Industrial Motor Control
7th Edition
ISBN: 9781133691808
Author: Stephen Herman
Publisher: Cengage Learning
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Textbook Question
Chapter 54, Problem 1RQ
Why are NEMA symbols representing such components as push buttons, limit switches, and float switches not used in a programmable controller schematic?
Expert Solution & Answer
To determine
The reason why the NEMA symbols representing the components like push buttons, limit switches and the float switches are not used in the programmable control switches.
Explanation of Solution
The NEMA symbols are the symbols that are used to represent the electrical components.
Since, the PLC recognize only the closed and the open contacts only and it do not recognize that whether the swtich is connected to a component like push button, float swtich or the limit swtich. This is why the NEMA swtich is used in the programming of PLC.
Thus, to give the idea to PLC about the type of components connected, the NEMA symbols are used.
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Chapter 54 Solutions
Industrial Motor Control
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