This article isnt a preferred design specification. If you apply basic physics and basic electrical theory, you can clearly see article 250 is right and equipment manuals that require isolated grounding are wrong and other references agree. Also, ieee 142 describes the correct way to provide an isolated ground and it isnt the method proposed by many. We could easily address 10 more top tips for article 250. The external grounding earthing electrode system may consist of, but is not limited to, the following components, shown in figure 44. Recommended practice for powering and grounding sensitive electronic equipment. International association of electrical inspectors. For commercial and industrial substations the recommended ground resistance is 25 ohms or less. The interconnection and grounding of the nonelectrical metallic elements of a system is covered first.
I already know about soares book on grounding and ieee 142 they are on order. This is a discussion of the basic principles behind grounding systems and how grounding is related to safety and. International association of electrical inspectors, 1980. The overlap increases the net resistance of each rod, making the grounding electrode system less effective than if the rods were spaced farther apart. Feb 12, 2018 for reference, see ieee 142 and soares book on grounding. Soares book on grounding download ebook pdf, epub, tuebl.
This book is a revision of ieee std 142 1991, the ieee green book. Ieee emerald book, standard 11001999 or latest edition, ieee, new york, ny. Ok, i seem to always work in an area i havent before. Recognized as an american national standard ansi ieee std 1421991 revision. Ive been using soares book on grounding for 15 years.
When you ground, you connect something to the earth you can read more about this distinction in the ieee 142, the green book and in the national electrical code, article 250 and in other sources. Ground plates shall be free of paint or other nonconductive coatings. The problems of system grounding, that is, connection to ground of neutral, of the corner of the delta, or of the midtap of one phase, are covered. Soares has long been the grounding standard for field people in the electrical industry, while ieee 142 has long been the grounding standard for electrical engineers. Ieee 142 and soares book on grounding use the same physics and electrical theory as article 250. Soares book on grounding and bonding 9th edition book. Soares grounding electrical distribution systems for safety. Electrical inspectors publication, soares book on grounding and bonding. Ieee recommended practice for equipment grounding and. Ieee std 142 2007 revision of ieee std 142 1991 ieee recommended practice for grounding of industrial and commercial power systems sponsor power systems engineering committee of the ieee industry applications society approved 7 june 2007 ieee sa standards board. According to the ieee green book 3, the grounding electrode resistance of large electrical substations should be 1 ohm or less. Ieee 142 and soares book on groundinguse the same physics and electrical theory as article 250. Nor is the ieee undertaking to perform any duty owed by any other person or entity to another.
Ieee recommended practice for grounding of industrial and. The color book set is composed of volumes as follows. Ok, i seem to always work in an are electric power. Soares book on grounding and bonding, th edition nec 2017.
Any person utilizing this, and any other ieee standards document, should rely. As with the rest of the nec, it serves the purpose stated in article 90 to be sure the installation is,and remains,safe. Some refer to ground as a common reference point within the electrical system or as 1 ieee std 142 2007 ieee green book the return path for current flow to operate the. Two good sources for more information on this are soares book on groundingand ieee 142. Ground plates shall be free of paint or other nonconductive coatings nfpa.
To ground handbook and the international association of. Soares book on grounding and bonding, th edition nec 2017 international association of electrical inspectors, kathryn p. Soares contains some examples of maximum lengths as a function of. Its an easy read that is written for learning and understanding, not just a reference like nfpa 70 nec code book. Grounding is a present tense word grounding indicates a process that is ongoing grounding is an action required at enclosures and equipment in electrical circuits from the source or service to the final outlets on the circuit it is accomplished by using an equipment grounding conductor of any type specified in 250.
It reflects the experience and sound judgment of a working group made up of engineers active in the design and operation of electrical. Ieee guide for safety in ac substation grounding ieee std. Since grounding bonding is such a big part of power quality, i get a new book every 3 years. May 02, 2017 soares book on grounding and bonding, th edition nec 2017 international association of electrical inspectors, kathryn p. Groundingandbonding nationalelectricalcode article250 byjim. Soares book on grounding and bonding, th edition nec. Ieee std 1421991, also known as the ieee green book, covers some of the practical aspects of grounding, such as equipment grounding. This is followed by a discussion of the objectives of equipment grounding and bonding, including minimizing electric shock hazard to personnel, providing. An abbreviated bibliography of power quality information sources. In publishing and making this document available, the ieee is not suggesting or rendering professional or other services for, or on behalf of, any person or entity. Pdf ieee standard 1421991 the green book vicente martinez.
Soares book on grounding and bonding 9th edition by. While this approach greatly limits damage to the machine, it can produce high transient overvoltages during faults and also makes it difficult to locate the fault. This site is like a library, use search box in the widget to get ebook that you want. Ground earth resistance in low voltage grounding electrode system in an industrial or commercial installation with systems operating less than 600 volts. When you consider that soares is a product of the international association of electrical inspectors, this division of labor makes sense. Not only does this book explain how and why certain grounding methods are used, but it does so in a logical way, balancing text with photos and illustrations. Facility and equipment grounding to enhance equipment. The grounding and bonding of equipment in industrial and commercial power systems is covered in this recommended practice. Eustace soares book, grounding electrical distribution systems for safety was originally published in 1966 and was based upon the 1965 edition of the national electrical code. This, however, is exactly what iaei has achieved with this edition of soares. Information is given on how to ground the system, where the system should be grounded, and how to select equipment for the ground of the neutral circuits. Ansiieee standard 142, recommended practice for grounding of industrial and commercial power systems green book and soares book on grounding use the same physics and electrical theory as art. Red book ieee std 1411993 r1999, recommended practice for the electric power distribution for industrial plants.
Principles of electrical grounding pfeiffer engineering. Temporary grounding and bonding techniques safe practice guide ihsa. For power quality concerns this assumption leaves the grounding resistance to chance. Ieee recommended practice for powering and grounding. Ieee142 and soares book on grounding use the same physics and electrical theory as article 250. Inspectors iaei soares book on grounding are recommended see access. So when you think of grounding, you could think of it as earthing to keep things straight in your mind. The iaei book even gives some of the history of grounding requirements in the u. The problems of system grounding, that is, connection to ground of. Grounding electrical distribution systems for safety. This low resistance is required due to the high potential to earth of the electrical system. If you want to learn about grounding and bonding, this is the book. Principles of electrical grounding john pfeiffer, p. The grounding and bonding requirements contained in this column apply to solidly grounded.
Ieee std 1422007 revision of ieee std 1421991 ieee. This recommended practice has served electrical engineers seeking electrical system grounding information since the first edition in 1956. Grounding versus bonding part 1 of 12 mike holt enterprises. Ieee142 and soares book on grounding use the same physics and. Soares book on grounding, international association.
In this th edition of soares text, through the use of examples and detailed illustrations, iaei has again tried to set forth clearly the theory and practice of grounding and bonding, allowing you to have tools to better master the subject. This is a discussion of the basic principles behind grounding systems and how grounding is related to safety and the effective operation of circuit protection devices such as fuses and circuit breakers. That process has been ongoing with each successive code cycle. Click download or read online button to get soares book on grounding book now. This book is a revision of ieee std 1421991, the ieee green book. Green book ieee std 142 2007, recommended practice for grounding of industrial and commercial power systems. B61 the iaei soares book on grounding, 4th edition. Soares book on grounding and bonding, 2014 explains how and why certain grounding methods are used, but it does so in a logical way, balancing text with photos and illustrations. Data for guessworkfree design of high resistance grounded systems, ieee.