View this email as a Web page Please add Code Watch to your Safe Sender list.

May 29, 2007 A Penton Media Publication Vol. V No. 10

Cast Your Vote Now!

250.142 Use of Grounded Neutral Conductor for Equipment Grounding (Bonding)

What's Wrong Here?

Code Q&A

Code Quiz

EC&M Code Change Conferences

Let's Go Racing! Win a Free Road America Race Weekend for Two

About this Newsletter
This twice-a-month
e-newsletter is brought to you from the publisher of EC&M magazine.

CodeWatch will:

  • Let you know what could be changing in the Code®.
  • Help you brush up on your ability to apply the Code®.
  • Test your knowledge of the Code® with a Q&A format.
  • Provide information on upcoming Code® seminars and shows.
  • Give you an opportunity to sound off on Code®-related issues.

    We want to make sure we're providing you with the content you need to better manage your business or enhance your technical skills. E-mail us and let us know what you want to see in future issues of this e-newsletter. We will do our best to address your request in a future issue of CodeWatch.

  • Subscriptions
    To unsubscribe from this newsletter go to: Unsubscribe

    To subscribe to this newsletter, go to: Subscribe

    To get this newsletter in a different format (Text or HTML), or to change your e-mail address, please visit your profile page to change your delivery preferences.

    Back Issues
    Missed an issue? Visit the CodeWatch archive on EC&M's Web site.

    Tell a friend about CodeWatch
    Do you know of someone who'd like to receive CodeWatch? Visit the subscriber site, enter their e-mail address and spread the wealth!

    To find out how to advertise in this newsletter, e-mail David Miller or call him at (312) 840-8487.

    The designations "National Electrical Code” and “NEC” refer to the National Electrical Code®, which is a registered trademark of the National Fire Protection Association.




    EC&M Product of the Year Competition
    Cast Your Vote Now!
    Do you want the opportunity to win $100? Then visit the EC&M Web site by June 22 to cast your vote in EC&M's Product of the Year competition and help us identify the best new product introduced to the electrical industry in 2006.

    When you visit the EC&M Web site, an automatic poll will pop up. (Note: If you have a pop-up blocker program, it may prevent you from seeing the poll. Temporarily disable the program to allow the poll to appear on your computer.) You then need to type in your contact information, choose your favorite product, and click submit. It's that simple. For additional information on each category winner, click on the product name in the pop-up poll window and it will bring you to a page that features product summaries for all 24 category winners.

    A panel of seven judges initially narrowed the field from 108 entrants down to 24 category winners, and now we need your help to determine the Platinum, Gold, and Silver Award winners. The competition has honored innovation and excellence in product development in the electrical industry for the past seven years.

    Fluke 117 Electrician's Multimeter with Non-Contact voltage. Designed by electricians. Engineered by Fluke.
    Compact true-rms meter for commercial applications. The Fluke 117 is the ideal meter for demanding settings like commercial buildings, hospitals and schools. The 117 includes integrated non-contact voltage detection to help get the job done faster. For more information, click here.

    Top 50 NEC Rules

    250.142 Use of Grounded Neutral Conductor for Equipment Grounding (Bonding)

    By Mike Holt
    To remove dangerous voltage on metal parts from a ground fault, the metal parts of electrical raceways, cables, enclosures, and equipment must be bonded to an effective ground-fault current path in accordance with 250.4(A)(3).

    Supply side of service equipment. A grounded neutral conductor can be used as the effective ground-fault current path for metal parts of equipment, raceways, and other enclosures. Because an equipment grounding (bonding) conductor isn't run from the utility to electrical services, the grounded neutral service conductor can serve as the effective ground-fault current path to the utility power source. The effective ground-fault current path for service equipment is provided by the installation of the main bonding jumper at service equipment in accordance with 250.24(B) [250.28].

    Where no equipment grounding (bonding) conductor is run to a separate building or structure disconnect, the grounded neutral conductor can serve as the effective ground-fault current path to the source. This is accomplished by bonding the grounded neutral conductor to the equipment grounding (bonding) conductor at the separate building or structure building disconnecting means in accordance with 250.32(B)(2).

    Caution: Using the grounded neutral conductor as effective ground-fault current path poses potentially dangerous consequences and should only be done after careful consideration. The safest practice is to install an equipment grounding (bonding) conductor with the feeder conductors to the building or structure to serve as the effective ground-fault current path, as provided by 250.32(B)(1).

    On a separately derived system, the effective ground-fault current path is established when the system bonding jumper is installed between the metal enclosure of the separately derived system and the grounded neutral terminal in accordance with 250.30(A)(1). Failure to install the system bonding jumper as required by 250.30(A)(1) will create a condition where dangerous touch voltage from a ground fault will remain on the metal parts of electrical equipment.

    Load side equipment. To prevent dangerous voltage on metal parts, the grounded neutral conductor must not be bonded to the equipment grounding (bonding) conductor on the load side of service equipment, except as permitted by 250.142(A).

    Exception No. 1: The grounded neutral conductor can serve as the effective ground-fault current path for existing ranges, dryers, and ovens [250.140 Ex].

    Exception No. 2: The grounded neutral conductor can be bonded to the meter enclosure on the load side of the service disconnecting means if:

    1. No service ground-fault protection is installed,
    2. Meter enclosures are located immediately adjacent to the service disconnecting means, and
    3. The grounded neutral conductor is sized no smaller than specified in Table 250.122.

    Editor's note: This information was extracted from Mike Holt's textbook, Understanding the National Electrical Code

    Need help defining the parameters of your facility's next Arc Flash Hazard Evaluation? ESA's electrical engineers have written a detailed, customizable specification to help you determine what you need for your study. This Arc Flash tool is provided in a Word document that can be easily updated with your facility's unique requirements. Request your Free Arc Flash Study Specification:

    Code Challenge
    What's Wrong Here?
    By Joe Tedesco
    Think you know how this installation violates the NEC?

    Visit EC&M's Web site to see the answer.
    Hint: Power in a pinch

    Code Q&A
    By Mike Holt
    Q. Can I install conductors from different panels in the same raceway?

    Visit EC&M's Web site to see the answer.

    Code Quiz
    By Steven Owen
    Q. What is the minimum size and metal thickness required for a junction box constructed of sheet steel, with one 4-inch RMC conduit (per wall) connected on opposite walls of the box (i.e., directly across from one another)? The conductors within the raceways are 600kcmil type XHHW. The outer diameter (O.D.) of each of these insulated conductors is 1.2 inches.

    1. 24 inch by 24 inch. There is no requirement for metal thickness.
    2. 32 inch by 24 inch. Metal thickness = 1.35 millimeters (0.053 inches).
    3. 32 inch by 32 inch. Metal thickness = 1.35 millimeters (0.053 inches).
    4. 43.2 inches by 43.2 inches. Metal thickness = 1.35 millimeters (0.053 inches).

    Visit EC&M's Web site for the answer and explanation.

    Cool Electronic Cabinets
    Summer will be here soon! Prevent hot weather failures. EXAIR Cabinet Coolers are the low cost way to purge and cool electronic controls with 20 degree Fahrenheit air. All models are UL Listed and maintain the NEMA 4, 4X or 12 rating of the enclosure. Many cooling capacities are available. Web site offers detailed information, downloadable drawings and PDF literature. EXAIR Corporation

    Shows and Events
    EC&M Code Change Conferences
    Where do you turn when you need accurate information on changes to the National Electrical Code? Acknowledged as the leaders in providing information on the NEC, EC&M magazine and EC&M Seminars have been the preferred sources of this information for more than 60 years. Seven Code change conferences have been scheduled in the fall of 2007. Host cities include: Atlanta, Boston, Dallas, Orlando, Philadelphia, St. Louis, and Seattle.

    As an approved provider with the National Council of Examiners for Engineering and Surveying (NCEES), through its Registered Continuing Education provider Program (RCEPP), professional engineers attending any of our 2008 Code change conferences will receive Professional Development Hours (PDHs), a requirement for re-licensing in many states. The conferences are also approved by every state that has a continuing education requirement for contractors and electricians.

    For additional information on the dates and locations of these events, click here.

    Let's Go Racing! Win a Free Road America Race Weekend for Two
    EC&M magazine and Generac Power Systems have teamed up to offer an expenses-paid weekend (August 10-12, 2007) featuring two of the world's fastest racing series. The third annual Generac Power Weekend is one thrilling day of American LeMans series racing (the Generac 500) and an equally exciting day of Champ Car racing at its finest (the Generac Grand Prix). It's your chance to see both series compete in a single weekend at one of North America's most beautiful tracks. Located in the hilly heart of Wisconsin's scenic Kettle Moraine area, Road America is a four-mile permanent road course that tests drivers with 14 challenging turns.

    Enter by July 10, 2007. Visit the Generac Power Systems virtual booth at the EC&M E-Tradeshow. Full contest rules are available online in the Generac E-Tradeshow booth. For more information about the Generac Power Weekend, go to

    You are subscribed to this newsletter as #email#

    For questions concerning delivery of this newsletter, please contact our Customer Service Department at:
    Customer Service Department
    A Penton Media publication
    US Toll Free: 866-505-7173
    International: 847-763-9504

    Penton | 1166 Avenue of the Americas, 10th Floor | New York, NY 10036

    Copyright 2014, Penton. All rights reserved. This article is protected by United States copyright and other intellectual property laws and may not be reproduced, rewritten, distributed, re-disseminated, transmitted, displayed, published or broadcast, directly or indirectly, in any medium without the prior written permission of Penton Media, Inc.