EMT Support

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EMT Support

  • Yes. Strap within 3 ft

    Votes: 25 58.1%
  • No, You can strap within 10 ft.

    Votes: 18 41.9%

  • Total voters
    43
  • Poll closed .
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pete m.

Senior Member
Location
Ohio
I believe I'm with Don on this one. I would say a literal interpretation would require securement within 3' of the transition between raceways.

It would appear that the NEC makes a clear distinction between "conduit" and "tubing". I'm just not sure why. For the installation in the OP there are two different types of raceway and each could be considered as "terminating" at the joining of the two.

344.30 Securing and Supporting.
(A) Securely Fastened. RMC shall be securely fastened within 900 mm (3 ft) of each outlet box, junction box, device box, cabinet, conduit body, or other conduit termination.

358.30 Securing and Supporting.
(A) Securely Fastened. EMT shall be securely fastened in place at least every 3 m (10 ft). In addition, each EMT run between termination points shall be securely fastened within 900 mm (3 ft) of each outlet box, junction box, device box, cabinet, conduit body, or other tubing termination.

FWIW, I wouldn't have a problem if there was not securement within 3 feet in the installation that Gus described in the OP. I just can't put my finger on the safety issue.

Pete
 

Little Bill

Moderator
Staff member
Location
Tennessee NEC:2017
Occupation
Semi-Retired Electrician
I believe I'm with Don on this one. I would say a literal interpretation would require securement within 3' of the transition between raceways.

It would appear that the NEC makes a clear distinction between "conduit" and "tubing"
. I'm just not sure why. For the installation in the OP there are two different types of raceway and each could be considered as "terminating" at the joining of the two.

344.30 Securing and Supporting.
(A) Securely Fastened. RMC shall be securely fastened within 900 mm (3 ft) of each outlet box, junction box, device box, cabinet, conduit body, or other conduit termination.

358.30 Securing and Supporting.
(A) Securely Fastened. EMT shall be securely fastened in place at least every 3 m (10 ft). In addition, each EMT run between termination points shall be securely fastened within 900 mm (3 ft) of each outlet box, junction box, device box, cabinet, conduit body, or other tubing termination.



The definition of RMC and EMT only differ by the terms "threadable" and "unthreaded" "thinwall". Both are considered raceways. As was stated in another post, the terms "or other conduit termiation" or "other tubing termination" are listed with items that the wires terminate at or are accessible in. I think the purpose of the support within 3' of terminations is to protect wires form being pulled out should the raceway drop or come apart. Since the transition is neither where wires terminate or are accessible, the coupling/adapter shouldn't be considered a termination.
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
Art 358 States:
"(A) Securely Fastened. EMT shall be securely fastened in place at least every 3 m (10 ft). In addition, each EMT run between termination points shall be securely fastened within 900 mm (3 ft) of each outlet box, junction box, device box, cabinet, conduit body, or other tubing termination."

Okay I missed the fact that there is a transition but I am not sure why that would matter. That being said the article above clearly states it must be strapped within 3' of other tubing terminations. Now what does that mean? It seems to indicate that no box is necessary and the transition point would require a strap. Why I don't know as I firmly believe one is not required within 3' of where the emt is coupled together.
 

iwire

Moderator
Staff member
Location
Massachusetts
Okay I missed the fact that there is a transition but I am not sure why that would matter.

It matters because the code section for RMC requires a support with three feet of RMC termination and the code section for EMT requires support for EMT within 3 feet of the EMT termination. Both of those raceway types do in fact terminat at the transition.

Each respective code section can not be 'stretched' to cover other types of raceways because they are not in each Articles scope.
 
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jeremysterling

Senior Member
Location
Austin, TX
Based on the code wording, I see the connection between the two types of raceways as a "termination" for each raceway. One raceway ends and the other starts. With couplings in the same type of raceway, the raceway does not have a termination.

When you change from conduit to tubing, I think it is clear that the conduit and tubing both end or start at that point.

I believe I'm with Don on this one.

I'm with Don and Pete. Someone start a poll!
 

sameguy

Senior Member
Location
New York
Occupation
Master Elec./JW retired
What is being said is that two (2) straps will be needed then, one for the end of the rig. and one for the emt both within 3' of the coupling. I only do it if it is needed for support. I vote no.
 

paul

Senior Member
Location
Snohomish, WA
Good thing most inspectors don't read this board and actually use common sense when applying the code. I don't know of a single inspector that would shoot someone down in this. I transitioned from 2" GRS to EMT just the other day on a strut rack. The transition was not supported within 3' and I can tell you that a gymnast could do their bar routine on this run without fear of it coming apart. However they might hit their knees on some plumbing pipes nearby. :) There is no safety issue involved, as was already stated.
 

Jim W in Tampa

Senior Member
Location
Tampa Florida
I am not voting yet. I do not see anything in nec saying that changing conduit type forces us to call it terminated. If we call it terminating then what we have in a run of EMT is several sticks each terminated at a coupling. And we all know thats not so. It is a transition but a transition does not mean terminated just means continued in another size or material,
If anything it has more support at this coupling near the floor in concrete than any other place in the run. I simply can't see this as terminated. No logic in that view. I am not convinced yet.
 

iwire

Moderator
Staff member
Location
Massachusetts
Good thing most inspectors don't read this board and actually use common sense when applying the code. I don't know of a single inspector that would shoot someone down in this. I transitioned from 2" GRS to EMT just the other day on a strut rack. The transition was not supported within 3' and I can tell you that a gymnast could do their bar routine on this run without fear of it coming apart. However they might hit their knees on some plumbing pipes nearby. :) There is no safety issue involved, as was already stated.

No one has said it is a safety problem, we are just talking about what the words in the book say.:cool:
 

Chamuit

Grumpy Old Man
Location
Texas
Occupation
Electrician
I usually start strapping 2 to 3 feet from the first termination and every 5 feet afterwards. Better stability. Code requirements is minimum anyway.
 

al hildenbrand

Senior Member
Location
Minnesota
Occupation
Electrical Contractor, Electrical Consultant, Electrical Engineer
Look at it like this if it terminates then you can pull wire there.
I agree. Even though there are two different types of raceway connected to each other in a go-from fitting, neither terminates as there is no access to the conductors. The two different types of raceway are coupled together to form one continuous raceway system subject to 300.12, 300.18 and the 3xx.26 Number of Bends in One Run cap of 360 degrees. The raceway system terminates only at its far ends, not at the go-from fitting in the middle of the system.
 

Twoskinsoneman

Senior Member
Location
West Virginia, USA NEC: 2020
Occupation
Facility Senior Electrician
I agree. Even though there are two different types of raceway connected to each other in a go-from fitting, neither terminates as there is no access to the conductors. The two different types of raceway are coupled together to form one continuous raceway system subject to 300.12, 300.18 and the 3xx.26 Number of Bends in One Run cap of 360 degrees. The raceway system terminates only at its far ends, not at the go-from fitting in the middle of the system.

The problem is 358.30(A) says "each EMT run between termination points shall be..."
I have to say that the EMT run ends where the EMT ends. I can't agree that the "EMT run" extends beyond the EMT...:)

I've changed my mind since reading the OP but now I believe you would have to strap within 3 feet on both sides of the transition... Though I wouldn't think it was intended to be that way
 

skeshesh

Senior Member
Location
Los Angeles, Ca
I agree with Jim.

The problem is 358.30(A) says "each EMT run between termination points shall be..."
I have to say that the EMT run ends where the EMT ends. I can't agree that the "EMT run" extends beyond the EMT...:)

I dont see your point. You're equating "termination" with the end of the conduit run which is the whole point of this discussion. End of a run can be a transition.
 

al hildenbrand

Senior Member
Location
Minnesota
Occupation
Electrical Contractor, Electrical Consultant, Electrical Engineer
The problem is 358.30(A) says "each EMT run between termination points shall be..."
I have to say that the EMT run ends where the EMT ends. I can't agree that the "EMT run" extends beyond the EMT...:)
2011 NEC
358.30 Securing and Supporting.
EMT shall be installed as a complete system in accordance with 300.18 and shall be securely fastened in place and supported in accordance with 358.30(A) and (B).

(A) Securely Fastened. EMT shall be securely fastened in place at least every 3 m (10 ft). In addition, each EMT run between termination points shall be securely fastened within 900 mm (3 ft) of each outlet box, junction box, device box, cabinet, conduit body, or other tubing termination.
The thing that "securely fastens" is referenced to the "tubing termination", not the "termination point".

Only a "tubing termination" is included in the list with outlet box, junction box, device box, cabinet and conduit body.

Again, I believe a "tubing termination" is a two word term. I believe it means a fitting or assembly that is listed for the conductors to emerge from the end of the raceway.

A coupling is not listed for conductors to emerge from, nor is a "go-from" coupling. Therefore, even though two different types of raceway may end in a "go-from" coupling, no termination can occur.
 
Personally, I think it's splitting hairs, if you look at 334.30 for RMC, I think the intent, of terminating is (the end of the "raceway"). After reading 334.30, it mentions "supports to prevent transmission of stresses to termination" I really don't see how you would be imposing stresses to the changeover fitting by not supporting it within 3ft.
 

Twoskinsoneman

Senior Member
Location
West Virginia, USA NEC: 2020
Occupation
Facility Senior Electrician
The thing that "securely fastens" is referenced to the "tubing termination", not the "termination point".

Only a "tubing termination" is included in the list with outlet box, junction box, device box, cabinet and conduit body.

Again, I believe a "tubing termination" is a two word term. I believe it means a fitting or assembly that is listed for the conductors to emerge from the end of the raceway.

A coupling is not listed for conductors to emerge from, nor is a "go-from" coupling. Therefore, even though two different types of raceway may end in a "go-from" coupling, no termination can occur.

I certainly see your point. However your basing it on your own definition of "tubing termination" which isn't clearly defined in the code... So I guess it comes to a matter of agreeing to disagree. I certainly wouldn't red tag someone for not doing it. I don't do it myself. But in your scenario the EMT run doesn't terminate. That doesn't make sense to me.
 

Twoskinsoneman

Senior Member
Location
West Virginia, USA NEC: 2020
Occupation
Facility Senior Electrician
Personally, I think it's splitting hairs, if you look at 334.30 for RMC, I think the intent, of terminating is (the end of the "raceway"). After reading 334.30, it mentions "supports to prevent transmission of stresses to termination" I really don't see how you would be imposing stresses to the changeover fitting by not supporting it within 3ft.

I agree with you about the intent. We are just discussing technicalities.
 

cadpoint

Senior Member
Location
Durham, NC
The bigger question is did your vote the way you did and which way and why; before one read all the questions and the code Article(s)? :) OR just voted on a trained response?

I would strap it right after the 90, I'd just consider it supporting the first three feet!

I've been enlightened by the correct reading of the Article(s)!

It's interesting how the voting has gained on an incorrect application! What's with that! :)

At first reading of the thread I thought it was a trick question; with maybe some consideration for the fact the the concrete is considered as holding the 90...
That's not A code article....

Thank Augie47 ...
 
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