Style manual as a standard term, meaning failure of insulation on. This 2hour interactive online course is intended to familiarize the reader with some of the major changes contained in the 2008 nec, and is suitable for anyone exposed to the nec at any level. Electrical system grounding that is connected to earth will limit the voltage imposed by which of the following. I cant recall the section title in the nec which covers grounding conductors, but there should be a section devoted to this subject. Bond all metal raceways and enclosures that contain or support service conductors 250. Free online access to the nec and other electrical standards. Michael casey is a partner with casey, omalley associates. Includes a cdrom with an interactive study center that helps you retain what youve learned, and study for the electricians exam. In this latest code cycle, the code making panels cmps sifted through 3,688 change proposals. The format and language used in this code follows guidelines established by nfpa and published in the nec.
Also i have always been under the impression that is a grounding source is present that you are required to run a grounding conductor to it. Metal frame of the building or structure where the following methods are used to make an earth connection. National electrical code 2008 fasttabs for softcover, looseleaf and handbook by building tech boo. National electrical code 2008 handbook download pdfepub. Soares book on grounding and bonding, nec2008 international association of electrical inspectors, james w. It was issued by the standards council on july 26, 2007, with an effective date of august. Women and children are sensitive to values as low as threefourths that amount. In this article, we will take a closer look at these changes and. Hence, some of the key definitions of wiring and grounding terms from the 2002 national electrical code nec include ground. Grounding electrode system utility transformer service conductor service disconnect feeder branch circuit subpanel main bonding jumper 250. Since grounding conductors are meant to only carry fault current theres no need to fill the conduit with extra ground wires.
Nec states that the resistance to ground shall not exceed 25 ohms. You have reached 0 of 0 points, 0 not categorized 0% question 1 of 15. Article 250 covers the grounding requirements for providing a path to the earth to reduce overvoltage from lightning, and the bonding requirements for a lowimpedance fault current path back to the source of the electrical supply to facilitate the opera. A homes electrical service equipment is a critical component of the homes. Afci protection requirement in 2008 nec afci breaker. Best recommended consulting and inspector training firm based in san diego. National electrical code 2008 handbook download pdf. All mechanical elements used to terminate a grounding electrode conductor or bonding jumper to a grounding electrode shall be accessible. National electrical code 2008 edition this edition of nfpa 70, national electrical code, was prepared by the national electrical code committee and acted on by nfpa at its june association technical meeting held june 37, 2007, in boston, ma. Interestingly, the nec requires raceways and enclosures that contain feeder or branch conductors to connect to the circuit equipment grounding conductor 250. Metal parts of electrical raceways, cables, enclosures, or equipment must be bonded together and to the supply source in a manner that creates a lowimpedance path. This is the conductive object that makes the connection to the planet. There are many other general rules, such as sizing of conductors, overcurrent protection, grounding of equipment and motor applications in chapters 14.
Within the building main electrical room, install a copper bus bar, 14 by 4 inches of sufficient length two feet minimum to act as the grounding electrode system termination point for. Completely revised and updated to reflect all 2008 code changes, mcgrawhills national electrical code 2008 handbook, 26th edition provides the essential putthecodeintopractice guidance that users require in the field and in the office. Plus, a reference table that illustrates not only what types. Instead of afci breaker, combination type arc fault circuit interrupter is now required, and this is not a gfci afci protection combination. Gain a firm understanding of the national electrical code and how it applies to grounding and bonding techniques with the 2008 edition of stallcups electrical grounding and bonding simplified. Nfpa delivers free online access to all nfpa standards to enhance public safety and to serve the publics increasing interest in technical information. In the field, this meant an inspector had to have some. Agricultural wiring materials and electric code update.
Pdf download national electrical code 2008 handbook. Verify equipment is listed and installed in accordance with manufacturers installation instructions 90. Electrical grounding and bonding download ebook pdf, epub. Connects directly to the grounding electrode with a layin style lug. Impedance to earth from the nearby signal light pole measured. Verify which wiring method is used and it is listed for the. Article 250 grounding and bonding mike holt enterprises. This bond is in addition to any other bonding requirements as specified by local code. Integrated mounting holes provide quick, easy and compact. When the word ground is mentioned, people normally think of a connection to a water pipe or ground rod. Significant changes for the nec 2008 electrical contractor. Not only does it have to be sized properly to carry the electrical load, but it has to be installed properly. Whenever grounding conditions appear questionable, dont guess and dont take chances. Its hard to believe its that time again, but the 2008 nec is upon us.
Groundingandbonding nationalelectricalcode article250 byjim. Now, the 2014 nec allows one conductor to serve both purposes as long as it does not carry any objectionable current in accordance with 250. There were 3,688 proposals for changes to the national electrical code nec and 2,349 comments processed by the national fire protection association nfpa staff at its headquarters in quincy, mass. There were special requirements in article 547 for grounding of submersible pump motors. Electrical grounding and bonding download ebook pdf. This video was extracted from mike holts understanding the national electrical code volume 1. Connected connecting to ground or to a conductive body that extends the ground connection. One item to note is a change made in the 2011 edition of the nec for 250. April 24, 2008 2008 nec article 100 bonded bonding. Jun 02, 2014 this free pdf contains the scope, definition, application of other articles, and general requirements for grounding and bonding. This grounding method must be approved by purdue on a case by case basis. Soares book on grounding and bonding, th edition nec 2017. Nec study guide according to the nec, the maximum distance from the point of entrance to the building that the water pipe may be used as a grounding electrode interconnect is. A minimum 58 inch x 10 foot approved copper plated rod copper weld type or approved equal has been installed a minimum 9 feet into the ground for each.
Grounding electrode system and grounding electrode conductor part iii znec 250. Determine which installations or portions of the installations are covered by nec rules 90. Every subject is referenced to the 2008 national electrical code, and there are 21 pages of the most needed nec tables to help your wiring pass inspection the first time. Others were more significant, such as new articles, sections, exceptions, and fine print notes. Nec grounding heres a good document pdf file that talks about the testing procedure and other aspects of ground resistance testing. Nfpa 70, national electrical code nfpa 70b, recommended practice for electrical equipment maintenance.
Grounding electrodes recognized in the nec are provided in 250. Groundingandbonding nationalelectricalcode article250 by. Pay careful attention to the definitions that apply to grounding and bonding both here and in article 100 as you begin the study of this important article. A significant change occurred in the 2008 national electrical code nec at section 250. Based on the 2008 nec, this handson guide illustrates code provisions concerning circuit and system grounding. Grounding nec 250 grounding is provided as a safety precaution.
Mike holts illustrated guide to grounding versus bonding 2008 edition wanswer key by mike holt. Table 250 102 c 1 grounded conductor main bonding jumper table 250 102 c 1 grounded conductor main bonding jumper pdf nec 2008 table 250 122 minimum size equipment grounding grounding and bonding 2017 nec. Part a covers separately derived systems where the neutral or grounded conductor. Grounding electrode conductor and bonding jumper connection to grounding electrodes. Two buildings common service, grounding requirements. Use and understanding of defined grounding and bonding terms help in proper application of nec rules. Part 1 appeared in the july 2007 issue of electrical contractor, and part 2 appeared in the october 2007 issue. Nfpa 70e, standard for electrical safety in the workplace. For sizing any bond conductor required on the load side of fuses or circuit breakers. Understanding ground resistance testing a quote from this document pg. The national electrical code has been extensively revised for 2008, and contains a lot of new information to digest. Connected to establish electrical continuity and conductivity.
Significant changes for the 2008 nec part 3 electrical. Nevertheless, it is not a guarantee that no electrical shock will occur. In addition, all of the homes branch circuits and feeders. Bondinggrounding clamps listed to ul 467 comply with this requirement. This video was extracted from mike holts understanding the national electrical code volume 1, based on the 2008 nec. Some of the resulting changes were minor editorial revisions. A homes electrical service equipment is a critical component of the homes electrical wiring system. Terminates utility grounding conductors such as power, telephones, cable, etc. Electrical grounding and bonding written in accordance with the 2008 national electrical code, this new book provides readers with a comprehensive introduction to the essential elements of electrical grounding and bonding.
1150 1504 81 532 1492 1204 294 113 652 77 1468 257 580 902 1491 1465 467 397 1394 1367 1308 551 1444 1024 724 1396 1092 1217 838 1489 1003 875 865 1371 117