Motors, Motor Circuits, and Controllers

Bijan Ghayour, P.E.

Course Outline

This 6-hour course is intended to cover the design and application of motors, motor controllers, and motor control centers for different projects. The course provides the necessary rules, minimum basic legal requirements, and guidance for the design, and the installation of motors, motor feeders, motor feeder short-circuit and ground fault protection, motor disconnecting means, motor circuit conductors, motor controller, motor control circuits, motor overload protection, and motor thermal protection.

Special applications such as adjustable speed drives, multi-speed motors, part-winding motors, secondary controllers, and secondary resistors are also covered.

The course materials are based entirely on the Article 430 of the national Electrical code NFPA 70. It will be necessary for the student to obtain a copy of NFPA 70, 2008 revision.

This course includes a multiple-choice quiz at the end, which is designed to enhance the understanding of course materials.

Learning Objective

The purpose of this course is to make the student familiar with the rules and the code requirements for the application and protection of motors, motor controllers, and motor control centers in industrial, commercial, government, and utility projects

At the conclusion of the course the student will be familiar with the:

• Scope of the NFPA 70 Article 430;
• Definition of the terms utilized in NFPA 70 Article 430;
• Ampacity and motor rating determination;
• Marking on motors and multimotor equipment;
• Marking on controllers;
• Wiring space requirements in enclosures;
• Location of motors;
• Motor circuit conductors;
• Feeder and demand factor;
• Motor and branch-circuit overload protection;
• Motor branch-circuit short-circuit and ground-fault protection;
• Motor feeder short-circuit and ground-fault protection;
• Motor controllers;
• Motor control centers;
• Disconnecting means;
• Adjustable-speed drive systems;
• Motors over 600 volts nominal; and
• Grounding of the motors for all voltages.
  

Intended Audience

This course is intended for professional electrical engineers, electrical designers, project engineers, and maintenance personnel involved in the application, specification, design, installation, service, and maintenance of induction motors and associate controllers or control centers.

Benefit to Attendees

This course will assist individuals and organizations in the application of motors, motor controllers, and motor control centers for different projects. Through explanation of rules and use of the tables the attendee will be able to design and specify motors and motor control centers in compliance with National Electrical Code NFPA 70.

Course Introduction

This 6-hours course covers the legal requirements for the application of induction motors in industrial, commercial and utility installations. Topics such as the size of the conductors supplying power to motors, nameplate values, explanation of the markings on motors and multimotor equipment, locked-rotor indicating code letters, wiring space requirements in enclosures, motor terminal housing, equipment grounding connections and motor bushing will be discussed. Other topics of interest such as location of motors, duty cycle service, multimotor and combination-load equipment, feeder demand factor, motor overload, short-circuit and ground fault protection, will also be discussed.

Course Content

The course materials are based entirely on the Article 430 of the national Electrical code NFPA 70. It will be necessary for the student to obtain a copy of NFPA 70, 2008 revision. A copy of the NFPA 70 could be purchased from the following websites:

http://www.nfpa.com/
http://www.global.ihs.com/

MOTORS, MOTOR CIRCUITS, AND CONTROLLERS

NFPA 70, Article 430, Table of Contents

1. General
2. Motor Circuit Conductors
3. Motor and Branch-Circuit Overload protection
4. Motor Branch-Circuit Short-Circuit and ground Fault Protection
5. Motor Feeder Short-Circuit and Ground Fault Protection
6. Motor Control Circuits
7. Motor Controllers
8. Motor Control Centers
9. Disconnecting Means
10. Adjustable Speed Drive Systems
11. Over 600 volts, Nominal
12. Protection of Live Parts- All Voltages
13. Grounding- All Voltages
14. Tables

Course Summary

This course is intended to cover the design and application of motors, motor controllers, and motor control centers for different projects. The course provides the necessary rules, minimum basic legal requirements, and guidance for the design, and the installation of motors, motor feeders, motor feeder short-circuit and ground fault protection, motor disconnecting means, motor circuit conductors, motor controller, motor control circuits, motor overload protection, and motor thermal protection.

Quiz

Once you finish studying the above course content, you need to take a quiz to obtain the PDH credits.

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DISCLAIMER: The materials contained in the online course are not intended as a representation or warranty on the part of PDH Center or any other person/organization named herein. The materials are for general information only. They are not a substitute for competent professional advice. Application of this information to a specific project should be reviewed by a registered architect and/or professional engineer/surveyor. Anyone making use of the information set forth herein does so at their own risk and assumes any and all resulting liability arising therefrom.

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