Originally Posted By: jmyers This post was automatically imported from our archived forum.
Bill,
Since this is a main lug panel, I would have to assume the Service Disconnect is upstream and present. It appears it may be a split buss to comply with the six disconnect, switch rule. If that is the case, there can be no more than six breakers or switches or any combination of, to turn off all the power to this property.
The neutrals and grounding wires need to be on separate bars, and the neutral needs to be floating (not bonded to the metal on the panel) if this is indeed an equipment panel (sub panel).
Neutral wires are only allowed one per termination, grounding wires would have to follow the manufacturers installation instructions as to how many of what size are allowed to be placed under each termination.
Hope that helps. 
Originally Posted By: jtedesco This post was automatically imported from our archived forum.
bmay wrote:
Joe, this is the main panel, do the neutrals pose a fire hazard? They have been that way for 25 years
Bill
Yes!
Quote:
A separate equipment grounding conductor terminal bar must be installed and bonded to the panelboard for the termination of feeder and branch-circuit equipment grounding conductors.
Where installed within service equipment, this terminal is bonded to the neutral terminal bar.
Any other connection between the equipment grounding terminal bar and the neutral bar, other than allowed in 250.32, is not permitted.
If this downstream connection occurs, current flow in the neutral or grounded conductor would take parallel paths through the equipment grounding conductors (the raceway, the building structure, or earth, for example) back to the service equipment.
Normal load currents flowing on the equipment grounding conductors could create a shock hazard. Exposed metal parts of equipment could have a potential difference of several volts created by the load current on the grounding conductors.
Another safety hazard created by this effect, where subpanels are used, is arcing or loose connections at connectors and raceway fittings, for example, creating a potential fire hazard.
Originally Posted By: Blaine Wiley This post was automatically imported from our archived forum.
Joe,
Which NEC did this appear in. It was common practice around here to either double the grounded conductor or place them in the buss bar in tandem with the ground until around 1990.
Originally Posted By: jtedesco This post was automatically imported from our archived forum.
Blaine:
I am sure that this was always considered as a fire and shock hazard, but don't have the specific date. I believe that those who allowed the combination you describe were misinformed, and probably were just following what they were taught.
Originally Posted By: bmay This post was automatically imported from our archived forum.
Joe T, I don’t get it. I understand the grounding bar and the neutral bar must be separated and that the two should not mix grounding points in the electrical box. If all grounds, (bare wires) are attached to separate bars, and all neutral wires are attached to opposing bars, is this still legal? Now the question remains, if grounds are double tapped to their own bars and neutrals double tapped to their own bars, is this in violation?
Originally Posted By: Blaine Wiley This post was automatically imported from our archived forum.
jtedesco wrote:
I am interested in reading the label if one is available, either on the inside or on the cover.
That is the key to the manufacturer's and other instructions often found with the equipment on the cabinet cover or cabinet itself.
I'll try to at least write down for you the manufacturers instructions pertaining to the wire size and number per terminal on the buss. They are usually hidden, but I try to see what they say when I see the double "neutral" lugging.
Originally Posted By: bmay This post was automatically imported from our archived forum.
Joe T, thanks for your help and the link. A few days ago we observed this very thing, double lugging of neutrals, on a rewire. And the city inspector had just passed it about 10 days prior to our inspection. Something tells me the city never opened the panel to check.
Originally Posted By: dhartke This post was automatically imported from our archived forum.
Joe
Your wisdom is always appreciated. I find it most valuable when answers are given in your own words (instead of NEC quotes) as you have done in this thread. It simply is easier for a non-electrician to understand.
Originally Posted By: jtedesco This post was automatically imported from our archived forum.
Greg:
See 110.3(B) in the National Electrical Code, the rules are formed around the product listing and the instructions are to be followed.
The PDF file above also includes that information.
The subject of loose neutrals should be expanded upon, and we have all seen or experience them during our career, that is those of us who are installers or inspectors.
Originally Posted By: Greg Fretwell This post was automatically imported from our archived forum.
Joe, the problem was that the manufacturer will list their lugs for more than one conductor, typically 2 or 3, and if they don’t specify that neutrals have to be one per lug it is up to the installer.
That is why Jim Pauley, Square D said “although the UL wording is adequate for the product standard, it is important that the NEC language is as clear as possible” in his proposal. (9-113)
This was 2002 code.
Did you ever work the code circuit with Jim?
He puts on a good show but now I think he is a VP or somthing with Schnider now and doesn’t do the road shows.
Originally Posted By: jtedesco This post was automatically imported from our archived forum.
Greg:
I worked the circuit with Jim years ago when he was involved with SquareD.
Let's talk about the hazards involved.
Here is a label that was part of a panelboard that was installed in 1980 not far from where I live. Read the notes, and if everyone would do the same on all of the questions concerning the subject of this thread, we may begin to understand.
Originally Posted By: Greg Fretwell This post was automatically imported from our archived forum.
As your label, and this one (GE) show, they can be somewhat confusing about how many wires or what “multiple wire” means. Square D is a little better specifying how many wires can be on a grounding bus. You can see why Jim wanted “clear” language in the NEC.
