Maricopa Community Colleges  ELA254   19886-20086 
Official Course Description: MCCCD Approval: 07/22/08
ELA254 19886-20086 LEC 3 Credit(s) 3 Period(s)
Basic Magnetic Motor Controls
Advanced instruction for journeyman electricians in industrial electric field including complex line diagrams and control circuits, solid state and electro-mechanical relays, and photo electric and proximity control.
Prerequisites: Apprentice status.
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MCCCD Official Course Competencies:
 
ELA254   19886-20086 Basic Magnetic Motor Controls
1. List the general ground rules for establishing good, safe work habits. (I)
2. Read line diagrams and identify the common electrical symbols which are the electrician's primary means of communication. (II)
3. Demonstrate the use of basic rules for working with line diagrams including the logical organization of all electrical circuits and the basic logic functions common to most circuits. (III)
4. Using wiring diagrams, illustrate the operation of manual contactors and motor starters in electrical devices. (IV)
5. Using wire diagrams, illustrate the operation of magnetic contactors and motor starters in electrical devices. (V)
6. Using wiring diagrams, illustrate the operation of alternating current/direct current (AC/DC) contactors and magnetic motor starters in electric devices. (VI)
7. Describe types of timers and timing circuits used in control work and apply timing functions with the help of a coding system. (VII)
8. List the three types of interlocking used when reversing motors and illustrate, using wiring diagrams, how to reverse the three motor types. (VIII)
9. List the stages in the distribution system and describe the role of common devices used in the system. (IX)
10. State the principals that an electrician should follow to decide which relay type to use in a given application and apply this knowledge to determine the correct relay type for any situation. (X)
11. Describe the types of control devices and how to connect and apply each type in a circuit. (XI)
12. Identify the more complicated circuits the industrial electrician will be required to connect and describe the theory of their operation. (XII)
13. Describe preventive maintenance techniques and methods for trouble-shooting circuits. (XIII)
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MCCCD Official Course Outline:
 
ELA254   19886-20086 Basic Magnetic Motor Controls
    I. Review of Electrical Tools, Instruments and Safety
        A. Organization of Electrical Tools
        B. Safety Rules
          1. Standard Safety Colors
          2. Four Classes of Fires
      II. Language of Controls
          A. Standard Electrical Symbols
          B. Line Diagrams
        III. Logic
            A. Line Diagrams
              1. Basic Rules That Apply
              2. Sections of a Line Drawing
              3. Logic Functions
            B. Basic Control Circuits
          IV. AC Manual Contactors and Motor Starters
              A. Line Diagram vs. Wiring Diagram
              B. Manual Contactors vs. Manual Starters
              C. Overload Protection
            V. Magnetism and Magnetic Solenoids
                A. Types of Magnets
                B. Types of Solenoids
                  1. Solenoid Application
                  2. Solenoid Problems
              VI. AC/DC Contactors and Magnetic Motor Starters
                  A. Types of Contactors and their Applications
                    1. Two Wire and Three Wire Control
                    2. AC vs. DC Contactors
                    3. Arc Suppression
                  B. Overload Protection - Types and Selection
                VII. Time Delay and Logic Applied to more Complex Line Diagrams and Control Circuits
                    A. Numerical Cross Reference System
                    B. Timers and Industrial Applications
                    C. Timing Code
                    D. ON - Delay/Off - Delay Timing Graph
                  VIII. Reversing Circuits
                      A. Motor Types
                        1. Three-phase Wye vs. Three-phase Delta
                        2. Single Phase
                        3. DC Motors
                      B. Reversing Circuits In Each Motor Type
                    IX. Power Distribution Systems
                        A. Transformers
                          1. Wye Connection
                          2. Delta Connection
                        B. Switchboards
                        C. Motor Control Centers
                        D. Busways
                      X. Relays
                          A. Electromechanical Relays
                          B. Actuating Reed Relays
                          C. Solid State Relays
                          D. Electromechanical vs. Solid State
                            1. Advantages
                            2. Disadvantages
                        XI. Applications and Installations of Control Devices
                            A. Pushbutton
                            B. Selector Switch
                            C. Limit Switch
                            D. Pressure Switch
                            E. Actuating Temperature Switch
                            F. Float Switch
                            G. Photo Electric Applications
                              1. Sensitivity Adjustment
                              2. Light Sources
                            H. Hall Effect Sensors
                          XII. Advanced Circuits
                              A. AC Reduced Voltage Starter
                                1. When to Use
                                2. Methods
                                3. Advantages and Disadvantages
                              B. Accelerating and Decelerating Methods and Circuits
                                1. Determining Braking Torque
                                2. Advantages and Disadvantages of Braking Methods
                                3. Speed Control of DC Motor
                                4. Speed Control of AC Motor
                            XIII. Preventive Maintenance and Trouble-Shooting
                                A. Preventive Maintenance Program
                                B. Test Instruments
                                  1. Testing a Fuse on Circuit Breaker
                                  2. Testing a Control Transformer
                                C. Causes of Motor Failure
                                D. Remarking a Three-Phase or DC Motor
                                E. Locating a Circuit in a Switchboard
                                F. Testing for an Open or Shorted Capicitator
                                G. Testing for a Good Diode
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