Section 110.14(A)

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bphgravity

Senior Member
Location
Florida
Proposal: Remove the FPN from above 110.14(A) and place it in the text as a requirement for terminal connections.

"...or smaller conductors. All terminations shall be made per the manufacturers tightening torque listing or labeling."

Substantiation: FPN's are not enforceable and the requirement of 110.3(B) is too general as torques specifications are commonly overlooked.

I plan on contacting several manufacturers of torque tools to get an annual sales account verses other common electrical tools. I predict sales of torque screwdrivers and wrenches are well bellow what you would expect for a tool needed for every panelboard and overcurrent device made. I have given seminars to over 500 electricians in the state of Florida and recall only a handfull claiming they own a torque tool of some kind. I even asked this on this forum without much results.
 

rbalex

Moderator
Staff member
Location
Mission Viejo, CA
Occupation
Professional Electrical Engineer
Re: Section 110.14(A)

I'd support this one in principal and reword as follows:

"Terminations shall be torqued per the manufacturer's instructions."
What this wording will do is require the product standards to include torque requirements, and any other unique issues if necessary, as part of the manufacture's instructions. Believe me, NEMA & UL will pick this up, especially if you say suggest they do.

You may also want to contact Jim Pauley at Square D for support. He was the primary originating author of 110.14(C). Theoretically 110.14(C) could have been enforced through 110.3(B) too; but so many folks were unaware that it became desirable to include it directly in the Code.
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
Re: Section 110.14(A)

I'd be willing to bet very few electricians even know there is a torque spec on terminations. Its why UL requires UL listed control panels have a specific label indictaing what that torque requirement is for each wire coming into a UL listed control panel.

Not that I believe anyone actually uses a torque wrench to tighten up their connections, except maybe on larger wires.
 

charlie

Senior Member
Location
Indianapolis
Re: Section 110.14(A)

I think the concept is great; however, how does the AHJ enforce this new rule? One of the basic tests is whether or not something is enforceable, this is not. The AHJ can not "test" the torque without ruining the original torque. With aluminum conductors, the re-torque would further deform the conductors.

This is one that I really like but I don't know how to do it. :confused:
 

612278

Member
Re: Section 110.14(A)

Hello-

The MFG of breakers can install "shear screws when the proper torque is applied, but is this what we want?

STEVE
 

pierre

Senior Member
Re: Section 110.14(A)

Torquing is a requirement already. Every time one installs a panel, there are torque requirements labeled inside of the enclosure.

We are supposed to follow manufacturer's installation instructions - 110.3(B)
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
Re: Section 110.14(A)

We are supposed to follow manufacturer's installation instructions - 110.3(B)
No!...We are required to follow the instructions included in the listing and labeling. These are not the same as the manufacturer's instructions. However, the torque requirements are listing and labeling instructions and must be followed per 110.3(B)
(B) Installation and Use. Listed or labeled equipment shall be installed and used in accordance with any instructions included in the listing or labeling.
Don
 

charlie

Senior Member
Location
Indianapolis
Re: Section 110.14(A)

I have been told by a UL representative that every screw, bolt, and nut are torqued for the UL tests. It makes no difference whether it is on a circuit breaker, receptacle, bus bar, or anything else. If it has threads and is required to be used for assembly, it gets torqued. :D
 

ryan_618

Senior Member
Re: Section 110.14(A)

Originally posted by don_resqcapt19:
We are supposed to follow manufacturer's installation instructions - 110.3(B)
No!...We are required to follow the instructions included in the listing and labeling. These are not the same as the manufacturer's instructions...
(B) Installation and Use. Listed or labeled equipment shall be installed and used in accordance with any instructions included in the listing or labeling.
Don
Don...I agree with you, but I found this link very interesting, which is from UL and seems to disagree with both of us...

THIS SITE

QuestionAre the installation instructions
part of the UL Listing?
Are all Listed products required
to have installation instructions?
Are installation instructions
reviewed by UL?


AnswerInstallation instructions
are considered to be a
part of the UL Listing.
The UL Standards for Safety used
to investigate products contain
specific requirements regarding
the content and appearance of the
instructions. Installation instructions
are not required to be
marked with the UL Mark, but
they are required to be provided
with the product bearing the UL
Mark. Some products are not required
to have installation instructions
when the National
Electrical Code contains all the
necessary installation requirements,
such as outlet boxes.
UL staff reviews the instructions,
both during the initial evaluation of
the product, as well as during the
continual Follow-Up Service at the
factories. The clarity of the instructions
is also reviewed.
Edited to include text from thread

[ October 26, 2004, 09:19 AM: Message edited by: ryan_618 ]
 

ryan_618

Senior Member
Re: Section 110.14(A)

Originally posted by charlie:
I think the concept is great; however, how does the AHJ enforce this new rule? One of the basic tests is whether or not something is enforceable, this is not. The AHJ can not "test" the torque without ruining the original torque. With aluminum conductors, the re-torque would further deform the conductors.

This is one that I really like but I don't know how to do it. :confused:
Charlie I couldn't agree more. I also think the idea is great, but there is no way that I can do this as an inspector.
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
Re: Section 110.14(A)

Ryan,
My comment to UL is, "you can't have it both ways!". UL has classified breakers for use in panles in violation of the panel manufacturer's instructions. They are telling us that we must follow the manufacturer's instructions but that classified breakers can be used in violation of those insttructions!
Don
 

bphgravity

Senior Member
Location
Florida
Re: Section 110.14(A)

Would it be out-of-line for an inspector to ask the installer if they have torqued the terminations per requirements? I have never had no or ever heard of an inspector even making this request. Maybe installers would be more inclined to torque terminations if the code makes it a specific requirement and inspectors make it an issue?
 

612278

Member
Re: Section 110.14(A)

HI everyone-

I've had a LA city inspector have me snug the terminals of a panel board, then do my final torque in his presence's.
 

ryan_618

Senior Member
Re: Section 110.14(A)

You know Don it's funny, I was arguing about this very thing...classified breakers and whether or not its a violation, when somebody showed me this link! As I stated before, I have always shared your thoughts on the subject and was absolutely blown away when I saw this from UL. I disagree with it wholeheartedly.
 

rbalex

Moderator
Staff member
Location
Mission Viejo, CA
Occupation
Professional Electrical Engineer
Re: Section 110.14(A)

Manufacture's instructions are always a consideration in product liability issues. And UL can indeed have it both ways; they write the rules on how they are willing to certify a product's use.

As an design engineer, I can only state that, if a product performs as it is certified and is installed as per that certification, it will perform safely in my design. I am usually qualified to say it is installed per the certification, but I am not qualified to say that it will perform properly. That is left to NRTLs or the manufactures, if necessary.

Both over and under torquing are potentially dangerous. I have found over-torquing more common.

I have never been an "official" AHJ, but I have never had a problem having my construction crews properly torque connections. Fairly early in a job I simply ask them what the torque requirements are. If they know, I ask them to show me how they did or intend to do it; if they don't know, I still ask the same question and essentially remind them of 110.3(B). Once we establish how it is to be done, I review enough to feel confident. It rarely takes more than a single inquiry and I've run jobs with literally millions of terminations.

There are enough "free wheel" torque wrenches and screwdrivers out there that checking for over torque isn't that difficult.
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
Re: Section 110.14(A)

Bob,
There are enough "free wheel" torque wrenches and screwdrivers out there that checking for over torque isn't that difficult.
Can you expand on that. It is my understanding that after the connection is torqued, the wire will "cold flow" and if you comeback at a later time and use the same torque wrench and setting that the set screw will turn producing more pressure against the conductor and result in an "over torque" condition.
Don
 

sandsnow

Senior Member
Re: Section 110.14(A)

Originally posted by don_resqcapt19:
Ryan,
My comment to UL is, "you can't have it both ways!". UL has classified breakers for use in panles in violation of the panel manufacturer's instructions. They are telling us that we must follow the manufacturer's instructions but that classified breakers can be used in violation of those insttructions!
Don
The manufacturers want you to buy their breaker. I've heard their arguments when classifed breakers first came out. There were no facts, just predictions of doom and gloom if you used a classifed breaker in their panelboard. :roll:
Now if someone has some evidence of a classifeied breake failing in a panelboard I'm all ears :eek:
 

rbalex

Moderator
Staff member
Location
Mission Viejo, CA
Occupation
Professional Electrical Engineer
Re: Section 110.14(A)

Don,

It?s a good question. Remember I was speaking from the perspective of the initial installation. However NFPA 70B and several NEMA maintenance guides such as PB.1 speak to it from a subsequent maintenance standpoint and they still give essentially the same advice; i.e., torque the terminations/connections per manufacturer?s instructions.

?Cold flow? is generally a result of over-torque, not a precursor to it. Aluminum is more prone to it than copper although both can experience it. Other factors such as heat cycling and whether the connection is designed to be self tensioning all play a part. Some methods and instructions are more forgiving than others. This is why I believe knowing the manufacturer?s instructions is critical.
 

iwire

Moderator
Staff member
Location
Massachusetts
Re: Section 110.14(A)

A company I worked for provided a service of opening up gear and checking torques. We would go back each year and put the torque wrench to the gear.

Each year the wire terminal rotated a bit to hit the specified torque. The conductors get to looking mighty flattened.

I question the value of doing this more than once in a switch gears life span. The once would be to verify all connections where tightened in the first place. Once this is done leave it alone.

The majority of electric gear is left alone and remains trouble free. IR testing seems like a better way to go.

This is just my uneducated opinion arrived at strictly from my own observations. In other words I may be way off base. :p
 

charlie

Senior Member
Location
Indianapolis
Re: Section 110.14(A)

It is common for a manufacturer to say that they will void the warranty if you use another manufacturer's circuit breakers. However, there are some manufacturers that are fighting back. For instance Siemens has a listing of circuit breakers for Square D type QO and has a $10,000 warranty so you may use them with impunity (lower right hand corner of the 1st page). :D
 
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