Industrial Motor Control
7th Edition
ISBN: 9781133691808
Author: Stephen Herman
Publisher: Cengage Learning
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Chapter 31, Problem 3RQ
Assume that all three motors shown in Figure 31–14 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. The stop button is shorted.
- b. 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.
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