Is this correct

Mike,

Watch the video.

It makes it clear that at no time was it permitted to have more than one neutral under a screw. Common yes, correct no,

Michael.

I am not disputing what UL Standard has to say nor am I disputing what a lot of the electrical geniuses have to say about the grounded neutral conductor and its termination.
What I am saying is simple and it is so simple that it is hard for most to understand. Let me try it this way. First let’s look at what the code had to say before the induction of 408.21 in the 2002 code cycle. Here is the page from the 1999 cycle.

This has gone unchanged for the past code cycles but what is important is the verbiage of that section. Unless the panel manufacturer included these instructions with the equipment when it was sold then the installer would only have the information outlined on the label that was included when the panel was sold. Most of the panels sold even as late as 2005 has clear language that the grounding bar which in service equipment is also the neutral bar will accept more than one conductor.
With the labels that the manufacturer furnished with the panels when they were sold Jim Pauley said that verbiage should be added to the NEC to assure the proper installations were being made.

Now let’s step outside the box and think about this a little more. To start this thinking process let me ask a couple of simple questions.

If all that was needed to enforce one white wire per screw why should there have to be a code section adopted to enforce something that the code is supposed to already state?

If the code already had verbiage to enforce one white wire per screw why wouldn’t someone like Mike Holt already know about it?

The simple answer to these questions is that UL Standard 67 had to be bought from UL in order to know what it contained and the standard was not included with the installation instructions.

Now let’s carry this thinking process a little future. Should I decide that I wanted to build my own panel I could call Met Lab. Which is one of the recognized testing labs and have them test and label my panel. They wouldn’t be allowed to use the specs of another testing lab such as UL for their testing as this would infringe on copyright material.
Here UL Standard 67 would not come into play at all.

The deal with UL Standard 67 is simply the instructions that the manufacturer is to use to design and manufacture the panel not the installation instructions for the electrician to use.
If this standard was to be used by the installer then there would be a booklet that came with every panel sold. What the installer has to use is the information that the manufacturer included with the panel which is the label glued to the inside.

The labeling of the panel board(to UL 67) is to assure compliance with the standard used to evaluate it including any required product labeling for conductor installation.

So in essence the single neutral per termination has always been there whether it was clearly stated in the NEC or not.

Michael

I agree with what you are saying in the post above as well as what Holt and others have said.

What I am trying to point out is that UL Standards are not part of the installation instructions that come with equipment when it is sold.

In order for an electrician, electrical inspector or a Home Inspector to obtain a copy of the UL Standards they would have to buy each and every copy. This would entail those who installed or inspected electrical equipment to have a library larger than the law library at the courthouse. This library would cost as much if not more than the building that housed the books.

Prior to the adoption of the text found in the 2002 code cycle the electrician, electrical inspector or Home Inspector only had 110.3(B) to enforce when it came to more than one white wire per screw. The label that was included with the panel had the installation instructions printed on that label and it included more than one conductor per screw.
To say that the doubling of conductors on the grounding terminal bar in a panel was not code compliant before the text was added to the code would be a false statement simply because the label in the panel allowed the installation.
To say that more than one white wire per screw was in violation of the listing of the panel would be true but the manufacturers was the ones that was in violation not the installers as they wasn’t providing the proper information with their installation instructions.

Please understand that I am not saying that doubled white wires shouldn’t be called out but with the same breath I am saying there is no verbiage prior to the 2002 cycle of the code that could be used to enforce UL Standard 67 to an installation which has more than one conductor per screw simply due to the fact that the standard is not part of the labeling of the panel.

In a discussion with someone else about the UL Standards I came across this;

http://i3.photobucket.com/albums/y63/jwelectric/AnnexA1.jpg

The NEC itself makes the statement that the UL Standards is for information only and not enforceable