Originally Posted By: Bob Badger This post was automatically imported from our archived forum.
Here is a question for you HIs and it is a subject that gets many different responses from electricians.
At the main panel (oops Service Panel  ) it is acceptable to put the grounding conductors along with neutrals on the same neutral bar.
Now when there is a separate grounding bar in the panel can I put the neutrals on that bar, they are after all electrically the same.
Here is a picture of a panel I have downstairs left over from a job temp service.
Would it be acceptable to terminate neutral conductors on the small right hand terminal bar?
Originally Posted By: rmoore This post was automatically imported from our archived forum.
If the panel was installed as a main (oops) service panel then the main neutral bar would have to be bonded to the cabinet. Once that is done, then yes, the small grounding bar could be used for neutrals. However?in this case I would add, why bother, as there is clearly enough room on the neutral bar(s) for any combination of breakers.
If the panel is installed as a ?sub-panel? (or non-service panel) as shown without the bonding jumper (as would be correct) then no, neutrals cannot go on the small grounding bar (or grounding conductors on the neutral bar). The why, is that it would create parallel paths back to the service panel for any unbalanced current in those circuits connected that way. This current is normally carried only by the insulated neutral (grounded) conductor. If, for example, the equipment grounding conductor between the sub and service panel was metallic conduit, then that conduit would likely be energized anytime an unbalanced load was put on those circuits with neutrals connected to the grounding bar. Not full voltage but probably enough to zap someone. You would have to be standing in the proverbial bucket of water to get zapped badly but the potential is there.
In short?the main service panel is the only place where neutral bars should be bonded and neutral and ground bars may be shared.
Bob...do electricians really vary on this?
-- Richard Moore
Rest Assured Inspection Services
Seattle, WA
www.rainspect.com
Originally Posted By: rmoore This post was automatically imported from our archived forum.
Ahhh…I think I see!
Neutral conductors are designed to carry current on a regular basis. By connecting them to this small ground-bar in a service panel we are forcing the path of this current to pass through the bar, screws, and the panel itself...rather than just the rated neutral bar and main grounded conductor.
I'm having a hard time finding where it actually says this is wrong but I have now changed my mind and don't think this is a good idea. Make my answer now NO...no matter whether the panel is service or sub. Still OK in a service panel to connect the grounding conductors to either the bonded neutral bar or that small ground bar as they are NOT designed to carry current on a regular basis.
When using this particular panela as a service panel, because of the abundant lugs on the neutral bar(s), I would suggest that the best idea would be to remove the small ground bar altogether...and of course install a bonding jumper.
How am I doing?
-- Richard Moore
Rest Assured Inspection Services
Seattle, WA
www.rainspect.com
Originally Posted By: Bob Badger This post was automatically imported from our archived forum.
rmoore wrote:
How am I doing?
You are doing great! 
Quote:
However?in this case I would add, why bother, as there is clearly enough room on the neutral bar(s) for any combination of breakers.
This statement also is dead on for this particular panel.
But this was one I had in the cellar that clearly shows what the problem could be.
When used as a service panel the neutrals and grounds can be on either of the large terminal bars on each side but only grounds can terminate on the small grounding bar.
By the way the bonding screw is hard to see but it is at the bottom of the left hand terminal bar.
This panel can also be used as a sub by removing the bus bar at the bottom between the two terminal bars, making one an isolated neutral and one a bonded grounding bar.
Here are some close ups.
Along with a 110.5 violation, the sticker makes it a 110.3(B) violation to use the small bar for neutrals.
(Looks like one of our guys lost the correct mounting screw too )
As it is in the picture it is worth pointing out the add on lug on the bottom right of the terminal bar is the correct way to terminate large conductors to this terminal bar, splitting the strands of wires into smaller groups to fit in the small holes is not correct.
Originally Posted By: Bob Badger This post was automatically imported from our archived forum.
dvalley wrote:
Bob,
So like I said...Neutrals float and ground wires bond, right?
David that would be correct for panels that do not have the service disconnect in them.
A panel that has the service disconnect in it must have the neutrals and grounds bonded.
This can mean both neutrals and grounds terminate on the neutral bar or they can terminate on separate bars if the bars are connected together with a properly sized conductor or a piece of factory installed bus bar.
If you see Neutrals landed on a grounding bar like the small one in the picture that has only the steel of the enclosure connecting it to the incoming power company neutral conductor that would be a violation.
You should not see the steel of an enclosure being used to carry normal current, it can and is used to carry fault current.
In short in a service panel both Neutrals and Grounding conductors can terminate on the neutral bar.
But in many cases neutral conductors must not terminate to a grounding bar.
Originally Posted By: roconnor This post was automatically imported from our archived forum.
Bob Badger wrote:
... the add on lug on the bottom right of the terminal bar is the correct way to terminate large conductors to this terminal bar, splitting the strands of wires into smaller groups to fit in the small holes is not correct. 
Good point. Also note that it would be incorrect to trim a wire (give it a "haircut") to make it fit in a terminal intended for a smaller wire ... 
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: roconnor This post was automatically imported from our archived forum.
Dave … As Bob pointed out, the grounds can terminate on the neutral bar in service panels with the MD (per the exception I mentioned above) … just not the other way around with neutrals on the ground bar …
But there is no such code restriction for ground wires (equipment grounding conductors), and multiple ground wires under one terminal would be allowed as long as the panel is listed for that (NEC 110.3.B). Look at the label on your own home panel, and it should tell you what is permitted for the ground wires.
-- 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 This post was automatically imported from our archived forum.
roconnor wrote:
Neutrals are required to have their own individual terminals (NEC 408.21).
That means that there can be no double lugged neutral wires (either multiple neutrals, or a neutral with a ground wire).
And this is an example of a panel label/listing which permits multiple ground wires on the bars (look at the last two which talk about the neutral and ground bars). Notice that it only talks about multiple (ground) wires on the "Ground Bar" or for "Equipment Grounding" ... 
-- 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: rmoore This post was automatically imported from our archived forum.
Bob Badger…
I just want to express my appreciation to you for taking the time to hang out here. This thread was a great example of asking the right question to get us thinking and then presenting information in a clear manner.
Many thanks...beer is on me if we ever meet.
-- Richard Moore
Rest Assured Inspection Services
Seattle, WA
www.rainspect.com
Originally Posted By: jfarsetta This post was automatically imported from our archived forum.
Bob, you staated tha where a panel has a service disconnect, the neutrals and grounds are bonded.
You did not clarify if this was the case in a main panel or sub-panel. It was my understanding that neutrals in a sub-panel must float. This opinion has never changed for me, as I dont view subs with a main disco any differently then a sub without one.
Am I incorrect?
-- Joe Farsetta
Illigitimi Non Carborundum
"Dont let the bastards grind you down..."
