Best way to wire an outdoor box

[clare]

Better yet, put a junction box on the inside, romex to the box, and individual conductors to the outside, - no clamp required.

[clare]

In answer to your second question, no.

[DerbyDad03]

:

Good thing cuz I have a few exterior boxes wired that way. I think I remember checking years go when I wired them but I figured I'd ask again just to remind myself.

Why does Romex have to be secured?

[clare]

Put a romex clamp on the inside end, strip a foot of the Romex and feed the "unsheathed" cable through the conduit - and if you read my previous post you do NOT need threaded bushings (because the conduit is threaded)

[RBM]

Apparently, you don't know what a threaded bushing is, or what it's for... either

[clare]

OK - you are talking about the insulator bushing that goes on the inside of the box. In which case there is no increase in the diameter of the conduit where it goes through the wall.

[HerHusband]

Mr. Flintstone,

Simple answer, don't use that kind of box. Those are designed for surface mounting with the cable coming in through conduit.

If you want a flush outlet with the cable coming in from the wall, use a regular "Remodel" style box. Hold it against the wall where you want to install it, and trace around the perimeter with a pencil (don't include the mounting flanges at the top and bottom). Take the box down, drill holes in each of the four corners, then use a jigsaw to cut out the square opening. Pull the romex out of the wall and feed it into the cable restraint in the back of the box. Slip the box in the opening, and tighten down the mounting screws so the "wings" on the back of the box swing out and lock the box to the wall. If the wall is too thick for the wings and/or you want additional strength, you can also add screws to the face of the box. Then install your electrical outlet or switch as usual. To keep things watertight install an outdoor rated electrical cover (the kind with the flaps that cover the outlets, or the full cover that lets you leave cords plugged in). I usually caulk around the perimeter of the wall opening before installing the box, just for a little added leak protection. The result is a nice clean installation, with a secure cable, and no box to bang against on the outside of the wall.

If you must use the surface mount box, install a pipe nipple on the back that is long enough to reach inside the wall. Then install an "anti-short bushing" on the opposite end of the pipe nipple so the sharp pipe edge won't cut into the cable. Then drill a hole large enough for the pipe nipple and bushing to fit through. If you have access to the stud on the backside of the wall, use a normal cable clamp to secure the cable to the stud within 12" of your box. Then feed the cable into the pipe nipple, caulk around the opening, and secure the box to the wall. Install your device and a waterproof cover.

Anthony Watson

[bud--]

An insulating bushing is required on the end of the nipple, but that is still a code violation - the romex has to be clamped the end of the pipe.

It is not particularly difficult to put a romex connector on the back of the box and seal box to wall.

I am beginning to understand how Holmes finds the disasters in Canadian houses.

[bud--]

Then you have a box on the inside which may be useful or not.

In general all wiring methods have to be secured to a box.

[DerbyDad03]

ote:

Not true as far as I understand it.

See the earlier posts from RBM and [e-mail], both of which confirmed my understanding that single conductors entering a box via conduit do not have be secured to the box.

Assuming that that is correct, then my question still stands.

Why does Romex have to be secured?

[RBM]

Bud is absolutely correct. All wiring methods must be secured to a box. You asked if individual conductors within a conduit must be secured, and they needn't be , however the wiring method, the conduit, must be secured to the box. Likewise, if you transition from one wiring method to another, they must be secured to each other. This is why you can's just thread a pipe nipple to the back of a bell box and slip the romex through it, (as Clare suggested), the pipe nipple needs to be clamped to the romex.

[clare]

Bud. You are not listening. You are seeing "canada" and getting your back up. If individual conductors enter the box, no clamp is required at that end - although the insulator inside the box is. The romex can be clamped at the inside end of the conduit nipple - which is attached inside the wall, so does not need to be passed through the hole. The hole only needs to pass the conduit . The proper way would be a junction box inside, on the end of the conduit, transitioning from romex to thhn, but using a threaded coupling, with a romex clamp on the inside end, and separated wires (unsheathed) into the box through the conduit, meets the requirement of code

[clare]

The Romex clamp keeps the wires from being put under tension at the conductor. The conduit protects the wire where it enters the box, giving the same protection to the connections.

[RBM]

It is not often that you have open space on the inside of a building, directly in line with an outside box, to locate an otherwise unnecessary junction box. This however would be a proper method to feed an outside box, and if this had been your first reply, and not your sixth try at it, you might be taken for someone that has a clue.

[clare]

If the wire comes through the header (rim joist) or the basement wall, which many do, there IS room for the junction box. If it comes through a studded wall a junctiom box can be installed in the wall with a blank cover. Not good in a nicely finished area.

I was working on the ASS U mption that the outside box was outside a basement wall, or rim joist like most I've worked on.

[trader4]

e:

Maybe. Sometimes.

If it comes

That's for sure.

In my experience, it's rare to see either of the above arrangements you are talking about. Around here, they just run the romex through the wood hole and into the box outside. The romex is secured inside with a staple close to where it enters the wall. From there it's inacessible, so virtually impossible for anyone to pull on it. And they pass inspection. I can show you AC disconnects all over the place installed that way that passed inspection. Does it technically meet NEC? Apparently not. But IMO in the grand scheme of things, it's safe.

One can also wonder if it is not routinely done this way and people are employing exotic solutions to comply, why there are not some simple clamps available for this express purpose.

[bud--]

And a problem if an unfinished area later becomes a "nicely finished area".

I can't understand the difficulty. It is not hard to use a romex clamp and do it right.