Grounding of Industrial and Commercial Power Systems

Course Outline

This 12-hour course provides for the study of recommended practices for grounding of electrical systems and the several methods and criteria that exist for power system grounding. The course is intended to (1) assist the engineer in making decisions on the subject of system grounding by presenting the basic reasons behind the decision for grounding or not grounding and by reviewing general practices and methods used; (2) provide the basic objectives, fundamental concepts, and current practices for equipment grounding; (3) cover static electricity, its generation, methods of safeguarding, and lightning-protection grounding; (4) the earth connection and its design; and (5) electronic equipment grounding.

The course materials are based entirely on the “IEEE Recommended Practice for Grounding of Industrial and Commercial Power Systems”, IEEE Std. 142-2007. It will be necessary for the student to obtain a copy of or have access to a copy of IEEE Std. 142-2007 “IEEE Recommended Practice for Grounding of Industrial and Commercial Power Systems”. This standard is a very useful resource and is recommended that all practicing electrical engineers involved in power system engineering and design should be familiar with and utilize this standard.

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

Learning Objective

At the conclusion of this course, the student will:

Understand some of the fundamental considerations for grounding of electrical systems;
Understand the regulations pertaining to system and equipment grounding applicable to industrial, commercial, and special occupancy facilities contained in the National Electric Code (NEC);
Be familiar with the terminology of system and equipment grounding;
Understand the purpose of system grounding;
Be familiar with the methods of system neutral grounding;
Understand the advantages attributed to ungrounded systems;
Understand the advantages attributed to grounded systems;
Know the reasons for limiting the ground fault current by resistance grounding;
Know the different classes of resistance grounding;
Know when to apply grounding transformers;
Be familiar with how to rate a three-phase grounding transformer;
Understand the advantages and disadvantages of the corner of the delta grounding system;
Understand the advantages and disadvantages of a grounding system that is one phase of a delta system grounded at midpoint;
Understand the need for locating the ground point at the power source;
Understand the methods used for system ground when there are multiple power sources;
Understand the methods used to minimize stray currents and potential in power systems;
Understand the importance and requirements for location of grounding connections in power systems;
Understand the methods used to avoid common-mode noise;
Understand how to limit transferred earth potentials;
Know the methods used for grounding industrial generators;
Understand the various configurations used and the recommended practices for grounding of an Uninterruptible Power System (UPS);
Know the correct configuration for grounding of an autotransformer in a power system;
Be familiar with the recommended practices for grounding a wye-wye transformer;
Know the basic objectives of an equipment grounding system;
Understand the fundamentals concepts for equipment grounding;
Understand the importance of location for surge arrestors and surge protective capacitors;
Know the differences between an electrical system ground and earth;
Be familiar with the design of earthing connections;
Understand the purpose of static grounding;
Be familiar with the fundamental causes of static electricity;
Know the instruments and devices used in measurements and detection of static electricity;
Be familiar with the methods of static control;
Understand the nature of lightning;
Be familiar with lightning protection principles;
Understand the nature of grounding resistance;
Know the recommended acceptable values for system ground resistance;
Be familiar with the methods used to calculate resistance to earth;
Understand the current-loading capacity for a connection to earth;
Be familiar with the methods and techniques of grounding system construction;
Be familiar with the methods for measuring resistance to earth;
Recognize the importance of properly grounding electronic equipment;
Understand the terminology used for grounding of electronic equipment;
Understand when and how to use an insulated grounding conductor;
Know the recommended methods for power distribution to a computer system;
Be familiar with the practice of grounding of signal wire shields; and
Be familiar with the method used to eliminate problems from radio frequency interference at computer installations.

Intended Audience

The intended audience is professional electrical engineers, project managers, and project engineers, involved in the analysis, engineering, and design of industrial and commercial power systems.

Benefit to Attendees

The course material provides a better understanding of the recommended practices and methods involved in the grounding of industrial and commercial power systems. The course material can be used as a reference source during the detail design of electrical power distribution at industrial and commercial facilities.

Course Introduction

This course provides for the study of recommended practices for grounding of electrical systems and the several methods and criteria that exist for power system grounding. The course is intended to (1) assist the engineer in making decisions on the subject of system grounding by presenting the basic reasons behind the decision for grounding or not grounding and by reviewing general practices and methods used; (2) provide the basic objectives, fundamental concepts, and current practices for equipment grounding; (3) cover static electricity, its generation, methods of safeguarding, and lightning-protection grounding; (4) the earth connection and its design; and (5) sensitive electronic equipment grounding.

Course Content

The course materials are based entirely on the “IEEE Recommended Practice for Grounding of Industrial and Commercial Power Systems”, IEEE Std. 142-2007. It will be necessary for the student to obtain a copy of or have access to a copy of IEEE Std. 142-2007 “IEEE Recommended Practice for Grounding of Industrial and Commercial Power Systems”. The recommended practice, commonly known as the “IEEE Green Book” is intended as a practical guide for engineers and designers that are responsible for the design of grounding systems in industrial and commercial facilities.

The IEEE Green Book is a useful reference tool that every practicing electrical engineering should have access to.

The “IEEE Recommended Practice for Grounding of Industrial and Commercial Power Systems”, IEEE Std. 142-2007 can be purchased from the following websites:

http://shop.ieee.com/
http://www.global.ihs.com/

IEEE Recommended Practice for Grounding of Industrial and Commercial Power Systems

IEEE Std. 142-1991

Chapter 1 – System Grounding
Chapter 2 – Equipment Grounding
Chapter 3 – Static and Lightning Protection Grounding
Chapter 4 – Connection to Earth
Chapter 5 – Electronic Equipment Grounding

Course Summary

The course materials are based entirely on selected chapters within the “IEEE Recommended Practice for Grounding of Industrial and Commercial Power Systems”, IEEE Std. 142-2007. It will be necessary for the student to obtain a copy of or have access to a copy of IEEE Std. 142-2007 “IEEE Recommended Practice for Grounding of Industrial and Commercial Power Systems”. This standard is a very useful resource and is recommended that all practicing electrical engineers involved in power system engineering and design should be familiar with and utilize this standard.

Related Links

For additional technical information related to this subject, please visit the following websites or web pages:

http://www.ansi.com/
http://www.ieee.com/
http://www.nfpa.com
http://www.nema.com

Quiz

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

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.

IEEE Recommended Practice for Grounding of Industrial and Commercial Power Systems

IEEE Std. 142-1991

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