Originally Posted By: roconnor This post was automatically imported from our archived forum.
Mike Parks wrote:
The electrode is not for fault protection.
Fault current will flow to earth through a ground rod or service pipe ("grounding electrode system"), but not enough to trip a breaker. Therefore connection to a grounding electrode (ground rod, service pipe, or both) can NOT be utilized to clear a fault [trip a breaker], and do not qualify as fault protection.
What clears a casing short (or ground fault) is the connection of the ground wire to the neutral at the service panel. This ensures that enough current will flow through the ground wire to trip the breaker.
Some people incorrectly think that if a ground rod is added to install an appliance in a remote location with an old 2-wire circuit that it is then "grounded" ... WRONG ... 
One appliance manufacturer actually had instructions that included installing a ground rod if a ground wire back to the panel wasn't available, so you have to be careful ...
-- Robert O'Connor, PE
Eagle Engineering ?
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NACHI Education Committee
I am absolutely amazed sometimes by how much thought goes into doing things wrong
Originally Posted By: Blaine Wiley This post was automatically imported from our archived forum.
Great information guys, and thanks for posting it. I understand it, and definately will never be able to explain it to one of my clients. Now after reading all of that, MY HAIR HURTS!!
Originally Posted By: Bob Badger This post was automatically imported from our archived forum.
roconnor wrote:
Bob ... I think NFPA is partially to blame for some people not understanding the grounding requirements due to the terminology they use in the NEC.
I am with you 100% on that. 
I know of one man and there may be others that submitted change proposals for the 2005 code that would change what we now refer to as the "Equipment Grounding Conductor" (EGC) to "Equipment Bonding Conductor"
I think Canada has already done this.
The CMPs (code making panels) have set it aside to look at this again for the 2008 code.
But they are taking this serious enough to set up a committee to look at how this would effect all the code articles.
This would be a code wide major change.
I am all for it, it would be tough at first but I really believe in the long run it will help stop the confusion of the earth as a fault clearing means.
To me equipment bonding conductor describes the function of what we presently call the EGC much better.
It would also do away with one of the conductors with a form of "ground" in the name.
Originally Posted By: roconnor This post was automatically imported from our archived forum.
… as a non-electrical professional I like the terms Hot, Neutral, and Ground wires … and then Bonding and Earth Connection (separate things in my mind) even though not per the NEC.
Blaine ... Don't mind the code banter here, just raising the bar on everybodys knowledge. And dont worry, your head will feel better soon, as long as you dont try to decipher the NEC ... 
Just remember that all outlet/circuit grounds and everything metal needs to have a ground wire run back to the main service panel, where it is connected to the neutral ... and the ground to neutral connection is ONLY at the main service panel.
Anything else is either a "concern" (e.g. old 2-prong outlets without a ground) or "safety hazard" (e.g. a sub-panel with a ground to neutral connection) that a sparky should check out ... and explain to the homeowner "why" it's a shock hazard. See how easy that is ... 
-- Robert O'Connor, PE
Eagle Engineering ?
Eagle Eye Inspections ?
NACHI Education Committee
I am absolutely amazed sometimes by how much thought goes into doing things wrong
Originally Posted By: Bob Badger This post was automatically imported from our archived forum.
roconnor wrote:
Bob ... as a non-electrical professional I like the terms Hot, Neutral, and Ground wires ... and then Bonding and Earth Connection (separate things in my mind) even though not per the NEC.:
Robert those are the terms I use on the job day to day, I would never say "run a ungrounded, a grounded and a grounding conductor" 
The problem is, and this does not really effect you guys, is a grounded conductor is not always a neutral.
A ungrounded conductor is not always a hot conductor.
