This article was posted 11/30/-0001 and is most likely outdated.

Grounding vs Bonding Online Training 11
 

 
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Many of you have completed our Online Continuing Education Courses which include video instruction and know this is a very fast way to obtain your CEU credits from the comfort of the chair you're sitting in. For the rest of you we are sending a weekly series of newsletters featuring an instructional page complete with videos.

To view the videos you will need to download the free Real Player Download Real Player plugin for your browser - if you don't already have it. After installing Real Player, you can view the videos by clicking on one of these icons:

  • Click on this icon Hi Res - Cable/DSL to view the video [ 8MB ]

Below is the full course page which includes these videos:

2002 Changes to the NEC®
PART II   Hi Res - Cable/DSL        Page 1 of 13

Sections

250.20 Systems Required to be Grounded and Bonded

Alternating-current systems (power supplies) must be grounded and bonded as provided in (A), (B), (C), or (D).

Author’s Comment: System grounding, the intentional bonding of the electrical supply source to the metal case, provides the low-impedance fault-current path necessary to clear a ground fault. Figure 250–43

(A) Alternating-Current Systems Below 50V. Alternating-current systems operating below 50V aren’t required to have the system bonded to the metal case unless: Figure 250–44

(1)The primary is supplied from a 277V or 480V circuit.

(2)The primary is supplied from an ungrounded power supply.

(3)Where installed as overhead conductors outside of buildings.

(B) Alternating-Current Systems Over 50V. Alternating-current systems over 50V that require a grounded neutral conductor must have the grounded neutral terminal [250.26] of the power supply bonded to the system metal parts in accordance with 250.30(A)(1). Such systems include: Figure 250–45

  • 2- or 3-wire, single-phase 120V or 120/240V systems
  • 4-wire, three-phase wye-connected 120/208V or 277/480V systems
  • 4-wire, three-phase delta-connected 120/240V
    systems


Figure 250–43
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Figure 250–44
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Figure 250–45
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04. Grounding versus Bonding Library - DVDs
Grounding and bonding problems are at epidemic levels. Surveys repeatedly show a high percentage of power quality problems are due to poor grounding and bonding. Electrical theory has been applied to this difficult to understand Article, making it easier for students to grasp the concepts of grounding and bonding. Additionally, Mike has color coded the graphics so you can easily differentiate between grounding and bonding. For a limited time, you can order the Entire Grounding versus Bonding Library including the textbook, 2 videos, MP3 Audio CD and the Online Program for this great price. You save over $200!

Product Code: 05GBDVD
ISBN: N/A
MultiMedia: Tape & CDROM & DVD

DVD/CD Return Policy: Unopened sealed DVD's or CD's may be returned within 10 days and we will credit your credit card or issue a refund for the price of the item(s). Opened items may not be returned unless they arrive defective.
Table of Contents
Sample Pages
Sample Graphic

Copyright © 2005 Mike Holt Enterprises,Inc.
1-888-NEC-CODE (1-888-632-2633)

 

Comments

  • I think it's Great The time and efort you put into this. Thank you Very much. A Lot of good info.

    J.A. Johnson Electric
    Reply to this comment

  • Mike I finally had a chance to look at your illustration on bonding and grounding systems. It's been a great help to me in the field. Mike if it's possible could you send to me illustrations on the relationship between compactance reactance, conductance, resistance and reluctance.


    Reply to this comment

  • I wish you would keep the window,s 95 format I don,t have a computer with that newer format so I can,t view the updates verry disapointing .. Tim Hales

    Tim Hales
    Reply to this comment

  • Mike! could you e-mail me some illustrations on primary voltages to transformer, I need to see the hook-up. I need to see from 2160 to 3 phaze delta and wye hook-up. I also need to see calculations on how many motors to put on a service ETC.

    Thanks for the information

    Floyd Mack of Wamba Remodeling Electrical Contractor.

    Floyd H. Mack
    Reply to this comment

  • Thanks for all the good info and graphics - keep up the good work

    Sonny Grooms
    Reply to this comment

  • Mike, I bought your book "Grounding vs Bonding". I have a small group of Electrical Designers here at the office, and we have all used it as a reference in our latest designs. It has been a real eye opener for us!

    Thanks

    Claude Lee Mcwhorter
    Reply to this comment

  • Mike, I bought your book "Grounding vs Bonding". I have a small group of Electrical Designers here at the office, and we have all used it as a reference in our latest designs. It has been a real eye opener for us!

    Thanks

    Claude Lee Mcwhorter
    Reply to this comment

  • Your new site is great. there is a lot of helpful information here that will help everone. Wally

    wally kammer
    Reply to this comment

  • I appreciate all the useful information you have shared with me in the past.

    Thanks again, Tom Quesada


    Reply to this comment

  • This is a fine tool for research. I am a professional plans examiner and often have to try to explain the reason for certain comments I make concerning electrical on plans. This is a fast and easy way to find information in laymans terms that I might use in my arguments.

    Keep up the good work

    Thank you

    Boyd Davis

    Boyd Davis
    Reply to this comment

  • On the last diagram bottom right the 4 wire 3 phase 120/240 volt.

    Wouldn't the voltage between neutral and high leg be 360 volts not 208?

    Dan
    Reply to this comment

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