Grounding vs Bonding Online Training

This article was posted 09/09/2005 and is most likely outdated.

Grounding vs Bonding Online Training 13

September 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.

To view the videos you will need to download the free 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 to view the video [ 8MB ]

Below is the full course page which includes these videos:

Grounding versus Bonding

PART II.

Page 3 of 13

Sections

250.24 Grounding and Bonding at Service Equipment.

(A) Grounding. Services supplied from a utility transformer that is grounded to the earth must have the grounded neutral conductor grounded to a suitable grounding electrode [250.50] in accordance with the following:

(1) Accessible Location. A grounding electrode conductor must connect the grounded neutral conductor to the grounding electrode and this connection can be made at any accessible location, from the load end of the service drop or service lateral, up to and including the service disconnecting means. Figure 250–51

Author’s Comment: Some inspectors require the grounding electrode conductor to terminate at the meter enclosure, while other inspectors insist that the grounding electrode conductor terminate at the service disconnect.

The Code allows this grounding (earthing) connection to be made at either of these locations.

(4) Main Bonding Jumper. When the grounded neutral conductor is bonded to the service disconnecting means [250.24(B)] by a wire or busbar [250.28], the grounding electrode conductor can terminate to either the grounded neutral terminal or the equipment grounding terminal within the service disconnect.

(5) Load-Side Neutral-to-Case Bonding. A neutral-to-case bond cannot be made on the load side of the service disconnecting means, except as permitted for separately derived systems [250.30(A)(1)] or separate buildings [250.32(B)(2)] in accordance with 250.142. Figure 250–52

Author’s Comment: If an improper neutral-to-case bond is made on the load side of service equipment, dangerous objectionable current will flow on conductive metal parts of electrical equipment in violation of 250.6(A). Objectionable current on metal parts of electrical equipment can cause electric shock and even death from ventricular fibrillation. Figure 250–53

(B) Main Bonding Jumper. An unspliced main bonding jumper complying with 250.28 must be installed between the grounded neutral terminal and the metal parts of the service disconnecting means enclosure in accordance with 250.24(C).

Figure 250–51
(Click on image to enlarge)

Figure 250–52
(Click on image to enlarge)

Figure 250–53
(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

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