Brain fade, neuterals and grounds on same bus ??

Originally Posted By: gbeaumont
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Hi to all,


I am suffering from complete brain fade this morning, and the more than I read about neutrals and grounds on the same bus the more confused I'm getting. ![icon_confused.gif](upload://qv5zppiN69qCk2Y6JzaFYhrff8S.gif)

The following picture is of a 200 anp main panel with main disconnect in a newly constructed module home, and the wiring that I'm concerned about has been added as part of an attic conversion.



I believe that this wiring is actually OK as the panel has its own main disconnect, but between a very late-night and a bottle of Merlot I'm just not sure

I hope that one of our electrical gurus can give me a quick definitive answer on this.

Regards

Gerry


--
Gerry Beaumont
NACHI Education Committee
e-mail : education@nachi.org
NACHI phone 484-429-5466

Inspection Depot Education
gbeaumont@inspectiondepot.com

"Education is a journey, not a destination"

Originally Posted By: jmyers
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Gerry,


You are allowed to mix the grounding and neutral conductors on the same bars in the first panel. The bars should be bonded together to the panel. Any panel after that would be considered a sub panel and the neutral and ground wires would have to be on seperate bars.

You are allowed one neutral wire per terminal, or per screw. The bare grounding wires you should follow the manufacturers specifications how many you are allowed under one terminal. Typically, it is like three #12's, four #14's, two #10's and so forth.

Joe Myers


Originally Posted By: Ed Griffin
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Not that I am any type of electrical expert, but I agree. It is common to have neutral and grounds going to the same bus, so long as there isn’t a separate bus provided for each. This can only be done at the main service panel so that in case of a short, the electricity is sent straight to the ground (earth).


Originally Posted By: Bob Badger
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Ed Griffin wrote:
This can only be done at the main service panel so that in case of a short, the electricity is sent straight to the ground (earth).


Ed I am not picking on you this is a misunderstanding that haunts the electrical trade, many electricians think the same thing.

In the case of a short we are not trying to send the electricity to earth.

Earth is not an electrical sponge.

Electricity goes back to the source, which for a house is the utility company transformer.

The path we want the current to use is the utility company's combination Neutral Grounding conductor.

This can all work fine with out any connection to earth, the ground rod is for other purposes, it has nothing to do with short circuits inside the house.

This is a greatly misunderstood section of the code.


--
Bob (AKA iwire)
ECN Discussion Forums
Mike Holt Code Forum

Originally Posted By: roconnor
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" (or Equipment Bonding Conductor), which is used to bond/connect everything metal back to the service neutral. Sometimes I also think of the rod driven into the ground as an “Earth Rod”. The terms are not universal, but helps me separate the two things.


I think there were proposals by NFPA committees to change the term equipment grounding conductor to "Equipment Bonding Conductor" ... I think they chickened out, since it would mean re-writing a lot of the code ... ![icon_eek.gif](upload://yuxgmvDDEGIQPAyP9sRnK0D0CCY.gif)

[P.S. I think the only sticky part is would something metal connected with a 3-prong cord then be "bonded", or would we still call it "grounded" ... ... I think it could still be called "grounded" since it's connected back to the service neutral which is grounded. Nobody said it would be easy ... ]


--
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: roconnor
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WOW … talk about topic drift … icon_eek.gif


I just realized how much I wrote after it posted ... it's a sore point for me with the NEC ...


--
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: gbeaumont
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Hi to all,


thank you to all, God knows what was wrong with me this morning but I just could not think straight I knew that I knew the right answer but I could not remember why ![icon_redface.gif](upload://f7DX2EWhmUfsDapWaYT3oJHMCj1.gif) ![icon_redface.gif](upload://f7DX2EWhmUfsDapWaYT3oJHMCj1.gif)

you all know what it gets like when you're trying to get a report finish and e-mailed

thanks again.

Regards

Gerry


--
Gerry Beaumont
NACHI Education Committee
e-mail : education@nachi.org
NACHI phone 484-429-5466

Inspection Depot Education
gbeaumont@inspectiondepot.com

"Education is a journey, not a destination"

Originally Posted By: dvalley
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Quote:
I knew that I knew the right answer but I could not remember why


Ya ...OK...Nice try![](upload://76W5ki8PdQbWSfITkgj2VftQLbi.gif)


--
David Valley
MAB Member

Massachusetts Certified Home Inspections
http://www.masscertified.com

"Some cause happiness wherever they go; others, whenever they go."

Originally Posted By: jpeck
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Just a clarification. Ground faults go to ground. Shorts go hot to neutral, not to ground.


Main electric service and disconnect - neutrals are bonded to ground. You done good. ![icon_biggrin.gif](upload://iKNGSw3qcRIEmXySa8gItY6Gczg.gif)


--
Jerry Peck
South Florida

Originally Posted By: Bob Badger
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jpeck wrote:
Just a clarification. Ground faults go to ground. Shorts go hot to neutral, not to ground.



Ground faults go to bonded metal objects, to say they go to ground makes it sound like they go to earth.

The only reason a ground fault trips a breaker is because of the bond between the neutral and grounding conductors resulting in a path back to the source not the "earth"

If you remove the bonding jumper at the service panel and have a ground fault in the building there is a very good chance the OCPD will not open.

There is a good chance that in the 2008 NEC we will see the term Equipment grounding conductor changed to Equipment Bonding Conductor.

This would be in the hope to clear up the misconceptions.


--
Bob (AKA iwire)
ECN Discussion Forums
Mike Holt Code Forum

Originally Posted By: jpeck
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Bob Badger wrote:
jpeck wrote:
Just a clarification. Ground faults go to ground. Shorts go hot to neutral, not to ground.


Ground faults go to bonded metal objects, to say they go to ground makes it sound like they go to earth.


True, it does leave it open for that impression. but ground faults do go to ground. Not to neutral, and not to hot, but to ground.

A ground fault only goes to the bonded metal object because that bond is to ground. Thus, the ground fault goes to ground.

Quote:
The only reason a ground fault trips a breaker is because of the bond between the neutral and grounding conductors resulting in a path back to the source not the "earth"


That's why I said "ground", not "earth". Almost everyone thinks of the conductors as "hot", "neutral", and "ground". In that reference, the ground fault goes to ground.

I mentioned my clarification above because, in case you missed it, a post above referred to a "short", but described a ground fault. I was trying to clear up that a "short" does not go to ground. that a "short" is "hot" to "neutral", and that a ground fault goes to ground (which is what was being described).

Being as you are making this clarification more technical, I will have to correct you.

Quote:
Ground faults go to bonded metal objects, to say they go to ground makes it sound like they go to earth.


Bob, ground faults do not go to bonded metal objects.

Ground faults will only go that that bonded metal object is the bond goes to ground (which you did not state, making an assumption that we would know what you were meaning, like I was making an assumption all would know what I was meaning).

Quote:
If you remove the bonding jumper at the service panel and have a ground fault in the building there is a very good chance the OCPD will not open.


Again, the same confusion, you need to specify "ground bonding jumper", not just "bonding jumper".

Quote:
There is a good chance that in the 2008 NEC we will see the term Equipment grounding conductor changed to Equipment Bonding Conductor.

This would be in the hope to clear up the misconceptions.


This was considered, and rejected, for the 2005 NEC. I am sure it will proposed again. The wording proposed for the 2005 NEC left it more confusing in some instances.


--
Jerry Peck
South Florida

Originally Posted By: Mike Parks
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Gerry


"I believe that this wiring is actually OK as the panel has its own main disconnect"

Are you implying that there is a disconnect ahead of this panel?

Do you have a pic of the top left side of the panel?

Mike P.


Originally Posted By: roconnor
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Very sticky terminology, even among electrical professionals. IMHO it’s better to leave the terms “ground” and “grounded” to only mean the connection of the neutral to earth (and thus the technically correct term “grounded conductor” for that wire). That will take some adjustment, as it is very common to refer to the bare/green wire as the “ground”. I don’t think there is any easy answer, but hopefully NFPA will take the bull by the horns and help fix that.


"Fault" does mean the hot contacting metal parts, and "Short" does mean the hot contacting the neutral. Many people think of both of these as a "short", but I did clarify that ... ![icon_wink.gif](upload://ssT9V5t45yjlgXqiFRXL04eXtqw.gif)


--
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: jmyers
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Mike,


While it is difficult to see, I believe there are a couple of places where the ground/neutral bar has two wires under one terminal (neutral and ground wires).

I did not take a good look for anything else since he was concerned about the neutral and grounding wires in the bars.

Joe Myers


Originally Posted By: roconnor
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Good point Mike, which is that if there was a separate service main disconnect (MD) ahead of the panel in a separate box, then that would be where the neutral and bond (“ground”) wires should be connected together … not at a panel without the MD (same thing for a sub-panel, where there would be no connection of the two) … icon_wink.gif


I think Gerry meant that the MD was part of that panel, so the neutral to bond wire connection there would be correct.

Couldn't resist throwing in the term "bond wire" ...


--
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: gbeaumont
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Hi to all,


yes to clear up any confusion the main disconnect, in fact the only disconnect is at the top of this panel.

I don't know what it is with you guys over this grounding and bonding issue, but every time this issue comes up I personally walk away from the discussion with a bigger headache than the one I entered with. ![icon_lol.gif](upload://zEgbBCXRskkCTwEux7Bi20ZySza.gif) ![icon_lol.gif](upload://zEgbBCXRskkCTwEux7Bi20ZySza.gif) ![icon_lol.gif](upload://zEgbBCXRskkCTwEux7Bi20ZySza.gif) ![icon_lol.gif](upload://zEgbBCXRskkCTwEux7Bi20ZySza.gif) ![icon_lol.gif](upload://zEgbBCXRskkCTwEux7Bi20ZySza.gif) ![icon_lol.gif](upload://zEgbBCXRskkCTwEux7Bi20ZySza.gif)

regards

Gerry


--
Gerry Beaumont
NACHI Education Committee
e-mail : education@nachi.org
NACHI phone 484-429-5466

Inspection Depot Education
gbeaumont@inspectiondepot.com

"Education is a journey, not a destination"

Originally Posted By: jmyers
This post was automatically imported from our archived forum.



Gerry,


Recently, they have been trying to improve the terminology in the NEC to clear up the same confusion that you have. I receive those proposed changes via Mike Holt. When you first read those issues you think you know what you are talking about, when you are finished, not only were you wrong but you leave more confused than when you started. ![icon_biggrin.gif](upload://iKNGSw3qcRIEmXySa8gItY6Gczg.gif)

Joe Myers


Originally Posted By: roconnor
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I hear ya Gerry, and agree that debating code terminology in not helpful and loses the point here. But the main points here should be taken very seriously. Past confusion over the terms/provisions can result in dangerous installations, and an HI needs to be able to understand and identify these … icon_wink.gif


It is not only Harry Homeowner who can be a hazard. There was once even an appliance manufacturer that stated in the installation manuals for a "ground rod" to be driven to "ground" appliances in the event that there was not a separate wire back to the panel for that ...

If there was a fault on that big metal appliance, it would remain hot without ever tripping a breaker. Then little Suzy downstairs in that damp basement with mom doing the laundry comes along and touches the appliance ... zap ...

Just my 2-nickles


--
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.



Jerry Peck


Again we are in the situation where only the words you choose are the correct ones, I bow to your greatness. ![nachi_sarcasm.gif](upload://6HQh6KbNiD73gqTNQInjrR2zeJw.gif)

I have an idea, with your vast knowledge why don't you start posting at Mike Holt's Code Forum?

But step up to the plate and use your real name (I do) so we know when we are in the presence of the master.

About 14,000 electricians you can teach the error of their ways.

I have been shown to be wrong at Mikes and I have no problem with that, no one knows everthing about the NEC.

But I do find it funny that here you find me wrong in each and every post.


--
Bob (AKA iwire)
ECN Discussion Forums
Mike Holt Code Forum

Originally Posted By: Mike Parks
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Robert


A "bond wire" is one that is used by Her Majesty's Royal Service.

Mike P.