Grounding vs Bonding Online Training

This article was posted 12/09/2005 and is most likely outdated.

Grounding vs Bonding: 250.50 Grounding Electrode System

December 9, 2005

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.

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Below is the full course page which includes these videos:

Grounding versus Bonding

PART III. GROUNDING ELECTRODE SYSTEM AND GROUNDING ELECTRODE CONDUCTOR

Page 2 of 14

Sections

250.50 Grounding Electrode System.

All grounding electrodes as described in 250.52(A)(1) through (A)(6) that are present at each building or structure must be bonded together to form the grounding electrode (earthing) system. Figure 250–91

Underground metal water pipe [250.52(A)(1)]
Metal frame of the building or structure [250.52(A)(2)]
Concrete-encased steel [250.52(A)(3)]
Ground ring [250.52(A)(4)]
Ground rod [250.52(A)(5)]
Grounding plate [250.52(A)(6)]

Exception: Concrete-encased electrodes are not required for existing buildings or structures where the conductive steel reinforcing bars aren’t accessible without disturbing the concrete.

Where an underground metal water pipe electrode, metal building or structure frame electrode, or concrete-encased electrode is not present, one or more of the following electrodes specified in 250.52(A)(4) through (A)(7) must be installed to create the grounding electrode (earthing) system. Figure 250–92

Ground rod [250.52(A)(5)]
Grounding plate [250.52(A)(6)]
Metal underground systems [250.52(A)(7)]

Figure 250–91
(Click on image to enlarge)

Figure 250–92
(Click on image to enlarge)

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

Comments

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Ron Gramm
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Reply from: chartchai
Hi All who would win joy, must share it; happiness was born a twin.
Reply to chartchai

In reference to the graphics showing clamped bonding of UFER ground to water pipe and structure, a caveat refering to a continuous #4 copper continuous or to #4 rebar minimum grounding electrode conductor is highly recommended for residential installation per 250.64 (C) Continuous. The residential requirement disqualifies permitted [250.64(C)] (1) through (4) in splicing exceptions where by physical installation, configurations are not applicable in residential conditions. (i.e. Majority of new construction uses cpvc plumbing, thus the UFER ground or one of other [250.52] choices are the primary system electrode that requires a contiuous grounding electrode conductor.) The details in your presentation are misleading to first year and even journey levels who are use to doing only commercial/industrial work. A detailed graphic example can be found in my book 'Residential NM Wiring with Bonding & Grounding'. Pages 98 and 101 give a good example of Grounding Electrode System conditions predominant in residential systems. Please note that the GEC must be a copper conductor to direct burial connections which in most cases will be in the concrete footing. Sincerely, Ben Jacks

ben jacks
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