double tapped neutral wires

[CHARLIE VAN FLEET]

hey all

inspected this 1998 single family home today.200 amp main,but there were two doubled tapped neutral wires under one tight down screw.i don't believe this is right.is it against code???

charlie

[John Arnold]

You are correct -- it is against code and has been for some time.

[Gunnar Alquist]

Charlie,

One of the problems is the way the code was written at that time. Code essentially said that it was OK, if the manufacturer said so. The catch was that manufacturers did not approve double tapping. However, you will find that the wording on the panel labels was less than clear. It gave permission to double grounding conductors and this was misinterpreted to mean the neutral. Take a look at the attached pic. That is from a service equipment panel and it does not allow multiple neutrals. But, it is easy to see (for me, at least) why electricians and inspectors thought it was OK.

1999 NEC: Art.110-14 (a) ... Terminals for more than one conductor and terminals used to connect aluminum shall be so identified.

(In other words, OK with NEC if OK with manufacturer)

This was modified (or clarified) in the 2002 edition

2002 NEC Art. 408-21 Grounded Conductor Terminations.
Each grounded conductor shall terminate within the panelboard in an individual terminal that is not also used for another conductor.

(Pretty clear now)

[Ted Menelly]

Gunnar

First, I have been in the situation to explain exactly that to clients. Older code, newer code, panel box, all stating something but contradicting the other. Such a common find to have contradictory info to pass along about findings thoughout the home.

I would not change my job for anything.

Second, a quote from you. "It IS as bad as you think, and they ARE out to get you.

Is that cynical, comical or just a deep thought.

Ted

[Gunnar Alquist]

Ted,

First. My problem is when I have to deal with electrical contractors who tell me that I'm wrong. In order to avoid an argument, I will often (verbally) admit that they are the "expert" and let it drop. I will tell my client that I believe that my information is correct and I will not change my report.

Second. I am basically shallow. My goofy comments are generally intended to be funny. I do get bored with them and change them periodically. Unless I am mistaken, every one of my signature/comments has been plagiarized. However, I do try to give credit when I know who originally quoted it. Not sure where I got this one. I am personally rather fond of quotes from Lincoln and Twain.

If you want to believe that I am a deep thinker, please feel free. Just don't expect too much.

[Shannon Guinn]

Ted,

First. My problem is when I have to deal with electrical contractors who tell me that I'm wrong. In order to avoid an argument, I will often (verbally) admit that they are the "expert" and let it drop. I will tell my client that I believe that my information is correct and I will not change my report.

Second. I am basically shallow. My goofy comments are generally intended to be funny. I do get bored with them and change them periodically. Unless I am mistaken, every one of my signature/comments has been plagiarized. However, I do try to give credit when I know who originally quoted it. Not sure where I got this one. I am personally rather fond of quotes from Lincoln and Twain.

If you want to believe that I am a deep thinker, please feel free. Just don't expect too much.


Gunnar, as long as you can cite the code section regarding whatever violation( most of the time I know if it's a violation but will have to look it up) there's really nothing the EC can say about it. I have found that the ones who get upset the most are new to the game or the ones who think that they don't make mistakes. It's good to see that you stick to your guns and don't change your report. When I first started inspecting (I'm a local electrical inspector) that was some of the best advice that I received; when you find something in error, to stick to your guns and be able to back your findings up with code and you'll be fine. The old adage of "You can't please all of the people all of the time" is one of the truest sayings I've heard.

[Gunnar Alquist]

Gunnar, as long as you can cite the code section regarding whatever violation( most of the time I know if it's a violation but will have to look it up) there's really nothing the EC can say about it. I have found that the ones who get upset the most are new to the game or the ones who think that they don't make mistakes. It's good to see that you stick to your guns and don't change your report. When I first started inspecting (I'm a local electrical inspector) that was some of the best advice that I received; when you find something in error, to stick to your guns and be able to back your findings up with code and you'll be fine. The old adage of "You can't please all of the people all of the time" is one of the truest sayings I've heard.

Shannon,

While I agree with you, there is one particular issue. I am not interested in getting into a discussion or debate with an electrical contractor, or any other contractor for that matter. Frankly, it takes too much time and effort to educate someone else, particularly when they believe that they are right and I am wrong. The reality is that the contractor generally knows much more about their particular trade than I do. It is typically just one or two things that they have wrong. Particularly when the code section is poorly written.

[Frank Mauck]

Need to kept in mind, there are many types of terminals for electrical connections besides the neutral bar in panels.Some of these terminals are designed to accept more than one conductor. The manufacture will state on how many conductors and what size conductors the terminals will accept.Generally the neutral bar in panels are not design for more than one conductor.

[Jerry Peck]

Generally the neutral bar in panels are not design for more than one conductor.


"Generally the neutral bar" being being key and meaning 'when used for neutral conductors', in which case the 'generally' is really 'always' - when used for neutral conductors.

When the neutral terminal bar is part of the service equipment, the bars are typically rated for use as equipment grounding conductor terminals also, and are typically rated for 2 conductors when used for equipment grounding terminals.

When not part of service equipment, many have neutral terminal bars with separate sections which can be separated and isolated from each other, one being used for neutrals (only one conductor per terminal) and the other being used for grounds (typically 2 conductors per terminal).

I've even seen a couple of panels which allowed 3 ground conductor if of the same size, material - basically if #14 AWG size and copper.

Just clarifying that "neutral terminal bars" may have "non-neutral" uses in many panels and that those have different ratings than when used for "neutral" uses.

[John Dirks Jr]

Here's a document you can share with clients to help explain the reasons why double tapping neutrals is not good.

http://home.comcast.net/~arundelhomeinspection/DoubledNeutralsGrounds.pdf

[David Banks]

Thanks John.

[Bruce Ramsey]

Similar but different question. Or maybe just clairification...

Interior distribution panel had multiple instances of 3 ground wires under a single set screw. Intermixed were set screws with 1 and 2 ground wires. I reported as too many ground wires under a single screw.

Electrical worker (not personally licensed but works for a licensed inspector :D ) reviews panel and reports condition is OK. Client calls me and wants me to clarify position. Electrical worker indicates he does it that way all the time and is not a problem. He claims the bar is full and he does not see a need to add a bar to resolve something that is not a problem. I suggest he move the 3rd wire to a hole with a single wire to make pairs. Still claims bar is full and condition is OK. I ask if he is willing to have the licensed electrician write that statement on company letterhead with license number. He said yeah. Hands phone back to client. I recommend to client to get a letter from electrician with license number indicating condition OK. Client agrees.

I read the article above and reviewed the NEC reference but neither seem to deal specifically with >=3 ground wires under a single set screw. Can someone help me find a definitive reference?

There were a few other conditions that did need correction so the service call was justified. Cover held on with pointy screws and several double taps.

[Jerry Peck]

Similar but different question. Or maybe just clairification...

Interior distribution panel had multiple instances of 3 ground wires under a single set screw. Intermixed were set screws with 1 and 2 ground wires. I reported as too many ground wires under a single screw.

Clarification: Read the label on the panel.

Many are limited to 2 groundING conductors, some allow 3 groundING conductors.

None have ever allowed 2 groundED conductors.


Electrical worker (not personally licensed but works for a licensed inspector :D ) reviews panel and reports condition is OK. Client calls me and wants me to clarify position. Electrical worker indicates he does it that way all the time and is not a problem.

Did you take that opportunity to thank him for admitting that he does it wrong all the time? Works wonders when you do. :)


He claims the bar is full and he does not see a need to add a bar to resolve something that is not a problem.

Tell him to lay down his Klein's and back away from the panel. Only after he takes a refresher course in BASIC code and wiring is he allowed to pick up his Klein's and do any more electrical work.


I suggest he move the 3rd wire to a hole with a single wire to make pairs. Still claims bar is full and condition is OK. I ask if he is willing to have the licensed electrician write that statement on company letterhead with license number. He said yeah. Hands phone back to client. I recommend to client to get a letter from electrician with license number indicating condition OK. Client agrees.

Before belittling the electrician any further (I took shots at him above too, hopefully you have covered the 'read the label' base for us), you need to read what the panel says is allowed.

He *might be right*. By accident, but nonetheless *right*. Making you ... (gulp) ... *wrong*. Meaning I ... should ... not ... taken ... those ... shots ... at him. :o

[Bruce Ramsey]

Called and emailed the Chief Electrical Engineer for the state asking for clarification or code reference regarding number of grounding wires under a set screw. He was out of the office for a few days but politely responded this morning.

His response was he has never seen a panel that allowed more than 2. He suggested I/electrician contact the manufacturer for their specific requirements. (Hey, that sounds familiar)

I guess I need to schedule an appointment with the client to further review the panel and provide additional research.

[Jerry Peck]

I guess I need to schedule an appointment with the client to further review the panel and provide additional research.


That will be specified in the label.

If the label is not there, then 1 is the maximum.

Why, because terminals for use for more than 1 conductor must be so identified, and, if the identification is gone, then they are not so identified, meaning *1* is the magic number. :)

[shane toby]

hey all

inspected this 1998 single family home today.200 amp main,but there were two doubled tapped neutral wires under one tight down screw.i don't believe this is right.is it against code???

charlie
[B]
Hi, im a journeyman electrician, its not just against code but also bad for your system and equipment!even if it was ok to do when that panel was installed, it is important to fix that as soon as possible. Neutals dont only complete the circuit but isxalso a retun path for unused energy. When you have two under the same screw they can become loose from expanding and contracting due to heating and cooling. Loose conectioms can cause arcing and to much heeat or even loss of netral which is bad for electroniv that or powered on. Also if it comes completly out it can hit the back of the panel and cause arcing as well. If it comes out completly it can hit a breaker causig a full backfeed wich will make that circuit 240v which is really bad for anything plugged into that circuit that isnt suppose to be. Also two under one can cause one o backfeed the other which is also bad too. They didnt know back when they said iit was ok that todays houses have all these electronics in em tooday that rely on those neutrals alot. So if u ever see a double tapped neutral it should be fixed asap. Its in the best intrest of the person who owns the panel not only to save damage to appliances and electronics but also save them from costlyvrepairs to there electrical system and even prevent fires. Thanks for reading

Shane T

[John Arnold]

[b]
...Also two under one can cause one o backfeed the other which is also bad too...

I'd like to understand how this could work. Why could there be "backfeed" when two neutrals are under the same screw, but not when they are each under a single screw on the same neutral bar?

[shane toby]

IMO that information incorrect for the reason that you've mentioned unless the two neutrals were in only contact with each other and not the neutral bar.

I'm a service tech now. I've taken class on this. Basically when there under the same screw touching each other it's no different than wire nutting em together. The neutral bar is designed to disperse or deplete the energy. When the wires are touching each other it will backfeed instead. When under its own screw the energy hits the bar before any other wire therefor being absorbed. When under the same screw the energy finds that the unused wire is a path of least resistance and will travel back. Not saying this happens in every instance but can and will happen depending on the circuit and what's on them when sharing the same lug or screw.

[Garry Blankenship]

Current code says terminations approved for more than one conductor shall be so identified. If it's not stated by the mfg. as OK for two or more conductors, not to code. There are lugs made for two conductors, but I've only seen them in larger conductor sizes. The 2002 section Gunnar cited no longer exists in the 2011 code book.

[shane toby]

Current code says terminations approved for more than one conductor shall be so identified. If it's not stated by the mfg. as OK for two or more conductors, not to code. There are lugs made for two conductors, but I've only seen them in larger conductor sizes. The 2002 section Gunnar cited no longer exists in the 2011 code book.

You are absolutely correct. But I'm basically talking about your average dwelling or residents panel. But even certain state and city codes can over rule that make you land them in there own lug or screw. I'm in Washington and our city and state codes are very strict. We have alot of stuff here that supersede the NEC.

[Jerry Peck]

The 2002 section Gunnar cited no longer exists in the 2011 code book.


1999 NEC: Art.110-14 (a) ... Terminals for more than one conductor and terminals used to connect aluminum shall be so identified.

(In other words, OK with NEC if OK with manufacturer)

This was modified (or clarified) in the 2002 edition

2002 NEC Art. 408-21 Grounded Conductor Terminations.
Each grounded conductor shall terminate within the panelboard in an individual terminal that is not also used for another conductor.

From the 2002 NEC:
- 110.14 Electrical Connections.
- - Because of different characteristics of dissimilar metals, devices such as pressure terminal or pressure splicing connectors and soldering lugs shall be identified for the material of the conductor and shall be properly installed and used. Conductors of dissimilar metals shall not be intermixed in a terminal or splicing connector where physical contact occurs between dissimilar conductors (such as copper and aluminum, copper and copper-clad aluminum, or aluminum and copper-clad aluminum), unless the device is identified for the purpose and conditions of use. Materials such as solder, fluxes, inhibitors, and compounds, where employed, shall be suitable for the use and shall be of a type that will not adversely affect the conductors, installation, or equipment.
- - - - FPN: Many terminations and equipment are marked with a tightening torque.
- - - (A) Terminals. Connection of conductors to terminal parts shall ensure a thoroughly good connection without damaging the conductors and shall be made by means of pressure connectors (including set-screw type), solder lugs, or splices to flexible leads. Connection by means of wire-binding screws or studs and nuts that have upturned lugs or the equivalent shall be permitted for 10 AWG or smaller conductors.
- - - - Terminals for more than one conductor and terminals used to connect aluminum shall be so identified.

From the 2011 NEC:
- 110.14 Electrical Connections. Because of different characteristics of dissimilar metals, devices such as pressure terminal or pressure splicing connectors and soldering lugs shall be identified for the material of the conductor and shall be properly installed and used. Conductors of dissimilar metals shall not be intermixed in a terminal or splicing connector where physical contact occurs between dissimilar conductors (such as copper and aluminum, copper and copper-clad aluminum, or aluminum and copper-clad aluminum), unless the device is identified for the purpose and conditions of use. Materials such as solder, fluxes, inhibitors, and compounds, where employed, shall be suitable for the use and shall be of a type that will not adversely affect the conductors, installation, or equipment.
- - Connectors and terminals for conductors more finely stranded than Class B and Class C stranding as shown in Chapter 9, Table 10, shall be identified for the specific conductor class or classes.
- - Informational Note: Many terminations and equipment are marked with a tightening torque.
- - (A) Terminals. Connection of conductors to terminal parts shall ensure a thoroughly good connection without damaging the conductors and shall be made by means of pressure connectors (including set-screw type), solder lugs, or splices to flexible leads. Connection by means of wire-binding screws or studs and nuts that have upturned lugs or the equivalent shall be permitted for 10 AWG or smaller conductors.
- - - Terminals for more than one conductor and terminals used to connect aluminum shall be so identified.

From the 2002 NEC:
- 408.21 Grounded Conductor Terminations.
- - Each grounded conductor shall terminate within the panelboard in an individual terminal that is not also used for another conductor.
- - - Exception: Grounded conductors of circuits with parallel conductors shall be permitted to terminate in a single terminal if the terminal is identified for connection of more than one conductor.

From the 2011 NEC:
- 408.41 Grounded Conductor Terminations. Each grounded conductor shall terminate within the panelboard in an individual terminal that is not also used for another conductor.
- - Exception: Grounded conductors of circuits with parallel conductors shall be permitted to terminate in a single terminal if the terminal is identified for connection of more than one conductor.

[Garry Blankenship]

I think that you're correct about the larger sizes. Here's one for larger conductors rated for two:

https://lh4.googleusercontent.com/-q1zd26S8Jik/TlECMba9dTI/AAAAAAAAACI/3IbD4iSzzDo/s640/Rob%2527s%2520Work%2520022.JPG

That is it Your Bobness. 400 amp feeders / panels are so common in commercial work those lugs were made to work for a 400 amp copper or alum feeder w/o having to change anything. If copper, a 500mcm, ( maybe 600 ? ), and if alum., parallel 250mcm. The same lug legal for either application.

[Garry Blankenship]

I'm a service tech now. I've taken class on this. Basically when there under the same screw touching each other it's no different than wire nutting em together. The neutral bar is designed to disperse or deplete the energy. When the wires are touching each other it will backfeed instead. When under its own screw the energy hits the bar before any other wire therefor being absorbed. When under the same screw the energy finds that the unused wire is a path of least resistance and will travel back. Not saying this happens in every instance but can and will happen depending on the circuit and what's on them when sharing the same lug or screw.

No offence Shane, but either your class or understanding of it is incorrect. The back-feed thing ain't happenin. Agree w/ your analogy "it's no different than wire nutting them together", but a neutral bar, ( call it a landing pad or terminal strip ), is electrically a giant wire nut. It does not matter whether the two wires being discussed are in the same hole or in individual holes at opposing ends of the neutral bar - - - their electrical properties would be the same. The reason two conductors in one hole are sometimes not allowed is the mechanics of the terminal may not secure two wires adequately.

[Bill Kriegh]

No offence Shane, but either your class or understanding of it is incorrect. The back-feed thing ain't happenin. Agree w/ your analogy "it's no different than wire nutting them together", but a neutral bar, ( call it a landing pad or terminal strip ), is electrically a giant wire nut. It does not matter whether the two wires being discussed are in the same hole or in individual holes at opposing ends of the neutral bar - - - their electrical properties would be the same. The reason two conductors in one hole are sometimes not allowed is the mechanics of the terminal may not secure two wires adequately.

If one of the wires under a terminal is to a multi-wire circuit and the terminal is loosened to remove the other wire, you have removed the neutral from the multi-wire circuit and now have 240 volts dividing itself among series loads, often resulting in the high pressure smoke being released from something. The same thing could conceivably happen if two circuits on different hot legs have neutrals sharing a connection and the neutrals remained touching when the terminal was loosened.

Fact is many terminals work just fine for connecting multiple wires - they just aren't listed (or in some cases permitted) to be used that way. I've been in many installations where multiple neutrals have been on the same terminal for 50 or more years with no signs of trouble. BUT, the home owner had enough sense to leave things alone. Been in others where, well, let's just say people didn't know all the ramifications of their actions.

[Joe Klampfer]

https://lh4.googleusercontent.com/-q1zd26S8Jik/TlECMba9dTI/AAAAAAAAACI/3IbD4iSzzDo/s640/Rob%2527s%2520Work%2520022.JPG

There is also a minimum conductor size... that small wire (appears as # 10 or # 8 ga) in the 600 mcm lug on the right could also be a problem.



Fact is many terminals work just fine for connecting multiple wires - they just aren't listed (or in some cases permitted) to be used that way. I've been in many installations where multiple neutrals have been on the same terminal for 50 or more years with no signs of trouble.

Completely agree. While the concerns spelled out above CAN potentially happen, but if the wires are of the same gauge & tight from original installation, the odds of a problem are likely one in a million. So in my report I may make mention of it, I would not however, make it out as a huge problem that needs to be addressed ASAP.

[Robert Mattison]

Gunnar Alquist read this old post, dated 06/24/2008.

I don't often get a chance to review older ones.

I am glad that your still a member.:cool:

[bob smit]

Trouble is... Some of those old panels did not have enough terminations.
But were in luck. One can add another buss bar and connect it with a proper size White jumper to the Neutral buss, thus creating an extended Neutral buss in service equipment.

This also works in the case when upgrading from a push-crapit where all the grounded/grounding conductors were cut short (cause the push-crapit buss assembly is at the top of the panelboard).

[Robert Mattison]

J.P., bob smith saids just add another neutral buss bar, inside the old electric panel. Connecting the new one to the existing one. Is this permit under the MFG, U.L. rules.

Now with that in mind, couldn't you just add a piece of white insulated
#12, #14, #10 etc, under the single screw, and wirenut your two individual white conductor to that one conductor underneath the set screw design for one conductor.;)

[Robert Mattison]

J.P., bob smith saids just add another neutral buss bar, inside the old electric panel. Connecting the new one to the existing one. Is this permit under the MFG, U.L. rules.

Now with that in mind, couldn't you just add a piece of white insulated
#12, #14, #10 etc, under the single screw, and wirenut your two individual white conductor to that one conductor underneath the set screw design for one conductor.;)

[Jerry Peck]

J.P., bob smith saids just add another neutral buss bar, inside the old electric panel. Connecting the new one to the existing one. Is this permit under the MFG, U.L. rules.

Only if the listing and labeling allowed same (the instructions on the panel would address that if allowed).


Now with that in mind, couldn't you just add a piece of white insulated
#12, #14, #10 etc, under the single screw, and wirenut your two individual white conductor to that one conductor underneath the set screw design for one conductor.;)

Some recent time ago when I was feeling loopy ... I said yes to that, then started feeling better and realized what I had said :( :o and corrected what I had said. And I'm feeling a bit loopy tonight trying to fight off a cold that my granddaughter so thoughtfully shared with all of us.


Not unless those two neutrals were for circuits not on the same phase.

Does not matter if the neutrals are on the same phase or not - one neutral in one terminal.

[Jim Port]

Jerry, someone was asking about pigtailing two neutrals and terminating the single pigtail on the buss. This could end up with 2 neutrals from the same leg of the panel combined into one pigtail that could overheat. If they were from opposite legs you would have created in effect a MWBC.

[Robert Mattison]

J.P. hope your feeling better.

My topic with the neutrals, was why go to the trouble of installing a new
neutrals buss bar, when the electrician doing the work could just slide a #10 or #8 or #6 wire underneath the last terminal screw, and splice onto that the two individual neutrals. Maybe write that panel is to small for the additonal loads added to it, recommend a upgrade to larger panel.;)

[Jerry Peck]

Jerry, someone was asking about pigtailing two neutrals and terminating the single pigtail on the buss. This could end up with 2 neutrals from the same leg of the panel combined into one pigtail that could overheat.



If they were from opposite legs you would have created in effect a MWBC.

And that would not overheat, I understand that, but that is not the only issue.

Would the rest of those newly created MWBC circuits meet the requirements for MWBC?

How does wire nutting the two neutral conductors together as described meet the following?
- 408.41 Grounded Conductor Terminations.
- - Each grounded conductor shall terminate within the panelboard in an individual terminal that is not also used for another conductor.
- - - Exception: Grounded conductors of circuits with parallel conductors shall be permitted to terminate in a single terminal if the terminal is identified for connection of more than one conductor.

That single neutral conductor in one terminal *does not* meet 408.41 as *each* grounded conductor *is not* terminating in its own terminal.

[Jerry Peck]

My topic with the neutrals, was why go to the trouble of installing a new neutrals buss bar, when the electrician doing the work could just slide a #10 or #8 or #6 wire underneath the last terminal screw, and splice onto that the two individual neutrals.

I understood what you were saying, and why, but because I understand it, and because you understand it, and because that "fix" is not costly, *does not make it a correct or allowed* "fix".

That's like driving 80 mph down I-95 everyday, no problem, it must be okay because ... "everyone else is doing it too" ... see if the Trooper will throw away the ticket he/she is writing because "everyone else is doing it too" so therefore it must be okay. :p I'm going to make a wild guess and say that the Trooper is not going to accept that.

[Robert Mattison]

Thanks J.P. I very much appreciated your response.

Now please correct me if what I follow up with is wrong in so many ways.

Then it is okay for the electrician to add additional neutral buss bar, within the panelboard so the grounded conductor terminates in its own individual terminal.

[Jerry Peck]

Then it is okay for the electrician to add additional neutral buss bar, within the panelboard so the grounded conductor terminates in its own individual terminal.

It depends. (That old standby answer you get so much of the time.)

It depends ... on if the neutral terminal bar you are adding is made by the manufacturer, and the panel is listed for that additional bar, and the bar is listed for that use, and ...

Thus the simple answer is 'No.', followed by the more complex answer of 'Unless ... ' (see the above items listed after 'it depends').

Generally speaking - the answer would be "No, you are not allowed to add an additional neutral terminal bar to the panel."

Now, if that was a service equipment panel, then one of the grounds taking up a neutral terminal hole could be moved to ground terminal with another ground if that panel was so listed (newer ones typically are, real old ones probably are not), or add another equipment ground terminal bar (which the panel is more likely listed for adding another ground terminal bar).

If that was not a service equipment panel, then any neutral terminal bar would have to be such that the neutral was properly isolated from ground, and if the panel was listed for an additional neutral terminal bar, and if the manufacturer made one, then it could be properly mounted and would properly isolate the neutral from ground.

I like the simple answer: "No." ;)

[bob smit]

Mr. Mattison, I'm glad you asked...
The simple answer is yes.
Standard practice has been and will always side on the way of common sense field installations where terminations are an issue. Tis why there are so many methods available to the installer.
Example: One can use any manf's mechanical lug in a panel if installed per that the lug manf's instructions. OZ Gedney (sp)? for instance, manufactures lugs, fittings, bonding means and such that can and are used in panelboards yet they themselves don't produce panelboards. A bonding jumper around a flexible raceway has a different manufacturer for; the raceway, the fittings, the jumper, the conductors inside, the termination fittings for the jumper, ETC... just too many examples to list!

This has always been understood, that field installations are many times required to meet code. Not everything performed inside a panelboard or any enclosure is required to be manufactured or designed by the manufacturer of said enclosure. There are general requirements such as 'capable to carry max current/load/voltage likely to be imposed' upon it. There are some specific requirements such as breakers or replacement parts or methods that maybe listed within the panelboard.

The most important of such jumpers would be the main bonding jumper, and here are the rules for it:
NEC 250.28, For a grounded system, main bonding jumpers and system bonding jumpers shall be installed as follows:
(A)copper or other.... A main bonding jumper and a system bonding jumper shall be a WIRE, BUS, SCREW, OR SIMILAR SUITABLE CONDUCTOR.
(B)screw shall be green....
(C)connected in manner per 250.8....
Let us see what 250.8 has to say.

NEC 250.8, Connection of Grounding and Bonding EQUIPMENT
(A)permitted methods. Grounding conductors and bonding jumpers shall be connected by one of the following means:
(1)Listed pressure connectors
(2)Terminal bars
(3)Pressure connectors listed as grounding and bonding equipment
(4)Exothermic welding process
(5)Machine screw-type fasteners that engage not less than two threads or are secured with a nut
(6)Thread-forming machine screws that engage not less than two threads in the enclosure
(7)Connections that are part of a listed assembly
(8)Other listed means

Notice #(7) lists connections that are part of a listed assembly. Notice also that this is just one of the methods available. One can field install multiple wireways such as troughs or gutters to inter-connect service or other panels all made by different manufacturers with the termination for a main bonding jumper, a system jumper, a grounding or grounded termination made in any manner listed above, not causing neutral current to run on grounding conductors. In commercial and especially industrial installations, all kinds and manner of bonding, grounding terminations and jumpers are utilized to perform the code requirement yet many are made by numerous manufacturers and are installed in numerous manners.

The list is obvious, the intent should be obvious, that means other than what a particular manufacturer makes for their panel can be used for bonding jumpers and terminations as long as it falls within at least one of the aforementioned list items.
Again, this has always been understood by the code, electricians, and any AHJ I've known including yours truly.

So the answer to your question is yes. Additional neutral or grounding busses and jumpers can and are used in panelboards and other enclosures as long as the jumpers and/or buss falls under one of the items in the list and the buss is listed for said purpose. Note that not all buss or terminal bars are manufactured by a panelboard manufacturer, yet they are listed for the purpose and can be used as necessary to meet the intent(s) of the code.

[Garry Blankenship]

Interesting stuff - - - it can be legal and it can be illegal. I have limited residential experience, but my personal answer was to braid as many ground wires together that would fit into the opening, ( 4 # 12s or so ), effectively making your own stranded conductor. Never mixed sizes. In doing so you do not burn so many lug openings and have enough openings left to terminate the neutral wires separately. I admit I was not thinking about the "open neutral" possibility which obviously matters, but was concerned that the insulation on the neutral wires could interfere with good contact, unless excessively stripped back.

[H.G. Watson, Sr.]

Current code says terminations approved for more than one conductor shall be so identified. If it's not stated by the mfg. as OK for two or more conductors, not to code. There are lugs made for two conductors, but I've only seen them in larger conductor sizes. The 2002 section Gunnar cited no longer exists in the 2011 code book.

Yes it sure does exist in the 2011 code! It was re-codified to 408.41 from 408.21 back in (IIRC) 2005 (when the entire article was re-codified), where it remains in Part III (Panelboards), unchanged in 2008 or 2011.

110.14 also remains, as does 110.14(A). Except for the recent addition of a single-sentance paragraph to the end of 110.14 (regarding more finely stranded conductors) and an editorial style change (FPN to "informational note", it also remains, as referenced, unchanged.

Different sized conductors, type, or length, do not meet the requirements of paralleled installations. The exception does not provide for tapping off. The photo recently provided pictures non-compliant conditions. The marking clearly indicates the size range when terminating two conductors - those 2 conductors MUST be the same size & type to share that terminal. To utilize the 408.41 Exception, the conductors must actually be a Code compliant circuit installation with paralleled (that includes same size, type, length & location) conductor(s) and still meet 110.14(A).




408.41 Grounded Conductor Terminations. Each grounded conductor shall terminate within the panelboard in an individual terminal that is not also used for another conductor.

Exception: Grounded conductors of circuits with parallel conductors shall be permitted to terminate in single terminal if the terminal is identified for connection of more than one conductor. .

[Garry Blankenship]

Acknowledging due credit to Gunnar and H.G. Both brought a distinction to the fore that I had not recognized. Regarding double tapped or multiple conductors in the same hole, both mfgs. and the code distinguish grounding conductors, ( ground wires ), from grounded conductors, ( neutrals ). Neither mfgs. nor the code appear to sanction multiple neutral wires in the same hole, but do green light multiple ground wires under the right conditions. I say "appear" because terminations approved for multiple conductors grays this a bit. So my updated understanding is that multiple neutrals are a "NO" , but multiple ground wires are sometimes "OK". Thanks H.G for discovering that NEC 408.21 was shuffled to NEC 408.41. I am sooo thankful Home Inspectors should not cite code :)

[H.G. Watson, Sr.]

Which photo are you referencing?

"The photo recently provided...".

Are you unfamiliar with the adverb: recently?


recently (adv): In the recent past.

recent (adj): 1. Of, belonging to, or occurring at a time immediately before the present. 2. Modern; new.

So, Robert Meier, I ask you:


Which photo provided to this nearly 4-and-a-half-year-long topic discussion would fit the description I used, specifically "the photo recently provided" ?!?

Hmmm. Still unsure?

I'll categorize & inventory the possibilities (all photos contributed to the discussion thread), for you to ponder. 8 photos have been "provided" to this topic discussion thus far:


A solitary photo contribution to this discussion in the last 46 months, provided in July 2012, only 10 days prior to the comment you quoted and inquired;
two individual photo posts provided in February 2008; or
five photos contributed in a single post in September 2008.So, Robert Meier, which DO YOU THINK is the best fit for "the photo recently provided"? A photo that was provided

10 days prior,
46 months prior, or
53 months priorto the date/time stamp of my comment?

[Nick Ostrowski]

HG, didn't you just admonish JP for his responses in another thread in the homeowner section? It goes both ways my dear Watson.

[Jerry Peck]

HG, didn't you just admonish JP for his responses in another thread in the homeowner section? It goes both ways my dear Watson.

Yeppers, he did, and all the while showing his arse as he was incorrect, he should have been admonishing himself.

Oh well, that is Watson for you.

Not sure why he is still around, though. I, and others, have said that he can, at times, provide excellent information, only we have to put up with the rest of his crap for a few gems ... not sure that his gems are worth the rest of his crap we put up with.

Oh well, it is Brian's site and his decisions, we have been through this before, then Watson goes silent for a while, then he comes back and starts out like a decent fellow ... but soon loses his cool again.

I looked up "dolt" after I used it and, dang if that does not describe him:
- Related to DOLT
- - Synonyms: airhead, birdbrain, blockhead, bonehead, bubblehead, chowderhead, chucklehead, clodpoll (or clodpole), clot [British], cluck, clunk, cretin, cuddy (or cuddie) [British dialect], deadhead, dim bulb [slang], dimwit, dip, dodo, idiot, donkey, doofus [slang], dope, dork [slang], dullard, dumbbell, dumbhead, dum-dum, dummkopf, dummy, dunce, dunderhead, fathead, gander, golem, goof, goon, half-wit, hammerhead, hardhead, ignoramus, imbecile, jackass, know-nothing, knucklehead, lamebrain, loggerhead [chiefly dialect], loon, lump, lunkhead, meathead, mome [archaic], moron, mug [chiefly British], mutt, natural, nimrod [slang], nincompoop, ninny, ninnyhammer, nit [chiefly British], nitwit, noddy, noodle, numskull (or numbskull), oaf, pinhead, prat [British], ratbag [chiefly Australian], saphead, schlub (also shlub) [slang], schnook [slang], simpleton, stock, stupe, stupid, thickhead, turkey, woodenhead, yahoo, yo-yo

[H.G. Watson, Sr.]

HG, didn't you just admonish JP for his responses in another thread in the homeowner section? It goes both ways my dear Watson.


Hey, Its one of scores of questions from the same individual, where he has quoted the answer to his supposed question. Singles out my posts to snip, quote & question, often.

Amazingly weak powers of observation? Participating on a forum, where each post appears in order, is dated, time stamped, the participant's name & location appears in conjunction with each post.

Figured it might be: a vocabulary issue; a cognitive, logic, or memory disfunction; ignorance or intentional. Whatever the case, I ANSWERED THE QUESTION, and did so without resorting to Peckmanship or Peckerheadism.

Asked (with ??) and answered with enthusiasm, and in the event that any of the possibilities I pondered might have driven the questioner's pattern & question - would be addressed, including the tools to answer his own similar questions in the future.

[Jim Port]

"The photo recently provided...".

Are you unfamiliar with the adverb: recently?


recently (adv): In the recent past.



recent (adj): 1. Of, belonging to, or occurring at a time immediately before the present. 2. Modern; new.
So, Robert Meier, I ask you:


Which photo provided to this nearly 4-and-a-half-year-long topic discussion would fit the description I used, specifically "the photo recently provided" ?!?

Hmmm. Still unsure?


I'll categorize & inventory the possibilities (all photos contributed to the discussion thread), for you to ponder. 8 photos have been "provided" to this topic discussion thus far:


A solitary photo contribution to this discussion in the last 46 months, provided in July 2012, only 10 days prior to the comment you quoted and inquired;
two individual photo posts provided in February 2008; or
five photos contributed in a single post in September 2008.
So, Robert Meier, which DO YOU THINK is the best fit for "the photo recently provided"? A photo that was provided

10 days prior,
46 months prior, or
53 months priorto the date/time stamp of my comment?

While the original date of this thread was years ago, it was resurrected on 7/20/12. The photo recently posted by Garry B was dated 7/22/12. I guess within the last 2 weeks is not recent enough?

[H.G. Watson, Sr.]

While the original date of this thread was years ago, it was resurrected on 7/20/12. The photo recently posted by Garry B was dated 7/22/12. I guess within the last 2 weeks is not recent enough?

Work at being obtuse or your natural state?

10 days one POSTED photo. All others more than 3 years old.

Garry Blankenship never POSTED a photo, he quoted a post from Meier dated 7/21/2012, wherein Meier inserted THE posted photo. If anything, Garry B, reposted via quoting, but ITS THE SAME photo. :rolleyes:

[Dan Harris]

Work at being obtuse or your natural state?

10 days one POSTED photo. All others more than 3 years old.

Garry Blankenship never POSTED a photo, he quoted a post from Meier dated 7/21/2012, wherein Meier inserted THE posted photo. If anything, Garry B, reposted via quoting, but ITS THE SAME photo. :rolleyes:

Geez hope I don't catch crap for bringing this back up :)

Oh well what the heck, here it is :D
Yesterday I wrote up dbl neutrals. An electrican showed up on the site,the customer asked him how much to correct this and a couple other items.

The sparkies response. The wires are too short, to correct it I would have to pigtail the wires, then stated it's safer to leave the dbl taps since they were tight and the wires were the same size.
He did admit it wasn't correct.
Oh well I tried, and it's still in my report