August 8, 2005 A PRIMEDIA Property Vol. III No. 15

445.18 - Disconnecting Means

Hang Up and Try Again

What's Wrong Here?

Code Q&A

Code Quiz

Potential Problems

Grounding vs Bonding Seminar

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.
  • Introduce you to the people who vote on the rule changes.
  • 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 sign up for your free subscription, click here: Subscribe

    To unsubscribe from this newsletter click here: Unsubscribe

    To get this newsletter in a different format (Text, AOL 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) 840-8497.

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



    Top 2005 Code Changes
    445.18 - Disconnecting Means
    By Mike Holt
    A change to this section permits a single generator to have multiple disconnecting means to allow flexibility and to provide a safer environment when maintenance is necessary. (Note: Code text has been paraphrased.)

    What the Code says:
    Generators must have one or more disconnecting means that disconnects all power, except where:
    (1) The driving means for the generator can be readily shut down, and
    (2) The generator isn't arranged to operate in parallel with another generator or other source of voltage.
    (Text new to the Code is underlined.)

    Behind the change: This rule is necessary because a single generator can be used to supply emergency, legally required, as well as optional standby power through different transfer switches. Be careful -- if one generator is used to supply emergency, legally required, as well as optional standby power, then there must be at least two transfer switches: one for emergency power and another for legally required as well as optional stand-by power [700.6(D)].

    Two Powerful Tools in One: The Fluke 1587 and 1577 Insulation Multimeters combine a digital insulation tester with a full-featured, true-rms digital multimeter in a single compact, handheld unit.

    Nightmare Installations
    Hang Up and Try Again
    A few years ago, while upgrading a 100A service panel located in a residential garage, I noticed what appeared to be two black TW or THW wires about the size of 8 AWG entering the panel without conduit (a not-uncommon practice of do-it-yourselfers). As I removed the incoming wires for the replacement, I found that what I thought were THW wires were actually two very old 2-pair phone cables. The four 20 AWG phone wires in each had been twisted together and connected to a 2-pole, 30A breaker, which fed a garage. Why there had never been a fire, I have no idea. The only load on the circuit was a yard light, but there was evidence that there had been other lights and receptacles connected at one time. Needless to say, all was replaced.
    Roger Roossinck
    Sparta, Mich.

    Send your 200-word story to us and it may appear in a future issue of CodeWatch. Authors of stories chosen will receive $25.

    Cool Electronic Cabinets
    Stop electronic control downtime due to heat, dirt and moisture. UL Listed Cabinet Coolers produce 20 degree Fahrenheit air from an ordinary supply of compressed air to cool electrical controls. Thermostat control minimizes air usage. Maintains the NEMA 4, 4X (stainless steel) and 12 rating of the enclosure. Web site offers detailed information, downloadable drawings and PDF literature.

    Code Challenge
    What's Wrong Here?
    By Joe Tedesco
    Got a guess for how this installation violates the NEC? Visit EC&M's Web site to see the answer.

    Hint: Recycling isn't always a good thing.

    Code Q&A
    By Mike Holt
    Q. What size grounding electrode conductor is required for a 1,200A service supplied with three sets of 600 kcmil conductors per phase?
    Visit EC&M's Web site to see the answer.

    Code Quiz
    By Steven Owen
    What's the minimum size THHN insulated conductor required for the power conversion equipment included as part of an adjustable speed drive system that uses a bypass device. The rated input of the power conversion equipment is 36A. The motor is rated 30 hp, 480VAC, 3-phase. The terminals at the power conversion equipment are rated 75°C.

    1. 10 AWG THHN
    2. 8 AWG THHN
    3. 6 AWG THHN
    4. 4 AWG THHN

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

    The National Electrical Code Internet Connection, the No. 1 rated Code Web site in the world, offers the following FREE products:
    Books, Code Quiz, DVDs, Graphics for PowerPoint, Newsletter, Online Training, Posters, Simulated Exams, Software, Video clips, and Videos
    Visit and stay current with important industry issues.

    Speak Out
    Potential Problems
    As Nightmare Installations shows, there's no shortage of shoddy electrical work. How often do you run across installations with Code violations when you perform service and maintenance work? Visit EC&M's Web site to tell us.

    "Get on with it!" That's what CodeWatch readers are saying about Code-making panels' approach to adding GFCI requirements to the NEC. Although less than one-third said the Code has adequately addressed the need for GFCIs, 40% said it was time to apply an across-the-board requirement for all receptacles.

    Shows and Events
    Grounding vs Bonding Seminar
    Grounding and bonding of electrical systems, sensitive electronic, and communications equipment is the most important and least understood activity in the electrical, data processing, and communications industry. At four two-day seminars, Code expert Mike Holt will explain the basics as well as the advance concepts necessary to understand the practical grounding and bonding rules in the NEC for systems not over 600V. Download the conference brochure for specific dates and locations.

    You are subscribed to this newsletter as <*email*>

    For questions concerning delivery of this newsletter, please contact our Customer Service Department at:
    US Toll Free: (866) 505-7173
    International: (402) 505-7173

    Primedia Business Magazines & Media
    9800 Metcalf Avenue
    Overland Park, KS 66212

    Copyright 2005, PRIMEDIA. 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 Primedia Business Magazines & Media Inc.