Strapping of EMT

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Re: Strapping of EMT

For all those who are thinking Erico (Caddy) products are being listed for the purpose, the reality is their listed products are not necessarily listed for what you may think, some of their listings are for positioning only. (what ever that means)

The bottom line is, there is no requirement for LISTED supports and tie wire works great.

Roger
 
Re: Strapping of EMT

Don and Bob,

I am not claiming they have to be "listed".
Nor am I limiting my question to conduit installed in steel stud walls. I'm asking about installed anywhere or everywhere in the example.

On the 4 types of wiring methods in my example, they all have the same wording in the code concerning "securing and supporting". That said, one should be able to use any type of securing, according to your logic. If that is the case, why could one not use a one hole EMT strap on one of the other methods or for that matter, on all of the methods? Or, are you both saying that one could?
 
Re: Strapping of EMT

Dave,
If that is the case, why could one not use a one hole EMT strap on one of the other methods or for that matter ...
In most cases, you can't because a strap designed for one type or size of conduit will not correctly fit another size or type and the raceway would not be "securely fastened in place" as required by the code rule.
Don
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Re: Strapping of EMT

Roger,
As Kpepin pointed out one can argue that xxx.6 in the raceway articles requires the use of listed supports. I really don't think this was the intent of the code rule, but conduit supports do fit the Article 100 definition of "fitting". I think this is a case of the code word "fitting" not exactly matching the trade use of the same word. In my area and other parts of the country, the trade use of the word means conduit body. CMP 8 has had this same trouble in the past. A number of years ago, the rule that now appears in 342.26 said "There shall not be more than the equivalent of four quarter bends (360 degrees total) between fittings. The CMPs intent was that the word fitting meant "conduit body", but the Article 100 defintion includes couplings and under the wording of the rule you were permitted 360? of bend between each coupling.
Don
 
Re: Strapping of EMT

Don, as bad as I hate it, I have to retract my earlier statement and agree.

See UL category DWFV (Conduit and Fittings) and subcategory DWMU (Conduit and Cable Hardware).

I also agree with you that the code rule did not intend a strap to be considered a fitting.

So with this being the case and as you brought up, we can now argue that if we are tagged for more than 360? in a run, we can install a listed strap and be good to go. :)

Roger
 
Re: Strapping of EMT

In most cases, you can't because a strap designed for one type or size of conduit will not correctly fit another size or type and the raceway would not be "securely fastened in place" as required by the code rule.
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Don,

I agree 100%. This is the exact same reason I would fail your installation of conduit that is secured with tie wire. And no, I'm not talking about steel studs.

Another article comes to mind:
358.30 Securing and Supporting.
EMT shall be installed as a complete system as provided in Article 300 and shall be securely fastened in place and supported in accordance with 358.30(A) and (B).
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The code uses the term "complete system". There isn't a manufacturere that offers "tie wire" as an option in any of their catalogs as an acceptable "securing" method for EMT.

This type of securing would not be "acceptable" to me and therefore would not pass inspection.
110.2 Approval.
The conductors and equipment required or permitted by this Code shall be acceptable only if approved.
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Also, EMT is "listed" by UL. The code says:
(B) Installation and Use. Listed or labeled equipment shall be installed and used in accordance with any instructions included in the listing or labeling.
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Since we are installing "listed" equipment we are responcible to install it according to the manufacturer's labeling and any instructions. Even in the NEC Handbook with drawings showing the proper securing of EMT, it shows one hole straps.

I can't imagine walking onto a job site and seeing tie wire securing EMT to the bottom of unistrut as it travels through the building!
 
Re: Strapping of EMT

Originally posted by websparky:
Roger,
except for supports within 3' of a box, there is no requirement for supports in horizontal runs.
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Am I mis-reading this below?
358.30 (A) Securely Fastened. EMT shall be securely fastened in place at least every 3 m (10 ft)........

AND

(B) Supports. Horizontal runs of EMT supported by openings through framing members at intervals not greater than 3 m (10 ft)......
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Roger,

You didn't respond the first time so, I thought I'd ask again.
 
Re: Strapping of EMT

Sorry Dave, I didn't mean to ignore you but Iwire answered this last night at 6:28 PM.

Let's look at 358.30(B) again, your selective quote is missing some words.

Your quote
(B) Supports. Horizontal runs of EMT supported by openings through framing members at intervals not greater than 3 m (10 ft)......
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to quote it in full
(B) Supports. Horizontal runs of EMT supported by openings through framing members at intervals not greater than 3 m (10 ft) and securely fastened within 900 mm (3 ft) of termination points shall be permitted.
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There is no supporting required over the openings themselves unless the framing is on 10'2" centers :D .

Roger

[ December 31, 2004, 02:35 PM: Message edited by: roger ]
 
Re: Strapping of EMT

Roger,

My mistake. Let me re-phrase.

When you said "there is no requirement for supports in horizontal runs." I took it at face value. Please help me understand when or where this is allowed.

Thanks,
 
Re: Strapping of EMT

"This type of securing would not be "acceptable" to me and therefore would not pass inspection. "

As an inspector i would hope you would not use that kind of reasoning to fail things.We should be inspected on nec rules not yours.Is your beef just a personal issue ?

No mfg. would ever suggest tie wire simply because they see no $$$$$ in it.

Is there anyone here that will honestly say that tie wire if used correctly would not hold emt better than one hole straps ? Not talking about looks just holding.

Seems odd that framing members (it did not say wood or steel )are approved and they are not listed.
 
Re: Strapping of EMT

Originally posted by jimwalker:

Seems odd that framing members (it did not say wood or steel )are approved and they are not listed.
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Jim,

I'm not talking about framing members.

I think you install mostly residential? If so, could you imagine using tie wire wrapped around a nail and holding EMT to the bottom of the joist?
 
Re: Strapping of EMT

This type of securing would not be "acceptable" to me and therefore would not pass inspection.

--------------------------------------------------------------------------------
110.2 Approval.
The conductors and equipment required or permitted by this Code shall be acceptable only if approved.
--------------------------------------------------------------------------------
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Jim,
This is not personal. You may not like it but, it is code.
 
Re: Strapping of EMT

"This type of securing would not be "acceptable" to me and therefore would not pass inspection. "

The part of this that bothers me is your using the word ME.Perhaps you did not mean it to sound like its your rule not nec.
I have only wired 2 houses in past year and now only doing commercial work and like it far better.

Looking at APPROVED puts this issue to a non nec issue.It's up to the AHJ to say if we can or can't use tie wire.Somehow this bothers me that nec did not make a rulling.
 
Re: Strapping of EMT

Looking at APPROVED puts this issue to a non nec issue.It's up to the AHJ to say if we can or can't use tie wire.Somehow this bothers me that nec did not make a rulling.
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Jim,

I meant "me" as in the inspector of the job.

The NEC actually did make a ruling on this and on other aspects of the code. They decided that they could not spell out and cover every possible situation so the decided the only way to handle it was to have the "AHJ" decide certain issues.
 
Re: Strapping of EMT

Dave,
I can't imagine walking onto a job site and seeing tie wire securing EMT to the bottom of unistrut as it travels through the building!
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If you have installed strut, it is unlikely that tie wire would be used. The only times I have seen tie wire used to secure and support conduit was when some part of the building structure was the support and the tie wire was used to secure the raceway to the structure.
This type of securing would not be "acceptable" to me and therefore would not pass inspection.
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In my opinion the use of tie wire is often a much more secure support system than the listed straps. If you red tagged me, I'd see you in court, because the courts are the ultimate interpreters of the code rules.
Also, where would you draw the line on the requirement of using "listed" supports? As I stated yesterday, two of the major manufactures of "strut" products do not have their products listed as "raceway supports". You'd have to red tag the use of these products too.
Don

[ December 31, 2004, 03:33 PM: Message edited by: don_resqcapt19 ]
 
Re: Strapping of EMT

Would be nice if nec used black ink instead of gray.Had they used the famous "shall not" then there is no argument.The way i deal with nec is if does not say shall not then i assume its legal.For now i will continue to use tie wire when it seems like the best choice.If the AHJ wants to stop approving this then fine but put it in writing and inforce it on everyone.There is a cost differance.Perhaps some wire company will get smart and get there wire LISTED then double the price on it.HMMMM this will be hard to stamp. :D
 
Re: Strapping of EMT

Posted by Jim:
HMMMM this will be hard to stamp. :D
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Guys, this just came in from the "Way-Back Machine return slot". It is a hard copy of an online thread from Dec. 31, 2014, . . .the whole thread is arguing over how hard/easy it is to use tie wire that is lumpy. The old timers are waxing poetic about the ease of use back when it was smooth.

;) :p
 
Re: Strapping of EMT

If you red tagged me, I'd see you in court, because the courts are the ultimate interpreters of the code rules.
Also, where would you draw the line on the requirement of using "listed" supports?
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Don,

I would not red tag the wire based on "listed".
I would red tag it based on
110.2 Approval.
The conductors and equipment required or permitted by this Code shall be acceptable only if approved.
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Which is based on 110.3 (A)(1),(2). Plus (B) would be used not because the support isn't listed but, because the wire isn't the "usual and customary" nor the "industry standard" for securing conduit systems.

Here in Ohio, if you had a beef with a local State Certified Building Department with State Certified Inspectors and you didn't like their judgement, you would appeal to the Division of Commerce, Board of Building Standards for the State.
In a case such as above, the local ruling would stand until and if it was over turned by the State Board. Everyone likes to threaten "I'll see you in court" but, in reality it very rarely makes it to past the Board of Building Standards.

I believe we are all on the same page as far as quality and workmanship. I doubt any of us would use wire to secure EMT in most installs.

I wonder if anyone here has a photo of an install that used wire through-out? I have never seen it in my career.
 
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