Is wiring sealed with Seal Tight code compliant?

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david

Senior Member
Location
Pennsylvania
Who determines what and when flexibility is required?:)

As an installer can't I determine I require a flexible raceway to make installation easier?

It strikes me you are trying to read it more restrictive then it is. :)

517.30 Essential Electrical Systems for Hospitals.
(3) Mechanical Protection of the Emergency System.
(3) Listed flexible metal raceways and listed metal sheathed cable assemblies in any of the following:

d. Where necessary for flexible connection to equipment

Interesting question I was removed as the electrical inspector in a hospital remodel / addition, when the electrical contractor foreman made that exact same argument. The owner of the contractors company sat on the board for the hospital
 

iwire

Moderator
Staff member
Location
Massachusetts
If you install a piece of LFMC between two boxes mounted to a wall I don't see how flexibility is required.

You see that as a fact not an opinion?

As far as installation, which is one of the articles prerequisites, there is almost no case where something cannot be hard piped, it is usally just a matter of how easy it would be.
 

infinity

Moderator
Staff member
Location
New Jersey
Occupation
Journeyman Electrician
You see that as a fact not an opinion?

As far as installation, which is one of the articles prerequisites, there is almost no case where something cannot be hard piped, it is usally just a matter of how easy it would be.

Forget the hard piped for a second, in your opinion two boxes fastened to a wall in a dry location with a 6" piece of LFMC and no needed protection from liquids, vapors, or solids is code compliant? How does that meet any of the four conditions required? IMO one cannot say that flexibility is required in that example.
 

big john

Senior Member
Location
Portland, ME
Forget the hard piped for a second, in your opinion two boxes fastened to a wall in a dry location with a 6" piece of LFMC and no needed protection from liquids, vapors, or solids is code compliant? How does that meet any of the four conditions required? IMO one cannot say that flexibility is required in that example.
Imagine a shallow obstacle between the two boxes that would prevent me from installing a perfectly straight 6" RMC nipple. Then I need a flexible wiring method to create a small saddle and bridge the space between the two boxes and LFMC would work.

350.10(1) says "conditions of installation" which reads to me that it is permitted if you need flexibility to more easily execute the installation. That is not necessarily saying it must remain movable after it is installed, which, if necessary would be more of a "condition of operation" or a "condition of maintenance."
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
The 'or protection from liquids' makes it a moot point.
I install it all the time where flexibility is not required and I don't need protection from liquids. LFCM is almost always in the specs for industrial instrument connections, even where the location does not require protection from liquids.
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
In my opinion if the equipment at one end of the conduit does not move or vibrate, flexibility is not required. The fact that bending conduit to make the connection might be difficult or impossible does not change that.

I think this is just poor code wording. FMC does not have this restriction.
 

jap

Senior Member
Occupation
Electrician
If you install a piece of LFMC between two boxes mounted to a wall I don't see how flexibility is required. It could certainly be replaced by a solid conduit like EMT. So in this example unless there are liquids, vapors or solids involved the wording of 350.10(1) would prohibit that installation.

You need to meet one of the 4 conditions, flexibility, liquid, vapors or solids to use this wiring method. You can't just use this because you had it on the truck or you like how it looks without have one of the four aforementioned conditions. IMO pretty stupid but that's the way that it's written.

If I installed a piece of LFMC horizontally between 2 boxes mounted on the wall I guess I could always say I needed flexibility in case I ever wanted to run a piece of conduit vertically between the 2 boxes in the future. :)

JAP>
 

infinity

Moderator
Staff member
Location
New Jersey
Occupation
Journeyman Electrician
In my opinion if the equipment at one end of the conduit does not move or vibrate, flexibility is not required. The fact that bending conduit to make the connection might be difficult or impossible does not change that.

I think this is just poor code wording. FMC does not have this restriction.

That was my point, it's poorly worded but it does mean that it's prohibited when none of the four conditions exist. It's one sentence and clear to me what it means, even if that flies in the face of the way we've been doing things for decades.

I'm not looking for an argument, I would install this just like I would install FMC which as Don has noted does not have the same restriction.
 
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