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Textbook Question
Chapter 39, Problem 4RQ
Refer to the circuit shown in Figure 39–9. Assume that timer TR is set for a delay of 10 seconds. When the Start button is pressed, the motor starts with its windings connected in wye. After a period of one minute, the motor has not changed from wye to delta. Which of the following could cause this condition?
- a. TR timer coil is open.
- b. S contactor coil is open.
- c. 1M starter coil is open.
- d. The control transformer fuse is blown.
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Chapter 39 Solutions
Industrial Motor Control
Ch. 39 - Name two requirements that must be met before a...Ch. 39 - Prob. 2RQCh. 39 - Prob. 3RQCh. 39 - Refer to the circuit shown in Figure 399. Assume...Ch. 39 - Refer to the circuit shown in Figure 39–9. Assume...Ch. 39 - Prob. 6RQCh. 39 - The motor nameplate of a wye–delta starter motor...Ch. 39 - Prob. 8RQCh. 39 - Refer to the circuit shown in Figure 3914. What is...Ch. 39 - Refer to the circuit shown in Figure 39–14. When...
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Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, mechanical-engineering and related others by exploring similar questions and additional content below.Similar questions
- Refer to the circuit shown in Figure 97. Assume that when the forward push button is pressed the motor does not start, but when the reverse push button is pressed the motor will start in the reverse direction. When the stop button is pressed the motor stops running. Which of the following could NOT cause this problem? a. The forward push button is defective. b. The F starter coil is open. c. The overload auxiliary contact is open. d. The normally closed R contact is open.arrow_forwardRefer to the circuit shown in Figure 26–9. Assume that timer TR is set for a delay of 10 seconds. When the START button is pressed, the motor starts with its windings connected in wye. After a period of 1 minute, the motor has not changed from wye to delta. Which of the following could cause this condition? TR timer coil is open. S contactor coil is open. 1M starter coil is open. The control transformer fuse is blown.arrow_forwardRefer to the circuit shown in Figure 269. Assume that timer TR is set for a delay of 10 seconds. When the START button is pressed, the motor does not start. After a delay of 10 seconds, the motor suddenly starts with its stator windings connected in delta. Which of the following could cause this problem? a. TR timer coil is open. b. 2M contactor coil is open. c. S contactor coil is open. d. 1M starter coil is open.arrow_forward
- Refer 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_forwardRefer 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_forward
- Refer to the circuit shown in Figure 107. Assume that when the start button is pressed the motor does not start, but when the inch push button is pressed the motor runs at reduced speed. Which of the following could NOT cause this problem? a. The control transformer fuse is blown. b. M starter coil is defective. c. The start push button is defective. d. The stop push button is defective.arrow_forwardRefer to the circuit shown in Figure 33–7. When the low speed push button is pressed, the motor begins to run in low speed. When the high speed push button is pressed, the motor stops running. Which of the following could cause this problem? The 1L contactor coil is open. H contactor coil is open. PR relay coil is open. The 2L contactor coil is open.arrow_forwardRefer 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_forward
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