Need help with main panel board buss bar

[Mike Whitt]

Joe

With the greatest of respect for your knowledge just what are you trying to prove?

We are discussing multi conductor connection on a terminal bar in a panel and you come in here posting a bunch of links to multiwire branch circuits and are doing nothing more than mudding the waters of a discussion, why?

Barring all these links that you are so famous for what constructive do you have to add to the subject at hand.
What is your personal opinion on the matter?

If you want to post links at least post information that concerns the subject matter that is being discussed, please.

[jtedesco1]

Talking about open neutrals, and their hazards. I can post anything that is related.

I also recommend reading the subject of the: "The Grounded Neutral" in this publication.

[Mike Whitt]

Joe

I believe that the thread title is, “Need help with main panel board buss bar” not multiwire circuits nor, “Talking about open neutrals, and their hazards.”

What we were discussing was the use of one screw on a terminal bar to terminate more than one neutral.

You then come in here and post a story about some electrician in an industry that got hurt with a installation that involved a neutral that originated in another panel and then threw in some more links about multiwire circuits and finally one to a book that has over 800 pages that was written way back in 1913.

I am respectfully asking you what all this has to do with more than one conductor under a screw in a panel board?

In this thread you have offered nothing that would concern the subject matter of the original post. You seem dead set on doing nothing more than demolishing what has already been covered by those who have posted.

Yes I suppose that you can post anything you want anywhere on the internet that will allow you the privilege but some of us here are trying to get a better understanding about what and why some things that are floating around the internet mean.

In the original post of this thread the poster ask this question:

Originally Posted by smcintire

Need help with main panel board buss bar. how far back in the code books or any other listing is it a defect to double tap grounded conductors at the buss bar? I have found NEC 408.41 which appears to be 2005 code and NEC 408.21 from 2002 Code. I have always assumed this went back to the 60's. I am doing research on a house built in 1990 with numerous double taps. Prior to 2002 was it mostly dependent on manufactures or is there something else?

He did not ask about multiwire circuits and as an educator I have tried to give him an answer to his question instead of sending him to a bunch of junk links that has nothing at all to do with his question.
If you want to use a link to something at least try to link to something that has to do with the original question or post your opinion of the dangers involved in the use of one screw for more than one neutral.
Please, as an educator don’t be mudding the water so that the true meaning of the original question is completely lost.

I am eagerly awaiting to hear what YOUR, not a bunch of links, opinion on more than one neutral per screw might be.

[jtedesco1]

Only one grounded neutral conductor is permitted under the termination on a neutral bar, has been ever since they started making cabinets and panelboards.

Here's what can happen!

[Mike Whitt]

Originally Posted by jtedesco1

Only one grounded neutral conductor is permitted under the termination on a neutral bar, has been ever since they started making cabinets and panelboards.

Could you please give us some data that supports this statement.
The NEC did not address the matter until 2002 code cycle. The panel manufactures have never included any information in their installation instructions concerning the neutral conductor and still do not till this day.
Just what are you basing your statement on?
Just what do you see as the danger in doubling the neutrals?
Surely it is not the link that you have posted here.

Originally Posted by jtedesco1

Here's what can happen!

Are you saying that this man died from two neutrals under one screw?
The story said that he cut a cable.
Who is correct?

This is what I am talking about Joe. You still have offered nothing that addresses the original post.
Just what does the man in the attic have to do with double lugging a neutral?
How does the link contribute to the original post?
What part of the link helps the original poster understand the concept of double lugging the neutrals?
Help me to understand what you are trying to teach those that don’t understand the need to not double lug the neutral?
What I have done is post directly to the question and used information obtained that addresses the reasons why the doubling of neutrals is not allowed. I have tried to not muddy the subject with matters that don’t address the question nor a bunch of junk that serves no purpose at all.

[jtedesco1]

Here's the label on the inside of my condo panelboard cabinet cover!

The building was first occupied in 1981.

See the "Neutral Bar Wire Size"

[Mike Whitt]

Help me out Joe



Where does it say one wire per terminal?

I see that the ground bar will accept two or three #14 through #10 copper but I don't see where it says only one grounded wire per terminal, do you?

As a matter of fact the only information on the neutral is the tightening torque.

If this is a main panel as you say it is then 250.24 is going to require that the equipment grounding conductors, the grounding electrode conductor, the panel enclosure and the grounded (neutral) all be bonded togeather therefore there is no such thing as the equipment grounding terminal in this main panel. This must mean that any and all conductors connected to any and all terminal bars in this enclosure would carry the same weight.

Again I ask for some concrete danger in the installation of two neutrals under one screw except to the removal on one of the conductors while the other is energized.

[jtedesco1]

This is not the main it is a panel in my unit that is supplied by a Subfeeder OC device. The word Wire is singular!

[Michael Larson]

All right guys.

Since you both are licensed electricains answer me this:

1. If this has been a requirement since UL 67 came out, why haven't those who teach electricians been able to communicate this fact to all interesed parties?

2. I see a EGC and grounded conductor from the same circuit under a single screw very often. Why do so many licensed electricians do this? And what is the hazard associated with this?

[jtedesco1]

Look at the attachment here for many of the same questions, with many of the same answers by others, I like Roy's the best!

http://www.nachi.org/forum/search-819480.html

[Michael Larson]

Joe,

I know what the code says and I even participated in many of those threads.

My take away is that many old dog electricians(a some newer ones too I assume) refuse to change their methods until the AHJ call on it.

The 2002 NEC certainly clairified it for the AHJs but that still doesn't excuse the somewhat common practice of having a EGC and grounded conductor under the same screw.

I am surprised the that NFPA took so long to make the changes.

I asked the questions because this practice puts the HI in the position of calling it out as a problem and then having the electrician and or AHJ say it's not a real problem.

[jtedesco1]

Originally Posted by mlarson

Joe,

I know what the code says and I even participated in many of those threads.

My take away is that many old dog electricians(a some newer ones too I assume) refuse to change their methods until the AHJ call on it.

The 2002 NEC certainly clairified it for the AHJs but that still doesn't excuse the somewhat common practice of having a EGC and grounded conductor under the same screw.

I am surprised the that NFPA took so long to make the changes.

I asked the questions because this practice puts the HI in the position of calling it out as a problem and then having the electrician and or AHJ say it's not a real problem.

Very true, and this problem will never go away, the proposer was calling attention to a subject that was in the standards long before some of the installers were even born! I have had many discussions with some of the "old timers" who never had the options we have today with the vast amount of information available on the internet. Many of the issues we argue about here are so old they can vote. I guess we must take a firm position, and as far as I am concerned the issue is real and the subject is one that will put the person in front of a Judge and Jury in the minority.

I will stand behind any Home Inspector here who confronts someone who says it is OK and does not know of the hazards involved.

You should always identify all the defects you find!

That NEUTRAL will kill you under certain circumstances.

[Michael Larson]

Well said Joe T. Thank you.

[Mike Whitt]

Originally Posted by jtedesco1

This is not the main it is a panel in my unit that is supplied by a Subfeeder OC device. The word Wire is singular!

Yes it is singular in the grounding terminal but goes on to say that two or three can be installed.

Got to do better than that Joe.

[jtedesco1]

Originally Posted by Mike Whitt

Yes it is singular in the grounding terminal but goes on to say that two or three can be installed.

Got to do better than that Joe.

Yes you are correct -- for the "Equipment Grounding Conductor" -- aren't we discussing the "Grounded (Neutral)" conductor?