Introduction to Industrial Automation

 3 

Industrial Automation Synthesis ................................................................................79

3.1  Introductory Principles in Designing Automation Circuits ......................................79

3.1.1  The Latch Principle ..................................................................................... 79

3.1.2  The Principle of “Command” .....................................................................81

3.2  Step-by-Step Basic Automation Examples Synthesis .............................................. 82

3.2.1  Motor Operation with Thermal Overload Protection ................................ 82

3.2.2  Operation and Fault Indication .................................................................. 83

3.2.3  Machine Operation with Starting Delay ................................................... 84

3.2.4  Machine Operation with Stopping Delay................................................... 87

3.2.5  Periodic Operation of Machine with Two Time Constants ....................... 88

3.2.6  Machine Operation with Automatic or Manual Control.............................88

3.2.7  Operation of Two Machines with a Common Manual Command 

or Separate Automatic Commands............................................................ 89

3.2.8  Operation of Two Machines with a Common Automatic Command 

or Separate Manual  Commands ............................................................... 90

3.2.9  Operation of a Machine from Two or More Points ................................... 90

3.2.10  Control Panel for Operating n Machines ...................................................91

3.3  The Meaning of the Electrical and Mechanical Latch .............................................91

3.3.1  Sequential Start—Latch of Machines (Chain Latch)................................. 93

3.3.2  Motor Operation with Power Supply from Two Different Networks ........ 94

3.4  Automation Circuits for Motors ............................................................................ 95

3.4.1  Motor with Inversion in Rotation ............................................................... 95

3.4.2  Motor with a Star-Delta (Y-

Δ

) Start .......................................................... 96

3.4.3  Automation of Various Motor Types ......................................................... 97

3.5  Automation Circuits with Sensors ........................................................................... 98

3.5.1  Starting a Machine with Cancelling Ability .............................................. 98

3.5.2  Pump Operation Based on Level Control ............................................... 100

3.5.3  Operation of Two Pumps According to Demand .................................... 100

3.5.4  Automation of a Garage Door ..................................................................101

3.6  Automation Circuit Design Regulations ...............................................................102

3.7  Implementation of Automation Circuits ...............................................................105

3.8 Applications ..........................................................................................................107

3.8.1  Machine Operation Control from Multiple Positions ................................107

3.8.2  Operation Control of a Power Transformer ..............................................108

3.8.3  Operation of Two Pumps with a Cyclic Alteration, Based 

on a Low- High Demand ....................................................................... 109

3.8.4  Operation of Three Air Compressors with Predefined Combinations ......112

Problems .........................................................................................................................113

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