EMT TO FLEX TRANSITION COVERED IN DRYWALL?

Anyone know if you can legally cover a flex to EMT transition? Using a rated fitting of course.

What do they mean in 300.15 requiring a box or or conduit body for other listed items including a "switch point"? What is a "switch point" in this code as I can find no explanation? Are they saying transition from one conduit system to another? "Outlet" is already listed so I do not believe they mean a wall switch as outlet covers that.

300.15(F) says a fitting must be left exposed if used in lieu of a box or conduit body.

I cannot determine if I am required to use a box or conduit body and am instead using a fitting in lieu of them as allowed. But then it may be required to be accessible.

This is confusing so hopefully someone smarter than me can help.
Thanks!!
 
Last edited:

texie

Senior Member
Location
Fort Collins, Colorado
Occupation
Electrician, Contractor, Inspector
You need to look at Art 348. The key here is it a straight adapter as opposed to an angle or 90 degree. A straight adapter can be concealed. See 348.42.
 

infinity

Moderator
Staff member
Location
New Jersey
Occupation
Journeyman Electrician
Anyone know if you can legally cover a flex to EMT transition? Using a rated fitting of course.

What do they mean in 300.15 requiring a box or or conduit body for other listed items including a "switch point"? What is a "switch point" in this code as I can find no explanation? Are they saying transition from one conduit system to another? "Outlet" is already listed so I do not believe they mean a wall switch as outlet covers that.

300.15(F) says a fitting must be left exposed if used in lieu of a box or conduit body.

I cannot determine if I am required to use a box or conduit body and am using a fitting in lieu of them witch would mean I must not cover it.
I don't see how that section specifically addresses a transition from one wiring method to another.
 
I don't see how that section specifically addresses a transition from one wiring method to another.
I believe it is the section that states where a box or conduit body needs to be installed. It lists examples of when they are and are not required. Please direct me to the more appropriate section if you could. I could be totally lost. Thank you
 
Last edited:

texie

Senior Member
Location
Fort Collins, Colorado
Occupation
Electrician, Contractor, Inspector
My question was not with angled or straight connectors. Thank you for the article, I did read it again.
Yes, I think I understand you in that you are using a listed transition fitting. Same as a connector in this context. In my view 348.42 allows this.
In the old days we used to use a rigid coupling, SS connector and a straight flex connector cobbled together. Never really compliant but that was before transition adaptors were available.
 

jusme123

Senior Member
Location
NY
I believe it is the section that states where a box or conduit body needs to be installed. It lists examples of when they are and are not required. Please direct me to the more appropriate section if you could. I could be totally lost. Thank you
IMO, I think 300.15(F) applies to your install.
 

LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
One thing to which I pay attention when using flex is which end should get the outside end of the spiral, which most fittings grip better. In a case where one end is more likely to be stressed, or as in this case will be rendered inaccessible, the outside end should be oriented toward that end of the run.
 

S'mise

Senior Member
Location
Michigan
300.15 makes sense, you need to have access where wires might get jammed up in a transition.

But, I never understood why it's alowed to use flex in concealed locations.

To me, trying to fish wires through concealed flex with bends is almost as bad as going through an other than straight fitting.
 
300.15 makes sense, you need to have access where wires might get jammed up in a transition.

But, I never understood why it's alowed to use flex in concealed locations.

To me, trying to fish wires through concealed flex with bends is almost as bad as going through an other than straight fitting.
Thank you. I agree about pulling through flex. I only use flex when I am in effect, making a cable.
 

roger

Moderator
Staff member
Location
Fl
Occupation
Electrician
Thank you sir. This is exactly what I did not want to read but it does clearly answer my question. Code gods wanted changeover accessible.
No, it does not answer your question, you were not asking about transitioning a cable assembly to conduit or tubing.

I agree with texie in post #6

Roger
 
No, it does not answer your question, you were not asking about transitioning a cable assembly to conduit or tubing.

I agree with texie in post #6

Roger
Thanks Roger. I really appreciate your taking time, you are always helpful. I must be an idiot on this one. Does not compute. You and texie in #6 agree but I do not understand how 348.42 allows me to change from EMT to flex and then conceal this transition. (my original question) It simply states I may not use a 90 concealed. It is a big jump to read into that as OK to transition if using anything but a 90 is it not?

Yes sir you are correct. Cable was not my original question. However, I was curious about both- cable and flex transition to EMT but only posted flex transition as you noted. You see, 300.15(F) is vague at best to me. Why would I need a box when I have this handy listed connector? And as others have stated, good luck pulling through flex in many cases.
The cable transition and stating the stripping of jacket was clear in the link and that helped me make sense of it for MC.
 

roger

Moderator
Staff member
Location
Fl
Occupation
Electrician
Transitioning from EMT to FMC is simply changing one conduit to another and a straight fitting could be seen as a coupling, actually they are manufactured. A 90 would definitely be a problem if it is concealed and makes sense it's not allowed to be.

Roger
 

GerryB

Senior Member
I have seen FMC with changeovers in a terra-cotta wall where it will be mudded in. Is that code? I read in Art 348.12(6) that FMC can't be used underground or embedded in poured concrete or aggregate. I guess it is not really "embedded" but I have seen it a lot. Sorry this is kind of a follow up to the OP? Thanks
 

ActionDave

Moderator
Staff member
Location
Durango, CO, 10 h 20 min without traffic from wing
Occupation
wire pulling grunt
348.42...simply states I may not use a 90 concealed. It is a big jump to read into that as OK to transition if using anything but a 90 is it not?.....
No, it's anything but a big jump. The NEC limited its language about concealed flex fittings to ninety degree connectors. The leap in logic is to believe other fittings, that are not a ninety degree connector, are included.
 
Top