The article "CEC Methods of Grounding" in the latest edition of IAEI magazine is a perfect example of why the NEC should change the way it calls and defines aspects of grounding and bonding.

A special task committee was established after the 2005 NEC was released to investigate several proposals that were submitted to change the term equipment grounding conductors to equipment bonding conductors and perhaps provide a definition for "neutral".

While reading this article, it is clear that some of the functions that are being described as grounding are actually functions of bonding.

The purpose of grounding should be completely distinguished from the purpose of bonding. It has led to significant misconceptions on what is acheived when connecting non-current carrying metallic parts together verses connecting electrical equipment to Earth.

It is my understanding this task group has struck down the proposal and most if not all the terms and definitions regarding grouding and bonding will remain the same for the 2008 NEC. I think this is a mistake, and the article in the IAEI magazine proves it.

As an instructor and inspector, one of my greatest burdens is the explanation of the purpose and use of grounding and bonding. As long as the code and articles like this one continue to mix the two fundementals and describe the two aspects as one process and purpose, electricians will remain confused and misconceptrions will continue to flourish.

I'm not implying the article has incorrect information, however it does not provide a clear understand that the connection to earth is not the major function that the "code defined" grounding serves but is really a function of bonding.

I realize this article is referring to the CEC, however this same issue applies to nearly every article, paper, or standard written on grounding and bonding issues.

If you are a purist, there is really just one "grounding" conductor in most buildings. It goes to the ground electrode. Every other grounded conductor is either bonding equipment or carrying unbalanced circuit current.

You're the man Greg!

That sums it up nicely!

Of course this kicks the "grounding vs bonding" tar baby in a swimming pool.

The 680.26 "bonding" grid will certainly be the best "ground" in the system but we can't call it a ground electrode. Someone (Mike?) says he is not sure it should even be connected to the panel GES but that is unavoidable if you have a bonded pump or an underwater light. (via the EGCs)
Generally speaking we say the 8ga in 680.26 is "bonding" and the EGCs in the various equipment sections is "grounding". That actually seems backward if you have that big "Ufer" we call a concrete swimming pool and deck.
Personally I take some comfort that my screen cage is "grounded" to that big electrode, in case lightning does hit it. I went as far as to bring up a bunch of extra #8s to bond it several times around the perimeter. I figure it has become a Faraday cage of sorts.

NO don't connect the pool grid back to the main panel, please don't get me started on that one again...

The code sets up this problem. It tells you to avoid objectionable current yet permits and/or requires installaton that practically guarantee it. All normal operating current is supposed to return on the service grounded (neutral) conductor.

However, the code permits a significant reduction in the size of the grounded conductor per 220.61 - 2005 NEC. At the same time, the NEC has reqirements that are intended to reduce the grounding electrode system impedance to as low as possible. This creates a situation where more current will flow on grounded parts and through earth as opposed to the insulated system where it should be. Ohm's Law clearly proves this. The pool equipotential grid can produce the same result. Normal operating current will find its way through the bonding grid if it is of sufficently low imdeance and connected to the service equipment.

The only true way in which the NEC can get rid of this inconsistancy and provide a way in which systems are completely free of objectionable currents is to require equipment grounds (bonds) to be installed with the service entrance and all equipment be grounded through that. the only connection to earth would be at the (isolation) transformer.

Nick, I have 4 pumps, 2 heaters and 2 lights that are bonded together (680.26) and also are required to be "grounded" back to the panel. It is hard to say, with a sraight face, that the pool is not connected to the ground electrode system by the 65670 circular mils of copper in the EGCs. In fact the 4ga ground electrode conductor is the bottleneck.

I think you are all confused, except Nick.

Mike it is too soon to say if I'm confused or not (because I didn't read the article yet). Who authored it?

I was holding back on this topic because if we start on grounding vs. bonding it is going to go on forever, but maybe we need to do that. It has been a while I think.

Mike if you are out on your bike this weekend, tonight I will be at the Orlando Harley Davidson for the show there.

What am I confused about? Do you have some way to explain why current won't flow from the pool (680.26) bonding grid to the ground electrode system via the EGCs
In fact the current will be flowing the other way in most cases since a concrete pool is several orders of magnitude more effective than any 250 chapter III electrode. You may hate the idea but you can't stop it from happening without extensively rewriting 680. The slam dunk is the underwater light junction box. I would also be very troubled if an 11 kw immersion heater was not solidly bonded to the service and part of the pool bonding grid.