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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Which type of control system is used in the given block diagram? Write the definition.
I want you to draw a ladder logic diagram of a garage door to control it by PLC. In my case we have different inputs and outputs and all of them gotta be used in the diagram. I can perfectly interpret the diagram so no need to explain it, I will just require you to draw it.
INPUTS : open push button ( OPB ) - close push button ( CPB ) - open limit switch ( OLS ) - close limit switch ( CLS ) - obstacle detection sensor ( ODS ) - safety sensor ( SS ) - emergency stop push button ( ESPB ) - reset button ( RB )
OUTPUTS : motor starts ( MS ) - motor stops ( MSTP ) - motor forward ( MF ) - motor reverse ( MR ) - Error display ( ER )
OPERATİNG MODES : automatic mode ( AM ) - manual mode ( MM )
NECESSARY TIMERS : T1 ( delay door movement after obstacle detection ) - T2 ( delay door movement after reversing )
Here is my excercise for today. Please I am requiring a good logic diagram taking into consideration all what was mentioned before.
so to sum up, I want you to write a logic ladder diagram…
Chapter 54 Solutions
Industrial Motor Control
Ch. 54 - Why are NEMA symbols representing such components...Ch. 54 - Explain how to program an internal relay into the...Ch. 54 - Why are the contacts used to represent stop...Ch. 54 - Why is the output I/O used to energize a motor...Ch. 54 - Prob. 5RQCh. 54 - When programming in Boolean, what command is used...Ch. 54 - When programming in Boolean, what command is used...Ch. 54 - When programming in Boolean, what command is used...Ch. 54 - Why are the numbers 8 and 9 not used in an OCTAL-...
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