Understanding Motor Controls
4th Edition
ISBN: 9781337798686
Author: Stephen L. Herman
Publisher: Delmar Cengage Learning
expand_more
expand_more
format_list_bulleted
Concept explainers
Videos
Textbook Question
Chapter 12, Problem 3RQ
Assume that all three motors shown in Figure 12–14 are running. Now assume that the STOP button is pressed and motors #1 and #2 stop running, but motor #3 continues to operate. Which of the following could cause this problem?
- a. STOP button is shorted.
- b. The 2M contact between wire numbers 31 and 32 is hung closed.
- c. The 3M load contacts are welded shut.
- d. The normally open 3M contact between wire numbers 23 and 31 is hung closed.
Expert Solution & Answer
Trending nowThis is a popular solution!
Students have asked these similar questions
1. Why pulley have different diameters
2. Parts and functions of the squirrel cage induction motor
Q A motor of 15 horsepower, has a code letter L, and is operated on a 400-volt line. Find the locked rotor current
A motor, operating clockwise is coupled through a belt drive to rotate an industrial exhaust fan at 500 rpm. The diameter of the motor sheave is 4 in. and the sheave on the fan is 14 in. Determine the belt speed.
Knowledge Booster
Learn more about
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
- Referring to Figure 1214, assume that the normally open 2M contact located between wire numbers 23 and 29 is welded closed. Also assume that none of the motors are running. What would happen if: a. The number 2 push button was to be pressed before the number 1 push button? b. The number 1 push button was to be pressed first?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 Figure 436 and assume the motor is to rotate in the opposite direction. How can the belt slack be maintained on top?arrow_forward
- 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 16-11. Assume that the platform is located on the bottom floor. When the UP push button is pressed the pump motor does not start. Which of the following could not cause this problem? The contacts of limit switch LS1 are open. The contacts of limit switch LS2 are open. Motor starter coil M is open. The overload contact is open.arrow_forwardAn open winding in an electric motor means that A. the winding is making contact with the motor frame. B. one winding is making contact with another winding. C. a wire in one winding is broken. D. the centrifugal switch to the start winding is open.arrow_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_forwardWhat is the Design procedure in Determining the number of V-belts required?arrow_forwardThe device that prevents the engine from turning the armature of the starter motor is the. overrunning clutch pinion gear flywheel pole shoearrow_forward
- If the load in question 7 was supplied by two autotransformers connected in open delta, what would be the minimum standard size transformers that could be used to supply this load?arrow_forwardYou are Working as a plant electrician. You were told that a large DC motor was returned from the rewind shop and was installed on the previous shift. The motor seem to operate properly until the load was added. The motor then stopped, reversed direction, and begun to run at high speed. What is the probable cause of the trouble, and what would you do to correct the problem? Explain your answer.arrow_forwardA large motor has a full load current rating of 425 amperes. Current transformers with a ratio of 600:5 are used to reduce the current to the overload heaters. What should be the full load current rating of the overload heaters?arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
Understanding Motor ControlsMechanical EngineeringISBN:9781337798686Author:Stephen L. HermanPublisher:Delmar Cengage Learning
Refrigeration and Air Conditioning Technology (Mi...Mechanical EngineeringISBN:9781305578296Author:John Tomczyk, Eugene Silberstein, Bill Whitman, Bill JohnsonPublisher:Cengage Learning
Electrical Transformers and Rotating MachinesMechanical EngineeringISBN:9781305494817Author:Stephen L. HermanPublisher:Cengage Learning
Automotive Technology: A Systems Approach (MindTa...Mechanical EngineeringISBN:9781133612315Author:Jack Erjavec, Rob ThompsonPublisher:Cengage Learning
Understanding Motor Controls
Mechanical Engineering
ISBN:9781337798686
Author:Stephen L. Herman
Publisher:Delmar Cengage Learning
Refrigeration and Air Conditioning Technology (Mi...
Mechanical Engineering
ISBN:9781305578296
Author:John Tomczyk, Eugene Silberstein, Bill Whitman, Bill Johnson
Publisher:Cengage Learning
Electrical Transformers and Rotating Machines
Mechanical Engineering
ISBN:9781305494817
Author:Stephen L. Herman
Publisher:Cengage Learning
Automotive Technology: A Systems Approach (MindTa...
Mechanical Engineering
ISBN:9781133612315
Author:Jack Erjavec, Rob Thompson
Publisher:Cengage Learning
Mechanical Design (Machine Design) Clutches, Brakes and Flywheels Intro (S20 ME470 Class 15); Author: Professor Ted Diehl;https://www.youtube.com/watch?v=eMvbePrsT34;License: Standard Youtube License