Understanding Motor Controls
4th Edition
ISBN: 9781337798686
Author: Stephen L. Herman
Publisher: Delmar Cengage Learning
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Question
Chapter 31, Problem 12RQ
To determine
The factor that does not cause the problem.
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In relation to the circuit presented below, mark the alternative(s) that you consider correct.
1 To enable actuator A2 to advance, it is necessary to switch valve V2 to the leftmost position and ensure that valve V1 is in its initial (intermediate) position.
2 Switching valve V2 to the leftmost position allows actuator A2 to advance, but for this to happen, valve V1 must also be switched to the leftmost position.
3 When activating valve V1, using the locking lever installed on the left side of it, the two actuators (A1 and A2) are allowed to advance.
4 Hydraulic pump B1 is a simple variable displacement type.
5 Valves V1 and V2 have a TANDEM center.
Build a ladder logic diagram showing the timer delays.
Name
Section 5-2: Line Diagrams-Signals,
Decisions, and Actions
In the following application, a temperature switch controls a heating contactor and a flow switch is used to
ensure there is enough air flow. If there is not enough air flow, an alarm is sounded. Complete the required
information.
1. List all the signal devices in the circuit.
2. List all the action devices in the circuit.
3. List the decision part of the circuit that automatically sounds the alarm if there is a problem.
4. When the heating element is on during normal operation, is the flow switch open or closed?
CIRCULATING
2
L1
FAN
TEMPERATURE
SWITCH
TR
HEATING
ELEMENTS
FLOW
SWITCH
-HOT AIR
PADDLE
AIR FILTER
NORMALLY CLOSED
FLOW SWITCH
65
ALARM
(SOUNDS IF NO FLOW FOR
15 SECONDS OR MORE)
Date
HEATING
CONTACTOR
TR
ON-DELAY
TIMER
SUPPLY AIR
COLD AIR
(3) TIME SET= 15 SEC
© 2014 American Technical Publishers, Inc.
All rights reserved
Chapter 31 Solutions
Understanding Motor Controls
Ch. 31 - Prob. 1RQCh. 31 - Prob. 2RQCh. 31 - A wound rotor induction motor has a stator that...Ch. 31 - Name three factors that determine the amount of...Ch. 31 - Prob. 5RQCh. 31 - Explain why controlling the rotor current also...Ch. 31 - What is the function of a micro limit switch when...Ch. 31 - Prob. 8RQCh. 31 - What is rotor slip?
Ch. 31 - Prob. 10RQ
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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 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 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 4221. Assume that the THIRD SPEED push button is pressed. The motor starts in second speed, skipping first speed. After 5 seconds, the motor accelerates to third speed. Which of the following could cause this problem? a. S1 contactor coil is open. b. CR1 contactor coil is open. c. TRl timer coil is open. d. S1 load contacts are shorted.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_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
- 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 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_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_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_forwardWhat are the two basic classifications of timers?arrow_forwardRefer to the circuit shown in Figure 42–21. Assume that a fused jumper is connected across terminals 1 and 3 of TR2 timer. What would happen if the jumper were left in place and the FIRST SPEED push button pressed? The motor would start in its lowest speed and progress to second speed, but never increase to third speed. The motor would start operating immediately in third speed. The motor would not start. The motor would start in second speed and then increase to third speed.arrow_forward
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Understanding Motor ControlsMechanical EngineeringISBN:9781337798686Author:Stephen L. HermanPublisher:Delmar Cengage Learning
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ISBN:9781337798686
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