UL67 11th R2003 Panelboards

[joe tedesco]

12.3.10 An individual terminal shall be provided for the connection of each branch-circuit neutral conductor.​

In what edition was this sentence first added?

 

[jwelectric]

During the Feb. 2003 revision

 

[jwelectric]

To carry this question just a little deeper into this ongoing discussion;

Can UL Standard 67 be incorporated into the instructions included with the listing and labeling that is outlined in 110.3(B)?

For those that might not know what UL Standard 67 is more information can be obtained here as to what a standard is about and pricing for purchase.

I contend that a Standard is not part of the instructions included with the listing and labeling of equipment as outlined in 110.3(B) simply because it is a UL document that has to be purchased separately, at a very high cost if I might add ($1000.00), and therefore is not included as part of the instructions included with the listing and labeling.

 

[jim dungar]

A UL listing/label only says the device built at the factory in accordance with the appropiate UL standard.

I know there are some installation standards (in particular NEMA), but I know of no UL standard that deals with "field" installation.

 

[gndrod]

114.14(a)

114.14(a)

A UL listing/label only says the device built at the factory in accordance with the appropiate UL standard.

I know there are some installation standards (in particular NEMA), but I know of no UL standard that deals with "field" installation.

Jim, I agree totally. In all the years of installiing panels, not once have I found listed or labelled instructions on how many conductors are required in terminals within the equipment. I believe Article 110.14(a) 1981 'Terminals' was the second time I witnessed an AHJ enforce the ruling of using a single conductor in a main panel grounded termination. That statement is still unchanged to this day in the 2008.

Additionally, interpretation can go further to included grounding conductors as well, should an AHJ have a reason to enforce conductor termination safety. JMO rbj

 

[iwire]

In all the years of installiing panels, not once have I found listed or labelled instructions on how many conductors are required in terminals within the equipment.

I don't understand, every panel I have installed has had a label indicating the limitations and requirements of the terminals.

 

[iwire]

A UL listing/label only says the device built at the factory in accordance with the appropiate UL standard.

Jim, an HVAC unit has a Label that specifies the MCA, MOP voltage etc.

IMO that label is part of the listing and labeling that 110.3(B) references.

 

[jim dungar]

Jim, an HVAC unit has a Label that specifies the MCA, MOP voltage etc.

IMO that label is part of the listing and labeling that 110.3(B) references.

Bob,

I agree.

I did not mean to include "labels and instructions required as part of the UL Listing". I meant only to indicate the UL Label itself says the item was built to UL standards and does not specifically infer how to install or use the item.

 

[jwelectric]

This thread was started by Joe and he is seeking information concerning UL Standard 67 and how it relates to 408.21 of the 2002 code cycle (408.41 of the 05).

Joe contends that the standard can be used in conjunction with 110.3(B) to substantiate more than one neutral under one screw before the introduction of 408.21 of the 2002 code cycle as can be seen in this post.


What he is using to back his statements is the proposal made by Jim Pauley;
(Log #3287) 9- 113 - (384-21 (New) ): Accept

SUBMITTER: James T. Pauley, Square D Co.

RECOMMENDATION: Add a new 384-21 to read as follows:
384-21. 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.

SUBSTANTIATION: This revision is needed to coordinate the installation requirements with a long standing product standard requirement. Clause 12.3.10 of UL 67 (Panelboards) states ?An individual terminal shall be provided for the connection of each branch-circuit neutral conductor.? The requirement has been enforced in the past by a close review of the manufacturers markings and by NEC 110-3(b).

He also posted this label from the panel in his home and makes the statement that the word ?wire? is singular when it refers to the Neutral.

I made the statement that UL Standard 67 is used by UL and the manufacturers of panels and plays no role in what is included in the installation instructions with the listing and labeling that is enforced by 110.3(B).

I also contend that most panels now and then will have a statement on the label concerning the number of conductors that are allowed under one screw of the ground bar as outlined in the label that he posted. This is why section 408.21 was added to the 2002 code cycle (408.41 in 05 cycle).

Then came the question of what is a ground bar and what is a neutral bar. As can be seen by this Cutler Hammer panel there is no difference in the service panel. Either bar can be used for both the Equipment Grounds and the Neutrals.

After the second day of this discussion I start getting questions about adding a ground bar to the panel in order to move the grounded neutrals so there wouldn?t be more than one conductor per terminal. This picture was sent to me by email and the sender wanted to know if this would comply with 110.3(B) as outlined in UL Standard 67.

I replied by starting this thread so they could see the dangers of adding a ground bar to the panel and moving the grounded neutral to that bar.

To obtain a copy of UL Standard 67 it must be purchased from UL at a price of around one thousand dollars. I contend that if the standard must be purchased then it is not part of the instruction included with the listing and labeling therefore outside the scope of the NEC.
I also contend that when teaching classes UL Standard 67 should not be taught as being a requirement of 110.3(B) of the NEC.

 

[jwelectric]

Jim, I agree totally. In all the years of installiing panels, not once have I found listed or labelled instructions on how many conductors are required in terminals within the equipment. I believe Article 110.14(a) 1981 'Terminals' was the second time I witnessed an AHJ enforce the ruling of using a single conductor in a main panel grounded termination. That statement is still unchanged to this day in the 2008.

Additionally, interpretation can go further to included grounding conductors as well, should an AHJ have a reason to enforce conductor termination safety. JMO rbj

Yes I also agree that any UL standard is not part of the instructions included with the listing and labeling.

Every panel I have installed had information on the label concerning the ground terminal bar.

What 110.14(A) states is;
Terminals for more than one conductor and terminals used to connect aluminum shall be so identified.

This statement is unchanged from 1968 except, “and terminals used to connect aluminum” was added in the 1971 cycle.


If the label in the panel states that up to three conductors sizes #10 and smaller are allowed then the instructions on the label will allow the installations and still be in compliance with 110,3(B) and 110.14(A).

It was due to this debate that Jim Pauley made the proposal of one screw one neutral.

 

[joe tedesco]

Here's a picture

Here's a picture

Here's a picture of a panelboard for use concerning this discussion.

UL 67, 12.3.10 An individual terminal shall be provided for the connection of each branch-circuit neutral conductor.​

 

[jwelectric]

Here's a picture of a panelboard for use concerning this discussion.

UL 67, 12.3.10 An individual terminal shall be provided for the connection of each branch-circuit neutral conductor.​

Joe

In this panel the ground bar on the left could not be used to land the grounded neutral conductors on simply because there is no bonding jumper installed between the two bars.

To land the neutral on the bar on the left would make the panel enclosure itself part of the circuits or in other words it would energize the enclosure.

Now explain just what if any of this has to do with Standard 67 being part of the instructions included with the listing and labeling.

(B) Installation and Use. Listed or labeled equipment shall be installed and used in accordance with any instructions included in the listing or labeling.

 

[jim dungar]

Yes I also agree that any UL standard is not part of the instructions included with the listing and labeling....

...Every panel I have installed had information on the label concerning the ground terminal bar....

...It was due to this debate that Jim Pauley made the proposal of one screw one neutral.

I interpret Pauley's proposal as being an attempt to make the installation requirements (NEC) correspond to manufacturing requirements (UL). Because the NEC is generally a permissive code (if it doesn't say no then it is okay) and in your label example the singular form of the word "wire" only infers a limit of one conductor.

 

[jwelectric]

I interpret Pauley's proposal as being an attempt to make the installation requirements (NEC) correspond to manufacturing requirements (UL). Because the NEC is generally a permissive code (if it doesn't say no then it is okay) and in your label example the singular form of the word "wire" only infers a limit of one conductor.

What has happened is more and more people are buying ground bars and adding them to a panel to have the space to install the grounded (neutral) conductor under one screw. This has led to the grounded neutral being installed like the picture below which in my opinion is a far greater danger than two under one screw or the neutral and the equipment ground of the same circuit under one screw.

According to the comments in NEC 2002 Analysis of Changes on page 252 the only danger in having two neutrals under one screw is,

But to get back to the point of Standard 67, there are some educators out there that are teaching that to have two neutrals under one screw is a violation of 110.3(B) as outlined in UL Standard 67.
I contend that UL Standard 67 plays no role what so ever in the instructions included in the listing and labeling of a panel.
For Standard 67 to be quoted as a code violation the Standard would be required to be included with the panel when the panel was sold and not purchased separately at the price of $1000.

 

[jim dungar]

But to get back to the point of Standard 67, there are some educators out there that are teaching that to have two neutrals under one screw is a violation of 110.3(B) as outlined in UL Standard 67.
I contend that UL Standard 67 plays no role what so ever in the instructions included in the listing and labeling of a panel.
For Standard 67 to be quoted as a code violation the Standard would be required to be included with the panel when the panel was sold and not purchased separately at the price of $1000.

Basically I agree. You can not cite a manufacturering standard as an installation requirement.
Although it would be okay for them to say that it violates 110.3(B) based on the panel termination information/label if one is required by UL 67.

 

[gndrod]

Bob,

I agree.

I did not mean to include "labels and instructions required as part of the UL Listing". I meant only to indicate the UL Label itself says the item was built to UL standards and does not specifically infer how to install or use the item.

I interpreted that as well.

Bob, Is there a label you can post that has a detailed reference to the single grounded conductor per terminal UL references? rbj

 

[joe tedesco]

Annex A Product Safety Standards

Annex A Product Safety Standards

Annex A Product Safety Standards​

Annex A is not a part of the requirements of this NFPA document but is included for informational purposes only.​

This informational annex provides a list of product safety standards used for product listing where that listing is required by this Code. It is recognized that this list is current at the time of publication but that new standards or modifications to existing standards can occur at any time while this edition of the Code is in effect.

This annex does not form a mandatory part of the requirements of this Code but is intended only to provide Code users with informational guidance about the product characteristics about which Code requirements have been based.