Understanding Motor Controls
4th Edition
ISBN: 9781337798686
Author: Stephen L. Herman
Publisher: Delmar Cengage Learning
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Chapter 21, Problem 10RQ
To determine
Identify how to reset a magnetic overload relay when its contacts are open.
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Chapter 21 Solutions
Understanding Motor Controls
Ch. 21 - Refer to Figure 21–1 to answer the following...Ch. 21 - Refer to Figure 211 to answer the following...Ch. 21 - Refer to Figure 211 to answer the following...Ch. 21 - Prob. 4RQCh. 21 - Prob. 5RQCh. 21 - Prob. 6RQCh. 21 - Prob. 7RQCh. 21 - Refer to Figure 21–1 to answer the following...Ch. 21 - Refer to Figure 21–1 to answer the following...Ch. 21 - Prob. 10RQ
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- Refer to Figure 211 to answer the following questions. How much voltage will be applied to coil 1CR when it is energized?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_forwardRefer to the circuit shown in Figure 16-11. Assume that the platform is located on the lower floor. When the UP push button is pressed, the platform rises. When the platform reaches the upper floor, however, the pump does not turn off but continues to run until the overload relay opens the overload contacts. Which of the following could cause this problem? a. The solenoid valve opened when limit switch LS1 opened. b. The UP push button is shorted. c. Limit switch LS1 did not open its contacts. d. Limit switch LS2 contacts did not reclose when the platform began to rise.arrow_forward
- Refer to the schematic in Figure 7-10. Assume that when the START button is pressed, the control transformer fuse blows. What is the most likely cause of this trouble? Figure 7-10 Numbers are placed beside all components.arrow_forwardTo answer the following questions refer to the circuit in Figure 416. When the pressure switch closes, which starter will energize first, 1M or 2M? Explain your answer.arrow_forwardWhat pin numbers are connected to the coil of an 8-pin control relay?arrow_forward
- To 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_forwardRefer to the circuit shown in Figure 25–5. 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? TR1 coil is open. S2 coil is open. S1 coil is open. R coil is open.arrow_forwardTo answer the following questions refer to the circuit in Figure 416. The pressure switch is shown as: a. Normally open b. Normally closed c. Normally open held closed d. Normally closed held openarrow_forward
- Refer 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_forwardTo answer the following questions refer to the circuit in Figure 416. What is the purpose of the rotary switch connected after the pressure switch?arrow_forwardRefer to Figure 21–1 to answer the following questions. Assume that HOA SW 120 has been set in the auto position. List four ways by which coil CR-8 could be energized.arrow_forward
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