Standard

 

ELC 212 – Motor Controls

Course Description:

Introduces the application of motor controls in the industrial environment.  Topics include:  AC/DC motors, AC/DC drives, MCC and contractors, NEC and NEMA standards, ladder diagrams, and power sources.

 

Competency Areas:

Hours:

 

 

 

AC/DC Motors

Class

4

AC/DC Drives

D. Lab

4

MCC and Contractors

P. Lab/O.B.I.

0

NEC and NEMA Standards

Credit

6

Ladder Diagrams

 

 

Power Sources

 

 

 

 

 

Prerequisites:  

ELC 115

Corequisites:

 

Course Guide

 

Competency

After completing this section, the student will:

Hours

Class

D. Lab

P. Lab/

O.B.I.

AC/DC MOTORS

10

14

0

DC motors

Describe the operation and construction of the following DC motors:  (a) shunt, (b) series, (c) compound, and (d) PME.

 

 

 

AC motors

Describe the operation and construction of the following AC motors:  (a) induction, (b) series, and (c) synchronous.

 

 

 

AC/DC DRIVES

4

2

0

SCR drive

Explain SCR drive principle of operation.

 

 

 

Variable frequency

Explain variable principle of operation.

 

 

 

MCC AND CONTRACTORS

11

15

0

Manual controllers

Describe manual controllers for AC motors.

 

 

 

 

Describe types of solid state controllers.

 

 

 

 

Explain the meaning of across the line starting.

 

 

 

 

Explain automatic starter operation.

 

 

 

 

Describe typical starting methods.

 

 

 

 

Describe automatic starters from DC control operation.

 

 

 

 

Describe methods to automatically start AC motors.

 

 

 

 

Describe how to change the direction of a DC motor.

 

 

 

Speed control

Describe how to control the speed of a DC motor.

 

 

 

 

Describe methods of speed control for AC motors.

 

 

 

NEC AND NEMA STANDARDS

3

2

0

NEC

Demonstrate an understanding of NEC and NEMA standards.

 

 

 

NEMA

List the sources for information on NEC and NEMA standards.

 

 

 

 

Recognize compliance with NEC and NEMA standards.

 

 

 

LADDER DIAGRAMS

8

4

0

Schematic symbols

Draw schematic symbols representing the major components used in industrial motor control circuits.

 

 

 

Motor control circuit

Draw a ladder diagram of a motor control circuit given a standard schematic drawing.

 

 

 

 

Wire a motor control circuit from a ladder diagram.

 

 

 

 

Explain a motor control circuit operation using a ladder diagram.

 

 

 

POWER SOURCES

4

3

0

Basic transformers

Describe basic transformer theory.

 

 

 

Three-phase

Describe typical single-phase and three-phase power systems.

 

 

 

 

Draw and analyze a wye-to-delta and delta-to-wye phase power source.

 

 

 

 

Describe a three-phase AC to DC conversion system.

 

 

 

 

Suggested Resources

 

Books:

 

Berutti, A. (Ed.).  (1991).  Practical guide to motors and motor controls.  Overland Park, KS: Intertec.

Bryan, E. A., et al.  (1995).  Troubleshooting and understanding electrical and motor controls: Video guide and workbook.  Atlanta: Industrial Text Co.

Bryan, L. A., et al.  (1995).  AC motor controls and troubleshooting: Video booklet/workbook.  Atlanta: Industrial Text Co.

Bryan, L. A., et al.  (1995).  DC motor controls and troubleshooting: Video booklet/workbook.  Atlanta: Industrial Text Co.

Hartwell, F. P. (Ed.).  (1996).  Understanding NE code rules on motors and motor controls.  Overland Park, KS: Intertec.

Keljik.  (1995).  Electric motors and motor controls training.  Albany, NY: Delmar.

Miller, R., & Miller, M. R.  (1991).  Electric motor controls.  Englewood Cliffs, NJ: Prentice Hall.

Tel-A-Train, Inc. Staff.  (1991).  Maintaining and troubleshooting industrial motor controls.  Chattanooga: Author.

Traister, J.  (1994).  Complete handbook of electric motor controls.  Englewood Cliffs, NJ: Prentice Hall.