OK to transition from EMT to flexible metallic conduit within a wall?

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Jon456

Senior Member
Location
Colorado
It seems to me it wouldn't be prohibited as long as the cumulative bends don't exceed 360 deg, but I'd like to get confirmation.
 

iwire

Moderator
Staff member
Location
Massachusetts
It seems to me it wouldn't be prohibited as long as the cumulative bends don't exceed 360 deg, but I'd like to get confirmation.

The fitting must not be in the wall

300.15(F) Fitting. A fitting identified for the use shall be permitted in lieu of a box or conduit body where conductors are not spliced or terminated within the fitting. The fitting shall be accessible after installation.
 

Jon456

Senior Member
Location
Colorado
So how are conduit connectors able to be used to terminate a raceway at a load center that is recessed in the wall? Those fittings are not accessible.
 

iwire

Moderator
Staff member
Location
Massachusetts
So how are conduit connectors able to be used to terminate a raceway at a load center that is recessed in the wall? Those fittings are not accessible.

Fair question. :)

In my opinion we have to start here.



300.15 Boxes, Conduit Bodies, or Fittings ?Where Required.
A box shall be installed at each outlet and switch
point for concealed knob-and-tube wiring.

Fittings and connectors shall be used only with the specific
wiring methods for which they are designed and listed.

Where the wiring method is conduit, tubing, Type AC
cable, Type MC cable, Type MI cable, nonmetallic-sheathed
cable, or other cables, a box or conduit body shall be installed
at each conductor splice point, outlet point, switch point, junction
point, termination point, or pull point, unless otherwise
permitted in 300.15(A) through (L).

I guess you could argue that your plan is not making that transition a pull point so you may well be good to go.

You may have taught me something.
 
I have never heard of this. I have changed over many times in a wall from EMT to flex... Never had a problem although that don't make it right. I'll have to read this section closely. I do know that fittings such as 90? connectors, LBs, etc can not be buried.
 

Cow

Senior Member
Location
Eastern Oregon
Occupation
Electrician
I agree it doesn't make sense. For example, two 4 square bracket boxes mounted in a wall.

I connect them together with emt. Pass.
I connect them together with flex. Pass
I run emt halfway, then transition to flex. Fail.

That can't be the codes intention...
 

Jon456

Senior Member
Location
Colorado
The more I think about this, the more I'm convinced that it is acceptable as long as the coupling is non-angled and the fitting is not intended to be a "splice point, outlet point, switch point, junction point, termination point, or pull point."

We're not prohibited from using a coupling between two sections of EMT (? 358.42) for concealed raceway installations. And we're not prohibited from using a non-angled coupling between two sections of FMC for concealed raceway installations (?348.42). So why would code prohibit a non-angled coupling between a section of EMT and a section of FMC for a concealed raceway installation?

Although a coupling is not considered a conduit termination, I think it would be prudent to securely fasten the FMC within 12" of the coupling, and the EMT within 3' of the coupling.
 

mivey

Senior Member
It is not a conductor splice point, conductor outlet point, conductor switch point, conductor junction point, conductor termination point, or conductor pull point so I don't see the issue.
 

electricalist

Senior Member
Location
dallas tx
A co worker ask me a similar question . But to comment on the original post. Here I see a lot of emt hr to first fixture about 3 ' flex with a flex to emt connector then pipe to the next flex to fixture. Mostly in things like strip mall can lights outside . So my co worker was running new 120 v plug circuits they left the 4 square and conduit going up the wall. . To refeed that outlet location would it be the same as flex but you would have to strip of enough outer sheathing to react from change over to box. Thanx
 

mivey

Senior Member
To refeed that outlet location would it be the same as flex but you would have to strip of enough outer sheathing to react from change over to box. Thanx
Sheathing? That sounds like MC cable.

It used to be that for MC cable to conduit you had to have a box. From 1996.300-15(b):"...A box shall be installed at the connection point between any such cable system and a raceway system..." and there was an exception for sleeving.

Since the focus went from the cable system to the conductors themselves, it sounds like they changed it so that if the conductors aren't disturbed then a non-accessible fitting is fine since it is not "in lieu" of a box or body.

I'm not positive, but that would be my first take.
 

JES2727

Senior Member
Location
NJ
No box or conduit body is need at that location. It is like a coupling.

Since the focus went from the cable system to the conductors themselves, it sounds like they changed it so that if the conductors aren't disturbed then a non-accessible fitting is fine since it is not "in lieu" of a box or body.

I'm not positive, but that would be my first take.

I disagree. You're saying the fitting is not 'in lieu' of a box because the conductors aren't "disturbed" (spliced or terminated). That's a direct contradiction to 300.15(F), which says if the conductors aren't spliced or terminated ("disturbed") a fitting may be used 'in lieu' of a box.

The fitting must not be in the wall
300.15(F) Fitting. A fitting identified for the use shall be permitted in lieu of a box or conduit body where conductors are not spliced or terminated within the fitting. The fitting shall be accessible after installation.
 

electricalist

Senior Member
Location
dallas tx
I think they need to put a picture next to accessible. I dont know where it was ever ok to splice inside a conduit body unless ur about to in a LB LR LL etc
 

mivey

Senior Member
I disagree. You're saying the fitting is not 'in lieu' of a box because the conductors aren't "disturbed" (spliced or terminated). That's a direct contradiction to 300.15(F), which says if the conductors aren't spliced or terminated ("disturbed") a fitting may be used 'in lieu' of a box.

NEC said:
Where the wiring method is conduit, tubing, Type AC cable, Type MC cable, Type MI cable, nonmetallic sheathed cable, or other cables, a box or conduit body shall be installed at each conductor splice point, outlet point, switch point, junction point, termination point, or pull point, unless otherwise permitted in 300.15(A) through (L).
300.15(F) only excludes two conditions. The section as a whole has several conditions that require a box or body.

No box or body is required because we do not have:
conductor splice point,
conductor outlet point,
conductor switch point,
conductor junction point,
conductor termination point, or
conductor pull point

so the rest of the section does not matter, sub (F) included.

Just an opinion and I am not convinced either way.
 

MasterTheNEC

Host of ElectricianLIVE.com
Location
McKinney, Texas
Occupation
Master Electrician & Director of Codes and Standards
The original intent of this "transition" was typically to transition from EMT to "AC" or "MC" cable where the outer sheathing is removed and stripped off of the "AC" or "MC" and the exposed conductors extended down the EMT. If you are changing wiring methods from a conduit or tubing to a cable method then I believe the fitting shall be accessible after installation. If you are going from one conduit method to another (as depicted in the OP's question) then I would have no problem with this taking place within the wall.

Again my opinion...for what it is worth. The AHJ will make the call:angel:
 
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