Transitioning from in-wall wiring to EMT (conduit)...

[SQLit]

a box with a conduit connector on side side and a romex connector on the other would work.

[sleepdog]

I have the same situation with some #6 stranded wire I'm running for a subpanel out to the garage. It's 50ft of three wire in a black jacket and I wanted to run it in from the back through the joist cavity. But the back of the subpanel I have does not have a rear knock-out, so I have to run the feeder in through the top of the panel, which leaves the cable exposed on the wall.

If anyone can advise, I don't want the cable exposed on the wall. I'm thinking of having a metal conduit run from the panel up to a j-box in the corner of the wall/ceiling. Run the cable into the j-box from the ceiling with the jacket on. Out the other side of the j-box through conduit, to the sub-panel. Does this make sense? I'd remove the outer jacket from the cable run into the conduit.

Do they make j-boxes that big for #6 stranded (heat concern?) or is there some kind of transition device used to go from sheathed cable to conduit?

Thanks!

[RBM]

You can use an EMT to Romex connector

[RBM]

There is no need to have a junction box as you don't have a junction. You can use whatever size conduit you need, and if you can't find an EMT to romex connector in the size you need, you can get an EMT connector, a threaded coupling, and a romex connector of whatever size you want and thread them together

[RBM]

No, just keep it as close as you can. The object is to protect the cable from damage

[blueman]

I would like to run regular Romex up the interior wall of our garage and then switch to conduit running along the ceiling.

What do I need to do to transition at the point where the Romex exits the wall and enters the conduit?

I assume I need some type of brushing to hold the wire in place and prevent it from scraping. Beyond that is it sufficient just to push the conduit entrance up tight to the exit hole from the wall?

What specifically do I need to use here?

Thanks

[blueman]

Is a box necessary? I would prefer something less intrusive since the conduit itself looks "ugly" enough...

[blueman]

In my case where I am transitioning from Romex in a wall to a conduit along the garage ceiling do I need anything to make sure that the transition stays snug against the wall without any of the Romex peaking through?

[James "Cubby" Culbertson]

So you're planning to pull the romex through the EMT? I believe code allows this but it seems to me a j-box to transition from the Romex to regular wire might make more sense. Cheers, cc

[gfretwell]

Where does this urban legend come from?

When you strip off the jacket you have some unidentifed wire in the pipe of some sort but it would be tough to convince an inspector what it was. All the identification is on the jacket.

[_firstname_]

They make direct EMT-to-Romex fittings. I have only ever seen them in

1/2", to small Romex; the Romex clamp (officially known as NM cable, BTW) is 3/8", and suitable for 14-2, 12-2, and maybe even for 14-3 and 12-3. The next large solution has already been mentioned: Use an EMT-to-threaded connector, followed by a threaded coupling, followed by a clamp for the Romex.

To make sure you hide all the cable in the wall, drill a hole deep enough that the first 1/2" or 1" of the EMT is hidden in the wall. By the way, drywalling around the EMT will be no fun, hard to get it nice and smooth.

There is one more annoying little issue: the EMT has to be grounded, at the minimum by being connected to a grounded metal box on at least one end. If you use an EMT-to-NM fitting, or the method with the threaded coupling, there is no place to attach the ground, so you better hope you can ground from the other end. Also, the NEC allows small sections of unstripped Romex in conduit only. If you have a long run in conduit, you shall strip the outer jacket off; the conductors used inside the Romex are perfectly happy to continue on inside the conduit.

For the rear exit from the subpanel: What I've seen done is simply to drill or punch a hole in the back of the subpanel. Do the experts think that this is legal? We did this to two of our panels, and passed inspection, but that means nothing (could be that our inspector was a fool or sloppy).

Getting a J-box for three strands of #6 cable is trivial. Just look up the rules in the NEC for required cable volume per conductor. I would use at the very minimum a 4" square box, because #6 cable is stiff enough that working with it in anything smaller is an incredible pain, and has the risk of chafing the insulation. In general, using bigger boxes makes life much more pleasant.

[Chris Lewis]

I had the reverse situation: romex on the ceiling, wanting to run the cables surface-mounted down the wall. (garage workshop, walls already finished - these were drops to bench height outlets).

I chose grey PVC electrical conduit. Surface mounted a PVC outlet box, ran the conduit up to the ceiling. There is 1x3 lathe (for mounting drywall) on the ceiling, immediately adjacent to the wall. Bored a hole in the lathe so that the conduit would emerge just flush with the top of the lathe. Ran the romex down the conduit with a small bit of slack at the top. No boots or anything. The inspector was quite happy with it.

But with EMT you'll need fittings to prevent cutting the insulation. See the other postings.

[Chris Lewis]

According to :

This is almost always perfectly legal[1], as long as you use the appropriate strain relief. Ie: knock-out sized hole, cable box clamp.

[1] Ie: if you don't exceed box fill and it's legal to have that cable in the box. [Canadian codes, for example, wouldn't permit you doing this for an ordinary circuit conductor in the main breaker compartment.]

[Bob]

Standard practice (possibly code) prohibits exposed Romex less than 7 feet above the floor, so you may want to just use conduit all around.

[blueman]

The Romex runs up the *interior* of the wall so is not exposed

[blueman]

According to NEC, what is the smallest size EMT that you can run 14-2 Romex through?

Are you saying that NEC does not allow Romex to run up through EMT but needs to be stripped first?

I am pretty sure our electrician wired the basement with exposed Romex running along the ceiling and then dropping down through EMT to get to the wall outlets.

Can you clarify please?

[Chris Lewis]

According to :

In the OPs situation, there'd still be jacket on part of the wire.

[RBM]

[Wayne Whitney]

As others have said, the exact opposite is true. It's fine to run Romex through EMT (but perhaps inefficient, design wise, as Romex is much bigger than individual conductors, so you need bigger EMT). Stripping Romex of the outer jacket and running the individual conductors in EMT creates a situation where the conductors aren't labeled for their use, so it is not strictly NEC-compliant.

Well, Table 1 of Chapter 9 Tables (2002 NEC) gives percent usable cross section of conduit and tubing for conductors: 1 conductor, 53%;

2 conductors, 31%; 3 or more conductors, 40%. However, Note 2 to Table 1 says "Table 1 applies only to complete conduit or tubing systems and is not intended to apply to sections of conduit or tubing used to protect exposed wiring from physical damage."

So I think that means that for short runs used just to protect Romex from physical damage (e.g. a riser in a basement to go from a surface mounted outlet to an exposed overhead run), you can use whatever size it will fit in and is convenient.

As to "complete conduit systems", I know 12-2 romex has a diameter of

0.39 in, so it has an equivalent circular cross-section of 0.119 in^2. 1/2" EMT is sufficient, as it has an interior diameter of 0.622 in, for an area of 0.304 in^2, 53% of which is 0.161 in^2. If 1/2" EMT can handle a single 12-2 cable, it can handle a single 14-2 cable.

Cheers, Wayne

[Chris Lewis]

According to Wayne Whitney :

As a FYI, I've installed (and had approved) single runs of 14/2, 14/3,

12/3 and even 10/2 in half inch electrical PVC conduit. Most were NMD, but the 12/3 was NMW (equivalent to your UF - direct burial rated). [Surface mount, used as a cable protection, max length 7'].