MCCCD Program Description

Motors, Controls and Wiring Diagrams

Course: FAC115

First Term: 2024 Fall

Lecture 3.0 Credit(s) 3.0 Period(s) 3.0 Load
Subject Type: Occupational
Load Formula: S - Standard Load

Description: Principles of three-phase motors. Wye and delta wiring. Calculation of motor current draw. Sequence of operation, wiring diagram and electrical components associated with industrial equipment. Procedures for evaluating electrical problems. Safety stressed.

MCCCD Official Course Competencies
1. Explain principles of operation for three-phase motors. (I) 2. Identify wye and delta types of wiring diagrams and explain high/low voltage for each. (II) 3. Explain the terms synchronous speed and major factors determining amounts of induced voltage into rotors. (III) 4. Explain the function of torque and how it is produced in motors. (IV) 5. Using the data on motor nomenclature plates and the National Electrical Code (NEC), calculate motor current draw. (V) 6. Compare and contrast wye and delta transformers. (VI) 7. Translate line wiring diagrams to ladder diagrams. (VII) 8. Given electrical components for an industrial process, write sequences of operations. (VIII) 9. Draw ladder diagrams into line diagrams for designing control panels. (IX) 10. Using the theory of electrical circuits, write a procedure for evaluating electrical problems, including appropriate safety procedures. (X)
MCCCD Official Course Competencies must be coordinated with the content outline so that each major point in the outline serves one or more competencies. MCCCD faculty retains authority in determining the pedagogical approach, methodology, content sequencing, and assessment metrics for student work. Please see individual course syllabi for additional information, including specific course requirements.

MCCCD Official Course Outline
I. Three phase motors A. Operation B. Types (rotors) 1. Squirrel cage 2. Wound rotor 3. Synchronous C. Field factors 1. Voltage phase angle 2. Change in polarity 3. Arrangement of stator windings II. Motor wiring diagrams A. Wye 1. High voltage 2. Low voltage B. Delta 1. High voltage 2. Low voltage C. Twelve-lead motors D. Direction change III. Synchronous speed and voltage induction A. Definitions B. Factors for induction 1. Strength of field 2. Turns of wire 3. Speed IV. Motor torque A. Major factors 1. Strength of magnetic field - starter 2. Strength of magnetic field - rotor 3. Phase angle of currents B. Load effects C. Phase angle - maximum torque D. Function V. Code letters and current draw A. Types of rotors B. NEC tables C. Calculations VI. Transformers A. Wye type 1. Phase voltage 2. Line voltage 3. Step up 4. Step down B. Delta type 1. Phase voltage 2. Line voltage 3. Step up 4. Step down VII. Wiring diagrams A. Pictorial B. Line VIII. Wiring diagram development A. Components B. Sequence of operation C. Diagramming IX. Ladder/line diagrams - control panels A. Component location B. Terminal identification C. Wire numbering D. Illustrating X. Electrical circuit evaluation procedure A. Electrical theory B. System type C. Operating sequence D. Procedure 1. Electrical supply 2. Operating loads 3. Non-operating loads 4. Sequence 5. Safety

MCCCD Governing Board Approval Date: February 27, 2024

All information published is subject to change without notice. Every effort has been made to ensure the accuracy of information presented, but based on the dynamic nature of the curricular process, course and program information is subject to change in order to reflect the most current information available.