344.30(C) RMC Unsupported

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Natfuelbilll

Senior Member
So I think this section allows up to 18" of unsupported rigid conduit with the conduit termination at the end. Okay I think I got it.

1. is a coupling a conduit termination?

2. Does this rigid conduit termination coupling satisfy the securely fastened requirement of 350.30(A) for a hunk of sealtite connected to the conduit termination?

3. If not, then is the solution to securely fasten the sealtite within 12" of it's end?

4. or, to support the conduit coupling?
 

augie47

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Location
Tennessee
Occupation
State Electrical Inspector (Retired) DINOSAUR
This is new in '08 and will probably be refined in time. It is my opinion, and only that, that this allows the designated raceways to be installed between such things as enclosures without supporting. I do not think it applies to the continuation of the raceway system.
 

cowboyjwc

Moderator
Staff member
Location
Simi Valley, CA
344.30(C). Where oversized, concentric or eccentric knockouts are not encountered, type ______ shall be permitted to be unsupported where the raceway is not more than 18 inches in length and remains in unbroken lengths (without coupling). Such raceway shall terminate in an outlet box, junction box, device box, cabinet, or other termination at each end of the raceway.

I maybe could have explained that better in my first post. (and my spelling was horrible, I was in a hurry)

The language is the same for 342.30(C), 344.30(C), 352.30(C), 355.30(C) and 358.30(C)
 
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Natfuelbilll

Senior Member
Okay no coupling other than at the end of the conduit. What are some examples of "...other termination at each end of the raceway." ?
 

Smart $

Esteemed Member
Location
Ohio
344.30(C). Where oversized, concentric or eccentric knockouts are not encountered, type ______ shall be permitted to be unsupported where the raceway is not more than 18 inches in length and remains in unbroken lengths (without coupling). Such raceway shall terminate in an outlet box, junction box, device box, cabinet, or other termination at each end of the raceway.

I maybe could have explained that better in my first post. (and my spelling was horrible, I was in a hurry)

The language is the same for 342.30(C), 344.30(C), 352.30(C), 355.30(C) and 358.30(C)
OK... but I believe the thread progression is a little off track. I'm of the impression the OP is wanting to know how to support a RMC transitioned to LFMC which then terminates the raceway run. The transition from RMC to LFMC with RMC coupling and LFMC connector is a debateable issue in and of itself, though most everyone does it regardless of any prohibition.
 

K8MHZ

Senior Member
Location
Michigan. It's a beautiful peninsula, I've looked
Occupation
Electrician
This is new in '08 and will probably be refined in time. It is my opinion, and only that, that this allows the designated raceways to be installed between such things as enclosures without supporting. I do not think it applies to the continuation of the raceway system.

I read it exactly that way. It's too bad that if that is what they mean, they just don't come out and say it. Instead we get, "Such raceway shall terminate in an outlet box, junction box, device box, cabinet, or other termination at each end of the raceway."

OK, since the word 'or' is used, we can also say, "Such a raceway shall terminate in a termination at each end of the raceway". :confused:

Uh....where else would the termination of a raceway be other than at the end? :confused:
 

cowboyjwc

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Location
Simi Valley, CA
OK... but I believe the thread progression is a little off track. I'm of the impression the OP is wanting to know how to support a RMC transitioned to LFMC which then terminates the raceway run. The transition from RMC to LFMC with RMC coupling and LFMC connector is a debateable issue in and of itself, though most everyone does it regardless of any prohibition.

I agree and so I quoted the code section. A transition would be a coupling. And LFMC is not listed as one of the conduits you can use without supports.
 

Smart $

Esteemed Member
Location
Ohio
I agree and so I quoted the code section. A transition would be a coupling. And LFMC is not listed as one of the conduits you can use without supports.
But a transition from one type of conduit to another is not a raceway termination.

PS: I don't know of any conduit type you can use without support :D
 
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cowboyjwc

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Staff member
Location
Simi Valley, CA
But a transition from one type of conduit to another is not a raceway termination.

PS: I don't know of any conduit type you can use without support :D

Exactly and the sections I quoted tell you how it has to be terminated and you can only install it unsupported as noted, again, in the code sections I quoted.

Now to really claify it, as an inspector, since you are only required to have your first support 3' from the box for the types of conduit in those sections, I would never require you to support an 18" piece.:)
 

Smart $

Esteemed Member
Location
Ohio
Exactly and the sections I quoted tell you how it has to be terminated and you can only install it unsupported as noted, again, in the code sections I quoted.

Your transition from the above to the below is clear as mud. ;)

Now to really claify it, as an inspector, since you are only required to have your first support 3' from the box for the types of conduit in those sections, I would never require you to support an 18" piece.:)
 

Smart $

Esteemed Member
Location
Ohio
Still holding my breath....

??? What do you mean?

A non-NEC definition of a raceway termination is where the conductors contained therein become accessible. This usually occurs at enclosures, boxes, conduit bodies, etc.

It is impossible to terminate a raceway solely with a coupling. Yet there are combination-type fittings which when joined through a KO into a coupling will make a raceway termination.
 

Natfuelbilll

Senior Member
Consider a rmc with SO cable exiting through a coupling and compression strain relief fitting. Can the conduit "fly" (without support) for 18" ?
 

augie47

Moderator
Staff member
Location
Tennessee
Occupation
State Electrical Inspector (Retired) DINOSAUR
Now to really claify it, as an inspector, since you are only required to have your first support 3' from the box for the types of conduit in those sections, I would never require you to support an 18" piece.:)

Not every inspector reads it that way. "The conduit must be supported within 3 ft" to some only means you CAN go up to three feet and if your conduit is less than 3 ft long, a support is still needed.
In the '11 ROPs Mike Holt mentioned in submittals for each of the ***.30 sections that, as written, (without ***.30) a 3 INCH piece of conduit would need support.
It appears the '11 draft has increased the 18" to 30".
 

Smart $

Esteemed Member
Location
Ohio
Consider a rmc with SO cable exiting through a coupling and compression strain relief fitting. Can the conduit "fly" (without support) for 18" ?
IMO, the only req't for this scenario is 344.30(A). As such, the conduit could "fly" up to 5 ft. (not that I would actually go to 5 ft on smaller trade sizes). A bit extreme, but that is how it is written.

344.30(C) is for unsupported raceway, period. Once it is supported (even one support) the req't is rendered moot. Additionally, this requirement will likely not make it into the 2011 NEC.
 
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