Originally Posted By: Ed Griffin This post was automatically imported from our archived forum.
I need a little education.
System grounding basicly protects the system from lightning and such, right? It directs the electricity towards the ground by a rod, copper pipe…, right?
Bonding does what? Connects components together? For what purpose, safety?
Lastly, subpanels should have floating neutrals, right? Why? What would happen if the neutral was tied to the ground?
Originally Posted By: Bob Badger This post was automatically imported from our archived forum.
Grounding the neutral to earth helps protect against high voltages from lightning or utility high voltage faults imposed on the low voltage (240/120) on the customer side of the transformer.
This could be a 13,800 volt primary breaking and landing on the bare neutral of the overhead feed to a house.
Bonding the neutral to the panel and the rest of the metal objects likely to be energized provides a reliable fault current path back to the power source (the power company transformer) this is necessary to provide enough current to trip breakers quickly.
A sub panel that is has its neutral bonded to the grounding conductors will cause current that should be carried only on the neutral conductor to split and flow on both the grounding conductors and the neutral conductors.
Originally Posted By: Bob Badger This post was automatically imported from our archived forum.
tlempe wrote:
Bob theres a great book that will answer all your questions its from Rex Cauldwell and its called wiring a house, it goes into detail on this subject
Gee I hope you meant Ed not Bob  as I have been wiring structures since I was 17 and I am 39 now.
I am pretty well versed on grounding and bonding, do you think I have made a misstatement?
Originally Posted By: roconnor This post was automatically imported from our archived forum.
Bob … I am sure he meant to refer Ed to that book …
Ed ... I like how you separate out "grounding" and "bonding" in your mind. They are two completely different things. In fact, if you think of the green/bare wire of a circuit as a "bond wire" it might actually make more sense ...
-- 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.
I was just joking around anyway.
I got some PMs telling me I have to go to school.
If you are starting out in your knowledge of wiring methods that book is excellent advice.
If you would like to know more about grounding and bonding I would say get a "Soares Book on Grounding" I have heard a lot of good things about this book.
Originally Posted By: Bob Badger This post was automatically imported from our archived forum.
I am sorry if I was not easily understood.
That said it has been my experience here at NACHI that there is a great deal of joking around and that makes it a fun place. 
Originally Posted By: jtedesco This post was automatically imported from our archived forum.
I am attending an NEC Forum NFPA workshop on how to install AFCI’s. When I am able, I will make the information I received available.
Here is an image that will give us some idea of what some of the problems are, and although the industry has shown tests and videos and there are lots of Pros and Cons, many are going to support the use of this device:
