Best way to wire an outdoor box

[fred.flintstone]

I'm referring to this kind of electrical box.

When wiring one of these waterproof outdoor boxes on a wall, I've found that it's not possible to use the traditional methods. What I mean is that when the box sits flat against the wall, you cant use a romex clamp on the back. I dont care to have the wire exposed where it enters the box from the top, bottom or side, so I always bring the wire in the rear hole. The problem is that you cant clamp it, unless you make a large enough hole for the whole clamp. While that may seem ok, it's really not, because water will get behind the box and into the wall.

While my method may not be up to code (due to lack of a clamp), I've simply drilled a 1/2" hole in the wall, ran the wire thru that hole and used silicone caulk around the romex. After the silicone drys, I just let the wire come thru the hole in the box without a clamp. Before wiring it, I put more silicone in the threaded hole around the cable to seek water from entering this box.

Is there any other method for doing this?

[RBM]

There are other types of connectors, that can be used, but all of them will still require a hole around 1 1/4" diameter. I typically lay a small bead of silicone around the top and half way down the sides of the box to prevent water entry between the box and structure. It is a requirement to seal the threaded knockouts as well, or water will seep into the box.

[Steve Barker]

put the clamp on the inside. use an offset screwdriver to tighten the screws. Or keep doing what you're doing.

[clare]

Short conduit stub in the box, stuff it in the hole and seal it with caulk or spray foam, or "dum-dum". Pull the wire in.

[RBM]

To do it correctly, you'd still need a connector on the end of the conduit

[clare]

Yes - but a lot more compact than a Romex clamp.

[John Grabowski]

*I usually cut the screws on the Romex connector to make it more compact. I stuff the hole in the wall with duct seal and caulk around the box. In a pinch I have used a button connector, but they don't always hold well in a threaded knockout.

[bud--]

What connector are you using on the end of the conduit.

Is the conduit stub attached to the waterproof box? That connector also requires a larger hole.

Or maybe you are creating a future Holmes project.

I use RBM's method, with John G's modification. Some waterproof boxes I drill a hole in the bottom in case water gets in.

bud--

[fred.flintstone]

Thanks to all who replied.

What is a button connector?

[RBM]

I actually do the button connector thing as well. I like the fact that it's an insulator, so if the cable sheath gets cut, nothing will short. I do use my dikes and modify the button so it fits tight , yet allows enough room to get the cable through

[RBM]

That was my thought as well. Pipe nipple to threaded coupling to romex connector, or emt connector to emt to emt/NM choke fitting. How is any of that more compact

[DerbyDad03]

Wouldn't a threaded PVC terminal connector and a length of PVC conduit through the wall be a bit more compact than a Romex connector on the back of the box?

Don't know...just asking.

[trader4]

Yes, but then if you pull the romex through it, which is what the OP was using, then you still don't have the romex clamped. I've seen a lot of them done and passed though where they just pulled the romex through the wall, into a hole on the box, with no clamp. It doesn't seem like the worse thing in the world either, as long as the cable is otherwise secured nearby before it goes through the wall.

[RBM]

A little bit, but you still have to clamp the romex to the conduit.

[RBM]

The proper thing to use would be a romex connector threaded into the back of the box. In my opinion, it makes for a sloppy job, plus I've had too many occasions where there were sharp burrs on the romex connector which cut through the jacket, and the conductors and shorted the cable. This is why I like the Arlington black buttons. (NM-94) They're plastic, so they insulate. They also hold the cable adequately, and like you say, where's it going to go. The only caveat is that the buttons aren't exactly designed for threaded entries, but with a little improv, they work great.

[DerbyDad03]

What if you transition to single conductors via a junction box inside the house before going through the wall?

Do single conductors entering a box via conduit have to be secured in any manner?

[RBM]

That would be fine. If you had a box on the inside, with a knockout in the back that lined up with the knockout on the outside bell box, you could cut a short piece of pvc with male adapters on each end, locknut one end on the inside and thread the outside end into the box. It's just not the most likely scenario.

[clare]

The BEST way is actuallu a piece of rigid conduit threaded directly into the back of the weatherproof box, stuffed through the hole in the wall. Next best is conduit fitting (90 degree) threadeed into one of the ends of the weatherproof with the box either above or below the hole the conduit goes through. It can even be sceptre conduit (plastic)

[clare]

Granger part #3KG85 (Bell) or equivalent. weatherproof box has 3 threaded openings - top, bottom, and back. Plug top and bottom. Thread Granger Item # 2CLG3 (power first) or equivalent in the back hole and stuff it through the wall. Hole needs to be no more than 1.060 inches to fit the 1.050" diameter conduit.

My local supply house has the parts (different brands) at roughly half the Granger price, a mile away, in stock.

[clare]

And a hunk of rigid conduit even MORE compact.