December 22, 2005 A Prism Business Media Property Vol. III No. 24

CONTENTS
Article 820 -- Community Antenna Television and Radio Distribution Systems
Part VI. Listing Requirements
820.182 CATV Raceways

The Mysterious Blinking Christmas Tree

What's Wrong Here?

Code Q&A

Code Quiz


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!


    Advertising
    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.
     
    ADVERTISEMENT

    ADVERTISEMENT
    Top 2005 Code Changes
    Article 820 -- Community Antenna Television and Radio Distribution Systems
    Part VI. Listing Requirements
    820.182 CATV Raceways
    By Mike Holt
    New subsections added to recognize the use of raceways designed for coaxial cables. (Note: Code text has been paraphrased.)

    What the Code says:
    (A) Plenum Coaxial Raceways. Plenum-rated raceways for coaxial cables must be listed as being suitable for use in ducts, plenums, or other environmental air spaces.     (Text new to the Code is underlined.)

    Behind the change: Where used in ducts, plenums, or other environmental air spaces, listed plenum communications raceway can only contain Type CATVP cable [820.179(A)].

    What the Code says:
    (B) Riser Coaxial Raceway. Riser rated raceways for coaxial cables must be listed as being suitable to be run vertically through more than one floor.

    Behind the change: Listed riser-rated coaxial raceways run vertically and penetrating more than one floor can only contain CATVR and CATVP cables [820.179(B)].

    ADVERTISEMENT
    Achieve Your
    Performance Goals
    Anticipate, prevent and troubleshoot motors, electrical and equipment maintenance with fast, accurate non-contact temperature measurements with Fluke infrared thermometers. www.fluke.com/codewatch_temp

    Nightmare Installations
    The Mysterious Blinking Christmas Tree
    I received a residential trouble call from a new customer whose Christmas tree lights would just come on and go off by themselves. The lights were plugged into a receptacle at the bottom of their spiral staircase.

    After finding no problems in the receptacle wiring of the branch circuit serving the tree (the lights were off at this time), I decided to check other receptacles in the area for power. Finding no problems, I went back to the tree, and the lights were now on. However, they quickly went off. I thought that plugging the tester into the receptacles might have helped make the circuit so I did it one receptacle at a time. Finally, after checking the receptacles in the master bathroom the tree lights were working again. But they soon went out! Naturally, I thought the wiring problem was somewhere in the bathroom and proceeded to take out the switches and receptacles one at a time.

    After checking all the connections, I finally found a motion sensor in the master bathroom walk-in closet that controlled a light fixture (which was located partially under the staircase). The load side of the sensor was not only wired to serve the light in the closet but it also fed the receptacle where the tree was plugged in. Every time someone would walk to the closet, the tree lights would come on for a limited time, and then automatically turn off. Since this was such a large house nobody could relate the two occurrences.

    M. Vince Brewer
    Frisco Electric, Inc.

    ADVERTISEMENT
    Cool Electronic Cabinets
    Low-cost Cabinet Coolers 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.
    www.exair.com/15/540_12b.htm

    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: Too much of a good thing.
    Code Q&A

    By Mike Holt

    Q. What are the NEC grounding requirements for a satellite dish?

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

    By Steven Owen

    Q. What is the minimum circuit ampacity and minimum size conductor required for the feeder conductors supplying the following group of electric arc welders?

    • one each -- 80A rated, non-motor generator, 100% duty cycle.
    • one each -- 70A rated, motor generator, 90% duty cycle.
    • one each -- 60A rated, non-motor generator, 70 % duty cycle.
    • one each -- 50A rated, non-motor generator, 80% duty cycle.
    • four each -- 40A rated, motor generator, 60% duty cycle.
    • four each -- 25A rated, non-motor generator, 40% duty cycle.
    Terminals at the feeder overcurrent device and in the welder disconnects are rated 75°C. The feeder consists of one conductor per phase, which is specified as THHN insulated, dry location.

    A) 350 kcmil THHN
    B) 400 kcmil THHN
    C) 500 kcmil THHN
    D) 600 kcmil THHN

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

    ADVERTISEMENT
    www.NECcode.com
    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 www.NECcode.com and stay current with important industry issues.

    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
    or custserv@newsletter.primediabusiness.com

    Prism Business Media
    9800 Metcalf Avenue
    Overland Park, KS 66212

    Copyright 2005, Prism Business Media. 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 Prism Business Media